- Email: [email protected]
Cystic schwannoma of the falx cerebri
Case reports / Journal of Clinical Neuroscience 14 (2007) 589–592 9. Currier BL, Eismont FJ. Infections of the spine. In: Herkowitz HN, Garfin SR, Balderston RA, et al., editors. The Spine. 4th ed. Philadelphia: W.B. Saunders; 1999. p. 1207–29. 10. Vrzala J, Pilat P, Teyssler P. Osteomyelitis of the spine and its surgical treatment: personal experience. Acta Chir Orthop Traumatol Cech 2001;68:380–3. 11. Carek PJ, Dickerson LM, Sack JL. Diagnosis and management of osteomyelitis. Am Fam Physician 2001;63:2413–20. 12. Gross T, Kaim AH, Regazzoni P, et al. Current concepts in posttraumatic osteomyelitis: a diagnostic challenge with new imaging options. J Trauma 2002;52:1210–9. 13. Tehranzadeh J, Wong E, Wang F, et al. Imaging of osteomyelitis in the mature skeleton. Radiol Clin North Am 2001;3:223–50. 14. Ozates M, Ozkan U, Bukte Y, et al. Lumbar epidural brucellar abscess causing nerve root compression. Spinal Cord 1999;3337:448–9. 15. Demirci I. Brucella diskitis mimicking herniation without spondylitis: MRI findings. Zentralblatt fur Neurochirurgie 2003;64:178–781. 16. Stabler A, Reiser MF. Imaging of spinal infection. Radiol Clin North Am 2001;39:115–35.
589
17. Broder KW, Moise PA, Schultz RO, et al. Clinical experience with linezolid in conjunction with wound coverage techniques for skin and soft-tissue infections and postoperative osteomyelitis. Ann Plast Surg 2004;52:385–90. 18. Mader JT, Shirtliff ME, Bergquist S, et al. Antimicrobial treatment of chronic osteomyelitis. Clin Orthop 1999;360:47–65. 19. Steed DL. Debridement. Am J Surg 2004;187:71S–4S. 20. Tsukayama DT. Pathophysiology of posttraumatic osteomyelitis. Clin Orthop 1999;360:22–9. 21. Fischer B, Vaudaux P, Magnin M, et al. Novel animal model for studying the molecular mechanisms of bacterial adhesion to boneimplanted metallic devices: role of fibronectin in Staphylococcus aureus adhesion. J Orthop Res 1996;14:914–20. 22. Townsend DE, Ashdown N, Pearman JW, et al. Genetics and epidemiology of methicillin-resistant Staphylococcus aureus isolated in a Western Australian hospital. Med J Aust 1985;142:108–11. 23. Perez-Lopez C, Villarejo-Ortega FJ, Carceller-Benito F, et al. Spinal epidural abscess caused by Acinetobacter baumannii mimicking a herniated lumbar disc. Revista de Neurologia 2005;40:98–101.
doi:10.1016/j.jocn.2005.12.006
Cystic schwannoma of the falx cerebri Erhan C ¸ elikog˘lu a, Tayfun Hakan b
b,*
, Mustafa Bozbug˘a
a
a _ Kartal Education and Research Hospital, Neurosurgery Department Istanbul, Turkey _ Haydarpasßa Numune Education and Research Hospital, Neurosurgery Department Istanbul, Turkey
Received 1 February 2006; accepted 30 April 2006
Abstract Intracranial parenchymal schwannomas unrelated to a major cranial nerve are uncommon and dural schwannomas are rare. We report a 23-year-old woman without neurofibromatosis admitted with a 3-month history of seizures and left hemiparesis. Radiological investigation revealed a huge cystic tumour in the right cerebral hemisphere, attached to the falx cerebri. The solid part of the tumour showed contrast enhancement. The patient underwent excision of the tumour via a right-sided parietal craniotomy. The histological diagnosis was schwannoma. Recognition of these potentially curable tumours is important and they should be excised if possible. 2006 Elsevier Ltd. All rights reserved. Keywords: Cystic schwannoma; Dura; Falx; Schwannoma
1. Introduction Schwannomas account for 8% of all intracranial tumours and most are acoustic schwannomas.1 They arise commonly from nerves in the head and neck but very rarely from the dura and falx of the brain without stigma of neurofibromatosis.2–6 Five patients with schwannoma attached to the falx cerebri have previously been described.1,6–8 We present a young woman with a huge cystic schwannoma at-
*
Corresponding author. Tel.: + 90 532 324 32 84. E-mail address: [email protected] (T. Hakan).
