Curr Neurol Neurosci Rep (2014) 14:438 DOI 10.1007/s11910-014-0438-8
NEURO-OPHTHALMOLOGY (A KAWASAKI, SECTION EDITOR)
Update on the Surgical Management of Idiopathic Intracranial Hypertension Nisha Mukherjee & M. Tariq Bhatti
Published online: 1 March 2014 # Springer Science+Business Media New York 2014
Abstract Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure due to an unknown cause. In most cases, IIH can be managed with medical therapy and weight reduction. Surgical treatment of IIH is reserved for patients who cannot tolerate medical therapy, are nonadherent to medical therapy, develop progressive symptoms despite maximal medical therapy, or present with fulminant visual loss. To date, there has been no randomized controlled trial to evaluate the surgical treatment of IIH, and our current knowledge of the efficacy and complications of these procedures is based on retrospective and observational studies. This review discusses the indications for surgical intervention in IIH and provides an overview of the recently published data on the efficacy and complications of these interventions. A surgical management algorithm is also presented to guide the clinician when evaluating a patient with IIH.
Keywords Idiopathic intracranial hypertension . Venous sinus stent . Lumboperitoneal shunt . Ventriculoperitoneal shunt . Optic nerve sheath fenestration . Bariatric surgery
Introduction Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure (ICP) in the absence of central nervous system disease, and normal cerebrospinal fluid (CSF) composition with no identifiable secondary cause such as a medication (e.g., minocycline). In most cases, IIH can be treated effectively with the use of ICP-lowering agents and weight reduction [1]. Surgical treatment of IIH is reserved for those patients who cannot tolerate medical therapy, are nonadherent to medical therapy, or develop progressive symptoms despite maximal medical therapy [1]. There are also rare cases of fulminant IIH in which patients present with severe visual loss requiring an immediate decrease in ICP [1, 2]. Surgical methods of treatment include optic nerve sheath fenestration (ONSF), CSF diversion [i.e., lumboperitoneal shunt (LPS) or ventriculoperitoneal shunt (VPS)], venous sinus stenting, and bariatric surgery. The purpose of this article is to review the indications for surgical intervention in IIH and present the recently published data on the efficacy and complications of the various surgical treatment modalities.
Surgical Management
This article is part of the Topical Collection on Neuro-Ophthalmology N. Mukherjee : M. T. Bhatti Department of Ophthalmology, Duke Eye Center, Duke University Medical Center, Durham, NC, USA M. T. Bhatti Department of Neurology, Duke University Medical Center, Durham, NC, USA M. T. Bhatti (*) Duke Eye Center, DUMC 3802, Durham, NC 27710-3802, USA e-mail: [email protected]
To date, there has not been a randomized controlled trial (RCT) to evaluate the medical or surgical treatment of IIH; therefore, the evidence for treatment is based on clinical experience, case reports, case series, and retrospective studies. In most cases, IIH can be treated medically with the use of an ICP-lowering agent (e.g., acetazolamide) in addition to a weight-reduction program [1, 3]. Serial lumbar punctures are an inadequate and temporary strategy that can be considered in the rare patient who is pregnant or not suitable for medical or surgical therapy. Although no specific guidelines have been published regarding the specific amount of CSF to drain for
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each lumbar puncture, at Duke University we remove a minimum of 15–20 ml with the goal to obtain a closing pressure of at least 100 mmH2O. A lumbar drain may be helpful in some patients who require immediate decompression and/or are waiting for a more definitive surgical procedure [4].
Optic Nerve Sheath Fenestration ONSF is warranted in patients with impending or progressive visual loss with minimal or tolerable headaches [1]. In a metaanalysis based on retrospective data for ONSF performed on 423 eyes in patients with IIH, visual acuity improved in 50 % of eyes and visual field improved in 72 % of eyes (mean follow-up of 21.1 months) [5]. Visual field or visual acuity worsened in only 11 % of cases. Unfortunately, information regarding headache and papilledema was not provided. In a recent study of 62 IIH patients with bilateral papilledema who underwent unilateral ONSF, there was a decrease in the median grade of papilledema in the eye operated on from grade 3 before surgery to grade 0.5 by 12 months and in the eye that was not operated on from grade 2 before surgery to grade 1 12 months after surgery [6] (Table 1). Additionally, the visual field improved in both the eye operated on and the contralateral eye after unilateral ONSF. Moreau et al. [7] recently published the largest retrospective medical record review to date on ONSF. Four hundred and fifty-five eyes underwent ONSF for progressive visual loss due to IIH, with 95.8 % and 96.9 % of eyes operated on demonstrating stabilization or improvement in vision and visual fields, respectively ONSF can not only stabilize or improve vision but can also have a positive effect on headaches. The scant published data have shown improvement in headache after ONSF in up to 50 % of symptomatic patients [8, 9, 10••, 11]. In a case series of 17 patients, 76 % of the cohort experienced headache relief after ONSF [12]. In another case series of 86 patients, 31 % had relief of headaches after ONSF [13]. A retrospective medical record review of 17 pediatric eyes with IIH treated with ONSF revealed a decrease in papilledema and improved vision after ONSF, and these patients also had significant improvement of headaches [14]. Sixty-six percent of patients reported a headache prior to ONSF, with only 25 % reporting a headache after surgery. In addition, 33 % of patients had nausea before surgery, and this completely resolved in all patients after surgery. Transient visual obscuration was present in 25 % of patients prior to surgery, and in only 8 % of patients after surgery. Despite these positive findings, in our opinion ONSF should not be recommended as the primary surgical procedure for patients with headaches as the prominent symptom of their disease (see later). ONSF can be associated with both minor and major ocular complications (Table 2). In a review of 317 cases, the complication rate of ONSF ranged between 4.8 and 45 %, with a
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mean of 12.9 % [1]. Thirteen percent of cases were deemed a failure, which was defined as progressive visual loss despite ONSF or the need for reoperation. In addition, case reports have described patients with progressive visual loss after ONSF due to sustained elevated ICP [15]. In an experimental rat model, significant optic nerve atrophy and degeneration of retinal ganglion cells was discovered after ONSF, implying that in humans, retinal ganglion cell neurodegeneration may be an unintended consequence of the procedure [16].
CSF Diversion Reduction of ICP by CSF diversion is primarily attained through an LPS or a VPS. Although preference for the type of CSF diversion procedure depends on the surgeon and the institution, in general LPS is more commonly performed [1]. As the obesity rate rises in the USA, so does the incidence of CSF diversion for management of IIH [17]. Curry et al. [17] found that the total number of CSF shunting procedures for management of IIH increased by 350 % between 1988 and 2002, a rise mirroring the increasing incidence of obesity. In addition to the ONSF data, Feldon [5] published metaanalysis results on LPS and VPS for management of IIH. Unfortunately, information on papilledema, visual function, and headache was not reported in most of the cases published, limiting the data that could be included in the meta-analysis. In the LPS group (n = 44), 22.7 % had resolution of papilledema and 15.9 % had improvement of papilledema, but information about papilledema for most patients (61.4 %) was not available. Headache resolution or improvement was achieved in 18.2 % and 27.3 % of cases, respectively. Visual symptoms or signs resolved in 5.9 % of cases, improved in 29.5 % of cases, remained unchanged in 15.9 % of cases, and worsened in 4.5 % of cases (44.2 % of the case reports did not contain information on the visual status). In comparison, for the VPS group (n=31), papilledema resolved in all reported cases, although for 45 % of patients there was no documented data on papilledema. Nearly 40 % of patients who underwent VPS reported improvement in vision, but most had no change in vision (61.3 %). There was no information regarding the outcome of headache in 29 of the 31 patients. Since the meta-analysis performed by Feldon in 2007, only a few case series and no RCTs have been published on the efficacy of CSF diversion. Tarnaris et al. [18•] retrospectively reviewed the results of LPS or VPS in 29 patients with IIH (Table 1). Twenty-four patients underwent LPS and five patients underwent VPS. Headaches improved in 71 % of patients in the LPS group and in 60 % of patients in the VPS group. Visual acuity documented at the last follow-up examination (mean follow-up of 28.9±31.8 months) improved in 42 % of patients in the LPS group and in 40 % of patients in the VPS group. No significant difference was found in both
35 (27.1–42.9)
35 (27.1–42.9)
LPSc
VPSd
LPS
25
9
Abubaker 18 et al. [19]
NA (8–65)
32 (13–57)
Bilateral ONSF
10
32 (13–57)
Mean age in years (range)
Unilateral ONSF
No. of Procedure patients
62
Alsuhaibani et al. [6]
CSF diversion Tarnaris procedures et al. [18•]
ONSF
Authors
4 years (6 months to 7 years)
28.9 months (±31.8)
12 months (100 % of patients) 28.9 months (±31.8)
12 months (65 % of patients)
Follow-up
NA
NA
40 % improved; 60 % no change/ worse 100 % improved
NA
-2b
NA
89 % improved
100 % improved
Patients who Specific underwent complications unilateral ONSF were not reported had equal reduction in the grade of papilledema in the fellow eye (the eye not operated on)
Complications
Comments
71 % improved; 29 20.5 % complication 1 patient from the LPS group was rate in the LPS/ % no change/ lost to follow-up, VPS group (shunt worse the information infection, shunt reported is based obstruction, intraon 24 patients; 5 abdominal pain, patients from the low ICP with VPS group were low-pressure lost to follow-up, headaches, the information malposition of reported is based catheter tip, CSF on 5 patients leak, intracerebral hemorrhage); 35 % shunt revision rate (mean time for revision 14.3±17.9 months); of the 35 % of patients who underwent revision, 67 % underwent more than 1 revision 60 % improved; 40 % no change/ worse 1 patient from the 89 % improved LPS had 60 % LPS group revision rate and needed 11 % failure rate; conversion to VPS had 30 % VPS owing to revision rate and malposition of 14 % failure rate
NA
-2b
NA
Headache
Papilledema
NA
NA
Significant improvement in both the eye operated on and the fellow eyea (p=0.017 for the eye operated on, p=0.009 for the fellow eye)
NA
42 % improved; 58 % no change/ worse
Visual field
Visual acuity
Outcome
Table 1 Summary of studies on surgical management of idiopathic intracranial hypertension (IIH), 2011 to present
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Venous sinus stent
LPS
VPS
49
4
Radvany et al. [27•]
12
24.2 (3–52)
30.3 (±8.5)
Right or left 39 (21–55) tranverse sinus stent
Stereotactic VPS
NA (8–65)
VPS
7
30.3 (±8.5)
Mean age in years (range)
No. of Procedure patients
