J Neurosurg 75:475-477, 1991
Traumatic pericallosal aneurysm in a patient with no major trauma Case report MORIS SENEGOR, M.D.
Neurological Surgery Associates of Cincinnati, Cincinnati, Ohio The case of a young woman who developed a traumatic distal anterior cerebral artery ("pericallosal') aneurysm from a roller-coaster ride is described. She presented with a subarachnoid hemorrhage (SAH) restricted to the interhemispheric fissure. The initial angiogram was normal but repeat angiography at 8 days revealed the aneurysm. After craniotomy and clipping the patient made a satisfactory recovery. This is the only reported case of a traumatic aneurysm arising under circumstances not usually considered as trauma. It raises questions about the pathophysiology of the formation of such aneurysms and suggests that traumatic pericallosal aneurysms should be considered in SAH of unknown etiology. This case provides further evidence that repeat angiography occasionally helps reveal an aneurysm when the initial study fails to do so. KEY WORDS aneurysm, traumatic anterior cerebral artery
NTRACRANIAL aneurysms caused by trauma are rare. 9~824 Traumatic aneurysms have been described in various locations in the intracranial and extracranial circulation. ~'3~'~~ The distal anterior cerebral artery ("pericallosal") is a well-known location for traumatic aneurysms, 6'~1,12,21.23,z5 probably because of the unique relationship of the artery with the edge of the falx. Such aneurysms have generally been reported after major head injuries. We recently encountered a patient who developed a pericallosal aneurysm without any history of major trauma. Her aneurysm was thought to arise due to a roller-coaster ride. The case and its implications as well as relevant literature are discussed.
I
Case Report This 32-year-old woman had been previously healthy and had not suffered any trauma until she rode five roller-coasters at an amusement park. The fifth subjected her to a three-story near free-fall followed by four complete upside-down loops. After the fall and the first loop, she felt a sudden severe headache and lost consciousness for the remainder of the ride. She then became drowsy and confused, and complained of a severe headache. She had no focal neurological deficit.
Examination. An initial computerized tomography scan revealed a subarachnoid hemorrhage (SAH) localized at the interhemispheric fissure, but complete anJ. Neurosurg. / Volume 75/September, 1991
9 subarachnoid hemorrhage
giography performed within 16 hours of ictus was unremarkable (Fig. 1 left). The patient was admitted for observation. Angiography was repeated on the 8th day after presentation and disclosed a left distal anterior cerebral artery aneurysm (Fig. 1 right). By this time the patient was neurologically intact. Operation. On Day 10 the aneurysm was approached surgically and found to be located exactly at the point where the artery crossed the inferior edge of the falx. There was a small intraparenchymal clot on the lateral surface of the aneurysm where it was imbedded into the cingulate gyms. The aneurysm lay along a straight segment of the vessel with no branching points nearby. When the anatomy of the aneurysm was surgically exposed, a diagnosis of traumatic aneurysm was made. Clipping proceeded uneventfully. The patient made a satisfactory recovery. Postoperative angiography confirmed obliteration of the aneurysm (Fig. 2). Discussion We have presented a case of SAH that occurred during a roller-coaster ride in a previously healthy person. The etiology of the hemorrhage was initially unclear, but the aneurysm was discovered upon repeat angiography. We have no doubt about the traumatic origin of the aneurysm because of its unique location away from any branching points and adjacent to the falx edge. After extensively questioning the patient and 475
M. S e n e g o r
FIG. 1. Left internal carotid angiograms in this patient. Left: Admission angiogram revealing no abnormalities 16 hours after subarachnoid hemorrhage. Right." Repeat angiogram on Day 8 showing a distal anterior cerebral artery aneurysm (arrow).
