Neuro-radiology
Neuroradiology (1992) 34:70-72
9 Springer-Verlag 1992
Large cystic intraparenchymal brain metastasis from prostate cancer L. I. Bland, W. C. Welch, and S.-H. Okawara Division of Neurosurgery, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA Received: 18 June 1991
Summary. A large, cystic, intraparenchymal brain metastasis from prostate cancer is reported. The clinical and radiological features of prostate carcinoma metastatic to the brain parenchyma are reviewed. Key words: Prostate cancer - Hyperostosis - Metastasis Central nervous system (CNS) involvement from prostate carcinoma is most commonly due to compression from bony metastases, with the spinal cord being more frequently involved than the brain [1, 2]. In autopsy series of 1885 patients with prostate cancer, metastases to the lumbosacral spine occurred in 15 % and to the skull in only 2 % [3]. Metastatic prostate carcinoma commonly spreads locally from a calvarial lesion to the contiguous meninges. Thus, epidural metastases are common. However, subdural and intraparenchymal metastases from prostate cancer are extremely rare, because the dura mater serves as an effective barrier [4-6]. We report an unusual case of a large, cystic, intraparenchymal brain metastasis from prostate cancer associated with hyperostosis of the skull.
Case report This 56-year-old male presented to Strong Memorial Hospital with two partial complex seizures, a 6-month history of left cheek pain, and a 1-week history of left orbital pain, periorbital swelling, and diplopia. He had been treated with decongestants and tetracycline for a presumed sinusitis and cellulitis. Neurological examination revealed proptosis of the left eye, chemosis and lateral periorbital edema. Visual acuity was O D J1 and OS J16. Goldman visual fields were normal. The patient had poor short-term memory, diplopia, limitation of all extraocular movements of the left eye, and a diminished left corneal reflex. There was mild right hemiparesis. The white blood cell count (8.1) and erythrocyte sedimentation rate [14] were normal. Head CT demonstrated a large ring-enhancing lesion in the left anterior temporal lobe adjacent to a hyperostotic sphenoid wing; the lesion extended into the lateral wall of the orbit and compressed the left cavernous sinus (Fig. 1). The carotid arteriogram showed displacement of the left middle cerebral artery complex superiorly, and faint tumor blush in the left middle fossa.
Fig. 1 a, b. Head CT scan with contrast medium (Omnipaque) a A large cystic ring enhancing lesion in the left anterior temporal lobe (arrow) b Hyperostosis of the left sphenoid bone (arrow); the inhomogeneously ringenhancing temporal lesion (arrowhead) extends into the left orbit inferolaterally
71 At operation, the left sphenoid wing was hyperostotic and soft. The dura was incised, revealing a grayish-pink, gritty, partially cystic mass within the subdural space densely adherent to the pia-arachnoid membrane. Cortical incision demonstrated an intraparenchymal round mass having a large cystic component which was removed. A small amount of residual tumor entering the orbit via the optic canal and superior orbital fissure was not pursued. Pathological examination revealed metastatic well-differentiated adenocarcinoma of the prostate which stained positively for prostatic specific antigen (PSA) and prostatic acid phosphatase (PAP). The tumor invaded the sphenoid bone, dura mater, and cerebral cortex, but spared the temporal bone. There was evidence of intratumoral hemorrhage. Postoperatively the right hemiparesis and left third and fourth cranial nerve palsies resolved. The proptosis and left sixth nerve palsy persisted. Postoperative CT showed total removal of the left temporal lobe lesion with residual tumor within the left orbit. Bone scan showed diffuse activity of the skeleton. Serum PAP and PSA levels were elevated at 6.7 and > 100 respectively; chest radiographs and abdominal CT scans were normal. Radiation therapy and bilateral orchiectomy were performed. At a 9-month followup examination, the patient was seizure-free and doing well.
