106
Letters to the Editor / Clinical Neurology and Neurosurgery 116 (2014) 104–108
Neurological deficits secondary to unruptured intracranial aneurysms: Recovery following microsurgical clipping versus endovascular coil embolization Keywords: Intracranial aneurysm Stroke Neurological manifestations Microsurgery Endovascular procedures
[4] Kraus RR, Kattah J, Bortolotti C, Lanzino G. Oculomotor palsy from an unruptured posterior communicating artery aneurysm presenting with cerebrospinal fluid pleocytosis and enhancement of the third cranial nerve. Case report. J Neurosurg 2004;101(2):352–3. [5] Lanzino G. Cranial nerve III palsy. J Neurosurg 2012;117(5):902, discussion 902–3. [6] Guresir E, Schuss P, Setzer M, Platz J, Seifert V, Vatter H. Posterior communicating artery aneurysm-related oculomotor nerve palsy: influence of surgical and endovascular treatment on recovery: single-center series and systematic review. Neurosurgery 2011;68(6):1527–33, discussion 1533–4. [7] Schuss P, Guresir E, Berkefeld J, Seifert V, Vatter H. Influence of surgical or endovascular treatment on visual symptoms caused by intracranial aneurysms: single-center series and systematic review. J Neurosurg 2011;115(4): 694–9.
Dale Ding ∗ University of Virginia, Department of Neurosurgery, Charlottesville, USA
Dear Sir, I have read, with great interest, a recently published article in Clinical Neurology and Neurosurgery by Moteki et al. titled ‘Progressive visual field defect caused by an unruptured middle cerebral artery aneurysm’ [1]. The authors describe a case of a 50-year-old patient who presented with a progressively worsening partial left upper quadrantanopsia which was initially monocular but became binocular over a period of two years. The patient was diagnosed by magnetic resonance angiography with a 7 mm, unruptured right middle cerebral artery (MCA) aneurysm. The aneurysm projected superiorly into the inferior frontal lobe, resulting in edema of the surrounding cortex. Three months after the aneurysm was treated with microsurgical clipping, the edema had diminished, and the patient’s visual deficit had partially recovered. Postoperative diffusion tensor imaging (DTI) did not identify involvement of Meyer’s loop by the resolving edema. The authors postulated that the preoperative edema from the aneurysm resulted in effacement of Meyer’s loop thereby causing the visual symptoms. However, the lack of preoperative DTI is a glaring weakness of this case report. Nevertheless, this case brings up the interesting topic of neurological deficits secondary to unruptured aneurysms. A classic and well-studied example of this phenomenon is a posterior communicating artery (PCOM) aneurysm causing an oculomotor nerve palsy (ONP) [2]. The two primary accepted mechanisms of PCOM aneurysm related ONP are direct compression and aneurysmal pulsation [3]. Other mechanisms for this phenomenon, such as neural vascular supply disruption and inflammation, have also been proposed although the evidence to support them is less substantial [4,5]. A systematic review of 201 patients with ONP secondary to PCOM aneurysms treated with surgical clipping or endovascular coiling demonstrated that the clipping cohort had significantly higher rates of ONP resolution for patients presenting with either complete ONP (55 versus 32%, P = 0.006) or any degree of ONP (92 versus 74%, P = 0.001) [6]. A subsequent review did not find a benefit to dissection of the aneurysm dome off of the oculomotor nerve [3]. Clipping has also been shown to be superior to coiling for recovery of visual deficits resulting from anterior circulation aneurysms which supports the authors’ treatment approach in this case [7]. Future advances in neuroimaging technology may allow improved delineation of structural and functional neuroanatomy, therefore providing further insight into common and rare pathologies affecting the visual pathways. References [1] Moteki Y, Kawamoto T, Namioka T, Yokote A, Kawamata T. Progressive visual field defect caused by an unruptured middle cerebral artery aneurysm. Clin Neurol Neurosurg 2013;115(10):2182–5. [2] Soni SR. Aneurysms of the posterior communicating artery and oculomotor paresis. J Neurol Neurosurg Psychiatry 1974;37(4):475–84. [3] Guresir E, Schuss P, Seifert V, Vatter H. Oculomotor nerve palsy by posterior communicating artery aneurysms: influence of surgical strategy on recovery. J Neurosurg 2012;117(5):904–10.
