ACTA NEUROCHIRURGICA 9 by Springer-VerJag 1978 Acta Neurochirurgica 40, 45--53 (1978) Regional Neurological Centre, Newcastle General Hospital *, Newcastle upon Tyne, and Department of Neurology and Neurosurgery, Middlesbrough General Hospital, Middlesbrough **, England U n r u p t u r e d Intracranial A n e u r y s m s An Unusual Source of Epilepsy By R. P. Sengupta*, M. Saunders**, and P. R. R. Clarke** With 6 Figures Summary Six patients with epilepsy were found to have intracranial aneurysms, mainly in the middle cerebral territory. The mechanism of production of these presenting symptoms is considered to be a minor haemorrhage with localized destruction of brain, or calcification in the aneurysmal wall behaving as a hamartoma. In the differential diagnosis of factors causing epileptic attacks, an intracranial aneurysm should be considered, and its presence should be excluded by angiography before any blind surgical procedure for epilepsy is undertaken. Intracranial a n e u r y s m s usually present w i t h subarachnoid h a e m o r r h a g e . Less often they p r o d u c e s y m p t o m s suggestive of cranial n e r v e dysfunction, or intracranial turnout w h e n v e r y large. W h e n the patient presents with e p i l e p t i f o r m attacks the presence of an intracranial a n e u r y s m is rarely considered. In this p a p e r we r e p o r t six patients w h o sought medical advice for v a r y i n g types of epilepsy and whose aneurysms were discovered unexpectedly. T h e mechanism of p r o d u c t i o n of epilepsy and the i m p o r tance of detecting these aneurysms are discussed. Case Reports Case 1 (D. R.): A 43-year-old electrician was referred to a neurology clinic with a history of two major seizures during the previous year. On each occasion the starting point of the seizures was in the left arm. Examination: The general and neurological examinations were normal. The electroencephalogram showed a severe disturbance in the right hemisphere concentrated in the right temporal region; because of this abnormal finding the patient was admitted for further investigation. Right carotid angiograms showed a large saccular aneurysm arising at the primary division of the middle cerebral artery (Fig. 1). 0001-6268/78/0040/0045/$01.80 46 R . P . Sengupta et al.: A neurosurgical opinion held that surgery was not indicated, since his only complaint was epilepsy, and this was controlled by phenobarbitone 30 mg three times a day. However, six months later he was readmitted to the hospital following a severe subarachnoid haemorrhage, from which he subsequently died. Postmortem examination was not performed. Case 2 (R. P.): A 52-year-old electrical engineer was admitted to a neurosurgical ward in April 1974, having been referred by a psychiatrist because of Fig. 1. Case 1. Right carotid angiogram. Lateral view showing aneurysm arising from the middle cerebral artery depression, lapse of memory and recurrent headache. In January 1974 for no apparent reason he removed a wheel from a parked car and stole it. l i e was totally at a loss to account for this. Examination: The patient looked depressed and agitated. Routine general and neurological examinations were normal X-rays of the skull, brain scan, and pneumoencephalogram were all normal. The electroencephalogram showed an abnormal focal discharge in the left temporal region. A left carotid angiogram revealed a small aneurysm arising from the middle cerebral artery at its trifurcation (Fig. 2). There was no spasm or haematoma. A diagnosis of temporal lobe epilepsy was made, and he was treated with anticonvulsant therapy. Although there was no history of a subarachnoid haemorrhage it was decided that the aneurysm should be clipped. This was done through a left temporal craniotomy in May 1974. At operation there was no evidence of Unruptured Intracraniai Aneurysms 47 a previous haemorrhage. The temporal lobe, however, looked small and pale in comparison to the appearance of the frontal lobe. He had an uneventful recovery, and a check angiogram confirmed satisfactory occlusion of the aneurysm. He was discharged home on anticonvulsant therapy, and is now leading a normal life. He was last seen on 7th February 1977. He remains on anticonvulsant therapy and has had no fits. Case 3 (P. W.): A 56-year-old housewife with a diagnosis of temporal lobe epilepsy was referred to Mr. E. A. Turner of Birmingham, England, by a Fig. 2. Case 2. Left carotid angiogram. AP view showing middle cerebral aneurysm psychiatrist for consideration of stereotaxic temporal lobotomy. For 30 years she had had frequent seizures with an aura of dizziness and with subsequent falling. In spite of anticonvulsant therapy, the attacks became more frequent, and the patient developed an aggressive personality. On several occasions she had to be admitted for injuries caused by fights between herself and her husband, and on one occasion she was treated for a pneumothorax caused by a blow from a poker. There was a past history of a blackboard falling on her head when she was a child. While at school she had chorea. Examination: There was swelling of her legs with pitting oedema. Her speech was slurred. There was an external strabismus; all four limbs showed incoordination. Routine X-rays of the skull revealed a calcified shadow in the right temporal region (Fig. 3). Further