Discussion Intraparenchymal and subdural brain metastases from prostate carcinoma are rare, especially in the clinical literature. Only nine histologically verified cases of metastatic prostate cancer to the subdural space have been reported, of which seven were associated with subdural hematomas [5]. The incidence of parenchymal brain metastases in autopsy series performed on patients with prostate cancer is 1%; the vast majority of these lesions were clinically silent [7]. A n t e m o r t e m diagnosis of intraparenchymal metastases has been achieved in only 0.10.2 % of patients with prostate cancer in clinical series
{7, 81 A literature review revealed 37 well-documented cases of prostate cancer metastatic to the brain parenchyma [1, 2, 7-20]. Cases without histological verification, or those which did not specify an intraparenchymal location and/or included meningeal or calvarial lesions in their series have been excluded [4, 10, 21-32]. The diagnosis was confirmed at autopsy in 30 of 37 cases (80 %), and was made antemortem in 7 cases (20 %); 4 cases were located in the cerebellum (11%), 4 in both the cerebrum and cerebellum (11% ), 2 in the brain stem (5 %), and 1 within the lateral ventricle (3 % ). In addition, there are 6 reports of prostate cancer metastatic to the pituitary gland [11, 19, 33, 34]. The majority of patients with prostate cancer metastatic to the brain parenchyma had evidence of diffuse metastatic disease with elevated PAP and PSA levels, positive bone scans, and involvement of the lymphatics, lung, and/or liver. Based on 7 cases where such information was supplied [1, 2, 7, 18] the mean time interval be-
tween the initial diagnosis of prostate cancer and the development of intraparenchymal metastases is 3.8 years. This case is unusual for several reasons. The prostatic cancer first presented as an intraparenchymal brain metastasis; only 3 other cases out of 37 had similar presentation [8, 9, 17]. It is the only report we know of prostate cancer mimicking a cystic meningioma with hyperostosis in which intraparenchymal and subdural lesions were found [35]. In a review of 15 cases of metastases from prostate cancer simulating a meningioma, Lippman et al. [36] found that 13 of the 15 patients presented with hyperostosis of the orbital and sphenoid wing and/or proptosis. However, all of these patients had bone metastases without penetration of the meninges. None demonstrated a cystic component to the epidural tumor. Three patients in this series demonstrated a tumor blush on arteriography from the external carotid artery which supplied osteoblastic bone metastases. Only 6 histologically verified cases of parenchymal metastases from prostate cancer have been evaluated by head CT [2, 7, 8, 14, 17]. As in epidural metastases, the typical CT picture is that of homogeneous enhancement with the precontrast scan depicting a hypodense, isodense, or hyperdense lesion [36]. In our case, the sterile cyst cavities had evidence of microscopic intratumoral hemorrhage. Microscopic intratumoral hemorrhage, massive intracerebral hemorrhage, and subarachnoid hemorrhage have been reported in association with prostatic parenchymal metastases in 5, 4, and 1 case(s) respectively [2, 8, 9, 11, 16, 18]. However, none of these cases demonstrated cyst formation in the tumor. Prostate cancer may simulate a cystic meningioma and/or brain abscess, clinically and radiographically and, therefore, should be considered in the differential diagnosis of an elderly male presenting with an intracranial lesion with concomitant hyperostosis.
References 1. Catane R, Kaufman J, West C, Merrin C, Tsukada Y, Murphy GP (1976) Brain metastasis from prostatic carcinoma. Cancer 38: 2583-2587 2. Smith VC, Kasdon DL, Hardy RC (1980) Metastatic brain tumor from the prostate: two unusual cases. Surg Neuro114:189-191 3. Saitoh H, Hida M, Shimbo T, Nakamura K, Yamagata J, Satoh T (1984) Metastatic patterns of prostatic cancer: correlation between sites and number of organs involved. Cancer 54: 30783084 4. Burbridge B, Tchang SPK (1989) Computed tomographic evaluation of intracranial metastases from carcinoma of the prostate. J Assoc Can Radio140:234-237 5. Cheng CLY, Greenberg J, Hoover LA (1988) Prostatic adenocarcinoma metastatic to chronic subdural hematoma membranes. J Neurosurg 68:642-644 6. Penley MW, Kim YC, Pribram HFW (1981) Subdural metastases from prostatic adenocarcinoma. Surg Neurol 16:131-134 7. Lynes WL, Bostwick DG, Freiha FS, Stamey TA (1986) Parenchymal brain metastases from adenocarcinoma of prostate. Urology 28:280-287 8. Barolat-Romana G, Maiman D, Dernbach R Choi H (1984) Prostate carcinoma presenting as intracranial hemorrhage. J Neurosurg 60:414-416