FIG. 2. Postoperative angiogram showing that the aneurysm (arrow) has been satisfactorily clipped. 476
her family and finding no history of significant trauma, we concluded that her trauma had to be one of the roller-coaster rides she took on the day of her ictus. The last ride during which she lost consciousness is the most likely culprit. We found it interesting that evidence of vessel injury, which most likely occurred due to movement of the artery against the falcial edge during the ride, did not appear on the early angiogram. The aneurysm, albeit small, appeared 8 days later. Over 40 traumatic anterior cerebral artery aneurysms have been described in the literature..,~,6~9,~1,12,15.2o,21,25,28 Direct trauma to the vessel from iatrogeniC or penetrating ~9 injuries has been described in rare cases. However, by far the most common cause is indirect trauma due to motor-vehicle accidents or falls. These patients usually have significant associated evidence of trauma such as skull fractures, mass lesions of the brain, and systemic injuries, Fleischer, et al., j~ described one case of a football injury accompanied by no loss of consciousness or other associated injuries, where a traumatic pericallosal aneurysm was discovered. There are no reports in the literature of a "traumatic" aneurysm arising in a patient lacking any history or physical evidence of trauma at presentation. In this regard our case is quite unique. Our case also raises the question of why a relatively mild trauma caused by a roller-coaster ride would lead to aneurysm formation when severe injuries sustained in falls and road accidents rarely do so. Discussions in the literature unanimously agree that compression of the artery against a stationary falcial edge by shearing forces, causing a brain shift, is responsible for the forJ. Neurosurg. / Volume 75/September, 1991
Traumatic pericallosal aneurysm mation of such aneurysms. ~'L' ~,~:~2~ It is possible that the rare trauma victim sustaining such an aneurysm has an inherent and rare anatomical predisposition to this disorder. Adhesions to the edge of the falx were noted by Nakstad, el a]., 2~ in their three cases. A pre-existing adhesion to the falcial edge could be a catalyst for aneurysm formation. By the time such aneurysms come to surgery, distortions in the anatomy from the associated hemorrhage may not allow the surgeon ~0 appreciate such adhesions. In our case, the entire interhemispheric fissure had extensive early adhesions s e c o n d a v to the 10-day-old hemorrhage. Thus, the pathophysiology of formation of such aneurysms remains speculative at best. The majority of traumatic pericallosal aneurysms are discovered late (up to 9 weeks) after trauma. A number of reports have demonstrated significant enlargement of these aneurysms on serial an~ograms. ~'2''21252~ Smith and Bardenheier ~5 reported a case similar to ours in which the initial angiogram was normal and a later study showed the aneurysm. Therefore, traumatic pericallosal aneurysms may be overlooked early after the trauma and, if untreated, they have a tendency to grow.- '-Our case is also an example of SAH of unknown etiology. This is a well-studied subject =~ ~~ ')~4~7 22,z~and its incidence in the literature varies between 5% and 24%.4-~6 The role of repeal angiography in these patients is controversial. It is clear, however, that repeat angiography does reveal a small percentage of aneurysms that initial studies fail to demonstrate.14A7-2226 Our case is a reminder that traumatic pericallosal aneurysms should be included in the differential diagnosis of SAH of unknown etiology, especially if the hemorrhage is restricted to the interhemispheric fissure. O u r experience provides additional evidence that repeat angiography in such cases may be beneficial.
Acknowledgments The author acknowledges the assistance of Gayle Winkfield in the preparation of the manuscript and of Kim Wilkens and Robert Miller in the preparation of the figures.
