Journal of Clinical Neuroscience 21 (2014) 2239–2242
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Case Reports
Malignant peripheral nerve sheath tumor of the cauda equina with craniospinal metastasis Jonathan G. Thomas a,⇑, Christie Lincoln b, J. Clay Goodman c, Shankar P. Gopinath a a
Department of Neurosurgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Department of Radiology, Baylor College of Medicine, Houston, TX, USA c Department of Pathology & Immunology and Neurology, Baylor College of Medicine, Houston, TX, USA b
a r t i c l e
i n f o
Article history: Received 19 September 2013 Accepted 23 February 2014
Keywords: Craniospinal metastasis Malignant peripheral nerve sheath tumor Spinal tumor
a b s t r a c t Intradural spinal malignant peripheral nerve sheath tumors (MPNST) are extremely rare, with only 20 adult patients reported to our knowledge, and only four primary tumors arising from the cauda equina. A 49-year-old man presented with back pain, constipation, and lower extremity weakness and was found to have a large intradural lesion involving the cauda equina. Imaging of the rest of his neuraxis revealed additional small left temporal lobe, cervical, and thoracic lesions. The patient underwent laminectomy for tumor debulking and biopsy, as gross total resection was not possible due to envelopment of the cauda equina. Histopathology revealed a MPNST with high cellularity, elevated proliferative indices, and nerve fascicle invasion. After the debulking, the patient reported improvement in his symptoms. However, 6 weeks later, the patient began having severe headaches, and his left temporal lobe lesion was found to have increased significantly in size, requiring craniotomy for palliative resection. The authors report the first adult patient with sporadic spinal MPNST with craniospinal metastasis to our knowledge. Imaging of the entire neuraxis is recommended for initial workup of these lesions, which are capable of intradural spread. The best treatment approach is unclear, but total surgical resection should be attempted, barring infiltration and engulfment of the nerve roots or widespread dissemination. Ó 2014 Elsevier Ltd. All rights reserved.
1. Background and importance Malignant peripheral nerve sheath tumors (MPNST) are a rare form of sarcoma with an incidence of less than 0.001% in the general population [1]. The majority of MPNST occur in patients with neurofibromatosis type 1, who carry a 10% lifetime risk of developing this tumor [2]. Rarely, MPNST may arise from malignant degeneration of a neurofibroma, schwannoma, ganglioneuroma, or pheochromocytoma. They usually involve peripheral nerves of the trunk, extremities, or head and neck area [3]. Primary intradural spinal MPNST are a rare entity, with four pediatric patients and 20 adult patients reported in the literature [4]. Only four of these adult cases have involved the cauda equina primarily. Here we report an adult patient with a primary sporadic MPNST of the spine with evidence of craniospinal metastasis on presentation. 2. Clinical presentation A 49-year-old man without significant past medical history presented to the Emergency Department with 2 weeks of increased ⇑ Corresponding author. Tel.: +1 713 798 4696. E-mail address: [email protected] (J.G. Thomas).
back and leg pain and severe constipation. He had a history of smoking a half-pack per day, but no family history of cancer or neurofibromatosis. On neurologic examination, he had decreased light touch and pinprick sensation in the S1 distribution bilaterally, hypoactive Achilles reflex, diminished rectal tone, and 4/5 strength in his distal lower extremities. No cutaneous stigmata were identified. He underwent MRI of his lumbar spine which showed a large enhancing intradural mass filling the thecal sac below the conus level (Fig. 1A, B). Imaging of his chest, abdomen and pelvis did not reveal any additional pathology. MRI of the remainder of his neuraxis identified areas of enhancement in his left anterior temporal lobe and posterior to the thoracic spinal cord (Fig. 1C, D) and an area of intradural extramedullary nodular enhancement anterior to the cervical spinal cord. With the plan to debulk the tumor and obtain tissue for diagnosis, the patient was taken to surgery for L4, L5, and S1 laminectomies. Once the dura was opened, as expected, the tumor was found to be tightly investing the nerve roots. The tumor mass was debulked but full dissection of the nerve roots from the tumor could not be performed due to the adherence. Intraoperative cytological imprints and cryostat sections of the specimen revealed cohesive spindle cells, and permanent sections revealed high cellularity and nuclear atypia with penetration and entrapment of nerve fascicles (Fig. 2). The tumor stained strongly for S100 and vimentin with focal cytoplasmic staining for glial fibrillary acidic protein.
