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develop signs and symptoms within 48 h of IVIG infusion. Very rarely IVIG may cause posterior reversible encephalopathy.[4] The exact mechanism of IVIG induced aseptic meningitis/ encephalopathy is not known. Immunoglobulin G can penetrate the meninges and brain parenchyma and usually remains in the CSF for 48 h post-termination of infusion. Several factors have been implicated in the pathogenesis of meningitis/encephalopathy: Direct inflammatory response to the IVIG, cerebrovascular reactivity, hypersensitivity response and cytokines release.[5] Wada et al. demonstrated the excitotoxic effect of IVIG, increase in glutamate and glutamine complex peak on MR spectroscopy in acute encephalopathy following IVIG.[6]
Conclusion Meningoencephalitis can occur as a very rare self-limiting complication of IVIG treatment.
Javeria Nooraine, Rajesh B. Iyer, S. Raghavendra Department of Neurology, Vikram Hospital, Bengaluru, Karnataka, India E-mail: [email protected]
References 1. 2. 3. 4. 5. 6.
Duhem C, Dicato MA, Ries F. Side-effects of intravenous immune globulins. Clin Exp Immunol 1994;97 Suppl 1:79-83. Kaarthigeyan K, Burli VV. Aseptic meningitis following intravenous immunoglobulin therapy of common variable immunodeficiency. J Pediatr Neurosci 2011;6:160-1. Sekul EA, Cupler EJ, Dalakas MC. Aseptic meningitis associated with high-dose intravenous immunoglobulin therapy: Frequency and risk factors. Ann Intern Med 1994;121:259-62. Voltz R, Rosen FV, Yousry T, Beck J, Hohlfeld R. Reversible encephalopathy with cerebral vasospasm in a Guillain-Barré syndrome patient treated with intravenous immunoglobulin. Neurology 1996;46:250-1. Preminger-Shapiro R, Nussinovitch M, Soen G, Varsano I. Aseptic meningitis: A frequent side-effect of intravenous immunoglobulin? Eur J Pediatr 1995;154:866-7. Wada A, Yoshida R, Oda K, Fukuba E, Uchida N, Kitagaki H. Acute encephalopathy associated with intravenous immunoglobulin therapy. AJNR Am J Neuroradiol 2005;26:2311-5.
Sixth nerve schwannoma Sir, Schwannomas represent approximately 7-10% of all primary intracranial tumors. The most frequent are in eight and fifth cranial nerves.[1] Schwannoma arising from the sixth cranial nerve is exceedingly rare. Due to its close proximity to fifth and eight nerves and similar clinical and radiological findings, it is difficult to diagnose sixth nerve schwannoma preoperatively.[2,3] A 42-year-old male presented with a history of diplopia on the left lateral gaze and intermittent headache for 6 months. There was no family history suggestive of neurofibromatosis. Neurological examination revealed left 6th nerve paralysis [Figure 1a]. Magnetic resonance imaging (MRI) brain revealed a left cerebellopontine angle lesion iso to hypointense on T1-WI [Figure 2a] hyperintense on T2-WI [Figure 2b] enhancing heterogeneously on contrast [Figure 2c]. The internal acoustic meatus was of normal size. A small enhancing component of the tumor was seen going toward the Dorello’s canal [Figure 2c arrow head]. Patient underwent left retromastoid suboccipital craniotomy and gross total excision of tumor under intraoperative cranial nerve monitoring. The tumor was arising from 6th cranial nerve. He had an uneventful recovery. At 3 months follow-up, the MRI brain was normal [Figure 2d] and sixth nerve paralysis improved to normal [Figure 1b]. Histopathological examination revealed a cellular tumor composed of spindle-shaped cells with oval-to-spindle nuclei and a moderate amount of cytoplasm. The tumor cells were arranged in palisading pattern and formed verocay bodies [Figure 3]. All the cranial nerves except first and second have covering myelin sheath composed of Schwann cells and are potential sites for developing schwannoma. Most common location of intracranial schwannoma is in the cerebello-pontine angle where they arise from the vestibular division of the eighth nerve. Other common
Access this article online Quick Response Code:
Website: www.neurologyindia.com
a
PMID: *** DOI: 10.4103/0028-3886.128354
b Received: 09-01-2014 Review completed: 09-01-2014 Accepted: 02-02-2014 Neurology India | Jan-Feb 2014 | Vol 62 | Issue 1
Figure 1: (a) Pre-operative and (b) post-operative clinical photograph
99
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to suspect the isolated sixth nerve involvement and tumor going anteriorly toward Dorello’s canal [Figure 2b and c arrow head] is an important finding in favor of sixth nerve schwannoma.