References 1. Acosta C, Williams PE Jr, Clark K: Traumatic aneurysms of the cerebral vessels. J Neurosurg 36:531-536, 1972 2. Alexander MSM, Dias PS, Uttley D: Spontaneous subarachnoid hemorrhage and negative cerebral panangiography. Review of 140 cases. J Neurosurg 64:537-542, 1986 3. Asari S, Nakamura S, Yamada O, et ah Traumatic aneurysm of peripheral cerebral arteries. Report of two cases. J Neurosurg 46:795-803, 1977 4. B~guelin C, Seiler R: Subarachnoid hemorrhage with normal cerebral panangiography. Neurosurgery 13: 409-411, 1983 5. Brismar J, Sundb~rg G: Subaracbnoid hemorrhage of unknown origin: prognosis and prognostic factors. J Neurosurg 63:349-354, 1985 6. Buckingham M J, Crone KR, Ball WS, et al: Traumatic intracranial aneurysms in childhood: two cases and a Z Neurosurg. / Volume 75/September, 199I
review of thc literature. Neurosurgery 22:398-408, 1988 7. Cosgrove GR. Villemure JG, Melanqon D: Traumatic intracranial aneurysm due to arterial injury at surgery. Case report. J Neurosurg 58:291-294, 1983 8. Eskesen V, Serensen EB, Rosenorn J, et al: The prognosis in subarachnoid hemorrhage of unknown etiology. J Neurosurg 61:1029-1031, 1984 9. Fern' DJ Jr, Kempe LG: False aneu~,sm secondary, to penetration of the brain through orbitofacial wounds. Report of two cases. J Neurosurg 36:503-506, 1972 10. Fleischer AS. Guthkelcb AN: Management of high cervical intracranial carotid artery traumatic aneurysms. J Trauma 27:330-332, 1987 11. Fleischer AS, Patton JM, Tindall GT: Cerebral aneurysms of traumatic origin. Surg Neurol 4:233-239, 1975 12. Fox JL: Intracranial Aneurysms. New York: SpringerVerlag, 1983. Vol 1, p 426 13. Giombini S, Bruzzone MG, Pluchino F: Subarachnoid hemorrhage of unexplained cause. Neurosurgery 22: 313-316, 1988 14. lwanaga H, Wakai S, Ochiai C, et al: Ruptured cerebral aneurysm missed by initial angiographic study. Neurosurgery 27:45-51, 1990 15. Jackson FE, Gleaves JRW, 3anon E: Traumatic aneurysms. Cranial and intracranial. US Navy Med 63: 34-40, 1974 16. Jakobsson KE, Carlsson C, Elfverson J, el al: Traumatic aneurysms of cerebral arteries. A study of five cases. Acta Neurochir 71:91-98, 1984 17. Jaul R, Fredriksen TA, Ringkj~b R: Prognosis in subarachnoid hemorrhage of unknown etiology, d Neurosurg 64:359-362, 1986 18. Martin EM, Hummelgard AB: Traumatic aneurysms. J Neurosci Nurs 18:89-94, 1986 19. Meguro K, Rowed DW: Traumatic aneurysm of the posterior inferior cerebellar artery caused by fracture of the clivus. Neurosurgery 16:666-668, 1985 20. Menezes AH, Graf CJ: True traumatic aneurysm of anterior cerebral arte~. Case report. J Neurosurg 40: 544-548, 1974 21. Nakstad P, Nornes H, Hauge HN: Traumatic aneurysm of the pericallosal arteries. Neuroradiology 28:335-338, 1986 22. Nishioka H, Torner JC, Graf CJ, et al: Cooperative Study of lntracranial Aneurysms and Subarachnoid Hemorrhage: a long-term prognostic study. [II. Subarachnoid hemorrhage of undetermined etiology. Arch Neurol 41: 1147-1151, 1984 23. Nov AA, Cromwell LD: Traumatic pericallosal aneurysm. J Neuroradiol 11:3-8, 1984 24. Parkinson D, West M: Traumatic intracranial aneurysms. J Neurosurg 52:11-20, 1980 25. Smith KR Jr, Bardenheier JA III: Aneurysm of the pericallosal artery caused by closed cranial trauma. Case report. J Neurosurg 29:551-554, 1968 26. Suzuki S, Kayama T, Sakurai Y, et ah Subarachnoid hemorrhage of unknown cause. Neurosurgery 21: 310-313, 1987 27. Thompson JR, Harwood-Nash DC, Fitz CR: Cerebral aneurysms in children. AJR 118:I63-175, 1973 28. Umebayashi Y, Kuwayama M, Handa J, et al: Traumatic aneurysm of a peripheral cerebral artery: case report. Clin Radiol 21:36-38, 1970 Manuscript received October 3, 1990. Accepted in final form February 1l, 1991. Address reprint requests to: Moris Senegor, M.D., 10550 Montgomery Road #33, Cincinnati, Ohio 45242. 477
Traumatic pericallosal aneurysm in a patient with no major trauma Case report MORIS SENEGOR, M.D.