72 9. Baumann MA, Holoye PY, Choi H (1984) Adenocarcinoma of prostate presenting as brain metastasis. Cancer 54:1723-1725 10. Castaldo JE, Bernat JL, Meier FA, Schned AR (1983) Intracranial metastases due to prostatic carcinoma. Cancer 52: 17391747 11. Demierre B, Berney J (1983) Metastases intracraniennes du cancer de la prostate. Neurochirurgie 29:143-149 12. France LH (1968) Contribution a 1'etude des metastases cerebrales. 1. Correlations anatome-cliniques de 150 cas. Minerva Neurochirurg 12:195-209 13. Globus JH, Meltzer T (1942) Metastatic tumors of the brain. Arch Neurol Psychiatry 48:163-226 14. Huang T, Lung Ty, Li C (1984) Unusual radiologic features of metastatic prostatic carcinoma confirmed by immunohistochemical study. Urology 23:218-223 15. Krastling K (1906) Beitrag zur Statistik und Kasuistik metastatischer Tumoren, besonders der Carcinommetastasen im Zentralnervensystem. Z Krebsforsch 4:315 16. Lewis L (1967) Cerebellar metastasis from prostatic carcinoma. Neurology 17:698-702 17. Loseke N, Retif J, Noterman J, Flament-Durand J (1981) Inferior red nucleus syndrome (Benedikt's syndrome) due to a single intramesencephalicmetastasis from a prostatic carcinoma. Acta Neurochirurg 56:59-64 18. Sarma DR Godeau L (1983) Brain metastasis from prostatic cancer. J Surg Onco123:173-174 19. Taylor HG, Lefkowitz M, Skoog SJ, Miles B J, McLeod DG, Coggin JT (1984) Intracranial metastases in prostate cancer. Cancer 53:2728-2730 20. Tom MI (1946) Metastatic tumors of brain. Can Med Assoc J 54: 265-268 21. Arnheim FK (1948) Carcinoma of the prostate. A study of the postmortem findings in one hundred and seventy-six cases. J Uro160:599-603 22. Baker AB (1942) Metastatic tumors of the nervous system. Arch Patho134:495-537 23. Baker GS (1951) Metastatic tumors of the brain. Surg Clin North Am 31:1143-1145 24. Courville CB (1950) Pathology of the central nervous system, 3rd edn. Pacific Press, Mountain View, Calif., pp 426-428
25. Flocks RH, Boatman DL (1943) Incidence of head and neck metastases from genitourinary neoplasms. Laryngoscope 83: 1527-1539 26. Franks LM (1956) The spread of prostate cancer. J Pathol Bacterio172:603-611 27. German WJ (1938) Carcinomatous metastases to the brain. Ann Surg 108:980-985 28. Lesse S, Netsky MG (1954) Metastasis of neoplasms to the central nervous system and meninges. Arch Neurol Psychiatry 72: 133-153 29. McCrea LE, Karafin L (1958) Carcinoma of the prostate: metastases, therapy, and survival. J Int Colon Surg 29:723-728 30. Mintz ER, Smith GG (1934) Autopsy findings in 100 cases of prostatic cancer. N Engl J Med 211:479M87 31. Staubitz W J, Oberkircher OJ, Lent MH (1954) Clinical results of the treatment of prostatic carcinoma over a ten-year period. J Uro172:939-945 32. The Veterans Administration Cooperative Urological Research Group (1968) Factors in the prognosis of carcinoma of the prostate. J Urot 100:59%5 33. Meyer PC, Reah TG (1953) Secondary neoplasms of the central nervous system and meninges. Br J Cancer 7:438-448 34. Winkelman NW, Eckel JL (1927) Metastatic carcinoma of the central nervous system. J Nerv Ment Dis 66:133-142 35. Umansky F, Pappo 1, Pizov G, Shalit M (1988) Cystic changes in intracranial meningiomas: a review. Acta Neurochir (Wien) 95: 13-18 36. Lippmann SM, Buzaid AC, Iacono RR Steinbronn DV, Stanisic TH, Rennels MA, Yang PJ, Garewal HS, Ahmann FR (1986) Cranial metastases from prostate cancer simulating meningioma: report of two cases and review of the literature. Neurosurgery 19:820-823 L. I. Bland, M. D. University of Rochester School of Medicine and Dentistry Division of Neurosurgery 601 Elmwood Avenue Rochester, NY 14642 USA
Neuroradiology (1992) 34:70-72
9 Springer-Verlag 1992
Large cystic intraparenchymal brain metastasis from prostate cancer L. I. Bland, W. C. Welch, and S.-H. Okawara Division of Neurosurgery, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA Received: 18 June 1991
Summary. A large, cystic, intraparenchymal brain metastasis from prostate cancer is reported. The clinical and radiological features of prostate carcinoma metastatic to the brain parenchyma are reviewed. Key words: Prostate cancer - Hyperostosis - Metastasis Central nervous system (CNS) involvement from prostate carcinoma is most commonly due to compression from bony metastases, with the spinal cord being more frequently involved than the brain [1, 2]. In autopsy series of 1885 patients with prostate cancer, metastases to the lumbosacral spine occurred in 15 % and to the skull in only 2 % [3]. Metastatic prostate carcinoma commonly spreads locally from a calvarial lesion to the contiguous meninges. Thus, epidural metastases are common. However, subdural and intraparenchymal metastases from prostate cancer are extremely rare, because the dura mater serves as an effective barrier [4-6]. We report an unusual case of a large, cystic, intraparenchymal brain metastasis from prostate cancer associated with hyperostosis of the skull.