Kandasamy 17 et al. [21]
Sinclair et al. [20•]
Authors
Table 1 (continued)
Visual field
Papilledema
Headache
There was concern for venous sinus dissection in 1 patient. All patients Resolved 100 % before completely in stenting; resolved 16 % of in 92 % of patients, patients after improved in 42 stenting
Improved or stable in 79 % of eyesg 9 weeks Improved or (6–12 weeks) remained stable in 92 % of eyes
All patients underwent stereotactic neuronavigation insertion of VPS using a frameless stereotactic neuronavigation system; 5 of these patients had LPS failure No cases of intracranial hemorrhages, CSF shunt infection, or epilepsy. 5 patients required shunt revision
Data reported for combined LPS/ VPS outcomes
the catheter; symptoms resolved after VPS
21 months (9–49 Specific data on visual function were not included, but it was noted 82 % resolution; 18 % with months) that ophthalmologic findings after VPS, including visual acuity, symptomatic visual field, and papilledema, improved in 100 % of patients headaches
N/A
Complications
Comments
Improvement in visual acuity was statistically significant until 24 months postoperatively. There was also statistically significant improvement in visual obscurations. There was no statistically significant improvement in tinnitus or diplopia
LogMar 0.31±0.36 preoperatively, 0.21±0.31 at 6 months (p=0.001), 0.10±0.30 at 12 months (p=0.016), 0.08±0.25 at 24 months (p=0.109)f
80 % had improvement in symptoms after VPS (symptoms included headache, visual acuity loss, visual field defects, and papilledema); however, data on specific symptoms were not provided
Visual acuity
Outcome
92 % preoperatively; 96 % symptomatic 28 % reported lowpressure preoperatively; 65 % at 6 months headaches (all 63 % (p=0.002); 48 % LPS); 51 % symptomatic at at 12 months required revision 6 months (p=0.003), 44 % (59 % required (p=0.002); 77 at 24 months more than 1 % symptomatic (p=0.008) revision). at 12 months Revision (p=0.016), 79 occurred at a % symptomatic mean of at 24 months 7.5±16.4 months (p=0.031) after initial insertion
24 monthse
4 years (6 months to 7 years) 24 monthse
Follow-up
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Mean age in years (range)
23 months (4– 58.5)
Follow-up Visual field
Papilledema
Headache
Complications
g
f
e
d
c
b
a
Comments
% of patients; stable in 42 % of patients
experienced retro-orbital pain ipsilateral to the stent 70 % of patients had symptomatic improvement after placement of the stent; however, 1 patient developed a 5 patients underwent placement of a specific data regarding headache, papilledema, and visual function were not provided right common LPS (n=1) or a femoral artery VPS (n=4) for pseudoaneurysm; management of 4 patients persistent demonstrated insymptoms stent stenosis but despite successful none of these had venous sinus significant flow stenting limitation
Visual acuity
Outcome
As measured by mean deviation on visual field testing
A one-line improvement in visual acuity equates to a 0.1 improvement in LogMAR score
Medical records were retrospectively reviewed and outcome data were collected up to 24 months (for some patients there were no outcome data, and these patients were not included in the table)
Four patients from the VPS group were lost to follow-up. The information reported is based on five patients
One patient from the LPS group was lost to follow-up. The information reported is based on 24 patients
Reported as the change in papilledema from the baseline at 12 months using the Frisen papilledema scale
Visual field data presented in this article were provided only for patients who underwent unilateral ONSF. Patients underwent both Goldmann and Humphrey visual field testing
CSF cerebrospinal fluid, ICP intracranial pressure, LPS lumboperitoneal shunt, NA not available, ONSF optic nerve sheath fenestration, VPS ventriculoperitoneal shunt
Right or left 33 (14–52) transverse sinus stent
No. of Procedure patients
Ducruet 27 et al. [28]
Authors
Table 1 (continued)
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Table 2 Complications of surgical procedures for management of IIH [1, 11] Surgical procedure
Complications
ONSF
Conjunctival bleb, globe perforation, chemosis, subconjunctival Tenon’s cyst, dellen formation, corneal ulcers, microhyphema, angle closure glaucoma, tonic pupil or pupillary dysfunction, chorioretinal scar from excessive traction on the globe, branch retinal artery occlusion, central retinal artery occlusion, choroidal ischemia/ infarction, traumatic optic neuropathy, myelinated nerve fibers, optic nerve cyst formation, orbital apex syndrome, orbital infection, orbital hemorrhage, diplopia due to extraocular movement dysfunction Shunt obstruction, overshunting of CSF resulting in low ICP, infection, CSF leak, cerebellar tonsillar herniation (acquired Chiari 1 malformation), shunt dependency, lumbar radiculopathy, catheter migration resulting in abdominal pain/bowel perforation, subdural hemorrhage, subarachnoid hemorrhage, intracerebral hematoma, vision loss
CSF diversion (LPS and VPS)
Venous sinus stenting Bariatric surgery
Subdural hematoma, transient hearing loss, femoral pseudoaneurysm, venous sinus dissection, syncope, retro-orbital pain, stroke Infection, seroma, incisional hernias, anastomotic leak, anastomotic hemorrhage, ulcer, intraabdominal hemorrhage, pouch dilation, nutritional deficiency, metabolic disturbances
headache and visual outcomes between the LPS group and the VPS group. However, in both groups headache improved more frequently than visual dysfunction. These headache and vision findings contrast significantly with and are difficult to reconcile with the results of the meta-analysis by Feldon, but are most likely due to the small number of patients analyzed by Tarnaris et al. Abubaker et al. [19] performed a retrospective review of 18 patients who underwent LPS and seven patients that underwent VPS (Table 1). In the LPS group, all patients were noted to have improvement in visual function (visual acuity and visual field) after shunt placement. Both papilledema and headache improved or resolved in 61 % of patients; however, long-term follow-up data was not reported. The VPS group included ten patients, three of which underwent VPS after removal of the LPS. In all three patients with fulminant IIH, there was complete resolution of symptoms, including headache, visual acuity loss, visual field defects, and papilledema after placement of a VPS. Improvement in symptoms was noted in half of all patients but 20 % of patients continued to have symptoms despite placement of a VPS. A major limitation of the study was the lack of data regarding the specific symptoms that resolved and long-term follow-up results. In 2011, Sinclair et al. [20•] conducted the largest retrospective review of IIH patients treated with CSF diversion
(Table 1). Forty-nine patients underwent LPS and four patients underwent VPS. There was improvement in visual acuity from the baseline to 12 months, but this improvement was not statistically significant by 24 months. Sixty-five percent of patients had progressive visual deficits prior to shunting, and only 22 % of patients continued to have progressive visual deficits 12 months after shunting. At 24 months after shunting, the improvement in visual deficits was no longer statistically significant. There was a statistically significant reduction in transient visual obscurations, from 78 % of the cohort at baseline to 32 % of the cohort at 24 months after shunting. There was no statistically significant improvement in diplopia, color vision, or tinnitus. CSF diversion resulted in marked improvement of papilledema, with 92 % of patients with papilledema prior to shunting and only 44 % of patients with papilledema at 24 months. Ninety-six percent of patients had symptomatic headaches prior to shunting and 79 % of patients had symptomatic headaches at 24 months. Although this study failed to show an improvement in headaches after CSF diversion, the improvement of papilledema was impressive. Kandasamy et al. [21] reviewed 18 patients with IIH who underwent electromagnetic image-guided VPS (Table 1). All patients reported improvement or stabilization of vision after shunt placement at the last follow-up (mean follow-up of 21 months). Eighty-three percent of patients reported resolution of headache at the last follow-up. It is not known if a full neuro-ophthalmic examination was performed on these patients after surgery. An LPS with a programmable valve and ventricular assist device has been successfully implanted for symptomatic treatment of IIH. The device has the advantage of frequent ICP monitoring and adjustment of CSF filtration. In a case series of 40 IIH patients who underwent implantation of a programmable LPS, 25 % of the patients required shunt revision and 10 % developed shunt infection [22]. More studies are needed to determine the efficacy of these types of shunts. LPS and VPS can be associated with a number of complications, the commonest being shunt revision (Table 2). In 2004, Friedman and Jacobson [1] reviewed the published literature on LPS for IIH and noted the revision rate ranged from 38 to 64 %, with an overall rate of 52 %. The interval between shunt placement and the first revision was 9– 27 months [1]. Several studies have shown that LPS is associated with a greater number of revisions than VPS [19, 21, 23]. Sinclair et al. [20•] found a 51 % revision rate in their cohort of 53 patients who underwent either an LPS or a VPS (the revision rate for each individual procedure was not reported), with a mean time to revision of 7.5 months (±16.4 months). Abubaker et al. [19] followed 25 patients who underwent either an LPS or a VPS, and found the revision rate for LPS was 60 %, compared with only 30 % for VPS. The interval between shunt placement and the first
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revision was the same in both groups [19]. A case series of 21 patients who underwent LPS had a mean revision rate of three per patient during a mean follow-up of 21 months [24]. Apart from the high revision rate, this case series also found 30 % of patients developed cerebellar tonsillar herniation and there was a 33 % per patient infection rate. On the basis of these results, the authors of the study concluded that the complication rate of LPS is unacceptably high and an alternative method of CSF diversion should be pursued. This same institution published a case series of 18 patients who underwent electromagnetic image-guided VPS [21]. Only five of these patients required shunt revision during a mean follow-up of 21 months. No significant morbidity or mortality was reported in this case series. The authors of the study concluded that electromagnetic image-guided VPS is a safe and effective surgical treatment for IIH which may offer efficacy equal to that of LPS with fewer complications [21]. Other complications of CSF diversion include intracranial hypotension, catheter obstruction, catheter migration, lumbar radiculopathy, infection, and subdural, subarachnoid, or intracranial hemorrhage [1]. In our opinion, CSF diversion is a highly effective intervention in improving papilledema, visual function, and headaches. However, the results in a specific patient can be variable and in part appear to depend on the type of CSF diversion procedure chosen. Prospective randomized studies are needed to identify clinical, radiological, and laboratory characteristics that will improve the selection process of identifying an individual patient that will most benefit from CSF diversion.