Neurological Surgery Associates of Cincinnati, Cincinnati, Ohio The case of a young woman who developed a traumatic distal anterior cerebral artery ("pericallosal') aneurysm from a roller-coaster ride is described. She presented with a subarachnoid hemorrhage (SAH) restricted to the interhemispheric fissure. The initial angiogram was normal but repeat angiography at 8 days revealed the aneurysm. After craniotomy and clipping the patient made a satisfactory recovery. This is the only reported case of a traumatic aneurysm arising under circumstances not usually considered as trauma. It raises questions about the pathophysiology of the formation of such aneurysms and suggests that traumatic pericallosal aneurysms should be considered in SAH of unknown etiology. This case provides further evidence that repeat angiography occasionally helps reveal an aneurysm when the initial study fails to do so. KEY WORDS aneurysm, traumatic anterior cerebral artery
NTRACRANIAL aneurysms caused by trauma are rare. 9~824 Traumatic aneurysms have been described in various locations in the intracranial and extracranial circulation. ~'3~'~~ The distal anterior cerebral artery ("pericallosal") is a well-known location for traumatic aneurysms, 6'~1,12,21.23,z5 probably because of the unique relationship of the artery with the edge of the falx. Such aneurysms have generally been reported after major head injuries. We recently encountered a patient who developed a pericallosal aneurysm without any history of major trauma. Her aneurysm was thought to arise due to a roller-coaster ride. The case and its implications as well as relevant literature are discussed.
I
Case Report This 32-year-old woman had been previously healthy and had not suffered any trauma until she rode five roller-coasters at an amusement park. The fifth subjected her to a three-story near free-fall followed by four complete upside-down loops. After the fall and the first loop, she felt a sudden severe headache and lost consciousness for the remainder of the ride. She then became drowsy and confused, and complained of a severe headache. She had no focal neurological deficit.
Examination. An initial computerized tomography scan revealed a subarachnoid hemorrhage (SAH) localized at the interhemispheric fissure, but complete anJ. Neurosurg. / Volume 75/September, 1991
9 subarachnoid hemorrhage
giography performed within 16 hours of ictus was unremarkable (Fig. 1 left). The patient was admitted for observation. Angiography was repeated on the 8th day after presentation and disclosed a left distal anterior cerebral artery aneurysm (Fig. 1 right). By this time the patient was neurologically intact. Operation. On Day 10 the aneurysm was approached surgically and found to be located exactly at the point where the artery crossed the inferior edge of the falx. There was a small intraparenchymal clot on the lateral surface of the aneurysm where it was imbedded into the cingulate gyms. The aneurysm lay along a straight segment of the vessel with no branching points nearby. When the anatomy of the aneurysm was surgically exposed, a diagnosis of traumatic aneurysm was made. Clipping proceeded uneventfully. The patient made a satisfactory recovery. Postoperative angiography confirmed obliteration of the aneurysm (Fig. 2). Discussion We have presented a case of SAH that occurred during a roller-coaster ride in a previously healthy person. The etiology of the hemorrhage was initially unclear, but the aneurysm was discovered upon repeat angiography. We have no doubt about the traumatic origin of the aneurysm because of its unique location away from any branching points and adjacent to the falx edge. After extensively questioning the patient and 475
M. S e n e g o r
FIG. 1. Left internal carotid angiograms in this patient. Left: Admission angiogram revealing no abnormalities 16 hours after subarachnoid hemorrhage. Right." Repeat angiogram on Day 8 showing a distal anterior cerebral artery aneurysm (arrow).
