Epilepsia, 17:325-336,1976. Raven Press, New York
Computerized Transverse Axial Tomography in Epilepsy””’ H. Gastaut and J. L. Gastaut Groupe Hospitalier de la Timone, 13385 Marseilles, Cedex 4, France (Received June 4 , 1976)
We are reporting findings with computerized transverse axial tomography (CTAT) in 401 of 500 consecutive patients with epilepsy seen in the past 6 months. All patients had been examined neurologically and by EEG, and the seizures of 401 were classified according to the Classification of the International League against Epilepsy (Gastaut, 1969) (Table 1).The findings on CTAT are correlated with the electroclinical form of epilepsy and with etiology. Electroclinical Forms of Epilepsy Primary generalized epilepsy (corresponding roughly to essential or idiopathic epilepsy) (Table 2). Since 90% of patients had a normal CTAT, the conclusions can be drawn that (1) this form of epilepsy is usually not caused by a cerebral lesion but is due to a constitutional predisposition to epilepsy, either acquired or genetic; (2) tonic-clonic seizures of primary generalized epilepsy (grand mal) and absence seizures (petit mal) do not cause deterioration even though they recur frequently over years or decades (more than 1,000 grand ma1 attacks in 59 years in one case). Secondary generalized epilepsy (Table 3). This form of epilepsy is often due to encephalopathy in childhood. A cerebral lesion
Key words: Computerized axial tomography-Epilepsy (classification)-Brain tumorPorencephaly (in epilepsy) *Presented at the 21st European Congress of Electroencephalography and Epilepsy, Marseilles, France, September 8-11, 1975.
was found on CTAT in 61% of patients, confirming the “secondary” nature of this type of epilepsy, which is usually accompanied by mental retardation. Secondary generalized epilepsies have two major forms according to whether they are dependent upon a nonspecific encephalopathy (the West syndrome, LennoxGastaut syndrome, other syndromes not yet identified clearly), or upon a specific encephalopathy. Of the nonspecific encephalopathies (Table 3), all patients with the West syndrome had abnormal findings on CTAT. Two had global atrophy of unknown etiology, 1 had atrophy with Mongolism, 2 had agenesis of the corpus callosum, and 1 had a tumor. Of 42 patients with the Lennox-Gastaut syndrome, 25 (60%) had lesions, either widespread atrophy or focal lesions, including one tumor (Table 4). Of other nonspecific encephalopathies (Table 3), atrophy was diffuse in 4, with or without hydrocephalus; it was lobar or porencephaly in 2 patients. There were 13 patients with specific encephalopathies (Table 3), including 5 who were normal on CTAT: 2 with the LundborgUnverricht syndrome, 1 Ramsey-Hunt, 1 subacute sclerosing panencephalitis, and 1 patient with leucodystrophy. Those 8 patients who had lesions on CTAT were: 1 SturgeWeber-Krabbe syndrome, 1 Menke’s syndrome, 2 trisomia-21, 2 spinocerebellar degeneration, and 2 patients with tuberous sclerosis (Bourneville). Because the lesions were focal (“small area” atrophy usually posttraumatic, postinfectious or postischemic, tumors, etc.). in nearly half the
325
326
H . GASTAUT AND J. L. GASTAUT TABLE 1. The patients
Types of epilepsy
No. of patients
Nonclassifiable epilepsies Classifiable epilepsies Generalized Primary Secondary Partial Elementary symptomatology (motor or sensory) Complex symptomatology ( psychosensorimotor) Apparently generalized at the onset Other types Benign with Rolandic spikes Unilateral seizures Grand ma1 of late onset
6,000 (1974)b 1,409 4,591 1,731 1,306 425 2,860
500 (1975)Q 99 40 1 147 73 74 198
(24%) (77%) (38%) (28%) (9%) (62%)
459
(10%)
69
(17%)
1,821
(40%)
84
(22%)
580
(13%)
45
(11%)
15 16 25
( 4%) ( 4%) ( 6%)
(20%) (80%) (37%) (18%) (19%) (49%)
Assessment of the epilepsies in this =(1975) and in a previous b(1974) study (Gastaut. 1974; Gastaut et al.. 1975) according to the International Classification (Gastaut. 1969).