∗ Correspondence
to: University of Virginia, Department of Neurosurgery, P.O. Box 800212, Charlottesville, USA. Tel.: +1 434 924 2203; fax: +1 434 982 5753. E-mail address: [email protected] 10 October 2013 Available online 8 November 2013 http://dx.doi.org/10.1016/j.clineuro.2013.10.024
Potential role of flow-diverting stents for posterior cerebral artery aneurysms Keywords: Intracranial aneurysm Posterior cerebral artery Endovascular procedures Stent Stroke
Dear Sir, I have read, with great interest, a recently published article in Clinical Neurology and Neurosurgery by Kim et al. titled ‘Outcomes of multidisciplinary treatment for posterior cerebral artery aneurysms’ [1]. The authors describe the microsurgical and endovascular treatment outcomes for 25 patients with posterior cerebral artery (PCA) aneurysms. The majority of the aneurysms were at least 10 mm in diameter (56%) and located proximal to the P2P segment (76%). Microsurgery was the primary treatment for 60% of the aneurysms and successful in all but one case (4%) which was salvaged by endovascular coiling. An endovascular approach was the primary treatment for the remaining 40% of cases without any instances of technical failure. The rate of treatment-related permanent neurological morbidity was 20%. At a mean clinical follow-up of 43 months, a modified Rankin Scale score less than 3 was observed in 88% of patients. PCA aneurysms are rare lesions with unique patient (i.e. younger age) and lesion characteristics (i.e. larger, more likely to be non-saccular). A wide range of microsurgical and endovascular techniques, ranging from direct clip ligation to parent artery sacrifice, were used in this relatively small series which is a testament to the significant variability observed in PCA aneurysms. Notably, there were no cases which were treated with a flow-diverting stent (FDS). The use FDSs has been rapidly popularized with increasing reports of their remarkable ability to reconstruct the neck of large, complex intracranial aneurysms which would otherwise be very difficult to successfully treat via traditional microsurgical or
Letters to the Editor / Clinical Neurology and Neurosurgery 116 (2014) 104–108
Neurological deficits secondary to unruptured intracranial aneurysms: Recovery following microsurgical clipping versus endovascular coil embolization Keywords: Intracranial aneurysm Stroke Neurological manifestations Microsurgery Endovascular procedures
[4] Kraus RR, Kattah J, Bortolotti C, Lanzino G. Oculomotor palsy from an unruptured posterior communicating artery aneurysm presenting with cerebrospinal fluid pleocytosis and enhancement of the third cranial nerve. Case report. J Neurosurg 2004;101(2):352–3. [5] Lanzino G. Cranial nerve III palsy. J Neurosurg 2012;117(5):902, discussion 902–3. [6] Guresir E, Schuss P, Setzer M, Platz J, Seifert V, Vatter H. Posterior communicating artery aneurysm-related oculomotor nerve palsy: influence of surgical and endovascular treatment on recovery: single-center series and systematic review. Neurosurgery 2011;68(6):1527–33, discussion 1533–4. [7] Schuss P, Guresir E, Berkefeld J, Seifert V, Vatter H. Influence of surgical or endovascular treatment on visual symptoms caused by intracranial aneurysms: single-center series and systematic review. J Neurosurg 2011;115(4): 694–9.