Venous Sinus Stenting In 2002, Higgins et al. [25] described a patient with refractory IIH, and magnetic resonance venography findings consistent with partial bilateral transverse venous sinus obstruction, successfully treated with venous sinus stenting. Since that time, small case series have demonstrated the efficacy of venous sinus stenting in IIH, particularly in those patients with venographic and manometric evidence of venous sinus stenosis [26••]. Puffer et al. [26••] conducted a meta-analysis of venous sinus stenting in IIH based on retrospective data from seven case reports and eight case series totaling 143 patients. Prior to stenting, 128 patients reported headaches. After stent placement, the headaches completely resolved or improved in 88 % of the patients, remained unchanged in 10 % of the patients, and worsened in 2 % of the patients. Papilledema resolved in 97 % of the patients (106 of 110 patients). Of the 62 patients with visual changes prior to stenting, 87 % demonstrated improvement or resolution of symptoms after stent placement. Specific data regarding visual function were not included in the analysis.
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Since the publication of the meta-analysis by Puffer et al. in 2012, there have been only a few additional case series on venous sinus stenting for management of IIH (Table 1). Radvany et al. [27•] reviewed 12 patients with headaches and papilledema treated with venous sinus stenting. Visual acuity stabilized or improved in 91 % of eyes and color vision was stable or improved in 88 % of eyes after stenting. The mean deviation score on automated visual field testing was stable or improved in 79 % of eyes, and resolution of papilledema occurred in 91 % of patients. Notably, two patients developed recurrent papilledema 6 months after stenting, necessitating additional procedures. Headaches completely resolved in 17 % of patients and improved in 42 % of patients. Ducruet et al. [28] reviewed the outcome of 30 patients who underwent venous sinus stenting. All patients had headache and papilledema prior to stenting. Of the 23 patients from this initial cohort for which long-term follow-up data were available (the mean follow-up was 23 months), 70 % had symptomatic improvement after stenting, but specific data on visual function and other symptoms were not reported. Despite the very encouraging results, there is a clear need for RCTs with long-term follow-up to establish the role of venous sinus stenting in the armamentarium for treatment of IIH. As with any surgical procedure, venous sinus stenting is associated with complications, ranging from minor to lifethreatening (Table 2). In the review by Puffer et al. [26••], no patients died during or immediately after the procedure. Two percent of patients developed subdural hematoma and 6 % of patients developed minor complications, including transient hearing loss, femoral pseudoaneurysm, and syncopal episode [26••]. Radvany et al. [27•] reported no complications in 12 patients, although in one patient there was intraoperative concern for venous sinus dissection. Interestingly, all patients in this series reported retro-orbital pain ipsilateral to the site of stent placement immediately after the procedure, which universally resolved over a few days. Ducrett et al. [28] found 3 % of patients developed a right common femoral artery pseudoaneurysm that required treatment. Ahmed et al. [29] performed a cost analysis comparing resource use of venous sinus stenting for management of adult IIH with CSF shunting for management of childhood hydrocephalus. There was no significant difference in the cost of the initial procedure; however, long-term data showed that venous sinus stenting incurred significantly less cost than CSF shunting because of the higher revision and complication rates associated with CSF shunting.
Bariatric Surgery In 1974, Newborg [30] reported weight loss significantly reduced the symptoms of IIH. Since that time, a number of
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retrospective reviews have validated this finding [31–33]. In 2011, Fridley et al. [34] reviewed six individual case reports and five case series totaling 62 patients with IIH who underwent bariatric surgery. The mean body weight loss was recorded in 50 of these patients, ranging from 22.3 kg at 3 months to 64 kg at 18 months, with a mean weight loss of 45.5 kg. Patients who underwent bariatric surgery were noted to have a decrease in mean CSF pressure along with improvement in IIH symptoms. The mean preoperative CSF pressure recorded in 55 of the 62 patients was 370 mmH2O, and at the last postoperative follow-up (ranging from 6 to 34 months) the mean CSF pressure decreased to 153 mmH2O. Ninety-two percent of the 61 patients for which postoperative clinical data were available had resolution of or significant improvement in IIH symptoms. Ninety-seven percent of patients who had papilledema preoperatively had resolution of papilledema on follow-up examination, with the earliest documentation of resolution of papilledema being 6 months after surgery. Although limited postoperative data were available on the patients who were noted to have preoperative visual field deficits, 75 % had complete resolution, 17 % had nearcomplete resolution, and 8 % had stabilization of the visual field deficits. Two patients had a history of declining visual
acuity preoperatively and both experienced improvement in visual acuity postoperatively. Notably, 11 patients had undergone a CSF diversion procedure or ONSF prior to bariatric surgery. Egan et al. [35] reviewed four patients with symptomatic IIH treated with laparoscopic adjustable gastric banding surgery. The mean weight loss was 33.7 kg at the last follow-up (mean of 19.8 months), and all the patients reported improvement or total resolution of headache. No data on visual function were included in the analysis. A variety of complications are associated with bariatric surgery. A recent review found infections or seroma occurred in 4.3 % of patients after gastric bypass and in 3 % of patients after gastric banding [36]. After gastric bypass surgery, incisional hernia occurred in 4.5 % of patients and intestinal strictures occurred in 5 % of patients. Other complications of bariatric surgery include anastomotic leak or hemorrhage, ulcer, intra-abdominal hemorrhage, and pouch dilation after gastric banding. Metabolic adverse events after bariatric surgery have rarely been documented, with only one of the three studies reporting hypoglycemia [36] and one study reporting vitamin deficiency [37]. Other studies have noted nutritional deficiency and nephrolithiasis after gastric bypass in non-IIH patients [38–40]. It has been suggested that preoperative body
Non-fulminant IIH
Fulminant IIH
Maximal medical therapy 2 Lumbar drain
Progressive visual loss (minimal/no HA)
Progressive HA (w/ or w/o visual loss)
Repeat LP w/OP
Repeat LP w/OP 3
ONSF (worse eye) 5
CSF diversion 4
HA and/or visual loss w/ evidence of venous sinus stenosis
Venous sinus stent
ONSF (fellow eye) 6
ONSF (worse eye) 5
HA w/or w/o visual loss
CSF diversion 4
ONSF (worse eye) 5
Severe HA w/visual loss
CSF diversion 4
ONSF (fellow eye) 6
ONSF (fellow eye) 6
HA persists or progressive visual loss
Progressive visual loss
Visual loss with minimal/no HA
Visual loss with minimal/no HA
Check functional status of shunt
CSF diversion 4
ICP w/HA
Revise or replace shunt
ICP w/visual loss
ONSF (worse eye) 5
Revise or replace shunt
KEY
ONSF (fellow eye) 6 IIH=idiopathic intracranial hypertension; HA= headache; w/= with; w/o= without; ONSF= optic nerve sheath fenestration; CSF= cerebrospinal fluid; LP= lumbar puncture; OP= opening pressure; ICP= intracranial pressure 1 based on 5 criteria: 1) signs and symptoms due to increased ICP or papilledema; 2) increased ICP recorded during a lumbar puncture (LP) performed in the lateral decubitus position; 3) normal CSF studies; 4) normal neuro-imaging with no evidence of structural cause for increased ICP; and 5) no othera cause of increased ICP identified, including use of certain medications [1] 2 Progressive symptoms despite maximal medial therapy, intolerant to maximal medical therapy, or non-adherence to medical therapy 3 LP is both diagnostic and therapeutic. This allows assessment of CSF pressure and determines if lowering the ICP improves headache 4 The authors prefer ventriculoperitoneal shunting over lumboperitoneal shunting 5 “worse eye” refers to the eye with greater loss of vision and/or visual field 6 If papilledema or visual function improves, the patient may not need ONSF of the fellow eye
Fig. 1 Management strategy for idiopathic intracranial hypertension (IIH)
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mass index inversely correlates with the risk of nutritional deficiency after bariatric surgery [36, 41–43]. Although bariatric surgery appears to be a highly effective treatment strategy, the paucity of data precludes definitely recommending it to patients with IIH. In our practice, we do not actively encourage bariatric surgery for patients with IIH. Rather, we strongly recommend medical therapy in addition to a low-fat, low-sodium diet with an exercise program. If a patient wishes to pursue bariatric surgery for reasons other than IIH, we continue to closely monitor visual function during the procedure.
