Arq Neuropsiquiatr 2003;61(3-A):663-667

UNRUPTURED INTRACRANIAL ANEURYSM
PRESENTING WITH EPILEPTIC SEIZURE
José C. Sena¹, Yves Reynier², Bernard Alliez²
ABSTRACT - Intracranial aneurysms are frequently present with subarachnoid hemorrhage.Less often they
produce suggestive symptoms of cranial nerve dysfunction or intracranial tumor when very large. Their
association with epilepsy has rarely been reported; such concurrence may not be a coincidence. When the
patient presents with epileptiforme attacks the presence of an intracranial aneurysm is rarely considered. In
this paper we report the case of a 45-years-old patient with an unruptured aneurysm of the middle cerebral
artery with a 10 years history of epileptic seizure.
KEY WORDS: intracranial aneurysm, epilepsy, middle cerebral artery, giant aneurysm.

Epilepsia secundária a aneurisma cerebral não roto
RESUMO - Aneurismas intracranianos freqüentemente se apresentam com hemorragia subaracnóidea quando
rotos, porém quando gigantes sangram com menor freqüência e se comportam como verdadeiros tumores,
comprimindo estruturas cerebrais adjacentes, apresentando sintomatologia peculiar. Relatamos o caso de um
paciente de 45 anos que apresentava crises convulsivas generalizadas com evolução de 10 anos. A investigação
radiológica revelou presença de aneurisma gigante da artéria cerebral média, não roto. É realizada revisão da
literatura correlacionando a presença de aneurismas não rotos e epilepsia, pois esta associação é pouco
freqüente na literatura.
PALAVRAS-CHAVE: aneurisma intracraniano, epilepsia, artéria cerebral média, aneurisma gigante.

An unruptured aneurym can come to clinical attention in a variety of ways including mass effect,
headaches embolic events and seizures. Although it
has been recognized for many years that unruptured
cerebral aneurysm may cause epilepsy, this is not
common1-5. The most frequent causes of seizures are:
cerebrovascular disease 13.2%, developmental disorders 5.5 %, head trauma 4.1 %, brain tumors
3.6%, central nervous system (CNS) infection 2.6%,
degenerative CNS diseases 1.8%, and for the remaining (70 % of the cases) the etiology are unknow.
Aneurysms which cause epilepsy are usually large,
and situated on the middle cerebral artery6-9. Frankel
and Alpers10 describe one patient with a giant aneurysm of the middle cerebral artery, who had presented with complex partial seizures that had persisted for the 3 years prior to her death after aneurysmal surgery. In Bull’s7 series 4 out of 22 giant intracranial aneurysms presented initially epilepsy and
among 666 patients with seizures reported by Currie
et al.11, only one had an unruptured intracranial ane-

urysm of the middle cerebral artery. Solomon et al.12
reported epilepsy in 10 out of 202 unruptured intracranial berry aneurysms located outside cavernous
sinus. Seizures can preced discovery of the aneurysm
by many years. Seizures disorders of many year’s duration are also described in the series of Drake13.
Aneurysms can produce seizures by a number of mechanisms, including compression or infarction of adjacent brain tissue as well irritation of the underlying
cortex14,15.
We report a 45-year-old left-handed white man,
in the previous 10 years he had frequent seizures
with an aura, in which he felt an unpleasant taste in
his mouth, dizziness and subsequent falling. In spite
of anticonvulsant therapy, the attacks became more
frequent, and the patient developed an aggressive
personality; a computed tomography scan revealed
a much larger contrast enhancing mass in the rigth
temporal lobe, and carotid angiography showed there was a large aneurysm arising from the right middle
cerebral artery. In contrast to the ruptured aneurysm,

1

Centre Hospitalier de la Côte Basque – Bayonne, France; 2Centre Hospitalier Universitaire de Marseille, France.