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Case Reports / Journal of Clinical Neuroscience 21 (2014) 2239–2242
Fig. 1. MRI of the lumbar spine shows a diffuse infiltrative intradural process on (A) T2-weighted and (B) T1-weighted post-contrast sagittal sequences. Imaging of the rest of the neuraxis revealed intradural contrast-enhancing lesions in (C) the thoracic spine (sagittal T1-weighted post-contrast) and (D) the left temporal lobe (axial T1-weighted post-contrast).
The Ki67 stain revealed elevated proliferative index (7–10%) in large atypical cells throughout the tumor. Histopathology was consistent with MPNST. Postoperatively, the patient reported improvement in his pain and his constipation. Permanent pathologic examination was consistent with MPNST. Six weeks later, he began having severe headaches. MRI of the brain showed that the small left temporal lobe metastasis had increased markedly in size and was now causing significantly mass effect (Fig. 3). His cervical and thoracic lesions showed only slight interval growth. He underwent a palliative craniotomy for resection of the temporal lesion. Histopathology was consistent with MPNST.
3. Discussion Primary intradural MPNST of the cauda equina are very rare, with only four adult patients previously reported in the literature to our knowledge [4]. Generally, optimal treatment of MPNST requires total resection with clear margins – 5 year survival is 67% in cases of clear margins compared to 22% with positive margins [5]. However, the same oncologic resection principles can rarely be applied in spinal MPNST due to the location in the spinal canal and involvement of neural tissue. Adjuvant radiotherapy may improve rates of local control [5], so even after total resection in spinal MPNST, adjuvant radiotherapy should be considered.
Case Reports / Journal of Clinical Neuroscience 21 (2014) 2239–2242
2241
Fig. 2. Histopathological sections of malignant peripheral nerve sheath tumor of the cauda equina. (A) Hypercellular spindle cell neoplasm with marked nuclear atypia (hematoxylin and eosin, original magnification 200), (B) marked nuclear atypia and increased mitotic activity with aberrancy (hematoxylin and eosin, original magnification 400), (C) elevated proliferative activity on Ki-67 immunohistochemistry (original magnification 200) and (D) S100 immunoreactivity of many of the tumor cells, confirming neural crest derivation (original magnification 200) (This figure is available in colour at http://www.sciencedirect.com/).
To our knowledge, 19 adult patients with intradural MPNST of the spine have been reported [4], with an additional five pediatric patients. Twelve of these patients were adults with sporadic primary intradural MPNST (without previous radiation or history of neurofibromatosis type 1 or 2). None of these 12 patients had metastasis evident on presentation. Neuraxial metastases have been reported in MPNST in four children and in two adults with neurofibromatosis type 1, usually involving liver and/or lung. In total, the treatment methods and outcomes for primary sporadic spinal MPNST are widely disparate. Some have reported good outcome with no evidence of local or distant recurrences after total surgical removal of the lesion even without postoperative radiotherapy, while others report recurrence despite total resection. As our patient illustrates, metastasis can be present along the neuraxis at presentation. Compared to other reported cases, our patient presented late in the course of the disease, with large tumor dimensions and nerve root engulfment that precluded gross total resection as well as evidence of craniospinal metastasis on presentation. The rapid growth of his temporal lobe lesion compared to his cervical and thoracic lesions reflects heterogeneity of the biologic behavior of the tumor, perhaps dependent on site of growth. 4. Conclusion
Fig. 3. Follow-up axial T1-weighted MRI with contrast showing rapid growth of the left temporal lobe lesion.