investigation to elucidate the nature of this calcification became necessary, and bilateral carotid angiograms showed a large aneurysm arising from the right middle cerebral artery which was displaced by a presumed haematoma (Fig. 4). At operation the aneurysm was excised after clipping of its neck; following this she developed left hemiplegia. After a stormy post-operative period complicated by pulmonary embolism she recovered sufficiently to be able to return 48 R . P . Sengupta et al.: home. The hemiplegia persisted. At the last follow up, five years later, she had had no major fits but she remains an invalid with a left hemiplegia. Case 4 (M. D.): A 57-year-old housewife was referred to the neurological out patient department in September 1966. At the beginning of the year she had had a vagotomy and pyloroplasty for a duodenal ulcer. Since that time she had experienced two or three attacks in which she had felt a strange sensation followed by loss of consciousness. On recovering consciousness she was confused and complained of headache. During one of the attacks she bit her tongue and became rigid. She had suffered migrainous attacks for marly years. Although she did not Fig. 3. Case 3. Plain skulI film showing curvilinear calcification have major convuIsions, these attacks were considered to be a form of epilepsy, and she was treated with phenytoin 100 mg b.d. and phenobarbitone 30 mg b.d. Her attacks became welI controlled on this therapy and she attended the follow up clinic once a year. Apart from occasional episodes of depression and migrainous headaches she had no other problems. However, in June 1974 she was admitted as an emergency with a three week history of progressive sensory disturbance starting in the right hand and spreading to involve the whole arm, which had consequently become clumsy. She also had some speech difficulty. Examination revealed a mild expressive dysphasia with right hemiparesis most marked in the face and hand; there was generalized diminution of all sensory modalities in the right arm. Clinically an infiltrating neoplasm in the left hemisphere was considered, and carotid angiography was performed; this showed a large multilocular aneurysm of the middle cerebral artery (Fig. 5). The aneurysm was clipped on 1. 7. 1974. Her immediate post-operative recovery was uneventful, but two days later she developed worsening of the right Unruptured Intracranial Aneurysms 49 Fig. 4. Case 3. Right carotid angiogram showing aneurysm arising from the middle cerebral artery. Note the displacement of the middle cerebral vessels upward by calcified haematoma Fig. 5. Case 4. Left carotid angiogram; view through the orbit showing aneurysm arising from the middle cerebral artery 4 ActaNeurochirurgica,Vol. 40, Fasc.1--2 50 R . P . Sengupta et aL: hemiparesis and dysphasia. This gradually improved and she was discharge home on 13. 7. 1974. She was last seen in the follow up clinic in March 1977. She has had no further epileptic atta&s and continues on Phenobarbitone 30 mg b.d. and Phenytoin 100 mg b.d. Case 5 (R. J.): A 15-year-old right handed schoolboy was admitted to the Regional Neurological Centre for investigation of epilepsy in February 1975. Eight weeks prior to his admission, while watching television, he had an episode of involuntary turning of the head to the right. This was followed by a generalized convulsion and loss of consciousness with urinary incontinence. He did not complain of any headache, nausea, or vomiting. At the age of 18 months he had had a febrile convulsion but had remained well without treatment. Examination: The general and neurological examinations were normal. Plain X-rays of the skull revealed a curvilinear calcification in the anterior part of the right temporal region. The electroencephalogram showed the presence of generalized sharp and slow wave discharges, predominantly in the right temporal lobe. Bilateral carotid angiograms revealed an aneurysm at the trifurcation of the right middle cerebral artery (Fig. 6). Although there had been no subarachnoid haemorrhage, it was felt that obliteration of the aneurysm was desirable as a prophylactic measure. Accordingly the aneurysm was clipped through a right temporal craniotomy. Post-operatively he developed partial seizure activity which gradually subsided with anticonvulsant therapy. A check angiogram confirmed satisfactory obliteration of the aneurysm. Anticonvulsant therapy was continued and he has remained well since. He was last seen in the follow up clinic in December 1976. He had had no fits and continued on anticonvulsant therapy. Case 6 (A. B.): A 42-year-old right handed male had a major seizure while watching television, lie remained unconscious for twenty minutes, and was admitted to a medical unit. Examination: The general and neurological examinations were normal. Lumbar puncture revealed no abnormality. An electroencephalogram showed slow wave activity in the left temporal lobe. Bilateral carotid angiograms revealed a large saccular aneurysm arising from the left middle cerebral artery at its point of trifurcation. In view of the size of the aneurysm and its presence in the dominant hemisphere, it was decided that surgery was contraindicated, and the patient was given anticonvulsant therapy. However, six weeks later he was readmitted with a furthe r seizure; once