Dale Ding ∗ University of Virginia, Department of Neurosurgery, Charlottesville, USA
Dear Sir, I have read, with great interest, a recently published article in Clinical Neurology and Neurosurgery by Moteki et al. titled ‘Progressive visual field defect caused by an unruptured middle cerebral artery aneurysm’ [1]. The authors describe a case of a 50-year-old patient who presented with a progressively worsening partial left upper quadrantanopsia which was initially monocular but became binocular over a period of two years. The patient was diagnosed by magnetic resonance angiography with a 7 mm, unruptured right middle cerebral artery (MCA) aneurysm. The aneurysm projected superiorly into the inferior frontal lobe, resulting in edema of the surrounding cortex. Three months after the aneurysm was treated with microsurgical clipping, the edema had diminished, and the patient’s visual deficit had partially recovered. Postoperative diffusion tensor imaging (DTI) did not identify involvement of Meyer’s loop by the resolving edema. The authors postulated that the preoperative edema from the aneurysm resulted in effacement of Meyer’s loop thereby causing the visual symptoms. However, the lack of preoperative DTI is a glaring weakness of this case report. Nevertheless, this case brings up the interesting topic of neurological deficits secondary to unruptured aneurysms. A classic and well-studied example of this phenomenon is a posterior communicating artery (PCOM) aneurysm causing an oculomotor nerve palsy (ONP) [2]. The two primary accepted mechanisms of PCOM aneurysm related ONP are direct compression and aneurysmal pulsation [3]. Other mechanisms for this phenomenon, such as neural vascular supply disruption and inflammation, have also been proposed although the evidence to support them is less substantial [4,5]. A systematic review of 201 patients with ONP secondary to PCOM aneurysms treated with surgical clipping or endovascular coiling demonstrated that the clipping cohort had significantly higher rates of ONP resolution for patients presenting with either complete ONP (55 versus 32%, P = 0.006) or any degree of ONP (92 versus 74%, P = 0.001) [6]. A subsequent review did not find a benefit to dissection of the aneurysm dome off of the oculomotor nerve [3]. Clipping has also been shown to be superior to coiling for recovery of visual deficits resulting from anterior circulation aneurysms which supports the authors’ treatment approach in this case [7]. Future advances in neuroimaging technology may allow improved delineation of structural and functional neuroanatomy, therefore providing further insight into common and rare pathologies affecting the visual pathways. References [1] Moteki Y, Kawamoto T, Namioka T, Yokote A, Kawamata T. Progressive visual field defect caused by an unruptured middle cerebral artery aneurysm. Clin Neurol Neurosurg 2013;115(10):2182–5. [2] Soni SR. Aneurysms of the posterior communicating artery and oculomotor paresis. J Neurol Neurosurg Psychiatry 1974;37(4):475–84. [3] Guresir E, Schuss P, Seifert V, Vatter H. Oculomotor nerve palsy by posterior communicating artery aneurysms: influence of surgical strategy on recovery. J Neurosurg 2012;117(5):904–10.
∗ Correspondence
to: University of Virginia, Department of Neurosurgery, P.O. Box 800212, Charlottesville, USA. Tel.: +1 434 924 2203; fax: +1 434 982 5753. E-mail address: [email protected] 10 October 2013 Available online 8 November 2013 http://dx.doi.org/10.1016/j.clineuro.2013.10.024
Potential role of flow-diverting stents for posterior cerebral artery aneurysms Keywords: Intracranial aneurysm Posterior cerebral artery Endovascular procedures Stent Stroke
Dear Sir, I have read, with great interest, a recently published article in Clinical Neurology and Neurosurgery by Kim et al. titled ‘Outcomes of multidisciplinary treatment for posterior cerebral artery aneurysms’ [1]. The authors describe the microsurgical and endovascular treatment outcomes for 25 patients with posterior cerebral artery (PCA) aneurysms. The majority of the aneurysms were at least 10 mm in diameter (56%) and located proximal to the P2P segment (76%). Microsurgery was the primary treatment for 60% of the aneurysms and successful in all but one case (4%) which was salvaged by endovascular coiling. An endovascular approach was the primary treatment for the remaining 40% of cases without any instances of technical failure. The rate of treatment-related permanent neurological morbidity was 20%. At a mean clinical follow-up of 43 months, a modified Rankin Scale score less than 3 was observed in 88% of patients. PCA aneurysms are rare lesions with unique patient (i.e. younger age) and lesion characteristics (i.e. larger, more likely to be non-saccular). A wide range of microsurgical and endovascular techniques, ranging from direct clip ligation to parent artery sacrifice, were used in this relatively small series which is a testament to the significant variability observed in PCA aneurysms. Notably, there were no cases which were treated with a flow-diverting stent (FDS). The use FDSs has been rapidly popularized with increasing reports of their remarkable ability to reconstruct the neck of large, complex intracranial aneurysms which would otherwise be very difficult to successfully treat via traditional microsurgical or