Novel Surgical Procedures Internal cranial expansion (ICE) was first described for the treatment of Camurati–Engelmann disease [44]. ICE involves surgically increasing the volume of the intracranial compartment through removal of the inner calvarial table and cancellous bone of the skull. The increased volume allows the intracranial contents to expand, which lowers ICP. In a retrospective review of ten patients with IIH who underwent ICE, 70 % had symptomatic improvement or stabilization of symptoms at the last follow-up (mean 15.5 months) [45]. Specifically, 67 % of patients had resolution or improvement of headache. All the patients who presented with papilledema prior to surgical intervention had improvement after ICE. Other patients noted improvement in tinnitus, retro-orbital pain, and ear pain. Of note, all patients were treated medically prior to undergoing ICE. One patient underwent ONSF prior to ICE, and three patients underwent CSF diversion with multiple revisions prior to ICE. The ICE procedure is associated with a 20 % complication rate. Generalized tonic–clonic seizure, and sagittal sinus tear are two of the serious adverse events.
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surgical management of a patient with IIH is dependent on the patient’s presenting symptoms and the resources to the available clinician. In our practice, a patient with predominantly visual loss (in whom medical therapy has either failed or who is intolerant to medical therapy) is offered an ONSF. In contrast, if headache is the predominant symptom, then CSF diversion is offered, in particular a VPS because the efficacy and complication rate appears to be superior to those of an LPS. Programmable CSF diversion devices seem to be associated with fewer complications, but further clinical experience and studies are needed to determine their benefit. There is a subset of patients with IIH who can benefit—both from a vision perspective and from a headache perspective—from venous sinus stenting. Because of the relatively low complication rate and the high efficacy rate, venous sinus stenting should be considered in patients with radiological evidence of venous sinus stenosis. Bariatric surgery is a long-term management option for patients with IIH. The time for resolution of clinical manifestations is not immediate with bariatric surgery, and therefore it should not be considered for patients with progressive visual loss or intolerable headaches. Compliance with Ethics Guidelines Conflict of Interest Nisha Mukherjee and M. Tariq Bhatti declare that they have no conflict of interest. Funding was provided by an unrestricted departmental grant from Research to Prevent Blindness. Human and Animal Rights and Informed Consent This article does not contain any studies with human or animal subjects performed by any of the authors.
References Conclusions The decision to recommend surgery and choosing the appropriate surgical procedure for an individual patient with IIH can be very challenging. Unfortunately, there is no class I evidence to guide the clinical decision-making process. RCTs are desperately needed to determine the optimal surgical management. The Neuro-Ophthalmology Research Disease Investigator Consortium (NORDIC; see http://www.nordicclinicaltrials.com/ nordic) is currently planning a surgical IIH clinical trial. This trial will hopefully provide much needed information on the optimal surgical management of IIH. However, until such RCTs are performed, the clinician must rely on the current literature and clinical experience to determine the most appropriate treatment option (Fig. 1). Despite the limitations of the published data, a careful review of the current literature suggests that the optimal
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1. 2. 3. 4.
5.
6.
Friedman DI, Jacobson DM. Idiopathic intracranial hypertension. J Neuroophthalmol. 2004;24(2):138–45. Thambisetty M et al. Fulminant idiopathic intracranial hypertension. Neurology. 2007;68(3):229–32. Wall M. Idiopathic intracranial hypertension (pseudotumor cerebri). Curr Neurol Neurosci Rep. 2008;8(2):87–93. Rasul FT et al. Pseudotumor cerebri presenting with visual failure in promyelocytic leukemia: a case report. J Med Case Rep. 2012;6(1): 408. Feldon SE. Visual outcomes comparing surgical techniques for management of severe idiopathic intracranial hypertension. Neurosurg Focus. 2007;23(5):E6. Alsuhaibani AH et al. Effect of optic nerve sheath fenestration on papilledema of the operated and the contralateral nonoperated eyes
438, Page 10 of 11 in idiopathic intracranial hypertension. Ophthalmology. 2011;118(2):412–4. 7. Moreau A, Lao KC, Farris BK. Optic nerve sheath decompression: a surgical technique with minimal operative complications. J Neuroophthalmol. 2013. doi:10.1097/WNO. 0000000000000065. 8. Corbett JJ et al. Results of optic nerve sheath fenestration for pseudotumor cerebri. The lateral orbitotomy approach. Arch Ophthalmol. 1988;106(10):1391–7. 9. Corbett JJ, Thompson HS. The rational management of idiopathic intracranial hypertension. Arch Neurol. 1989;46(10):1049–51. 10.•• Spitze A et al. Optic nerve sheath fenestration vs cerebrospinal diversion procedures: what is the preferred surgical procedure for the treatment of idiopathic intracranial hypertension failing maximum medical therapy? J Neuroophthalmol. 2013;33(2):183–8. This article discusses the merits of ONSF versus CSF diversion in the management of IIH in a point–counterpoint format by several neuro-ophthalmologists. Major case reports and case series on both ONSF and CSF diversion are reviewed. 11. Brazis PW. Clinical review: the surgical treatment of idiopathic pseudotumour cerebri (idiopathic intracranial hypertension). Cephalalgia. 2008;28(12):1361–73. 12. Sergott RC, Savino PJ, Bosley TM. Modified optic nerve sheath decompression provides long-term visual improvement for pseudotumor cerebri. Arch Ophthalmol. 1988;106(10):1384–90. 13. Banta JT, Farris BK. Pseudotumor cerebri and optic nerve sheath decompression. Ophthalmology. 2000;107(10):1907–12. 14. Thuente DD, Buckley EG. Pediatric optic nerve sheath decompression. Ophthalmology. 2005;112(4):724–7. 15. Wilkes BN, Siatkowski RM. Progressive optic neuropathy in idiopathic intracranial hypertension after optic nerve sheath fenestration. J Neuroophthalmol. 2009;29(4):281–3. 16. Gellrich NC et al. Degeneration of retinal ganglion cells after optic nerve sheath fenestration in an experimental rat model. J Neuroophthalmol. 2009;29(4):275–80. 17. Curry Jr WT, Butler WE, Barker 2nd FG. Rapidly rising incidence of cerebrospinal fluid shunting procedures for idiopathic intracranial hypertension in the United States, 1988-2002. Neurosurgery. 2005;57(1):97–108, discussion 97-108. 18.• Tarnaris A et al. Is there a difference in outcomes of patients with idiopathic intracranial hypertension with the choice of cerebrospinal fluid diversion site: a single centre experience. Clin Neurol Neurosurg. 2011;113(6):477–9. A retrospective review of 34 patients with IIH who underwent CSF diversion with a mean followup of 31.8 months. VPS patients had fewer complications than LPS patients. 19. Abubaker K et al. Idiopathic intracranial hypertension: lumboperitoneal shunts versus ventriculoperitoneal shunts—case series and literature review. Br J Neurosurg. 2011;25(1):94–9. 20.• Sinclair AJ et al. Is cerebrospinal fluid shunting in idiopathic intracranial hypertension worthwhile? A 10-year review. Cephalalgia. 2011;31(16):1627–33. A 10-year retrospective review of 53 patients who underwent CSF diversion (predominantly LPS) for management of IIH. Visual outcomes significantly improved after CSF shunting; however, headache persisted in most patients after surgery. 21. Kandasamy J et al. Electromagnetic stereotactic ventriculoperitoneal CSF shunting for idiopathic intracranial hypertension: a successful step forward? World Neurosurg. 2011;75(1):155–60, discussion 32-3. 22. Nadkarni TD, Rekate HL, Wallace D. Concurrent use of a lumboperitoneal shunt with programmable valve and ventricular access device in the treatment of pseudotumor cerebri: review of 40 cases. J Neurosurg Pediatr. 2008;2(1):19–24. 23. McGirt MJ et al. Cerebrospinal fluid shunt placement for pseudotumor cerebri-associated intractable headache: predictors