again the general and neurological examinations were normal. On this occasion it was decided to treat the aneurysm surgically. Through a left temporal craniotomy, the aneurysm was exposed and ligated at its ne& with a silk ligature. Following the operation he developed right hemiplegia and aphasia, which improved sufficiently over the next few months for him to be able to return to his previous occupation. Shortly after discharge from hospital the patient moved to another part of the country and was lost to follow up. Discussion Although intracranial aneurysms rarely present with epilepsy, Sahs e t al. 5 (1969), in a cooperative study, recorded that 8~ of unruptured posterior communicating and 36~ of middle cerebral aneurysms presented with seizures. In this report all six patients with Unruptured Intracranlal Aneurysms 51 aneurysms came for medical advice for varying types of epileptic attacks. In each case the intracranial aneurysm was detected unexpectedly and was in the middle cerebral territory. Is this association between epilepsy and the presence of an aneurysm purely coincidental? The unusual morphological type and favoured location of Fig. 6. Case 5. Right carotid angiogram showing aneurysm arising from the middle cerebral artery these aneurysms in the temporal lobe would indicate that this may not be so. As their sizes were very variable it is difficult to suggest that epileptiform attacks are merely a manifestation of space occupying capacity. Although the mechanism of epilepsy due to intracranial aneurysm is not known, two hypotheses may be postulated. 1. Falconer and his colleagues 1 (1964) clearly demonstrated that a significant proportion of temporal lobe epilepsy is caused by pathologically identifiable lesions such as microgliomas or hamartomas. In two of our cases the walls of the aneurysms were slightly calcified; these lesions may have acted in the same way as hamartomas to cause epilepsy. 2. In some cases the aneurysm may leak without producing the clinical manifestations of a subarachnoid haemorrhage. These minor leakages may produce localized damage to the brain and act as 4* 52 R . P . Sengupta et al.: epileptogenic foci. Recurrent minor leaks could produce false aneurysms with calcification and subsequent epilepsy as discussed above. Whatever may be the mechanism of production of epilepsy in these cases, the detection of an intracranial aneurysm in these patients may be important from several aspects. The natural history of an intracranial aneurysms discovered accidentally is not known. However, from a total of 2621 patients with a first subarachnoid haemorrhage who had had antecedent clinical symptoms and signs, 95 had had seizures 5. In some cases at least, epileptic seizures may be a warning sign of a major haemorrhage from rupture of the aneurysm later as proved in Case 1. It has, moreover, been shown that spontaneous subarachnoid haemorrhage may occur in patients with severe epileptic seizures 4. Recurrent convulsive attacks in a patient harbouring an aneurysm may precipitate its rupture. Whether such an aneurysm should be treated surgically or not is also debatable. However, if the mechanism of production of the epilepsy, as suggested earlier, is accepted, surgical treatment is logical. All these patients with aneurysms treated by direct surgery survived, and their epilepsy was controlled by long term anticonvulsant therapy. Moreover, many neurosurgeons would advocate obliteration of any intracranial aneurysm to prevent a future rupture if it is surgically accessible with minimal risk to life or vital structures 3. Case 1 illustrates this view. Some forms of epilepsy are treated by stereotaxic destruction 2 of that area of the brain harbouring the focus. Case 3 was referred for this purpose. In the presence of an intracranial aneurysm such a procedure could be disastrous. Therefore, carotid angiography should be performed before undertaking this type of therapy, particularly in the temporal lobe. Acknowledgement We wish to thank Mr. E. A. Turner, Queen Elizabeth Hospital, Birmingham (Case 3) and Mr. R. M. Kalbag, Regional Neurological Centre, Newcastle upon Tyne (Case 4) for allowing us to report on their cases. References 1. Falconer, M. A., Serafetimides, E. A., Corsellis, J. A. N., Etiology and pathogenesis of temporal lobe epilepsy. Arch. Neurol. (Chicago) 10 (1964), 233--248. 2. Jelsma, R. K., Bertrand, C. M., Martinez, S. N., Monlina-Negro, P., Stereotaxic treatment of frontal lobe and centro-encephalic epilepsy. J. Neurosurg. 39 (1973), 42--51. Unruptured Intracranial Aneurysms 53 3. Mount, L. A., Brisman, R., Treatment of multiple intracranial aneurysms. J. Neurosurg. 35 (1971), 728--730. 4. Mularek, O., Owsianowski, M., Subarachnoid haemorrhage as a consequence of the epileptic status. Neurologia Neurochirurgia Polska 4 (1970), 475--478. 5. Sahs, A. L., Perret, G. E., Locksley, H. B., Nishioka, H., Intracranial Aneurysms and Subarachnoid Haemorrhage. A cooperative study. Philadelphia-Toronto: J. B. Lippincott. 1969. Authors' address: R. P. Sengupta, M.D., Regional Neurological Centre, Newcastle General Hospital, Newcastle upon Tyne, England, and M. Saunders, M.D., and P. R. R. Clarke, M.D., Department of Neurology and Neurosurgery, Middlesbrough General Hospital, Ayresome Green Lane, Middlesbrough, Cleveland, TS5 5AZ England.