a
c
b
The goal of the surgery is to preserve function and achieve complete excision. These tumors arise from nerve sheath of a fascicle, hence complete excision sparing the main nerve is possible. This patient had complete recovery of the 6th nerve function at 3 months follow up. This fact emphasizes the importance of meticulous dissection and excision of the tumor. Hence excision of tumor in the accessible location is recommended.
d
Figure 2: (a) T1-WI, (b) T2-WI, (c) post contrast magnetic resonance imaging (MRI) and (d) post-operative MRI (arrow heads showing tumor entering Dorello’s canal)
Rajinder Kumar, Anil Kothiwala, Ranajoy Ghosh1 Departments of Neurosurgery, and 1Neuropathology, All India Institute of Medical Sciences, New Delhi, India E-mail: [email protected]
References 1. 2. 3.
4.
Figure 3: Histopathological slide showing spindle-shaped cells arranged in palisading pattern with Verocay bodies
sites of origin are lower cranial nerves, fifth nerve and in the region of cavernous sinus.[1,2,4] First case of sixth nerve schwannoma was reported by Chen in 1981.[5] Tung has classified them into two types according to location.[6] Type 1 schwannomas are present in the cavernous sinus region and type 2 are present in prepontine cistern. In the absence of neurofibromatosis the isolated prepontine location is extremely rare. The exact site of origin is difficult to ascertain before surgery. However, this patient was diagnosed to be sixth nerve schwannoma before surgery. Isolated sixth nerve involvement in the absence of involvement of fifth, seventh and eight nerves, extension of tumor toward the Dorello’s canal seen in 3-Tesla MRI, helped in diagnosis. However sixth nerve involvement as a presenting feature could be seen in clival chordoma and cavernous sinus lesions.[1,6] Clinically and radiologically it may mimic vestibular schwannoma. However symptoms starting with diplopia due to sixth nerve involvement is the most important clinical feature 100
5. 6.
Sarma S, Sekhar LN, Schessel DA. Nonvestibular schwannomas of the brain: A 7-year experience. Neurosurgery 2002;50:437-48. Suetake K, Kurokawa Y, Uede T, Momota H, Hashi K. A case of abducens neurinoma mimicking acoustic neurinoma. Comput Med Imaging Graph 1998;22:257-61. Beppu T, Yoshida Y, Wada T, Arai H, Suzuki M, Kuroda K, et al. Trochlear and abducens nerve neurinomas accompanied by a cerebellopontine angle meningioma: Case report. Neurol Med Chir (Tokyo) 1997;37:416-21. Erlich SA, Tymianski M, Kiehl TR. Cellular schwannoma of the abducens nerve: Case report and review of the literature. Clin Neurol Neurosurg 2009;111:467-71. Chen BH. Neurinoma of the abducens nerve. Neurosurgery 1981;9:64-6. Tung H, Chen T, Weiss MH. Sixth nerve schwannomas. Report of two cases. J Neurosurg 1991;75:638-41. Access this article online Quick Response Code:
Website: www.neurologyindia.com PMID: *** DOI: 10.4103/0028-3886.128355
Received: 14-05-2013 Review completed: 15-05-2013 Accepted: 26-01-2014
Extracranial infrasellar craniopharyngioma Sir, A 68-year-old male patient presented with epistaxis Neurology India | Jan-Feb 2014 | Vol 62 | Issue 1
Copyright of Neurology India is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
develop signs and symptoms within 48 h of IVIG infusion. Very rarely IVIG may cause posterior reversible encephalopathy.[4] The exact mechanism of IVIG induced aseptic meningitis/ encephalopathy is not known. Immunoglobulin G can penetrate the meninges and brain parenchyma and usually remains in the CSF for 48 h post-termination of infusion. Several factors have been implicated in the pathogenesis of meningitis/encephalopathy: Direct inflammatory response to the IVIG, cerebrovascular reactivity, hypersensitivity response and cytokines release.[5] Wada et al. demonstrated the excitotoxic effect of IVIG, increase in glutamate and glutamine complex peak on MR spectroscopy in acute encephalopathy following IVIG.[6]
Conclusion Meningoencephalitis can occur as a very rare self-limiting complication of IVIG treatment.