MPNST of the cauda equina is a rare entity. Imaging of the neuraxis should be performed as these lesions are capable of intradural metastasis. The best treatment approach is unclear, but total surgical resection should be attempted, barring infiltration and engulfment of the nerve roots or widespread dissemination. Conflicts of Interest/Disclosures
Chemotherapy is usually ineffective, and is generally reserved for treatment of metastatic disease.
The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.
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Case Reports / Journal of Clinical Neuroscience 21 (2014) 2242–2244
References [1] Hajdu SI. Peripheral nerve sheath tumors. Histogenesis, classification, and prognosis. Cancer 1993;72:3549–52. [2] Tucker T, Wolkenstein P, Revuz J, et al. Association between benign and malignant peripheral nerve sheath tumors in NF1. Neurology 2005;65:205–11. [3] Stark AM, Buhl R, Hugo HH, et al. Malignant peripheral nerve sheath tumours– report of 8 cases and review of the literature. Acta Neurochir (Wien) 2001;143:357–63 [discussion 363–354].
[4] Xu Q, Xing B, Huang X, et al. Primary malignant peripheral nerve sheath tumor of the cauda equina with metastasis to the brain in a child: case report and literature review. Spine J 2012;12:e7–e13. [5] Wong WW, Hirose T, Scheithauer BW, et al. Malignant peripheral nerve sheath tumor: analysis of treatment outcome. Int J Radiat Oncol Biol Phys 1998;42:351–60.
http://dx.doi.org/10.1016/j.jocn.2014.02.028
Over-shunting associated myelopathy Brian M. Howard a,⇑, Eric A. Sribnick a, Sanjay S. Dhall b a b
Department of Neurological Surgery, Emory University School of Medicine, 1365-B Clifton Road, NE, Ste. 2200, Atlanta, GA 30322, USA Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
a r t i c l e
i n f o
Article history: Received 8 May 2014 Accepted 17 May 2014
Keywords: Hydrocephalus Intracranial hypotension Myelopathy Ventriculoperitoneal shunt
a b s t r a c t Intracranial hypotension typically presents following cerebrospinal fluid (CSF) leak, but can be induced by CSF diversion. Classically, patients present with positional headache, but less common symptoms include neck pain and cranial nerve palsies. To our knowledge, the neurosurgical literature contains six reports of patients with symptomatic cervical, epidural venous plexus engorgement as the result of CSF shunting. The patient presented herein is a 26-year-old woman with shunt-dependent, congenital hydrocephalus. She presented with rapidly progressive cervical myelopathy following ventriculoperitoneal shunt revision. Imaging revealed engorgement of the cervical epidural venous plexus and mass effect on the cervical spinal cord. ‘‘Over-shunting associated myelopathy’’ is a rare complication of CSF diversion that should be familiar to physicians who routinely evaluate patients with intracranial shunts. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Intracranial hypotension (IH) typically presents following posttraumatic or post-operative cerebrospinal fluid (CSF) leak, but can be induced by CSF diversion. Typically, patients present with positional headache [1]. We report a patient who presented with IH and ‘‘over-shunting associated myelopathy’’ (OSAM) from epidural venous plexus (EVP) engorgement after ventriculoperitoneal shunt (VPS) revision. 2. Case report The patient is a 26-year-old woman with shunt-dependent, congenital hydrocephalus. One shunt revision was required between initial placement during infancy and January 2012, when the patient developed a VPS malfunction. Imaging demonstrated hydrocephalus and migration of the distal catheter out of the peritoneal space. A successful distal revision was performed; however, the patient developed a second distal shunt malfunction that required revision in June 2012 (Fig. 1A). Four weeks later, the patient presented with neck pain and cervical myelopathy characterized by upper extremity dysesthesia, ataxic gait, and symmetric hyper-reflexia of the upper and lower extremities, Hoffman’s sign and clonus bilaterally and a positive Romberg sign. The patient had no prior history, signs or symptoms of cervical myelopathy. CT scan of the head confirmed interval decompression of the ventricles following shunt revision (Fig. 1B). MRI of the brain and cervical spine revealed characteristics of intracranial hypotension
⇑ Corresponding author. Tel.: +1 4047785969. E-mail address: [email protected] (B.M. Howard).