tached to the falx cerebri and report the clinical, radiological and pathological features. 2. Case report A 23-year-old woman was admitted with a 3-month history of generalized seizures. Neurological examination revealed no abnormality except for left hemiparesis. There was no relevant family history and she had no signs of neurofibromatosis. Cranial CT scan and MRI demonstrated a huge cystic tumour with an irregular mural nodule in the right parietal lobe. T1-weighted images were iso- and hypo-intense and
590
Case reports / Journal of Clinical Neuroscience 14 (2007) 589–592
Fig. 1. T1-weighted atial MRI showed an iso- and hypo-intense lesion enhancing intensely and heterogeneously (A,B). The cystic part of the tumor was hyperintense on T2-weighted atial MRI (C).
enhanced intensely and heterogeneously (Fig. 1A,B). The cystic part of the tumour was hyperintense on T2-weighted MRI (Fig. 1C). The cyst wall showed no enhancement. The MRI did not demonstrate a dural tail as would be expected for a meningioma or dural-based metastasis. The patient underwent a right-sided parietal craniotomy and gross total tumour resection. Once the dura mater was opened, it was seen that the solid part of the tumour had a loose attachment to the falx cerebri and the tumour was easily
dissected. Resection of the falx cerebri was not needed. There was no invasion of the brain parenchyma and also no definite cyst wall. Microscopic analysis of the tissue showed areas composed of spindle-shaped cells (Antoni type A) and hypo-cellular areas (Antoni type B) arranged in bundles and fascicles. There was diffuse and strongly positive immuno staining for S-100 protein. The diagnosis was schwannoma (Fig. 2). The postoperative period was unremarkable. She is now symptom-free on anticonvulsive therapy and there has been no growth of the tumour during the 4-year follow-up period. 3. Discussion
Fig. 2. The tissue showed areas composed of spindle-shaped cells (Antoni type A) (arrow) and hypo-cellular areas (Antoni type B) arranged in bundles and fascicles (asterisk). (H&E · 100).
The term schwannoma is used for benign tumours presumably derived from Schwann cells of the peripheral nervous system. Schwannomas without any apparent connection to the peripheral nervous system rarely arise within the cranium and approximately 60 cases have been reported.4,9 David et al.10 reported the first intracranial parenchymal schwannoma in 1965, in the lateral ventricle. In the English literature, Gibson et al.11 were the first to report such a case in 1966. Various locations including the cerebrum,8,12 medulla oblongata,13,14 and intraventricular15 and sellar region16 have been reported. Attachment of schwannomas to the falx cerebri is very unusual. Our patient is the sixth reported case (Table 1). The mean age of these patients is 18.8 years with three male and two female patients while the sex of one of the patients of Russell and Rubinstein1 is unknown. Most of the intra-
Table 1 Summary of reported schwannomas attaching to the falx cerebri Authors, year
Age, sex
Tumor location
Russel and Rubbinstein, 19891 Vaquero et al., 19906
17, ? 12, M 17, F
Falx, left frontal Falx, right parasagittal Falx, three lesions attaching to the anterior falx
Ghosh and Chandy, 19927 Horgan et al., 19988 Present case, 2006
27, M 27, M 23, F
Falx, posterior-frontal parasaggital Falx, torcula Falx, right parasagittal
Comment Diffuse local brain invasion Appeared 7 years after removal of left intraparenchymal schwannoma Cystic Cystic
Case reports / Journal of Clinical Neuroscience 14 (2007) 589–592
cranial schwannomas unrelated to a major cranial nerve reported in the literature have occurred in children and young adults as for our patient2,9,17,18 and there is a slight male preponderance.9 The clinical features of these tumours are non-specific. Headaches, chronic seizures and focal deficits are the most common symptoms.6,9,18 The first schwannomas attached to the falx cerebri were reported by Russell and Rubinstein.1 The patients were a 17-year-old teenager and a 12-year-old boy. The case reported by Vaquero et al.6 is not a de novo schwannoma of the falx. This patient was a 17-year-old girl with multiple schwannomas attached to the falx, but she had a history of surgery for excision of left intraparenchymal frontomedial schwannoma 7 years earlier and seeding of the tumour cells during previous surgery was presumed. Ghosh and Chandy7 reported a parasagittal schwannoma mimicking a meningioma in a 27-year-old man. Apart from our patient, only that reported by Horgan et al.8 was cystic. This was a 27-year-old man presenting with a soft mass of the occiput; the tumor was located on the torcula. They proposed the term dura-based intracranial schwannoma. Our patient had a huge cystic component with mass effect causing shift of the midline structures. There