Javeria Nooraine, Rajesh B. Iyer, S. Raghavendra Department of Neurology, Vikram Hospital, Bengaluru, Karnataka, India E-mail: [email protected]
References 1. 2. 3. 4. 5. 6.
Duhem C, Dicato MA, Ries F. Side-effects of intravenous immune globulins. Clin Exp Immunol 1994;97 Suppl 1:79-83. Kaarthigeyan K, Burli VV. Aseptic meningitis following intravenous immunoglobulin therapy of common variable immunodeficiency. J Pediatr Neurosci 2011;6:160-1. Sekul EA, Cupler EJ, Dalakas MC. Aseptic meningitis associated with high-dose intravenous immunoglobulin therapy: Frequency and risk factors. Ann Intern Med 1994;121:259-62. Voltz R, Rosen FV, Yousry T, Beck J, Hohlfeld R. Reversible encephalopathy with cerebral vasospasm in a Guillain-Barré syndrome patient treated with intravenous immunoglobulin. Neurology 1996;46:250-1. Preminger-Shapiro R, Nussinovitch M, Soen G, Varsano I. Aseptic meningitis: A frequent side-effect of intravenous immunoglobulin? Eur J Pediatr 1995;154:866-7. Wada A, Yoshida R, Oda K, Fukuba E, Uchida N, Kitagaki H. Acute encephalopathy associated with intravenous immunoglobulin therapy. AJNR Am J Neuroradiol 2005;26:2311-5.
Sixth nerve schwannoma Sir, Schwannomas represent approximately 7-10% of all primary intracranial tumors. The most frequent are in eight and fifth cranial nerves.[1] Schwannoma arising from the sixth cranial nerve is exceedingly rare. Due to its close proximity to fifth and eight nerves and similar clinical and radiological findings, it is difficult to diagnose sixth nerve schwannoma preoperatively.[2,3] A 42-year-old male presented with a history of diplopia on the left lateral gaze and intermittent headache for 6 months. There was no family history suggestive of neurofibromatosis. Neurological examination revealed left 6th nerve paralysis [Figure 1a]. Magnetic resonance imaging (MRI) brain revealed a left cerebellopontine angle lesion iso to hypointense on T1-WI [Figure 2a] hyperintense on T2-WI [Figure 2b] enhancing heterogeneously on contrast [Figure 2c]. The internal acoustic meatus was of normal size. A small enhancing component of the tumor was seen going toward the Dorello’s canal [Figure 2c arrow head]. Patient underwent left retromastoid suboccipital craniotomy and gross total excision of tumor under intraoperative cranial nerve monitoring. The tumor was arising from 6th cranial nerve. He had an uneventful recovery. At 3 months follow-up, the MRI brain was normal [Figure 2d] and sixth nerve paralysis improved to normal [Figure 1b]. Histopathological examination revealed a cellular tumor composed of spindle-shaped cells with oval-to-spindle nuclei and a moderate amount of cytoplasm. The tumor cells were arranged in palisading pattern and formed verocay bodies [Figure 3]. All the cranial nerves except first and second have covering myelin sheath composed of Schwann cells and are potential sites for developing schwannoma. Most common location of intracranial schwannoma is in the cerebello-pontine angle where they arise from the vestibular division of the eighth nerve. Other common
Access this article online Quick Response Code:
Website: www.neurologyindia.com
a
PMID: *** DOI: 10.4103/0028-3886.128354
b Received: 09-01-2014 Review completed: 09-01-2014 Accepted: 02-02-2014 Neurology India | Jan-Feb 2014 | Vol 62 | Issue 1
Figure 1: (a) Pre-operative and (b) post-operative clinical photograph
99
[Downloaded free from http://www.neurologyindia.com on Thursday, March 13, 2014, IP: 202.177.173.189] || Click here to download free Android application for this journal Letters to Editor
to suspect the isolated sixth nerve involvement and tumor going anteriorly toward Dorello’s canal [Figure 2b and c arrow head] is an important finding in favor of sixth nerve schwannoma.