FIG. 2. Postoperative angiogram showing that the aneurysm (arrow) has been satisfactorily clipped. 476
her family and finding no history of significant trauma, we concluded that her trauma had to be one of the roller-coaster rides she took on the day of her ictus. The last ride during which she lost consciousness is the most likely culprit. We found it interesting that evidence of vessel injury, which most likely occurred due to movement of the artery against the falcial edge during the ride, did not appear on the early angiogram. The aneurysm, albeit small, appeared 8 days later. Over 40 traumatic anterior cerebral artery aneurysms have been described in the literature..,~,6~9,~1,12,15.2o,21,25,28 Direct trauma to the vessel from iatrogeniC or penetrating ~9 injuries has been described in rare cases. However, by far the most common cause is indirect trauma due to motor-vehicle accidents or falls. These patients usually have significant associated evidence of trauma such as skull fractures, mass lesions of the brain, and systemic injuries, Fleischer, et al., j~ described one case of a football injury accompanied by no loss of consciousness or other associated injuries, where a traumatic pericallosal aneurysm was discovered. There are no reports in the literature of a "traumatic" aneurysm arising in a patient lacking any history or physical evidence of trauma at presentation. In this regard our case is quite unique. Our case also raises the question of why a relatively mild trauma caused by a roller-coaster ride would lead to aneurysm formation when severe injuries sustained in falls and road accidents rarely do so. Discussions in the literature unanimously agree that compression of the artery against a stationary falcial edge by shearing forces, causing a brain shift, is responsible for the forJ. Neurosurg. / Volume 75/September, 1991
Traumatic pericallosal aneurysm mation of such aneurysms. ~'L' ~,~:~2~ It is possible that the rare trauma victim sustaining such an aneurysm has an inherent and rare anatomical predisposition to this disorder. Adhesions to the edge of the falx were noted by Nakstad, el a]., 2~ in their three cases. A pre-existing adhesion to the falcial edge could be a catalyst for aneurysm formation. By the time such aneurysms come to surgery, distortions in the anatomy from the associated hemorrhage may not allow the surgeon ~0 appreciate such adhesions. In our case, the entire interhemispheric fissure had extensive early adhesions s e c o n d a v to the 10-day-old hemorrhage. Thus, the pathophysiology of formation of such aneurysms remains speculative at best. The majority of traumatic pericallosal aneurysms are discovered late (up to 9 weeks) after trauma. A number of reports have demonstrated significant enlargement of these aneurysms on serial an~ograms. ~'2''21252~ Smith and Bardenheier ~5 reported a case similar to ours in which the initial angiogram was normal and a later study showed the aneurysm. Therefore, traumatic pericallosal aneurysms may be overlooked early after the trauma and, if untreated, they have a tendency to grow.- '-Our case is also an example of SAH of unknown etiology. This is a well-studied subject =~ ~~ ')~4~7 22,z~and its incidence in the literature varies between 5% and 24%.4-~6 The role of repeal angiography in these patients is controversial. It is clear, however, that repeat angiography does reveal a small percentage of aneurysms that initial studies fail to demonstrate.14A7-2226 Our case is a reminder that traumatic pericallosal aneurysms should be included in the differential diagnosis of SAH of unknown etiology, especially if the hemorrhage is restricted to the interhemispheric fissure. O u r experience provides additional evidence that repeat angiography in such cases may be beneficial.
Acknowledgments The author acknowledges the assistance of Gayle Winkfield in the preparation of the manuscript and of Kim Wilkens and Robert Miller in the preparation of the figures.