Case report This 56-year-old male presented to Strong Memorial Hospital with two partial complex seizures, a 6-month history of left cheek pain, and a 1-week history of left orbital pain, periorbital swelling, and diplopia. He had been treated with decongestants and tetracycline for a presumed sinusitis and cellulitis. Neurological examination revealed proptosis of the left eye, chemosis and lateral periorbital edema. Visual acuity was O D J1 and OS J16. Goldman visual fields were normal. The patient had poor short-term memory, diplopia, limitation of all extraocular movements of the left eye, and a diminished left corneal reflex. There was mild right hemiparesis. The white blood cell count (8.1) and erythrocyte sedimentation rate [14] were normal. Head CT demonstrated a large ring-enhancing lesion in the left anterior temporal lobe adjacent to a hyperostotic sphenoid wing; the lesion extended into the lateral wall of the orbit and compressed the left cavernous sinus (Fig. 1). The carotid arteriogram showed displacement of the left middle cerebral artery complex superiorly, and faint tumor blush in the left middle fossa.
Fig. 1 a, b. Head CT scan with contrast medium (Omnipaque) a A large cystic ring enhancing lesion in the left anterior temporal lobe (arrow) b Hyperostosis of the left sphenoid bone (arrow); the inhomogeneously ringenhancing temporal lesion (arrowhead) extends into the left orbit inferolaterally
71 At operation, the left sphenoid wing was hyperostotic and soft. The dura was incised, revealing a grayish-pink, gritty, partially cystic mass within the subdural space densely adherent to the pia-arachnoid membrane. Cortical incision demonstrated an intraparenchymal round mass having a large cystic component which was removed. A small amount of residual tumor entering the orbit via the optic canal and superior orbital fissure was not pursued. Pathological examination revealed metastatic well-differentiated adenocarcinoma of the prostate which stained positively for prostatic specific antigen (PSA) and prostatic acid phosphatase (PAP). The tumor invaded the sphenoid bone, dura mater, and cerebral cortex, but spared the temporal bone. There was evidence of intratumoral hemorrhage. Postoperatively the right hemiparesis and left third and fourth cranial nerve palsies resolved. The proptosis and left sixth nerve palsy persisted. Postoperative CT showed total removal of the left temporal lobe lesion with residual tumor within the left orbit. Bone scan showed diffuse activity of the skeleton. Serum PAP and PSA levels were elevated at 6.7 and > 100 respectively; chest radiographs and abdominal CT scans were normal. Radiation therapy and bilateral orchiectomy were performed. At a 9-month followup examination, the patient was seizure-free and doing well.