are several reported cases arising from the dural base16,17,19–25 and a few from the tentorial area.2,4,5,26 The tumors located in the tentorial region are listed in Table 2. Only one of the tentorial schwannomas, the case of Oikawa et al.4 was cystic. The origin of intraparenchymal schwannomas of the cerebrum and dura is controversial. There are several theories to explain the origin of the ectopic Schwann cells. Aryanpur et al.13 suggested that aberrant, intramedullary nerve fibres might cause proliferation of Schwann cells, with a chronic stimulatory effect. Russell and Rubinstein1 used the term schwannosis to indicate a hamartous lesion composed of Schwann cells. It was postulated by Feigin and Ogata27 that the derivation of Schwann cells from multipotential mesencymal cells of the neural crest may be possible. Horgan et al.8 presumed that the tumour originated from small exteroceptive branches of the trigeminal nerve innervating the dura mater in those cases showing dural attachment. It seems wise to accept this idea in our case. Casadei et al.9 suggested a developmental basis as it is proposed that intracerebral schwannomas may arise from neural crest elements displaced during embryogenesis and the onset of these tumours is mostly at early ages. They also suggest that tumours associated with the ventricles may support this theory. Cyst formation, calcification, oedema and/or gliosis of the peritumoral area, and superficial or periventricular Table 2 Summary of reported schwannomas located around the tentorium Authors, year
Age, sex
Tumor location
Jabbour et al., 20032 Oikawa et al., 20024 Du et al., 200326 Ozawa et al., 20035
9, F 41, F 17, M 29, M
Tentorium, infratentorial Tentorium, infratentorial Tentorial hiatus Tentorium
Comment Cystic
591
location are the radiological and pathological features of intracerebral schwannomas.9,12,18 Although the contrast enhancement pattern was described as homogeneous in half the patients,18 it was heterogeneous in our case. The cyst may be very large and the tumour may be seen as a mural nodule as in our case. Among schwannomas of the falx cerebri, only the case of Horgan et al.8 and our case had a cystic component. Cyst formation has also been observed in some other dural schwannomas, particularly around the tentorium.2,4,26 However, the case presented here had such a large cystic component that it caused midline shift and the solid part was much smaller than the cystic part. The cyst may be in the tumour center secondary to tumour necrosis or there may be a large cyst secondary to mechanical trapping of CSF and leakage of blood from the tumour, causing adhesions and secondary arachnoid cyst formation.18 Entrapment seems most logical for the large cyst in our case. Neoplasms included in the differential diagnosis of intracranial schwannomas unrelated to major cranial nerves are pilocytic astrocytoma, high-grade astrocytoma, lymphoma, pleomorphic xanthoastrocytoma, meningioma, epidermoid (particularly for midline lesions having a cystic component), ganglioglioma and metastases.8,9,18 In conclusion, schwannomas arising from falx cerebri are rare tumours. They are slowly growing benign tumours and rarely show malignant change.28 The recognition of these potentially curable tumours is important and they should be excised if possible. References 1. Russell DS, Rubinstein LJ. Pathology of Tumours of the Central Nervous System. 5th edn. Baltimore: Williams & Wilkins; 1989, pp. 537–8. 2. Jabbour P, Rizk T, Lahoud GA, et al. Schwannoma of the tentorium cerebelli in a child. Case report. Pediatr Neurosurg 2002;36:153–6. 3. Nakayama K, Nakayama T, Matsuoka Y, et al. Supratentorial convexity leptomeningeal schwannoma: case report. Neurosurgery 2002;51:1295–7, discussion 1298. 4. Oikawa A, Takeda N, Aoki N, et al. Schwannoma arising from the tentorium at an unusual location: case report. Neurosurgery 2002;50:1352–5. 5. Ozawa N, Nakayama K, Ohata K, et al. Tentorial schwannoma: a case report. Br J Radiol 2003;76:421–4. 6. Vaquero J, Martinez R, Coca S, et al. Schwannomas of the falx. Surg Neurol 1990;34:160–3. 7. Ghosh S, Chandy MJ. Solitary ectopic intracerebral schwannoma. Br J Neurosurg 1992;6:163–6. 8. Horgan MA, Kernan JC, Delashaw JB, et al. Schwannoma of the torcula presenting as an occipital mass. Case illustration. J Neurosurg 1998;89:490. 9. Casadei GP, Komori T, Scheithauer BW, et al. Intracranial parenchymal schwannoma. A clinicopathological and neuroimaging study of nine cases. J Neurosurg 1993;79:217–22. 10. David M, Guyot JF, Ballivet J, et al. Schwannoid tumor of the lateral ventricle. Neurochirurgie 1965;11:578–81, French. 11. Gibson AA, Hendrick EB, Conen PE. Intracerebral schwannoma Report of a case. J Neurosurg 1966;24:552–7. 12. Ezura M, Ikeda H, Ogawa A, et al. Intracerebral schwannoma: case report. Neurosurgery 1992;30:97–100.