References 1. Acosta C, Williams PE Jr, Clark K: Traumatic aneurysms of the cerebral vessels. J Neurosurg 36:531-536, 1972 2. Alexander MSM, Dias PS, Uttley D: Spontaneous subarachnoid hemorrhage and negative cerebral panangiography. Review of 140 cases. J Neurosurg 64:537-542, 1986 3. Asari S, Nakamura S, Yamada O, et ah Traumatic aneurysm of peripheral cerebral arteries. Report of two cases. J Neurosurg 46:795-803, 1977 4. B~guelin C, Seiler R: Subarachnoid hemorrhage with normal cerebral panangiography. Neurosurgery 13: 409-411, 1983 5. Brismar J, Sundb~rg G: Subaracbnoid hemorrhage of unknown origin: prognosis and prognostic factors. J Neurosurg 63:349-354, 1985 6. Buckingham M J, Crone KR, Ball WS, et al: Traumatic intracranial aneurysms in childhood: two cases and a Z Neurosurg. / Volume 75/September, 199I
review of thc literature. Neurosurgery 22:398-408, 1988 7. Cosgrove GR. Villemure JG, Melanqon D: Traumatic intracranial aneurysm due to arterial injury at surgery. Case report. J Neurosurg 58:291-294, 1983 8. Eskesen V, Serensen EB, Rosenorn J, et al: The prognosis in subarachnoid hemorrhage of unknown etiology. J Neurosurg 61:1029-1031, 1984 9. Fern' DJ Jr, Kempe LG: False aneu~,sm secondary, to penetration of the brain through orbitofacial wounds. Report of two cases. J Neurosurg 36:503-506, 1972 10. Fleischer AS. Guthkelcb AN: Management of high cervical intracranial carotid artery traumatic aneurysms. J Trauma 27:330-332, 1987 11. Fleischer AS, Patton JM, Tindall GT: Cerebral aneurysms of traumatic origin. Surg Neurol 4:233-239, 1975 12. Fox JL: Intracranial Aneurysms. New York: SpringerVerlag, 1983. Vol 1, p 426 13. Giombini S, Bruzzone MG, Pluchino F: Subarachnoid hemorrhage of unexplained cause. Neurosurgery 22: 313-316, 1988 14. lwanaga H, Wakai S, Ochiai C, et al: Ruptured cerebral aneurysm missed by initial angiographic study. Neurosurgery 27:45-51, 1990 15. Jackson FE, Gleaves JRW, 3anon E: Traumatic aneurysms. Cranial and intracranial. US Navy Med 63: 34-40, 1974 16. Jakobsson KE, Carlsson C, Elfverson J, el al: Traumatic aneurysms of cerebral arteries. A study of five cases. Acta Neurochir 71:91-98, 1984 17. Jaul R, Fredriksen TA, Ringkj~b R: Prognosis in subarachnoid hemorrhage of unknown etiology, d Neurosurg 64:359-362, 1986 18. Martin EM, Hummelgard AB: Traumatic aneurysms. J Neurosci Nurs 18:89-94, 1986 19. Meguro K, Rowed DW: Traumatic aneurysm of the posterior inferior cerebellar artery caused by fracture of the clivus. Neurosurgery 16:666-668, 1985 20. Menezes AH, Graf CJ: True traumatic aneurysm of anterior cerebral arte~. Case report. J Neurosurg 40: 544-548, 1974 21. Nakstad P, Nornes H, Hauge HN: Traumatic aneurysm of the pericallosal arteries. Neuroradiology 28:335-338, 1986 22. Nishioka H, Torner JC, Graf CJ, et al: Cooperative Study of lntracranial Aneurysms and Subarachnoid Hemorrhage: a long-term prognostic study. [II. Subarachnoid hemorrhage of undetermined etiology. Arch Neurol 41: 1147-1151, 1984 23. Nov AA, Cromwell LD: Traumatic pericallosal aneurysm. J Neuroradiol 11:3-8, 1984 24. Parkinson D, West M: Traumatic intracranial aneurysms. J Neurosurg 52:11-20, 1980 25. Smith KR Jr, Bardenheier JA III: Aneurysm of the pericallosal artery caused by closed cranial trauma. Case report. J Neurosurg 29:551-554, 1968 26. Suzuki S, Kayama T, Sakurai Y, et ah Subarachnoid hemorrhage of unknown cause. Neurosurgery 21: 310-313, 1987 27. Thompson JR, Harwood-Nash DC, Fitz CR: Cerebral aneurysms in children. AJR 118:I63-175, 1973 28. Umebayashi Y, Kuwayama M, Handa J, et al: Traumatic aneurysm of a peripheral cerebral artery: case report. Clin Radiol 21:36-38, 1970 Manuscript received October 3, 1990. Accepted in final form February 1l, 1991. Address reprint requests to: Moris Senegor, M.D., 10550 Montgomery Road #33, Cincinnati, Ohio 45242. 477