Discussion Intraparenchymal and subdural brain metastases from prostate carcinoma are rare, especially in the clinical literature. Only nine histologically verified cases of metastatic prostate cancer to the subdural space have been reported, of which seven were associated with subdural hematomas [5]. The incidence of parenchymal brain metastases in autopsy series performed on patients with prostate cancer is 1%; the vast majority of these lesions were clinically silent [7]. A n t e m o r t e m diagnosis of intraparenchymal metastases has been achieved in only 0.10.2 % of patients with prostate cancer in clinical series
{7, 81 A literature review revealed 37 well-documented cases of prostate cancer metastatic to the brain parenchyma [1, 2, 7-20]. Cases without histological verification, or those which did not specify an intraparenchymal location and/or included meningeal or calvarial lesions in their series have been excluded [4, 10, 21-32]. The diagnosis was confirmed at autopsy in 30 of 37 cases (80 %), and was made antemortem in 7 cases (20 %); 4 cases were located in the cerebellum (11%), 4 in both the cerebrum and cerebellum (11% ), 2 in the brain stem (5 %), and 1 within the lateral ventricle (3 % ). In addition, there are 6 reports of prostate cancer metastatic to the pituitary gland [11, 19, 33, 34]. The majority of patients with prostate cancer metastatic to the brain parenchyma had evidence of diffuse metastatic disease with elevated PAP and PSA levels, positive bone scans, and involvement of the lymphatics, lung, and/or liver. Based on 7 cases where such information was supplied [1, 2, 7, 18] the mean time interval be-
tween the initial diagnosis of prostate cancer and the development of intraparenchymal metastases is 3.8 years. This case is unusual for several reasons. The prostatic cancer first presented as an intraparenchymal brain metastasis; only 3 other cases out of 37 had similar presentation [8, 9, 17]. It is the only report we know of prostate cancer mimicking a cystic meningioma with hyperostosis in which intraparenchymal and subdural lesions were found [35]. In a review of 15 cases of metastases from prostate cancer simulating a meningioma, Lippman et al. [36] found that 13 of the 15 patients presented with hyperostosis of the orbital and sphenoid wing and/or proptosis. However, all of these patients had bone metastases without penetration of the meninges. None demonstrated a cystic component to the epidural tumor. Three patients in this series demonstrated a tumor blush on arteriography from the external carotid artery which supplied osteoblastic bone metastases. Only 6 histologically verified cases of parenchymal metastases from prostate cancer have been evaluated by head CT [2, 7, 8, 14, 17]. As in epidural metastases, the typical CT picture is that of homogeneous enhancement with the precontrast scan depicting a hypodense, isodense, or hyperdense lesion [36]. In our case, the sterile cyst cavities had evidence of microscopic intratumoral hemorrhage. Microscopic intratumoral hemorrhage, massive intracerebral hemorrhage, and subarachnoid hemorrhage have been reported in association with prostatic parenchymal metastases in 5, 4, and 1 case(s) respectively [2, 8, 9, 11, 16, 18]. However, none of these cases demonstrated cyst formation in the tumor. Prostate cancer may simulate a cystic meningioma and/or brain abscess, clinically and radiographically and, therefore, should be considered in the differential diagnosis of an elderly male presenting with an intracranial lesion with concomitant hyperostosis.
References 1. Catane R, Kaufman J, West C, Merrin C, Tsukada Y, Murphy GP (1976) Brain metastasis from prostatic carcinoma. Cancer 38: 2583-2587 2. Smith VC, Kasdon DL, Hardy RC (1980) Metastatic brain tumor from the prostate: two unusual cases. Surg Neuro114:189-191 3. Saitoh H, Hida M, Shimbo T, Nakamura K, Yamagata J, Satoh T (1984) Metastatic patterns of prostatic cancer: correlation between sites and number of organs involved. Cancer 54: 30783084 4. Burbridge B, Tchang SPK (1989) Computed tomographic evaluation of intracranial metastases from carcinoma of the prostate. J Assoc Can Radio140:234-237 5. Cheng CLY, Greenberg J, Hoover LA (1988) Prostatic adenocarcinoma metastatic to chronic subdural hematoma membranes. J Neurosurg 68:642-644 6. Penley MW, Kim YC, Pribram HFW (1981) Subdural metastases from prostatic adenocarcinoma. Surg Neurol 16:131-134 7. Lynes WL, Bostwick DG, Freiha FS, Stamey TA (1986) Parenchymal brain metastases from adenocarcinoma of prostate. Urology 28:280-287 8. Barolat-Romana G, Maiman D, Dernbach R Choi H (1984) Prostate carcinoma presenting as intracranial hemorrhage. J Neurosurg 60:414-416