Curr Neurol Neurosci Rep (2014) 14:438 of treatment response and an analysis of long-term outcomes. J Neurosurg. 2004;101(4):627–32. 24. Karabatsou K et al. Lumboperitoneal shunts: are the complications acceptable? Acta Neurochir (Wien). 2004;146(11):1193–7. 25. Higgins JN et al. Venous sinus stenting for refractory benign intracranial hypertension. Lancet. 2002;359(9302): 228–30. 26.•• Puffer RC, Mustafa W, Lanzino G. Venous sinus stenting for idiopathic intracranial hypertension: a review of the literature. J Neurointerv Surg. 2013;5(5):483–6. A review of the current literature on venous sinus stenting for management of IIH. A total of 143 patients were analyzed. After venous sinus stenting, 88 % of patients had improvement in headache, 97 % had resolution of papilledema, and 87 % had improvement or resolution of visual symptoms. 27.• Radvany MG et al. Visual and neurological outcomes following endovascular stenting for pseudotumor cerebri associated with transverse sinus stenosis. J Neuroophthalmol. 2013;33(2):117–22. The outcome results of 12 patients with IIH and transverse sinus stenosis who underwent venous sinus stenting after medical therapy had failed are presented. Approximately 90 % of patients had improvement in visual function after stenting, and 58 % of patients had improvement in headache. Venous sinus stenting in patients with evidence of transverse sinus stenosis has a significant positive effect on visual dysfunction. 28. Ducruet AF et al. Long-term patency of venous sinus stents for idiopathic intracranial hypertension. J Neurointerv Surg. 2013. doi: 10.1136/neurintsurg-2013-010691. 29. Ahmed RM et al. Transverse sinus stenting for pseudotumor cerebri: a cost comparison with CSF shunting. AJNR Am J Neuroradiol. 2013. doi:10.3174/ajnr.A3806. 30. Newborg B. Pseudotumor cerebri treated by rice reduction diet. Arch Intern Med. 1974;133(5):802–7. 31. Johnson LN et al. The role of weight loss and acetazolamide in the treatment of idiopathic intracranial hypertension (pseudotumor cerebri). Ophthalmology. 1998;105(12):2313–7. 32. Kupersmith MJ et al. Effects of weight loss on the course of idiopathic intracranial hypertension in women. Neurology. 1998;50(4):1094–8. 33. Wong R et al. Idiopathic intracranial hypertension: the association between weight loss and the requirement for systemic treatment. BMC Ophthalmol. 2007;7:15. 34. Fridley J et al. Bariatric surgery for the treatment of idiopathic intracranial hypertension. J Neurosurg. 2011;114(1): 34–9. 35. Egan RJ et al. The effects of laparoscopic adjustable gastric banding on idiopathic intracranial hypertension. Obes Surg. 2011;21(2): 161–6. 36. Maggard-Gibbons M et al. Bariatric surgery for weight loss and glycemic control in nonmorbidly obese adults with diabetes: a systematic review. JAMA. 2013;309(21):2250–61. 37. Kim MK et al. The difference of glucostatic parameters according to the remission of diabetes after Roux-en-Y gastric bypass. Diabetes Metab Res Rev. 2012;28(5):439–46. 38. Juhasz-Pocsine K et al. Neurologic complications of gastric bypass surgery for morbid obesity. Neurology. 2007;68(21): 1843–50. 39. Sinha MK et al. Hyperoxaluric nephrolithiasis is a complication of Roux-en-Y gastric bypass surgery. Kidney Int. 2007;72(1):100–7. 40. Slater GH et al. Serum fat-soluble vitamin deficiency and abnormal calcium metabolism after malabsorptive bariatric surgery. J Gastrointest Surg. 2004;8(1):48–55, discussion 54-5. 41. Lee WJ et al. Effect of laparoscopic mini-gastric bypass for type 2 diabetes mellitus: comparison of BMI>35 and
NEURO-OPHTHALMOLOGY (A KAWASAKI, SECTION EDITOR)
Update on the Surgical Management of Idiopathic Intracranial Hypertension Nisha Mukherjee & M. Tariq Bhatti
Published online: 1 March 2014 # Springer Science+Business Media New York 2014
Abstract Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure due to an unknown cause. In most cases, IIH can be managed with medical therapy and weight reduction. Surgical treatment of IIH is reserved for patients who cannot tolerate medical therapy, are nonadherent to medical therapy, develop progressive symptoms despite maximal medical therapy, or present with fulminant visual loss. To date, there has been no randomized controlled trial to evaluate the surgical treatment of IIH, and our current knowledge of the efficacy and complications of these procedures is based on retrospective and observational studies. This review discusses the indications for surgical intervention in IIH and provides an overview of the recently published data on the efficacy and complications of these interventions. A surgical management algorithm is also presented to guide the clinician when evaluating a patient with IIH.
Keywords Idiopathic intracranial hypertension . Venous sinus stent . Lumboperitoneal shunt . Ventriculoperitoneal shunt . Optic nerve sheath fenestration . Bariatric surgery
Introduction Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure (ICP) in the absence of central nervous system disease, and normal cerebrospinal fluid (CSF) composition with no identifiable secondary cause such as a medication (e.g., minocycline). In most cases, IIH can be treated effectively with the use of ICP-lowering agents and weight reduction [1]. Surgical treatment of IIH is reserved for those patients who cannot tolerate medical therapy, are nonadherent to medical therapy, or develop progressive symptoms despite maximal medical therapy [1]. There are also rare cases of fulminant IIH in which patients present with severe visual loss requiring an immediate decrease in ICP [1, 2]. Surgical methods of treatment include optic nerve sheath fenestration (ONSF), CSF diversion [i.e., lumboperitoneal shunt (LPS) or ventriculoperitoneal shunt (VPS)], venous sinus stenting, and bariatric surgery. The purpose of this article is to review the indications for surgical intervention in IIH and present the recently published data on the efficacy and complications of the various surgical treatment modalities.
Surgical Management
This article is part of the Topical Collection on Neuro-Ophthalmology N. Mukherjee : M. T. Bhatti Department of Ophthalmology, Duke Eye Center, Duke University Medical Center, Durham, NC, USA M. T. Bhatti Department of Neurology, Duke University Medical Center, Durham, NC, USA M. T. Bhatti (*) Duke Eye Center, DUMC 3802, Durham, NC 27710-3802, USA e-mail: [email protected]
To date, there has not been a randomized controlled trial (RCT) to evaluate the medical or surgical treatment of IIH; therefore, the evidence for treatment is based on clinical experience, case reports, case series, and retrospective studies. In most cases, IIH can be treated medically with the use of an ICP-lowering agent (e.g., acetazolamide) in addition to a weight-reduction program [1, 3]. Serial lumbar punctures are an inadequate and temporary strategy that can be considered in the rare patient who is pregnant or not suitable for medical or surgical therapy. Although no specific guidelines have been published regarding the specific amount of CSF to drain for
438, Page 2 of 11
each lumbar puncture, at Duke University we remove a minimum of 15–20 ml with the goal to obtain a closing pressure of at least 100 mmH2O. A lumbar drain may be helpful in some patients who require immediate decompression and/or are waiting for a more definitive surgical procedure [4].
Optic Nerve Sheath Fenestration ONSF is warranted in patients with impending or progressive visual loss with minimal or tolerable headaches [1]. In a metaanalysis based on retrospective data for ONSF performed on 423 eyes in patients with IIH, visual acuity improved in 50 % of eyes and visual field improved in 72 % of eyes (mean follow-up of 21.1 months) [5]. Visual field or visual acuity worsened in only 11 % of cases. Unfortunately, information regarding headache and papilledema was not provided. In a recent study of 62 IIH patients with bilateral papilledema who underwent unilateral ONSF, there was a decrease in the median grade of papilledema in the eye operated on from grade 3 before surgery to grade 0.5 by 12 months and in the eye that was not operated on from grade 2 before surgery to grade 1 12 months after surgery [6] (Table 1). Additionally, the visual field improved in both the eye operated on and the contralateral eye after unilateral ONSF. Moreau et al. [7] recently published the largest retrospective medical record review to date on ONSF. Four hundred and fifty-five eyes underwent ONSF for progressive visual loss due to IIH, with 95.8 % and 96.9 % of eyes operated on demonstrating stabilization or improvement in vision and visual fields, respectively ONSF can not only stabilize or improve vision but can also have a positive effect on headaches. The scant published data have shown improvement in headache after ONSF in up to 50 % of symptomatic patients [8, 9, 10••, 11]. In a case series of 17 patients, 76 % of the cohort experienced headache relief after ONSF [12]. In another case series of 86 patients, 31 % had relief of headaches after ONSF [13]. A retrospective medical record review of 17 pediatric eyes with IIH treated with ONSF revealed a decrease in papilledema and improved vision after ONSF, and these patients also had significant improvement of headaches [14]. Sixty-six percent of patients reported a headache prior to ONSF, with only 25 % reporting a headache after surgery. In addition, 33 % of patients had nausea before surgery, and this completely resolved in all patients after surgery. Transient visual obscuration was present in 25 % of patients prior to surgery, and in only 8 % of patients after surgery. Despite these positive findings, in our opinion ONSF should not be recommended as the primary surgical procedure for patients with headaches as the prominent symptom of their disease (see later). ONSF can be associated with both minor and major ocular complications (Table 2). In a review of 317 cases, the complication rate of ONSF ranged between 4.8 and 45 %, with a
Curr Neurol Neurosci Rep (2014) 14:438
mean of 12.9 % [1]. Thirteen percent of cases were deemed a failure, which was defined as progressive visual loss despite ONSF or the need for reoperation. In addition, case reports have described patients with progressive visual loss after ONSF due to sustained elevated ICP [15]. In an experimental rat model, significant optic nerve atrophy and degeneration of retinal ganglion cells was discovered after ONSF, implying that in humans, retinal ganglion cell neurodegeneration may be an unintended consequence of the procedure [16].