592
Case reports / Journal of Clinical Neuroscience 14 (2007) 592–595
13. Aryanpur J, Long DM. Schwannoma of the medulla oblongata. Case report. J Neurosurgery 1988;69:446–9. 14. Lin J, Feng H, Li F, et al. Intraparenchymal schwannoma of the medulla oblongata. Case report. J Neurosurg 2003;98:621–4. 15. Erdogan E, Onguru O, Bulakbasi N, et al. Schwannoma of the lateral ventricle: eight-year follow-up and literature review. Minim Invasive Neurosurg 2003;46:50–3. 16. Goebel HH, Shimokawa K, Schaake T, et al. Schwannoma of the sellar region. Acta Neurochir (Wien) 1979;48:191–7. 17. Frim DM, Ogilvy CS, Vonsattal JP, et al. Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review. Pediatr Neurosurg 1992;18:190–4. 18. Zagardo MT, Castellani RJ, Rees JH, et al. Radiologic and pathologic findings of intracerebral schwannoma. AJNR Am J Neuroradiol 1998;19:1290–3. 19. Bando K, Obayashi M, Tsuneharu F. A case of subfrontal schwannoma. No Shinkei Geka 1992;20:1189–94, Japanese. 20. Funiu H, Kayama T, Sakurada K, et al. A dura-based intracranial schwannoma in the temporal fossa: a case report. No Shinkei Geka 2003;31:789–93, Japanese.
21. Harano H, Hori S, Kamata K, et al. A case report of subfrontal schwannoma. No Shinkei Geka 1974;2:643–7, Japanese. 22. Hockley AD, Hendrick EB. Unilateral proptosis and intracranial schwannoma. Surg Neurol 1975;4:509–12. 23. Huang PP, Zagzag D, Benjamin V. Intracranial schwannoma presenting as a subfrontal tumor: case report. Neurosurgery 1997;40:194–7. 24. Nagao S, Aoki T, Kondo S, et al. Subfrontal schwannoma: a case report. No Shinkei Geka 1991;19:47–51, Japanese. 25. Vassilouthis J, Richardson AE. Subfrontal schwannoma. Report of a case. Acta Neurochir (Wien) 1980;53:259–66. 26. Du R, Dhoot J, McDermott MW, et al. Cystic schwannoma of the anterior tentorial hiatus. Case report and review of the literature. Pediatr Neurosurg 2003;38:167–73. 27. Feigin I, Ogata J. Schwann cells and peripheral myelin within human central nervous tissues: the mesenchymal character of Schwann cells. J Neuropathol Exp Neurol 1971;30:603–12. 28. Woodruff JM, Selig AM, Crowley K, et al. Schwannoma (neurilemoma) with malignant transformation. A rare, distinctive peripheral nerve tumor. Am J Surg Pathol 1994;18:882–95.
doi:10.1016/j.jocn.2006.04.014
Deep brain stimulation: A new treatment for hypertension? A.L. Green
a,*
, S. Wang b, R.G. Bittar c, S.L.F. Owen b, D.J. Paterson b, J.F. Stein b, P.G. Bain d, D. Shlugman a, T.Z. Aziz a,b a
c
Department of Neurosurgery, Radcliffe Infirmary, Woodstock Road, Oxford OX2 6HE, UK b University Laboratory of Physiology, University of Oxford, Oxford, UK Departments of Surgery and Neurosurgery, Monash University and The Alfred Hospital, Melbourne, Victoria, Australia d Division of Neurosciences & Mental Health, Imperial College London, Charing Cross Campus, London, UK Received 3 February 2006; accepted 22 April 2006
Abstract We report a 61-year-old hypertensive man who underwent deep brain stimulation of the periventricular/periaqueductal grey area for the relief of chronic neuropathic pain affecting his oral cavity and soft palate. During intraoperative stimulation, we were able to modulate his blood pressure up or down, depending on electrode location. This is the first evidence that hypertension could be effectively treated with electrical stimulation of the midbrain. 2006 Elsevier Ltd. All rights reserved. Keywords: Blood pressure; Deep brain stimulation; Periaqueductal grey; Hypertension
1. Introduction Deep brain stimulation of the periventricular/periaqueductal gray area is increasingly being used as a treatment in chronic neuropathic pain.1,2 The periaqueductal gray area projects to all medullary regions that control blood *
Corresponding author. Tel.: +44 01 865 311188; fax: +44 01 865 224786. E-mail address: [email protected] (A.L. Green).