including diffusely enhancing, thickened meninges, pituitary gland enlargement, and low-lying cerebellum (Fig. 1C). Massively dilated epidural veins were noted ventrolateral to the spinal cord, causing severe canal stenosis with obliteration of the CSF space, deformation of the spinal cord, and T2 intramedullary signal changes (Fig. 1D). Vascular imaging of the brain and cervical spine showed engorgement of the upper cervical EVP, but no vascular malformation (not shown). A shunt tap was performed without spontaneous egress of CSF. CSF was easily withdrawn by gentle aspiration. On the basis of these imaging and clinical data, the patient was taken to the operating room for VPS exploration and valve revision. All components of the shunt were functional. The indwelling medium pressure valve was replaced with an adjustable valve (CodmanHakim, DePuy Orthopaedics, Warsaw, IL, USA) with a functional range from 30 to 200 mm of water. The valve was empirically set to open at a pressure of 140 mm of water to significantly raise the intracranial pressure, but allow for adjustment if the patient did not clinically improve. Post-operatively, the patient was observed for 48 hours then discharged. Eight weeks after surgery, the patient’s gait was drastically improved and she no longer required an assistive device to ambulate. Her hyper-reflexia was greatly diminished and clonus was no longer sustained. Hoffman’s sign was still elicited, but the degree of spread had significantly lessened. MRI of the cervical spine obtained 6 weeks after surgery revealed approximately 50% interval decrease in the degree of epidural venous engorgement anterior to the spinal cord (compare Fig. 1D and E green and blue bars 7.5 mm and 4.0 mm versus 4.9 and 1.9 mm, respectively; yellow bar [4.3 mm versus 3.0 mm, respectively] and purple arrowheads). Axial sequences showed restoration of the CSF space at all levels and that the mass effect and resultant intramedullary T2 signal change resolved (Fig. 1D compared to E).
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Case Reports
Malignant peripheral nerve sheath tumor of the cauda equina with craniospinal metastasis Jonathan G. Thomas a,⇑, Christie Lincoln b, J. Clay Goodman c, Shankar P. Gopinath a a
Department of Neurosurgery, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA Department of Radiology, Baylor College of Medicine, Houston, TX, USA c Department of Pathology & Immunology and Neurology, Baylor College of Medicine, Houston, TX, USA b
a r t i c l e
i n f o
Article history: Received 19 September 2013 Accepted 23 February 2014
Keywords: Craniospinal metastasis Malignant peripheral nerve sheath tumor Spinal tumor
a b s t r a c t Intradural spinal malignant peripheral nerve sheath tumors (MPNST) are extremely rare, with only 20 adult patients reported to our knowledge, and only four primary tumors arising from the cauda equina. A 49-year-old man presented with back pain, constipation, and lower extremity weakness and was found to have a large intradural lesion involving the cauda equina. Imaging of the rest of his neuraxis revealed additional small left temporal lobe, cervical, and thoracic lesions. The patient underwent laminectomy for tumor debulking and biopsy, as gross total resection was not possible due to envelopment of the cauda equina. Histopathology revealed a MPNST with high cellularity, elevated proliferative indices, and nerve fascicle invasion. After the debulking, the patient reported improvement in his symptoms. However, 6 weeks later, the patient began having severe headaches, and his left temporal lobe lesion was found to have increased significantly in size, requiring craniotomy for palliative resection. The authors report the first adult patient with sporadic spinal MPNST with craniospinal metastasis to our knowledge. Imaging of the entire neuraxis is recommended for initial workup of these lesions, which are capable of intradural spread. The best treatment approach is unclear, but total surgical resection should be attempted, barring infiltration and engulfment of the nerve roots or widespread dissemination. Ó 2014 Elsevier Ltd. All rights reserved.