CSF Diversion Reduction of ICP by CSF diversion is primarily attained through an LPS or a VPS. Although preference for the type of CSF diversion procedure depends on the surgeon and the institution, in general LPS is more commonly performed [1]. As the obesity rate rises in the USA, so does the incidence of CSF diversion for management of IIH [17]. Curry et al. [17] found that the total number of CSF shunting procedures for management of IIH increased by 350 % between 1988 and 2002, a rise mirroring the increasing incidence of obesity. In addition to the ONSF data, Feldon [5] published metaanalysis results on LPS and VPS for management of IIH. Unfortunately, information on papilledema, visual function, and headache was not reported in most of the cases published, limiting the data that could be included in the meta-analysis. In the LPS group (n = 44), 22.7 % had resolution of papilledema and 15.9 % had improvement of papilledema, but information about papilledema for most patients (61.4 %) was not available. Headache resolution or improvement was achieved in 18.2 % and 27.3 % of cases, respectively. Visual symptoms or signs resolved in 5.9 % of cases, improved in 29.5 % of cases, remained unchanged in 15.9 % of cases, and worsened in 4.5 % of cases (44.2 % of the case reports did not contain information on the visual status). In comparison, for the VPS group (n=31), papilledema resolved in all reported cases, although for 45 % of patients there was no documented data on papilledema. Nearly 40 % of patients who underwent VPS reported improvement in vision, but most had no change in vision (61.3 %). There was no information regarding the outcome of headache in 29 of the 31 patients. Since the meta-analysis performed by Feldon in 2007, only a few case series and no RCTs have been published on the efficacy of CSF diversion. Tarnaris et al. [18•] retrospectively reviewed the results of LPS or VPS in 29 patients with IIH (Table 1). Twenty-four patients underwent LPS and five patients underwent VPS. Headaches improved in 71 % of patients in the LPS group and in 60 % of patients in the VPS group. Visual acuity documented at the last follow-up examination (mean follow-up of 28.9±31.8 months) improved in 42 % of patients in the LPS group and in 40 % of patients in the VPS group. No significant difference was found in both
35 (27.1–42.9)
35 (27.1–42.9)
LPSc
VPSd
LPS
25
9
Abubaker 18 et al. [19]
NA (8–65)
32 (13–57)
Bilateral ONSF
10
32 (13–57)
Mean age in years (range)
Unilateral ONSF
No. of Procedure patients
62
Alsuhaibani et al. [6]
CSF diversion Tarnaris procedures et al. [18•]
ONSF
Authors
4 years (6 months to 7 years)
28.9 months (±31.8)
12 months (100 % of patients) 28.9 months (±31.8)
12 months (65 % of patients)
Follow-up
NA
NA
40 % improved; 60 % no change/ worse 100 % improved
NA
-2b
NA
89 % improved
100 % improved
Patients who Specific underwent complications unilateral ONSF were not reported had equal reduction in the grade of papilledema in the fellow eye (the eye not operated on)
Complications
Comments
71 % improved; 29 20.5 % complication 1 patient from the LPS group was rate in the LPS/ % no change/ lost to follow-up, VPS group (shunt worse the information infection, shunt reported is based obstruction, intraon 24 patients; 5 abdominal pain, patients from the low ICP with VPS group were low-pressure lost to follow-up, headaches, the information malposition of reported is based catheter tip, CSF on 5 patients leak, intracerebral hemorrhage); 35 % shunt revision rate (mean time for revision 14.3±17.9 months); of the 35 % of patients who underwent revision, 67 % underwent more than 1 revision 60 % improved; 40 % no change/ worse 1 patient from the 89 % improved LPS had 60 % LPS group revision rate and needed 11 % failure rate; conversion to VPS had 30 % VPS owing to revision rate and malposition of 14 % failure rate
NA
-2b
NA
Headache
Papilledema
NA
NA
Significant improvement in both the eye operated on and the fellow eyea (p=0.017 for the eye operated on, p=0.009 for the fellow eye)
NA
42 % improved; 58 % no change/ worse
Visual field
Visual acuity
Outcome
Table 1 Summary of studies on surgical management of idiopathic intracranial hypertension (IIH), 2011 to present
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Venous sinus stent
LPS
VPS
49
4
Radvany et al. [27•]
12
24.2 (3–52)
30.3 (±8.5)
Right or left 39 (21–55) tranverse sinus stent
Stereotactic VPS
NA (8–65)
VPS
7
30.3 (±8.5)
Mean age in years (range)
No. of Procedure patients
Kandasamy 17 et al. [21]
Sinclair et al. [20•]
Authors
Table 1 (continued)
Visual field
Papilledema
Headache
There was concern for venous sinus dissection in 1 patient. All patients Resolved 100 % before completely in stenting; resolved 16 % of in 92 % of patients, patients after improved in 42 stenting
Improved or stable in 79 % of eyesg 9 weeks Improved or (6–12 weeks) remained stable in 92 % of eyes
All patients underwent stereotactic neuronavigation insertion of VPS using a frameless stereotactic neuronavigation system; 5 of these patients had LPS failure No cases of intracranial hemorrhages, CSF shunt infection, or epilepsy. 5 patients required shunt revision
Data reported for combined LPS/ VPS outcomes
the catheter; symptoms resolved after VPS
21 months (9–49 Specific data on visual function were not included, but it was noted 82 % resolution; 18 % with months) that ophthalmologic findings after VPS, including visual acuity, symptomatic visual field, and papilledema, improved in 100 % of patients headaches
N/A
Complications
Comments
Improvement in visual acuity was statistically significant until 24 months postoperatively. There was also statistically significant improvement in visual obscurations. There was no statistically significant improvement in tinnitus or diplopia
LogMar 0.31±0.36 preoperatively, 0.21±0.31 at 6 months (p=0.001), 0.10±0.30 at 12 months (p=0.016), 0.08±0.25 at 24 months (p=0.109)f
80 % had improvement in symptoms after VPS (symptoms included headache, visual acuity loss, visual field defects, and papilledema); however, data on specific symptoms were not provided
Visual acuity
Outcome
92 % preoperatively; 96 % symptomatic 28 % reported lowpressure preoperatively; 65 % at 6 months headaches (all 63 % (p=0.002); 48 % LPS); 51 % symptomatic at at 12 months required revision 6 months (p=0.003), 44 % (59 % required (p=0.002); 77 at 24 months more than 1 % symptomatic (p=0.008) revision). at 12 months Revision (p=0.016), 79 occurred at a % symptomatic mean of at 24 months 7.5±16.4 months (p=0.031) after initial insertion
24 monthse
4 years (6 months to 7 years) 24 monthse
Follow-up
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Mean age in years (range)
23 months (4– 58.5)
Follow-up Visual field
Papilledema
Headache
Complications
g
f
e
d
c
b
a
Comments
% of patients; stable in 42 % of patients
experienced retro-orbital pain ipsilateral to the stent 70 % of patients had symptomatic improvement after placement of the stent; however, 1 patient developed a 5 patients underwent placement of a specific data regarding headache, papilledema, and visual function were not provided right common LPS (n=1) or a femoral artery VPS (n=4) for pseudoaneurysm; management of 4 patients persistent demonstrated insymptoms stent stenosis but despite successful none of these had venous sinus significant flow stenting limitation
Visual acuity
Outcome
As measured by mean deviation on visual field testing
A one-line improvement in visual acuity equates to a 0.1 improvement in LogMAR score
Medical records were retrospectively reviewed and outcome data were collected up to 24 months (for some patients there were no outcome data, and these patients were not included in the table)
Four patients from the VPS group were lost to follow-up. The information reported is based on five patients
One patient from the LPS group was lost to follow-up. The information reported is based on 24 patients
Reported as the change in papilledema from the baseline at 12 months using the Frisen papilledema scale
Visual field data presented in this article were provided only for patients who underwent unilateral ONSF. Patients underwent both Goldmann and Humphrey visual field testing
CSF cerebrospinal fluid, ICP intracranial pressure, LPS lumboperitoneal shunt, NA not available, ONSF optic nerve sheath fenestration, VPS ventriculoperitoneal shunt
Right or left 33 (14–52) transverse sinus stent
No. of Procedure patients
Ducruet 27 et al. [28]
Authors
Table 1 (continued)
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Table 2 Complications of surgical procedures for management of IIH [1, 11] Surgical procedure
Complications
ONSF
Conjunctival bleb, globe perforation, chemosis, subconjunctival Tenon’s cyst, dellen formation, corneal ulcers, microhyphema, angle closure glaucoma, tonic pupil or pupillary dysfunction, chorioretinal scar from excessive traction on the globe, branch retinal artery occlusion, central retinal artery occlusion, choroidal ischemia/ infarction, traumatic optic neuropathy, myelinated nerve fibers, optic nerve cyst formation, orbital apex syndrome, orbital infection, orbital hemorrhage, diplopia due to extraocular movement dysfunction Shunt obstruction, overshunting of CSF resulting in low ICP, infection, CSF leak, cerebellar tonsillar herniation (acquired Chiari 1 malformation), shunt dependency, lumbar radiculopathy, catheter migration resulting in abdominal pain/bowel perforation, subdural hemorrhage, subarachnoid hemorrhage, intracerebral hematoma, vision loss
CSF diversion (LPS and VPS)
Venous sinus stenting Bariatric surgery
Subdural hematoma, transient hearing loss, femoral pseudoaneurysm, venous sinus dissection, syncope, retro-orbital pain, stroke Infection, seroma, incisional hernias, anastomotic leak, anastomotic hemorrhage, ulcer, intraabdominal hemorrhage, pouch dilation, nutritional deficiency, metabolic disturbances