pressure, as well as having reciprocal connections with higher centers.3–6 Here we show reversal of hypertension with electrical stimulation of this area in an awake patient. 2. Case report A 61-year-old man presented with a 5-year history of intractable neuropathic pain affecting the right side of his soft palate, oral cavity and lateral side of the tongue. He described this as a constant ‘searing’ pain that gradually
589
17. Broder KW, Moise PA, Schultz RO, et al. Clinical experience with linezolid in conjunction with wound coverage techniques for skin and soft-tissue infections and postoperative osteomyelitis. Ann Plast Surg 2004;52:385–90. 18. Mader JT, Shirtliff ME, Bergquist S, et al. Antimicrobial treatment of chronic osteomyelitis. Clin Orthop 1999;360:47–65. 19. Steed DL. Debridement. Am J Surg 2004;187:71S–4S. 20. Tsukayama DT. Pathophysiology of posttraumatic osteomyelitis. Clin Orthop 1999;360:22–9. 21. Fischer B, Vaudaux P, Magnin M, et al. Novel animal model for studying the molecular mechanisms of bacterial adhesion to boneimplanted metallic devices: role of fibronectin in Staphylococcus aureus adhesion. J Orthop Res 1996;14:914–20. 22. Townsend DE, Ashdown N, Pearman JW, et al. Genetics and epidemiology of methicillin-resistant Staphylococcus aureus isolated in a Western Australian hospital. Med J Aust 1985;142:108–11. 23. Perez-Lopez C, Villarejo-Ortega FJ, Carceller-Benito F, et al. Spinal epidural abscess caused by Acinetobacter baumannii mimicking a herniated lumbar disc. Revista de Neurologia 2005;40:98–101.
doi:10.1016/j.jocn.2005.12.006
Cystic schwannoma of the falx cerebri Erhan C ¸ elikog˘lu a, Tayfun Hakan b
b,*
, Mustafa Bozbug˘a
a
a _ Kartal Education and Research Hospital, Neurosurgery Department Istanbul, Turkey _ Haydarpasßa Numune Education and Research Hospital, Neurosurgery Department Istanbul, Turkey
Received 1 February 2006; accepted 30 April 2006
Abstract Intracranial parenchymal schwannomas unrelated to a major cranial nerve are uncommon and dural schwannomas are rare. We report a 23-year-old woman without neurofibromatosis admitted with a 3-month history of seizures and left hemiparesis. Radiological investigation revealed a huge cystic tumour in the right cerebral hemisphere, attached to the falx cerebri. The solid part of the tumour showed contrast enhancement. The patient underwent excision of the tumour via a right-sided parietal craniotomy. The histological diagnosis was schwannoma. Recognition of these potentially curable tumours is important and they should be excised if possible. 2006 Elsevier Ltd. All rights reserved. Keywords: Cystic schwannoma; Dura; Falx; Schwannoma
1. Introduction Schwannomas account for 8% of all intracranial tumours and most are acoustic schwannomas.1 They arise commonly from nerves in the head and neck but very rarely from the dura and falx of the brain without stigma of neurofibromatosis.2–6 Five patients with schwannoma attached to the falx cerebri have previously been described.1,6–8 We present a young woman with a huge cystic schwannoma at-
*
Corresponding author. Tel.: + 90 532 324 32 84. E-mail address: [email protected] (T. Hakan).
tached to the falx cerebri and report the clinical, radiological and pathological features. 2. Case report A 23-year-old woman was admitted with a 3-month history of generalized seizures. Neurological examination revealed no abnormality except for left hemiparesis. There was no relevant family history and she had no signs of neurofibromatosis. Cranial CT scan and MRI demonstrated a huge cystic tumour with an irregular mural nodule in the right parietal lobe. T1-weighted images were iso- and hypo-intense and
590
Case reports / Journal of Clinical Neuroscience 14 (2007) 589–592
Fig. 1. T1-weighted atial MRI showed an iso- and hypo-intense lesion enhancing intensely and heterogeneously (A,B). The cystic part of the tumor was hyperintense on T2-weighted atial MRI (C).