Received 11 September 2002, received in final form 29 January 2003. Accepted 18 February 2003.
Dr. J.C. Sena - 7, Rue Albert Mora - 64 340 Boucau - France. E-mail: senajc@yahoo.com

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Arq Neuropsiquiatr 2003;61(3-A)

A

B

Fig 1 (A and B). Plain skull film showing curvilinear calcification (arrows).

reports concerning seizure in the unruptured group
are rare. The relevant literature on aneurysm as a
cause of epilepsy is reviewed.
CASE
A 45-year-old left-handed, white man, without history
of alcool abuse, was admitted to the emergency room
after a generalized tonic-clonic seizure with inconsciousness, tongue biting and urinary incontinence. He remained
inconscious for twenty minutes and did not complain of
any headache, nausea or vomiting, but he had generalized
fatigue. He was amnestic for the episode but he remembered all events up to and immediately after the event.
His family said that over the previous 10 years he had
experience many similar episodes and that during the 6
months before admission there had been a definite general
deterioration in his memory. There was no past history
suggestive of a prior subarachnoid hemorrhage or transient
ischemic events. On examination, he was alert and behaving
normally, but was unable to understand any written or
spoken language and was unable to say anything apart from
“yes” and “no”. There was no sign of meningism. General
physical examination showed normal results. Routine
laboratory tests were negative. Over the next 3 hours, his
language function gradually returned to normal.
On specific questioning he remembered that he had
had several episodes beginning with a peculiar sensation
spreading from abdomem to the chest associated with
bad taste in his mouth lasting several minutes, sweating
on the forehead and the sense of voices sounding distorded and distant followed of dizziness and subsequent
falling and seizure. In spite of anticonvulsivant therapy,
the attacks became more frequent and the patient developed an aggressive personality.

A large oval calcification was found in the rigth temporal region on the plain skull film (Fig 1). Severe disturbance
in the rigth hemisphere, with some sharp wave discharge
over the right temporal area were found on conventional
electroencephalogram. A computed tomography scan (CT)
revealed an ovoide contrast-enhancing mass of the rigth
temporal lobe (Fig 2). A four vessel retrograde femoral
arteriogram demonstrated a large aneurysm arising from
the middle cerebral artery (Fig 3).
Although there was no history of subarachnoid hemorrhage it was decided that aneurysm should be clipped
because anecdotal cases of incidental aneurysms left untreated that subsequently ruptured are well known. The
patient underwent a right fronto-temporal craniotomy.
No evidence of hemorrage products was found within the
surrounding subarachnoid space on adjacent brain to
indicate prior rupture. A partially thrombosed aneurysm
of the middle cerebral artery was confirmed. The aneurysm
was excised after clipping of its neck.
The patient had an uneventful recovery, and was discharged home on a regimen of 1200 mg of carbamazepine
daily for 24 months. He has been followed for 5 years and
has been seizure-free since the intervention.

DISCUSSION
Seizure is one of the oldest recorded medical conditions. The earliest written reference to epilepsy can
be found in the Babylonian code of Hammurabi
(Louvre Museum, Paris) written in the 17 th century
BC. One of the clauses in the code specifies that the
person buying a slave had the rigth to return him/
her within one month of being bought if he/she had
epilepsy. Galen, in 375 AD, distinguished between
seizures originating in the brain and those that had

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665

as a slowly enlarging intracranial mass causing progressive cranial nerve, brainsten, or cerebral hemispheric disfunction; as transient ischemic attacks or
cerebral infarction, as progressive dementia with or
without feactures of diencephalic amnesia and
seizures5,13.
Our case surviving patient had seizures for ten
years without clinical subarachnoid hemorrhage may
be added to other cases in the literature in which
recurrent seizures occurred for many years without
clinical manifestations of subarachnoid hemorrhage
from the giant aneurysms. In the collaborative aneurysms study reported by Locksley22,23 only 4% of the
2.621 patients who had a first subarachnoid hemorrhage had seizure before bleeding. In 151 cases
of unruptured aneurysms, seizure was detected in
36% of the middle cerebral artery and 8% of the
posterior communicating cerebral artery.

Fig 2. Contrast-enhanced axial CT demonstrating large right temporal mass.

their anatomical origin elsewhere in the body, and
designated the former as idiopathic and the latter
as symptomatic.
Seizure is a symptom, not a disease. Seizures can
be symptomatic of a brain tumor, brain abscess, encephalitis, meningitis, metabolic disturbance, drug
intoxication, drug withdrawal and unruptured cerebral aneurysm. Although it has been recognized for
many years that cerebral aneurysm may cause seizure, when the patient presents with seizures, the
presence of a giant unruptured intracranial aneurysm
is rarely considered3. Giant intracranial aneurysms
have been defined as those over 25 mm in diameter;
approximately 5% of all intracranial aneurysms are
more than 25 mm in diameter. These giant intracranial aneurysms behave differently from smaller aneurysms and pose different problems in management3,5,6,9,11,16-21. In some large series of giant unruptured intracranial aneurysms the majoritary present
with signs of a mass lesion; there is a prevailing opinion that giant aneurysms seldom rupture; only 40%
of giant aneurysms present with subarachnoid hemorrhage; the other 60 % may cause diagnostic difficulties when present in one of the following ways:

Morley and Barr24 described 28 patients with giant
aneurysms, 3 had seizures.Two of them had seizures
for many years before undergoing operation for the
occlusion to the neck of the aneurysm.In all patients
the aneurysms were located at the middle cerebral
artery. In a survey of 21 cases of giant aneurysms,
Liang-fu and Da-Jie25 reported epilepsy in 2 cases, both
located at the middle cerebral artery. Sengupta et al.26
reported 6 cases of seizures and unruptured aneurysm.
In all cases, the aneurysms were located at the middle
cerebral artery. The interval between onset of seizures
and diagnosis varied from 1 day to 30 years.
The types of seizure vary from generalized to focal and temporal lobe attacks14,27-40. Despite great
advances in the surgical, endovasculaire, and medical
management of patients with aneurysmal subarachnoid hemorrhage, the morbidity and mortality rates associated with this disease remain unacceptably
high. Only about 50% of patients admitted to neurosurgical centers with the diagnosis of aneurysmal
subarachnoid hemorrhage have a good outcome12.
The solution of the problem is to diagnose and treat
aneurysms prior to rupture. But, can aneurysms be
identified before rupture? Locksley22,23 reported that
only 10 to 15% of aneurysms cases present the
opportunity for diagnosis before rupture. Internal
carotid aneurysms (especially those at the posterior
communicating or ophthalmic junction) have the
greatest propensity for producing symptoms prior
to rupture; aneurysms in the region of the internal
carotid-posterior communicating junctions in 8%
had seizures, on the other hand 36% of middle cerebral aneurysms presented with seizures39,40. It is
not obvious how giant aneurysms of the middle cere-

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A

B

Fig 3 (A and B). Arteriograme demonstrates middle cerebral artery aneurysm.

bral artery cause epileptic seizures, some hypotheses may be postulated: compression and infarction
of temporal lobe structures seem important. The
mesial temporal lobe structures have a low seizure
threshold and are particularly epileptogenic if damaged. Minor leakages from the adventitia of the
giant aneurysmal fundus may produce localized damage to be brain and act as epileptogenic foci; transient or permanent focal disturbances in blood flow
to the temporal lobe could be caused by aneurysm
of the middle cerebral artery in several ways. The
anterior temporal or temporal-polar artery ostia
could be mechanically occluded or hemodynamically
compromised by the aneurysm or flow disturbances
emanating from it. Intraaneurysmal thrombus or
vasoconstrictor substances such as tromboxane A2
and prostaglandin A2, both of which may be formed
in an aneurysm, may embolize distally along either
of the vessels supllying the temporal lobe. These
vascular phenomena may aggravate the seizure
tendency caused by the mass effect on giant
aneurysm8,32,33.
The natural history of the accidentally discovered
aneurysms is not know. However of the 34 cases of

unruptured aneurysms treated non-surgically in the
cooperative study by Sahs et al.15, 9 cases or 26 %
eventually had a fatal subarachnoid hemorrhage. At
the present time, there is no way to predict with
certainty which patients with unruptured aneurysm
are in imminent danger. Therefore, if an appropriate
low-risk procedure can be offered, all young healthy
patients with incidental aneurysms should be
treated12. Recurrent convulsive attacks in a patient
harboring an aneurysm may precipitate its rupture,
accordingly, seizure may be a warning sign of a major
rupture. Therefore, it is justifiable to treat these aneurysms to prevent a future rupture15,26,34,35.
Magnetic resonance (MR) imaging examination
is essential in evaluation of patients with seizures
and unruptured intracranial aneurysm - abnormal
perianeurysmal MR signal, may indicate that the aneurysm is not an incidental finding but related to the
cause of the seizure8,41.
We conclude that a diagnosis of cryptogenic
epilepsy should be made only when every possible
etiologic factor has been eliminated although
patients should be carefully investigated and
followed to determine the basis of the seizures it

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should be recognized that in at least 50 % of patients
who have epileptic seizures without other abnormal
findings, no destructive lesion of the brain will
develop6.
Acknowledgements - We wish to thank Mrs De Conto Sena for assistance in the preparation of this paper.

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