headache and visual outcomes between the LPS group and the VPS group. However, in both groups headache improved more frequently than visual dysfunction. These headache and vision findings contrast significantly with and are difficult to reconcile with the results of the meta-analysis by Feldon, but are most likely due to the small number of patients analyzed by Tarnaris et al. Abubaker et al. [19] performed a retrospective review of 18 patients who underwent LPS and seven patients that underwent VPS (Table 1). In the LPS group, all patients were noted to have improvement in visual function (visual acuity and visual field) after shunt placement. Both papilledema and headache improved or resolved in 61 % of patients; however, long-term follow-up data was not reported. The VPS group included ten patients, three of which underwent VPS after removal of the LPS. In all three patients with fulminant IIH, there was complete resolution of symptoms, including headache, visual acuity loss, visual field defects, and papilledema after placement of a VPS. Improvement in symptoms was noted in half of all patients but 20 % of patients continued to have symptoms despite placement of a VPS. A major limitation of the study was the lack of data regarding the specific symptoms that resolved and long-term follow-up results. In 2011, Sinclair et al. [20•] conducted the largest retrospective review of IIH patients treated with CSF diversion
(Table 1). Forty-nine patients underwent LPS and four patients underwent VPS. There was improvement in visual acuity from the baseline to 12 months, but this improvement was not statistically significant by 24 months. Sixty-five percent of patients had progressive visual deficits prior to shunting, and only 22 % of patients continued to have progressive visual deficits 12 months after shunting. At 24 months after shunting, the improvement in visual deficits was no longer statistically significant. There was a statistically significant reduction in transient visual obscurations, from 78 % of the cohort at baseline to 32 % of the cohort at 24 months after shunting. There was no statistically significant improvement in diplopia, color vision, or tinnitus. CSF diversion resulted in marked improvement of papilledema, with 92 % of patients with papilledema prior to shunting and only 44 % of patients with papilledema at 24 months. Ninety-six percent of patients had symptomatic headaches prior to shunting and 79 % of patients had symptomatic headaches at 24 months. Although this study failed to show an improvement in headaches after CSF diversion, the improvement of papilledema was impressive. Kandasamy et al. [21] reviewed 18 patients with IIH who underwent electromagnetic image-guided VPS (Table 1). All patients reported improvement or stabilization of vision after shunt placement at the last follow-up (mean follow-up of 21 months). Eighty-three percent of patients reported resolution of headache at the last follow-up. It is not known if a full neuro-ophthalmic examination was performed on these patients after surgery. An LPS with a programmable valve and ventricular assist device has been successfully implanted for symptomatic treatment of IIH. The device has the advantage of frequent ICP monitoring and adjustment of CSF filtration. In a case series of 40 IIH patients who underwent implantation of a programmable LPS, 25 % of the patients required shunt revision and 10 % developed shunt infection [22]. More studies are needed to determine the efficacy of these types of shunts. LPS and VPS can be associated with a number of complications, the commonest being shunt revision (Table 2). In 2004, Friedman and Jacobson [1] reviewed the published literature on LPS for IIH and noted the revision rate ranged from 38 to 64 %, with an overall rate of 52 %. The interval between shunt placement and the first revision was 9– 27 months [1]. Several studies have shown that LPS is associated with a greater number of revisions than VPS [19, 21, 23]. Sinclair et al. [20•] found a 51 % revision rate in their cohort of 53 patients who underwent either an LPS or a VPS (the revision rate for each individual procedure was not reported), with a mean time to revision of 7.5 months (±16.4 months). Abubaker et al. [19] followed 25 patients who underwent either an LPS or a VPS, and found the revision rate for LPS was 60 %, compared with only 30 % for VPS. The interval between shunt placement and the first
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revision was the same in both groups [19]. A case series of 21 patients who underwent LPS had a mean revision rate of three per patient during a mean follow-up of 21 months [24]. Apart from the high revision rate, this case series also found 30 % of patients developed cerebellar tonsillar herniation and there was a 33 % per patient infection rate. On the basis of these results, the authors of the study concluded that the complication rate of LPS is unacceptably high and an alternative method of CSF diversion should be pursued. This same institution published a case series of 18 patients who underwent electromagnetic image-guided VPS [21]. Only five of these patients required shunt revision during a mean follow-up of 21 months. No significant morbidity or mortality was reported in this case series. The authors of the study concluded that electromagnetic image-guided VPS is a safe and effective surgical treatment for IIH which may offer efficacy equal to that of LPS with fewer complications [21]. Other complications of CSF diversion include intracranial hypotension, catheter obstruction, catheter migration, lumbar radiculopathy, infection, and subdural, subarachnoid, or intracranial hemorrhage [1]. In our opinion, CSF diversion is a highly effective intervention in improving papilledema, visual function, and headaches. However, the results in a specific patient can be variable and in part appear to depend on the type of CSF diversion procedure chosen. Prospective randomized studies are needed to identify clinical, radiological, and laboratory characteristics that will improve the selection process of identifying an individual patient that will most benefit from CSF diversion.
Venous Sinus Stenting In 2002, Higgins et al. [25] described a patient with refractory IIH, and magnetic resonance venography findings consistent with partial bilateral transverse venous sinus obstruction, successfully treated with venous sinus stenting. Since that time, small case series have demonstrated the efficacy of venous sinus stenting in IIH, particularly in those patients with venographic and manometric evidence of venous sinus stenosis [26••]. Puffer et al. [26••] conducted a meta-analysis of venous sinus stenting in IIH based on retrospective data from seven case reports and eight case series totaling 143 patients. Prior to stenting, 128 patients reported headaches. After stent placement, the headaches completely resolved or improved in 88 % of the patients, remained unchanged in 10 % of the patients, and worsened in 2 % of the patients. Papilledema resolved in 97 % of the patients (106 of 110 patients). Of the 62 patients with visual changes prior to stenting, 87 % demonstrated improvement or resolution of symptoms after stent placement. Specific data regarding visual function were not included in the analysis.
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Since the publication of the meta-analysis by Puffer et al. in 2012, there have been only a few additional case series on venous sinus stenting for management of IIH (Table 1). Radvany et al. [27•] reviewed 12 patients with headaches and papilledema treated with venous sinus stenting. Visual acuity stabilized or improved in 91 % of eyes and color vision was stable or improved in 88 % of eyes after stenting. The mean deviation score on automated visual field testing was stable or improved in 79 % of eyes, and resolution of papilledema occurred in 91 % of patients. Notably, two patients developed recurrent papilledema 6 months after stenting, necessitating additional procedures. Headaches completely resolved in 17 % of patients and improved in 42 % of patients. Ducruet et al. [28] reviewed the outcome of 30 patients who underwent venous sinus stenting. All patients had headache and papilledema prior to stenting. Of the 23 patients from this initial cohort for which long-term follow-up data were available (the mean follow-up was 23 months), 70 % had symptomatic improvement after stenting, but specific data on visual function and other symptoms were not reported. Despite the very encouraging results, there is a clear need for RCTs with long-term follow-up to establish the role of venous sinus stenting in the armamentarium for treatment of IIH. As with any surgical procedure, venous sinus stenting is associated with complications, ranging from minor to lifethreatening (Table 2). In the review by Puffer et al. [26••], no patients died during or immediately after the procedure. Two percent of patients developed subdural hematoma and 6 % of patients developed minor complications, including transient hearing loss, femoral pseudoaneurysm, and syncopal episode [26••]. Radvany et al. [27•] reported no complications in 12 patients, although in one patient there was intraoperative concern for venous sinus dissection. Interestingly, all patients in this series reported retro-orbital pain ipsilateral to the site of stent placement immediately after the procedure, which universally resolved over a few days. Ducrett et al. [28] found 3 % of patients developed a right common femoral artery pseudoaneurysm that required treatment. Ahmed et al. [29] performed a cost analysis comparing resource use of venous sinus stenting for management of adult IIH with CSF shunting for management of childhood hydrocephalus. There was no significant difference in the cost of the initial procedure; however, long-term data showed that venous sinus stenting incurred significantly less cost than CSF shunting because of the higher revision and complication rates associated with CSF shunting.