enhanced intensely and heterogeneously (Fig. 1A,B). The cystic part of the tumour was hyperintense on T2-weighted MRI (Fig. 1C). The cyst wall showed no enhancement. The MRI did not demonstrate a dural tail as would be expected for a meningioma or dural-based metastasis. The patient underwent a right-sided parietal craniotomy and gross total tumour resection. Once the dura mater was opened, it was seen that the solid part of the tumour had a loose attachment to the falx cerebri and the tumour was easily
dissected. Resection of the falx cerebri was not needed. There was no invasion of the brain parenchyma and also no definite cyst wall. Microscopic analysis of the tissue showed areas composed of spindle-shaped cells (Antoni type A) and hypo-cellular areas (Antoni type B) arranged in bundles and fascicles. There was diffuse and strongly positive immuno staining for S-100 protein. The diagnosis was schwannoma (Fig. 2). The postoperative period was unremarkable. She is now symptom-free on anticonvulsive therapy and there has been no growth of the tumour during the 4-year follow-up period. 3. Discussion
Fig. 2. The tissue showed areas composed of spindle-shaped cells (Antoni type A) (arrow) and hypo-cellular areas (Antoni type B) arranged in bundles and fascicles (asterisk). (H&E · 100).
The term schwannoma is used for benign tumours presumably derived from Schwann cells of the peripheral nervous system. Schwannomas without any apparent connection to the peripheral nervous system rarely arise within the cranium and approximately 60 cases have been reported.4,9 David et al.10 reported the first intracranial parenchymal schwannoma in 1965, in the lateral ventricle. In the English literature, Gibson et al.11 were the first to report such a case in 1966. Various locations including the cerebrum,8,12 medulla oblongata,13,14 and intraventricular15 and sellar region16 have been reported. Attachment of schwannomas to the falx cerebri is very unusual. Our patient is the sixth reported case (Table 1). The mean age of these patients is 18.8 years with three male and two female patients while the sex of one of the patients of Russell and Rubinstein1 is unknown. Most of the intra-
Table 1 Summary of reported schwannomas attaching to the falx cerebri Authors, year
Age, sex
Tumor location
Russel and Rubbinstein, 19891 Vaquero et al., 19906
17, ? 12, M 17, F
Falx, left frontal Falx, right parasagittal Falx, three lesions attaching to the anterior falx
Ghosh and Chandy, 19927 Horgan et al., 19988 Present case, 2006
27, M 27, M 23, F
Falx, posterior-frontal parasaggital Falx, torcula Falx, right parasagittal
Comment Diffuse local brain invasion Appeared 7 years after removal of left intraparenchymal schwannoma Cystic Cystic
Case reports / Journal of Clinical Neuroscience 14 (2007) 589–592
cranial schwannomas unrelated to a major cranial nerve reported in the literature have occurred in children and young adults as for our patient2,9,17,18 and there is a slight male preponderance.9 The clinical features of these tumours are non-specific. Headaches, chronic seizures and focal deficits are the most common symptoms.6,9,18 The first schwannomas attached to the falx cerebri were reported by Russell and Rubinstein.1 The patients were a 17-year-old teenager and a 12-year-old boy. The case reported by Vaquero et al.6 is not a de novo schwannoma of the falx. This patient was a 17-year-old girl with multiple schwannomas attached to the falx, but she had a history of surgery for excision of left intraparenchymal frontomedial schwannoma 7 years earlier and seeding of the tumour cells during previous surgery was presumed. Ghosh and Chandy7 reported a parasagittal schwannoma mimicking a meningioma in a 27-year-old man. Apart from our patient, only that reported by Horgan et al.8 was cystic. This was a 27-year-old man presenting with a soft mass of the occiput; the tumor was located on the torcula. They proposed the term dura-based intracranial schwannoma. Our patient had a huge cystic component with mass effect causing shift of the midline structures. There are several reported cases arising from the dural base16,17,19–25 and a few from the tentorial area.2,4,5,26 The tumors located in the tentorial region are listed in Table 2. Only one of the tentorial schwannomas, the case of Oikawa et al.4 was cystic. The origin of intraparenchymal schwannomas of the cerebrum and dura is controversial. There are several theories to explain the origin