1. Background and importance Malignant peripheral nerve sheath tumors (MPNST) are a rare form of sarcoma with an incidence of less than 0.001% in the general population [1]. The majority of MPNST occur in patients with neurofibromatosis type 1, who carry a 10% lifetime risk of developing this tumor [2]. Rarely, MPNST may arise from malignant degeneration of a neurofibroma, schwannoma, ganglioneuroma, or pheochromocytoma. They usually involve peripheral nerves of the trunk, extremities, or head and neck area [3]. Primary intradural spinal MPNST are a rare entity, with four pediatric patients and 20 adult patients reported in the literature [4]. Only four of these adult cases have involved the cauda equina primarily. Here we report an adult patient with a primary sporadic MPNST of the spine with evidence of craniospinal metastasis on presentation. 2. Clinical presentation A 49-year-old man without significant past medical history presented to the Emergency Department with 2 weeks of increased ⇑ Corresponding author. Tel.: +1 713 798 4696. E-mail address: [email protected] (J.G. Thomas).
back and leg pain and severe constipation. He had a history of smoking a half-pack per day, but no family history of cancer or neurofibromatosis. On neurologic examination, he had decreased light touch and pinprick sensation in the S1 distribution bilaterally, hypoactive Achilles reflex, diminished rectal tone, and 4/5 strength in his distal lower extremities. No cutaneous stigmata were identified. He underwent MRI of his lumbar spine which showed a large enhancing intradural mass filling the thecal sac below the conus level (Fig. 1A, B). Imaging of his chest, abdomen and pelvis did not reveal any additional pathology. MRI of the remainder of his neuraxis identified areas of enhancement in his left anterior temporal lobe and posterior to the thoracic spinal cord (Fig. 1C, D) and an area of intradural extramedullary nodular enhancement anterior to the cervical spinal cord. With the plan to debulk the tumor and obtain tissue for diagnosis, the patient was taken to surgery for L4, L5, and S1 laminectomies. Once the dura was opened, as expected, the tumor was found to be tightly investing the nerve roots. The tumor mass was debulked but full dissection of the nerve roots from the tumor could not be performed due to the adherence. Intraoperative cytological imprints and cryostat sections of the specimen revealed cohesive spindle cells, and permanent sections revealed high cellularity and nuclear atypia with penetration and entrapment of nerve fascicles (Fig. 2). The tumor stained strongly for S100 and vimentin with focal cytoplasmic staining for glial fibrillary acidic protein.
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Case Reports / Journal of Clinical Neuroscience 21 (2014) 2239–2242
Fig. 1. MRI of the lumbar spine shows a diffuse infiltrative intradural process on (A) T2-weighted and (B) T1-weighted post-contrast sagittal sequences. Imaging of the rest of the neuraxis revealed intradural contrast-enhancing lesions in (C) the thoracic spine (sagittal T1-weighted post-contrast) and (D) the left temporal lobe (axial T1-weighted post-contrast).
The Ki67 stain revealed elevated proliferative index (7–10%) in large atypical cells throughout the tumor. Histopathology was consistent with MPNST. Postoperatively, the patient reported improvement in his pain and his constipation. Permanent pathologic examination was consistent with MPNST. Six weeks later, he began having severe headaches. MRI of the brain showed that the small left temporal lobe metastasis had increased markedly in size and was now causing significantly mass effect (Fig. 3). His cervical and thoracic lesions showed only slight interval growth. He underwent a palliative craniotomy for resection of the temporal lesion. Histopathology was consistent with MPNST.
3. Discussion Primary intradural MPNST of the cauda equina are very rare, with only four adult patients previously reported in the literature to our knowledge [4]. Generally, optimal treatment of MPNST requires total resection with clear margins – 5 year survival is 67% in cases of clear margins compared to 22% with positive margins [5]. However, the same oncologic resection principles can rarely be applied in spinal MPNST due to the location in the spinal canal and involvement of neural tissue. Adjuvant radiotherapy may improve rates of local control [5], so even after total resection in spinal MPNST, adjuvant radiotherapy should be considered.