patients (Table 3), we may assume that the generalized clinical and EEG symptoms of such epilepsies are not due to the lesion per se but to some secondary factor (metabolic, immunological, viral) into which W.H.O. recommends research. Partial epilepsy (Table 5). A cerebral lesion was found on CTAT in 63% of these patients, the same proportion as in secondary generalized epilepsy. The lesions, however, were mainly focal (78%). The diffuse lesions (22%) were due in part t o the relatively few focal lesions in patients with seizures of complex symptoma-
TABLE 2 . Findings o n computerized transverse axial tomography (CTAT) in 7 3 patients with primary generalized epilepsy
Seizures Grand ma1 (with or without myoclonia) CTAT normal Petit ma1 (typical absences) CTAT normal Both petit and grand ma1 CTAT normal Other forms CTAT normal Total CTAT normal CTAT abnormal
No. of Datients 25 24 ( 9 6 % ) 20 18 ( 9 0 % ) 22 17 ( 7 7 % ) 6 6 (100%) 73 65 (89%) 8 (11%)
tology. Either CTAT is not reliable in demonstrating temporal lobe pathology, or some diffuse lesions cause partial attacks because temporolimbic structures have a low convulsive threshold. Epilepsy with symptoms due to Rolandic discharges (somatomotor and somatosensory) had the highest proportion of focal lesions, although the lesions affected Rolandic cortex in only half the cases. The mechanism by which subcortical (central grey matter) or cortical lesions that do not impinge on the Rolandic area cause Rolandic symptoms is not known. Apart from these three types of epilepsy, the characteristics of which are well described in the International Classification of the Epilepsies (Gastaut, 1969), we have studied the following groups. (1) All 15 children with benign epilepsy with Rolandic EEG paroxysms had a normal CTAT, confirming other evidence that this syndrome is not organic but rather a functional epilepsy similar to generalized primary epilepsy. (2) Of 25 patients with grand ma1 seizures of late onset (the clinical and EEG findings did not justify including them in the group of primary grand mal or of partial epilepsy with secondary generalized seizures), 1 0 were normal on CTAT and 15 had diffuse lesions. Such findings confirm the existence (which we suspected in 1974) of secondary generalized
CTAT IN EPILEPSY
TABLE 3. Findings on computerized transverse axial tomoDaPhY (CTAT) in 74 Patients with secondary generalized epilepsy
32 7
in only 59% (indirect confirmation), whereas the nontraumatic CTAT method revealed the tumor directly in every case. An example of the superiority of computerLesions on CTAT ized tomography is the case of a 41-year-old None Focal Diffuse man who had seizures of the right hand and West synface with dysphasia for 10 years. EEG, 6 0 1 5 drome angiography, pneumoencephalography, and Lennox-Gasscintigraphy were normal at the onset. Repeat taut syndrome 42 17 13 12 angiography at the age of 32 suggested an Other nonexpansive lesion in the left temporal lobe, and specific therefore surgery was performed. No tumor was epileptofound, but the patient was left with some genic paresis, and his seizures increased. During the encephalopathies 13 7 2 4 next 8 years, angiography and six scintigraphies Specific were performed and were normal and the EEG epilepshowed a temporal focus, thought to be togenic postoperative. CTAT showed a left centroparieencephtal tumor (Fig. 1)just posterior t o the operative alopathies 13 5 3 5 - site. Total 74 29 19 2 6 , Posttraumatic epilepsy (Table 8). There were 45 (61%) 27 patients (7%) with posttraumatic epilepsy Etiology established by a history of prolonged coma, 38 known 9 29 (76%) depressed fracture, fracture of the base of the Etiology skull, or neuropsychiatric sequelae. In 23 20 16 (44%) unknown 36 patients (85%), CTAT revealed focal lesions in 19 and diffuse lesions in 4. The site of the focal epilepsy in adults and particularly in old lesion was frontal or temporal or both in 17, people, depending on involutional or arterio- Parieto-OcciPital in only 2 Patients. These lesions varied from simple, fairly focal cortical pathic encephalopathy. atrophy to parenchymal affection of a whole Computerized Transverse Axial Tomography lobe (or more) with ventricular dilatation and cortical atrophy. In most patients the latter (CTAT) and the Etiology of Epilepsy type of lesion, probably cortical scarring and Epilepsy secondary to brain tumor (Table subjacent demyelination, leads t o parenchymal 6). In 53 patients, CTAT showed an expansive resorption and to formation of an arachnoid intracranial lesion. The diagnosis had been cyst or to porencephaly, with or without established in 1 0 of these patients by X-ray or operation. In 20 patients clinical and EEG findings made tumor likely. In 1 7 patients who TABLE 4. Findings on computerized tmnsverse axial tomography (CTAT) in 42 patients with had infrequent seizures, most of late onset, the Lennox-Gastaut syndrome tumor was not suspected, and the diagnosis had even been excluded by X-ray in 6 patients. No. of Thus, CTAT is by far the best method of CTAT findings patients diagnosing brain tumor in patients with ~~~~~l 17 epilepsy since the tumor was found in all our Global cort./subcort. atrophy 10 2 patients, and in 2 3 of the 24 in the series of Hemispheric cort./subcort. atrophy Payan and Gawler (1975). In our study, ~ ~ ~ ~ ~ atrophy ~ ~ b c o r t2 . 