of the ectopic Schwann cells. Aryanpur et al.13 suggested that aberrant, intramedullary nerve fibres might cause proliferation of Schwann cells, with a chronic stimulatory effect. Russell and Rubinstein1 used the term schwannosis to indicate a hamartous lesion composed of Schwann cells. It was postulated by Feigin and Ogata27 that the derivation of Schwann cells from multipotential mesencymal cells of the neural crest may be possible. Horgan et al.8 presumed that the tumour originated from small exteroceptive branches of the trigeminal nerve innervating the dura mater in those cases showing dural attachment. It seems wise to accept this idea in our case. Casadei et al.9 suggested a developmental basis as it is proposed that intracerebral schwannomas may arise from neural crest elements displaced during embryogenesis and the onset of these tumours is mostly at early ages. They also suggest that tumours associated with the ventricles may support this theory. Cyst formation, calcification, oedema and/or gliosis of the peritumoral area, and superficial or periventricular Table 2 Summary of reported schwannomas located around the tentorium Authors, year
Age, sex
Tumor location
Jabbour et al., 20032 Oikawa et al., 20024 Du et al., 200326 Ozawa et al., 20035
9, F 41, F 17, M 29, M
Tentorium, infratentorial Tentorium, infratentorial Tentorial hiatus Tentorium
Comment Cystic
591
location are the radiological and pathological features of intracerebral schwannomas.9,12,18 Although the contrast enhancement pattern was described as homogeneous in half the patients,18 it was heterogeneous in our case. The cyst may be very large and the tumour may be seen as a mural nodule as in our case. Among schwannomas of the falx cerebri, only the case of Horgan et al.8 and our case had a cystic component. Cyst formation has also been observed in some other dural schwannomas, particularly around the tentorium.2,4,26 However, the case presented here had such a large cystic component that it caused midline shift and the solid part was much smaller than the cystic part. The cyst may be in the tumour center secondary to tumour necrosis or there may be a large cyst secondary to mechanical trapping of CSF and leakage of blood from the tumour, causing adhesions and secondary arachnoid cyst formation.18 Entrapment seems most logical for the large cyst in our case. Neoplasms included in the differential diagnosis of intracranial schwannomas unrelated to major cranial nerves are pilocytic astrocytoma, high-grade astrocytoma, lymphoma, pleomorphic xanthoastrocytoma, meningioma, epidermoid (particularly for midline lesions having a cystic component), ganglioglioma and metastases.8,9,18 In conclusion, schwannomas arising from falx cerebri are rare tumours. They are slowly growing benign tumours and rarely show malignant change.28 The recognition of these potentially curable tumours is important and they should be excised if possible. References 1. Russell DS, Rubinstein LJ. Pathology of Tumours of the Central Nervous System. 5th edn. Baltimore: Williams & Wilkins; 1989, pp. 537–8. 2. Jabbour P, Rizk T, Lahoud GA, et al. Schwannoma of the tentorium cerebelli in a child. Case report. Pediatr Neurosurg 2002;36:153–6. 3. Nakayama K, Nakayama T, Matsuoka Y, et al. Supratentorial convexity leptomeningeal schwannoma: case report. Neurosurgery 2002;51:1295–7, discussion 1298. 4. Oikawa A, Takeda N, Aoki N, et al. Schwannoma arising from the tentorium at an unusual location: case report. Neurosurgery 2002;50:1352–5. 5. Ozawa N, Nakayama K, Ohata K, et al. Tentorial schwannoma: a case report. Br J Radiol 2003;76:421–4. 6. Vaquero J, Martinez R, Coca S, et al. Schwannomas of the falx. Surg Neurol 1990;34:160–3. 7. Ghosh S, Chandy MJ. Solitary ectopic intracerebral schwannoma. Br J Neurosurg 1992;6:163–6. 8. Horgan MA, Kernan JC, Delashaw JB, et al. Schwannoma of the torcula presenting as an occipital mass. Case illustration. J Neurosurg 1998;89:490. 9. Casadei GP, Komori T, Scheithauer BW, et al. Intracranial parenchymal schwannoma. A clinicopathological and neuroimaging study of nine cases. J Neurosurg 1993;79:217–22. 10. David M, Guyot JF, Ballivet J, et al. Schwannoid tumor of the lateral ventricle. Neurochirurgie 1965;11:578–81, French. 11. Gibson AA, Hendrick EB, Conen PE. Intracerebral schwannoma Report of a case. J Neurosurg 1966;24:552–7. 12. Ezura M, Ikeda H, Ogawa A, et al. Intracerebral schwannoma: case report. Neurosurgery 1992;30:97–100.