Bariatric Surgery In 1974, Newborg [30] reported weight loss significantly reduced the symptoms of IIH. Since that time, a number of
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retrospective reviews have validated this finding [31–33]. In 2011, Fridley et al. [34] reviewed six individual case reports and five case series totaling 62 patients with IIH who underwent bariatric surgery. The mean body weight loss was recorded in 50 of these patients, ranging from 22.3 kg at 3 months to 64 kg at 18 months, with a mean weight loss of 45.5 kg. Patients who underwent bariatric surgery were noted to have a decrease in mean CSF pressure along with improvement in IIH symptoms. The mean preoperative CSF pressure recorded in 55 of the 62 patients was 370 mmH2O, and at the last postoperative follow-up (ranging from 6 to 34 months) the mean CSF pressure decreased to 153 mmH2O. Ninety-two percent of the 61 patients for which postoperative clinical data were available had resolution of or significant improvement in IIH symptoms. Ninety-seven percent of patients who had papilledema preoperatively had resolution of papilledema on follow-up examination, with the earliest documentation of resolution of papilledema being 6 months after surgery. Although limited postoperative data were available on the patients who were noted to have preoperative visual field deficits, 75 % had complete resolution, 17 % had nearcomplete resolution, and 8 % had stabilization of the visual field deficits. Two patients had a history of declining visual
acuity preoperatively and both experienced improvement in visual acuity postoperatively. Notably, 11 patients had undergone a CSF diversion procedure or ONSF prior to bariatric surgery. Egan et al. [35] reviewed four patients with symptomatic IIH treated with laparoscopic adjustable gastric banding surgery. The mean weight loss was 33.7 kg at the last follow-up (mean of 19.8 months), and all the patients reported improvement or total resolution of headache. No data on visual function were included in the analysis. A variety of complications are associated with bariatric surgery. A recent review found infections or seroma occurred in 4.3 % of patients after gastric bypass and in 3 % of patients after gastric banding [36]. After gastric bypass surgery, incisional hernia occurred in 4.5 % of patients and intestinal strictures occurred in 5 % of patients. Other complications of bariatric surgery include anastomotic leak or hemorrhage, ulcer, intra-abdominal hemorrhage, and pouch dilation after gastric banding. Metabolic adverse events after bariatric surgery have rarely been documented, with only one of the three studies reporting hypoglycemia [36] and one study reporting vitamin deficiency [37]. Other studies have noted nutritional deficiency and nephrolithiasis after gastric bypass in non-IIH patients [38–40]. It has been suggested that preoperative body
Non-fulminant IIH
Fulminant IIH
Maximal medical therapy 2 Lumbar drain
Progressive visual loss (minimal/no HA)
Progressive HA (w/ or w/o visual loss)
Repeat LP w/OP
Repeat LP w/OP 3
ONSF (worse eye) 5
CSF diversion 4
HA and/or visual loss w/ evidence of venous sinus stenosis
Venous sinus stent
ONSF (fellow eye) 6
ONSF (worse eye) 5
HA w/or w/o visual loss
CSF diversion 4
ONSF (worse eye) 5
Severe HA w/visual loss
CSF diversion 4
ONSF (fellow eye) 6
ONSF (fellow eye) 6
HA persists or progressive visual loss
Progressive visual loss
Visual loss with minimal/no HA
Visual loss with minimal/no HA
Check functional status of shunt
CSF diversion 4
ICP w/HA
Revise or replace shunt
ICP w/visual loss
ONSF (worse eye) 5
Revise or replace shunt
KEY
ONSF (fellow eye) 6 IIH=idiopathic intracranial hypertension; HA= headache; w/= with; w/o= without; ONSF= optic nerve sheath fenestration; CSF= cerebrospinal fluid; LP= lumbar puncture; OP= opening pressure; ICP= intracranial pressure 1 based on 5 criteria: 1) signs and symptoms due to increased ICP or papilledema; 2) increased ICP recorded during a lumbar puncture (LP) performed in the lateral decubitus position; 3) normal CSF studies; 4) normal neuro-imaging with no evidence of structural cause for increased ICP; and 5) no othera cause of increased ICP identified, including use of certain medications [1] 2 Progressive symptoms despite maximal medial therapy, intolerant to maximal medical therapy, or non-adherence to medical therapy 3 LP is both diagnostic and therapeutic. This allows assessment of CSF pressure and determines if lowering the ICP improves headache 4 The authors prefer ventriculoperitoneal shunting over lumboperitoneal shunting 5 “worse eye” refers to the eye with greater loss of vision and/or visual field 6 If papilledema or visual function improves, the patient may not need ONSF of the fellow eye
Fig. 1 Management strategy for idiopathic intracranial hypertension (IIH)
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mass index inversely correlates with the risk of nutritional deficiency after bariatric surgery [36, 41–43]. Although bariatric surgery appears to be a highly effective treatment strategy, the paucity of data precludes definitely recommending it to patients with IIH. In our practice, we do not actively encourage bariatric surgery for patients with IIH. Rather, we strongly recommend medical therapy in addition to a low-fat, low-sodium diet with an exercise program. If a patient wishes to pursue bariatric surgery for reasons other than IIH, we continue to closely monitor visual function during the procedure.
Novel Surgical Procedures Internal cranial expansion (ICE) was first described for the treatment of Camurati–Engelmann disease [44]. ICE involves surgically increasing the volume of the intracranial compartment through removal of the inner calvarial table and cancellous bone of the skull. The increased volume allows the intracranial contents to expand, which lowers ICP. In a retrospective review of ten patients with IIH who underwent ICE, 70 % had symptomatic improvement or stabilization of symptoms at the last follow-up (mean 15.5 months) [45]. Specifically, 67 % of patients had resolution or improvement of headache. All the patients who presented with papilledema prior to surgical intervention had improvement after ICE. Other patients noted improvement in tinnitus, retro-orbital pain, and ear pain. Of note, all patients were treated medically prior to undergoing ICE. One patient underwent ONSF prior to ICE, and three patients underwent CSF diversion with multiple revisions prior to ICE. The ICE procedure is associated with a 20 % complication rate. Generalized tonic–clonic seizure, and sagittal sinus tear are two of the serious adverse events.
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surgical management of a patient with IIH is dependent on the patient’s presenting symptoms and the resources to the available clinician. In our practice, a patient with predominantly visual loss (in whom medical therapy has either failed or who is intolerant to medical therapy) is offered an ONSF. In contrast, if headache is the predominant symptom, then CSF diversion is offered, in particular a VPS because the efficacy and complication rate appears to be superior to those of an LPS. Programmable CSF diversion devices seem to be associated with fewer complications, but further clinical experience and studies are needed to determine their benefit. There is a subset of patients with IIH who can benefit—both from a vision perspective and from a headache perspective—from venous sinus stenting. Because of the relatively low complication rate and the high efficacy rate, venous sinus stenting should be considered in patients with radiological evidence of venous sinus stenosis. Bariatric surgery is a long-term management option for patients with IIH. The time for resolution of clinical manifestations is not immediate with bariatric surgery, and therefore it should not be considered for patients with progressive visual loss or intolerable headaches. Compliance with Ethics Guidelines Conflict of Interest Nisha Mukherjee and M. Tariq Bhatti declare that they have no conflict of interest. Funding was provided by an unrestricted departmental grant from Research to Prevent Blindness. Human and Animal Rights and Informed Consent This article does not contain any studies with human or animal subjects performed by any of the authors.
References Conclusions The decision to recommend surgery and choosing the appropriate surgical procedure for an individual patient with IIH can be very challenging. Unfortunately, there is no class I evidence to guide the clinical decision-making process. RCTs are desperately needed to determine the optimal surgical management. The Neuro-Ophthalmology Research Disease Investigator Consortium (NORDIC; see http://www.nordicclinicaltrials.com/ nordic) is currently planning a surgical IIH clinical trial. This trial will hopefully provide much needed information on the optimal surgical management of IIH. However, until such RCTs are performed, the clinician must rely on the current literature and clinical experience to determine the most appropriate treatment option (Fig. 1). Despite the limitations of the published data, a careful review of the current literature suggests that the optimal
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1. 2. 3. 4.
5.
6.
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