72 9. Baumann MA, Holoye PY, Choi H (1984) Adenocarcinoma of prostate presenting as brain metastasis. Cancer 54:1723-1725 10. Castaldo JE, Bernat JL, Meier FA, Schned AR (1983) Intracranial metastases due to prostatic carcinoma. Cancer 52: 17391747 11. Demierre B, Berney J (1983) Metastases intracraniennes du cancer de la prostate. Neurochirurgie 29:143-149 12. France LH (1968) Contribution a 1'etude des metastases cerebrales. 1. Correlations anatome-cliniques de 150 cas. Minerva Neurochirurg 12:195-209 13. Globus JH, Meltzer T (1942) Metastatic tumors of the brain. Arch Neurol Psychiatry 48:163-226 14. Huang T, Lung Ty, Li C (1984) Unusual radiologic features of metastatic prostatic carcinoma confirmed by immunohistochemical study. Urology 23:218-223 15. Krastling K (1906) Beitrag zur Statistik und Kasuistik metastatischer Tumoren, besonders der Carcinommetastasen im Zentralnervensystem. Z Krebsforsch 4:315 16. Lewis L (1967) Cerebellar metastasis from prostatic carcinoma. Neurology 17:698-702 17. Loseke N, Retif J, Noterman J, Flament-Durand J (1981) Inferior red nucleus syndrome (Benedikt's syndrome) due to a single intramesencephalicmetastasis from a prostatic carcinoma. Acta Neurochirurg 56:59-64 18. Sarma DR Godeau L (1983) Brain metastasis from prostatic cancer. J Surg Onco123:173-174 19. Taylor HG, Lefkowitz M, Skoog SJ, Miles B J, McLeod DG, Coggin JT (1984) Intracranial metastases in prostate cancer. Cancer 53:2728-2730 20. Tom MI (1946) Metastatic tumors of brain. Can Med Assoc J 54: 265-268 21. Arnheim FK (1948) Carcinoma of the prostate. A study of the postmortem findings in one hundred and seventy-six cases. J Uro160:599-603 22. Baker AB (1942) Metastatic tumors of the nervous system. Arch Patho134:495-537 23. Baker GS (1951) Metastatic tumors of the brain. Surg Clin North Am 31:1143-1145 24. Courville CB (1950) Pathology of the central nervous system, 3rd edn. Pacific Press, Mountain View, Calif., pp 426-428
25. Flocks RH, Boatman DL (1943) Incidence of head and neck metastases from genitourinary neoplasms. Laryngoscope 83: 1527-1539 26. Franks LM (1956) The spread of prostate cancer. J Pathol Bacterio172:603-611 27. German WJ (1938) Carcinomatous metastases to the brain. Ann Surg 108:980-985 28. Lesse S, Netsky MG (1954) Metastasis of neoplasms to the central nervous system and meninges. Arch Neurol Psychiatry 72: 133-153 29. McCrea LE, Karafin L (1958) Carcinoma of the prostate: metastases, therapy, and survival. J Int Colon Surg 29:723-728 30. Mintz ER, Smith GG (1934) Autopsy findings in 100 cases of prostatic cancer. N Engl J Med 211:479M87 31. Staubitz W J, Oberkircher OJ, Lent MH (1954) Clinical results of the treatment of prostatic carcinoma over a ten-year period. J Uro172:939-945 32. The Veterans Administration Cooperative Urological Research Group (1968) Factors in the prognosis of carcinoma of the prostate. J Urot 100:59%5 33. Meyer PC, Reah TG (1953) Secondary neoplasms of the central nervous system and meninges. Br J Cancer 7:438-448 34. Winkelman NW, Eckel JL (1927) Metastatic carcinoma of the central nervous system. J Nerv Ment Dis 66:133-142 35. Umansky F, Pappo 1, Pizov G, Shalit M (1988) Cystic changes in intracranial meningiomas: a review. Acta Neurochir (Wien) 95: 13-18 36. Lippmann SM, Buzaid AC, Iacono RR Steinbronn DV, Stanisic TH, Rennels MA, Yang PJ, Garewal HS, Ahmann FR (1986) Cranial metastases from prostate cancer simulating meningioma: report of two cases and review of the literature. Neurosurgery 19:820-823 L. I. Bland, M. D. University of Rochester School of Medicine and Dentistry Division of Neurosurgery 601 Elmwood Avenue Rochester, NY 14642 USA