592
Case reports / Journal of Clinical Neuroscience 14 (2007) 592–595
13. Aryanpur J, Long DM. Schwannoma of the medulla oblongata. Case report. J Neurosurgery 1988;69:446–9. 14. Lin J, Feng H, Li F, et al. Intraparenchymal schwannoma of the medulla oblongata. Case report. J Neurosurg 2003;98:621–4. 15. Erdogan E, Onguru O, Bulakbasi N, et al. Schwannoma of the lateral ventricle: eight-year follow-up and literature review. Minim Invasive Neurosurg 2003;46:50–3. 16. Goebel HH, Shimokawa K, Schaake T, et al. Schwannoma of the sellar region. Acta Neurochir (Wien) 1979;48:191–7. 17. Frim DM, Ogilvy CS, Vonsattal JP, et al. Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review. Pediatr Neurosurg 1992;18:190–4. 18. Zagardo MT, Castellani RJ, Rees JH, et al. Radiologic and pathologic findings of intracerebral schwannoma. AJNR Am J Neuroradiol 1998;19:1290–3. 19. Bando K, Obayashi M, Tsuneharu F. A case of subfrontal schwannoma. No Shinkei Geka 1992;20:1189–94, Japanese. 20. Funiu H, Kayama T, Sakurada K, et al. A dura-based intracranial schwannoma in the temporal fossa: a case report. No Shinkei Geka 2003;31:789–93, Japanese.
21. Harano H, Hori S, Kamata K, et al. A case report of subfrontal schwannoma. No Shinkei Geka 1974;2:643–7, Japanese. 22. Hockley AD, Hendrick EB. Unilateral proptosis and intracranial schwannoma. Surg Neurol 1975;4:509–12. 23. Huang PP, Zagzag D, Benjamin V. Intracranial schwannoma presenting as a subfrontal tumor: case report. Neurosurgery 1997;40:194–7. 24. Nagao S, Aoki T, Kondo S, et al. Subfrontal schwannoma: a case report. No Shinkei Geka 1991;19:47–51, Japanese. 25. Vassilouthis J, Richardson AE. Subfrontal schwannoma. Report of a case. Acta Neurochir (Wien) 1980;53:259–66. 26. Du R, Dhoot J, McDermott MW, et al. Cystic schwannoma of the anterior tentorial hiatus. Case report and review of the literature. Pediatr Neurosurg 2003;38:167–73. 27. Feigin I, Ogata J. Schwann cells and peripheral myelin within human central nervous tissues: the mesenchymal character of Schwann cells. J Neuropathol Exp Neurol 1971;30:603–12. 28. Woodruff JM, Selig AM, Crowley K, et al. Schwannoma (neurilemoma) with malignant transformation. A rare, distinctive peripheral nerve tumor. Am J Surg Pathol 1994;18:882–95.
doi:10.1016/j.jocn.2006.04.014
Deep brain stimulation: A new treatment for hypertension? A.L. Green
a,*
, S. Wang b, R.G. Bittar c, S.L.F. Owen b, D.J. Paterson b, J.F. Stein b, P.G. Bain d, D. Shlugman a, T.Z. Aziz a,b a
c
Department of Neurosurgery, Radcliffe Infirmary, Woodstock Road, Oxford OX2 6HE, UK b University Laboratory of Physiology, University of Oxford, Oxford, UK Departments of Surgery and Neurosurgery, Monash University and The Alfred Hospital, Melbourne, Victoria, Australia d Division of Neurosciences & Mental Health, Imperial College London, Charing Cross Campus, London, UK Received 3 February 2006; accepted 22 April 2006
Abstract We report a 61-year-old hypertensive man who underwent deep brain stimulation of the periventricular/periaqueductal grey area for the relief of chronic neuropathic pain affecting his oral cavity and soft palate. During intraoperative stimulation, we were able to modulate his blood pressure up or down, depending on electrode location. This is the first evidence that hypertension could be effectively treated with electrical stimulation of the midbrain. 2006 Elsevier Ltd. All rights reserved. Keywords: Blood pressure; Deep brain stimulation; Periaqueductal grey; Hypertension
1. Introduction Deep brain stimulation of the periventricular/periaqueductal gray area is increasingly being used as a treatment in chronic neuropathic pain.1,2 The periaqueductal gray area projects to all medullary regions that control blood *
Corresponding author. Tel.: +44 01 865 311188; fax: +44 01 865 224786. E-mail address: [email protected] (A.L. Green).
pressure, as well as having reciprocal connections with higher centers.3–6 Here we show reversal of hypertension with electrical stimulation of this area in an awake patient. 2. Case report A 61-year-old man presented with a 5-year history of intractable neuropathic pain affecting the right side of his soft palate, oral cavity and lateral side of the tongue. He described this as a constant ‘searing’ pain that gradually