Case Reports / Journal of Clinical Neuroscience 21 (2014) 2239–2242
2241
Fig. 2. Histopathological sections of malignant peripheral nerve sheath tumor of the cauda equina. (A) Hypercellular spindle cell neoplasm with marked nuclear atypia (hematoxylin and eosin, original magnification 200), (B) marked nuclear atypia and increased mitotic activity with aberrancy (hematoxylin and eosin, original magnification 400), (C) elevated proliferative activity on Ki-67 immunohistochemistry (original magnification 200) and (D) S100 immunoreactivity of many of the tumor cells, confirming neural crest derivation (original magnification 200) (This figure is available in colour at http://www.sciencedirect.com/).
To our knowledge, 19 adult patients with intradural MPNST of the spine have been reported [4], with an additional five pediatric patients. Twelve of these patients were adults with sporadic primary intradural MPNST (without previous radiation or history of neurofibromatosis type 1 or 2). None of these 12 patients had metastasis evident on presentation. Neuraxial metastases have been reported in MPNST in four children and in two adults with neurofibromatosis type 1, usually involving liver and/or lung. In total, the treatment methods and outcomes for primary sporadic spinal MPNST are widely disparate. Some have reported good outcome with no evidence of local or distant recurrences after total surgical removal of the lesion even without postoperative radiotherapy, while others report recurrence despite total resection. As our patient illustrates, metastasis can be present along the neuraxis at presentation. Compared to other reported cases, our patient presented late in the course of the disease, with large tumor dimensions and nerve root engulfment that precluded gross total resection as well as evidence of craniospinal metastasis on presentation. The rapid growth of his temporal lobe lesion compared to his cervical and thoracic lesions reflects heterogeneity of the biologic behavior of the tumor, perhaps dependent on site of growth. 4. Conclusion
Fig. 3. Follow-up axial T1-weighted MRI with contrast showing rapid growth of the left temporal lobe lesion.
MPNST of the cauda equina is a rare entity. Imaging of the neuraxis should be performed as these lesions are capable of intradural metastasis. The best treatment approach is unclear, but total surgical resection should be attempted, barring infiltration and engulfment of the nerve roots or widespread dissemination. Conflicts of Interest/Disclosures
Chemotherapy is usually ineffective, and is generally reserved for treatment of metastatic disease.
The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication.
2242
Case Reports / Journal of Clinical Neuroscience 21 (2014) 2242–2244
References [1] Hajdu SI. Peripheral nerve sheath tumors. Histogenesis, classification, and prognosis. Cancer 1993;72:3549–52. [2] Tucker T, Wolkenstein P, Revuz J, et al. Association between benign and malignant peripheral nerve sheath tumors in NF1. Neurology 2005;65:205–11. [3] Stark AM, Buhl R, Hugo HH, et al. Malignant peripheral nerve sheath tumours– report of 8 cases and review of the literature. Acta Neurochir (Wien) 2001;143:357–63 [discussion 363–354].
[4] Xu Q, Xing B, Huang X, et al. Primary malignant peripheral nerve sheath tumor of the cauda equina with metastasis to the brain in a child: case report and literature review. Spine J 2012;12:e7–e13. [5] Wong WW, Hirose T, Scheithauer BW, et al. Malignant peripheral nerve sheath tumor: analysis of treatment outcome. Int J Radiat Oncol Biol Phys 1998;42:351–60.