a
c
b
The goal of the surgery is to preserve function and achieve complete excision. These tumors arise from nerve sheath of a fascicle, hence complete excision sparing the main nerve is possible. This patient had complete recovery of the 6th nerve function at 3 months follow up. This fact emphasizes the importance of meticulous dissection and excision of the tumor. Hence excision of tumor in the accessible location is recommended.
d
Figure 2: (a) T1-WI, (b) T2-WI, (c) post contrast magnetic resonance imaging (MRI) and (d) post-operative MRI (arrow heads showing tumor entering Dorello’s canal)
Rajinder Kumar, Anil Kothiwala, Ranajoy Ghosh1 Departments of Neurosurgery, and 1Neuropathology, All India Institute of Medical Sciences, New Delhi, India E-mail: [email protected]
References 1. 2. 3.
4.
Figure 3: Histopathological slide showing spindle-shaped cells arranged in palisading pattern with Verocay bodies
sites of origin are lower cranial nerves, fifth nerve and in the region of cavernous sinus.[1,2,4] First case of sixth nerve schwannoma was reported by Chen in 1981.[5] Tung has classified them into two types according to location.[6] Type 1 schwannomas are present in the cavernous sinus region and type 2 are present in prepontine cistern. In the absence of neurofibromatosis the isolated prepontine location is extremely rare. The exact site of origin is difficult to ascertain before surgery. However, this patient was diagnosed to be sixth nerve schwannoma before surgery. Isolated sixth nerve involvement in the absence of involvement of fifth, seventh and eight nerves, extension of tumor toward the Dorello’s canal seen in 3-Tesla MRI, helped in diagnosis. However sixth nerve involvement as a presenting feature could be seen in clival chordoma and cavernous sinus lesions.[1,6] Clinically and radiologically it may mimic vestibular schwannoma. However symptoms starting with diplopia due to sixth nerve involvement is the most important clinical feature 100
5. 6.
Sarma S, Sekhar LN, Schessel DA. Nonvestibular schwannomas of the brain: A 7-year experience. Neurosurgery 2002;50:437-48. Suetake K, Kurokawa Y, Uede T, Momota H, Hashi K. A case of abducens neurinoma mimicking acoustic neurinoma. Comput Med Imaging Graph 1998;22:257-61. Beppu T, Yoshida Y, Wada T, Arai H, Suzuki M, Kuroda K, et al. Trochlear and abducens nerve neurinomas accompanied by a cerebellopontine angle meningioma: Case report. Neurol Med Chir (Tokyo) 1997;37:416-21. Erlich SA, Tymianski M, Kiehl TR. Cellular schwannoma of the abducens nerve: Case report and review of the literature. Clin Neurol Neurosurg 2009;111:467-71. Chen BH. Neurinoma of the abducens nerve. Neurosurgery 1981;9:64-6. Tung H, Chen T, Weiss MH. Sixth nerve schwannomas. Report of two cases. J Neurosurg 1991;75:638-41. Access this article online Quick Response Code:
Website: www.neurologyindia.com PMID: *** DOI: 10.4103/0028-3886.128355
Received: 14-05-2013 Review completed: 15-05-2013 Accepted: 26-01-2014
Extracranial infrasellar craniopharyngioma Sir, A 68-year-old male patient presented with epistaxis Neurology India | Jan-Feb 2014 | Vol 62 | Issue 1
Copyright of Neurology India is the property of Medknow Publications & Media Pvt. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