http://dx.doi.org/10.1016/j.jocn.2014.02.028
Over-shunting associated myelopathy Brian M. Howard a,⇑, Eric A. Sribnick a, Sanjay S. Dhall b a b
Department of Neurological Surgery, Emory University School of Medicine, 1365-B Clifton Road, NE, Ste. 2200, Atlanta, GA 30322, USA Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
a r t i c l e
i n f o
Article history: Received 8 May 2014 Accepted 17 May 2014
Keywords: Hydrocephalus Intracranial hypotension Myelopathy Ventriculoperitoneal shunt
a b s t r a c t Intracranial hypotension typically presents following cerebrospinal fluid (CSF) leak, but can be induced by CSF diversion. Classically, patients present with positional headache, but less common symptoms include neck pain and cranial nerve palsies. To our knowledge, the neurosurgical literature contains six reports of patients with symptomatic cervical, epidural venous plexus engorgement as the result of CSF shunting. The patient presented herein is a 26-year-old woman with shunt-dependent, congenital hydrocephalus. She presented with rapidly progressive cervical myelopathy following ventriculoperitoneal shunt revision. Imaging revealed engorgement of the cervical epidural venous plexus and mass effect on the cervical spinal cord. ‘‘Over-shunting associated myelopathy’’ is a rare complication of CSF diversion that should be familiar to physicians who routinely evaluate patients with intracranial shunts. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction Intracranial hypotension (IH) typically presents following posttraumatic or post-operative cerebrospinal fluid (CSF) leak, but can be induced by CSF diversion. Typically, patients present with positional headache [1]. We report a patient who presented with IH and ‘‘over-shunting associated myelopathy’’ (OSAM) from epidural venous plexus (EVP) engorgement after ventriculoperitoneal shunt (VPS) revision. 2. Case report The patient is a 26-year-old woman with shunt-dependent, congenital hydrocephalus. One shunt revision was required between initial placement during infancy and January 2012, when the patient developed a VPS malfunction. Imaging demonstrated hydrocephalus and migration of the distal catheter out of the peritoneal space. A successful distal revision was performed; however, the patient developed a second distal shunt malfunction that required revision in June 2012 (Fig. 1A). Four weeks later, the patient presented with neck pain and cervical myelopathy characterized by upper extremity dysesthesia, ataxic gait, and symmetric hyper-reflexia of the upper and lower extremities, Hoffman’s sign and clonus bilaterally and a positive Romberg sign. The patient had no prior history, signs or symptoms of cervical myelopathy. CT scan of the head confirmed interval decompression of the ventricles following shunt revision (Fig. 1B). MRI of the brain and cervical spine revealed characteristics of intracranial hypotension
⇑ Corresponding author. Tel.: +1 4047785969. E-mail address: [email protected] (B.M. Howard).
including diffusely enhancing, thickened meninges, pituitary gland enlargement, and low-lying cerebellum (Fig. 1C). Massively dilated epidural veins were noted ventrolateral to the spinal cord, causing severe canal stenosis with obliteration of the CSF space, deformation of the spinal cord, and T2 intramedullary signal changes (Fig. 1D). Vascular imaging of the brain and cervical spine showed engorgement of the upper cervical EVP, but no vascular malformation (not shown). A shunt tap was performed without spontaneous egress of CSF. CSF was easily withdrawn by gentle aspiration. On the basis of these imaging and clinical data, the patient was taken to the operating room for VPS exploration and valve revision. All components of the shunt were functional. The indwelling medium pressure valve was replaced with an adjustable valve (CodmanHakim, DePuy Orthopaedics, Warsaw, IL, USA) with a functional range from 30 to 200 mm of water. The valve was empirically set to open at a pressure of 140 mm of water to significantly raise the intracranial pressure, but allow for adjustment if the patient did not clinically improve. Post-operatively, the patient was observed for 48 hours then discharged. Eight weeks after surgery, the patient’s gait was drastically improved and she no longer required an assistive device to ambulate. Her hyper-reflexia was greatly diminished and clonus was no longer sustained. Hoffman’s sign was still elicited, but the degree of spread had significantly lessened. MRI of the cervical spine obtained 6 weeks after surgery revealed approximately 50% interval decrease in the degree of epidural venous engorgement anterior to the spinal cord (compare Fig. 1D and E green and blue bars 7.5 mm and 4.0 mm versus 4.9 and 1.9 mm, respectively; yellow bar [4.3 mm versus 3.0 mm, respectively] and purple arrowheads). Axial sequences showed restoration of the CSF space at all levels and that the mass effect and resultant intramedullary T2 signal change resolved (Fig. 1D compared to E).