4 evidence of a tumor was found by clinical Parietooccipital tumor 1 examination in only 21% of patients (progres- B l & , o m & (Bourneville) 2 sive neurological deficit or increased intra- Leucoblastic infiltrate 1 cranial pressure) (Table 7), by EEG (focal or Of 1 Focal lesion-type unknown 2 projected delta rhythm) in only 30%, by X-ray
328
H. GASTAUT AND J. L . GASTAUT TABLE 5. Findings o n computerized transverse axial tomography (CTAT) in 198 patients with the three forms of partial seizures
Form of partial seizures
Lesions on CTAT Focal
None With elementary symptomatology (motor or sensory) With complex symptomatology (psychosensorimotor ) With apparently generalized symptomatology Total
Diffuse
69
23
41
5
84
34
30
20
45
16
26
3
73 (37%)
97 (49%)
198
communication to the ventricle. A good example of these lesions was the CTAT (Fig. 2) of a 22-year-old man who had a severe head injury at the age of 14 with a right parieto-occipital depressed fracture. He was in a coma for 3 weeks. The surgical report described “laceration of the dura, retro-Rolandic contusion, laceration of the brain and evacuation of a great deal of cerebral matter.” The only neurological sequelae of the trauma were nocturnal seizures, adversive and left-sided at the onset. The psychological sequela was discrete intellectual deficit. Contrecoup lesions are also seen clearly by CTAT. In the case of a 20-year-old man who had an open right frontal fracture, the patient developed right-sided hemiplegia and somatomotor seizures after surgical resection of the right frontal pole. The EEG showed a right
28 (14%)
frontal spike focus. CTAT (Fig. 3) showed not only an enormous right frontal lesion, responsible for the EEG focus, but also a smaller atrophic lesion in the left centrotemporal region caused by contrecoup and responsible for the hemiplegia and the right-sided seizures. Almost exclusively fronto-orbital and temporal posttraumatic lesions have long been recognized by pathologists (Courville, 1945) and can be confirmed by CTAT. This precise visualization of a posttraumatic lesion can be extremely important for forensic medicine. For instance, the first patient cited above (Fig. 2) sued for damages, and the consultant for the defendant contested the surgical evidence. He said “evacuation of large amount of cerebral matter” was incompatible with the neurological condition of the patient; its existence, however, was confirmed by CTAT.
TABLE 6 . Findings o n computerized transverse axial tomography (CTAT) and seizures of 53 patients with brain tumor Epilepsy secondary to tumor Number Previously diagnosed Previously undiagnosed Incidence in epilepsya All 401 patients 222 patients with late onset Partial epilepsy With elementary symptomatology (motor or sensory) With complex symptomatology (psychosensorimotor ) With apparently generalized symptomatology Generalized epilepsy Unilateral epilepsy
No.
Percent
53 10 43
19 81
43 36 47
11 16
26
49
12
23
9 4 2
17 8 4
“Those 10 patients are not included whose tumor had probably already been diagnosed.
CTAT IN EPILEPSY TABLE 7 . Diagnostic yield of various methods in 47patients with epilepsy secondary to tumor Method No. of patients Clinical Progressive neurological deficit or intracranial hypertension suggesting tumor 10 (21%) EEG Continuous focal or “projected” delta waves suggesting tumor 14 (30%) Neuroradiology (in only 32 patients) Arteriogram or pneumoencephalogram 19 (59%) Computerized transaxial tomography Tumor visualized 47 (100%)
Postischemic Epilepsy The 20 patients in this category (5% of our patients) form two groups with different lesions on CTAT. Epilepsy after occlusion of the Sylvian artery or its branches, although rare (only 11
329
TABLE 8. Findings in 27 patients with posttmumatic epilepsy Incidence 271401 Clinical findings Primary generalized epilepsy 0 Secondary generalized epilepsy 4 Partial epilepsy 23 Seizures with Elementary symptomatology (motor or sensory) 7 Complex symptomatology (psycho8 sensorimotor) Apparently generalized symptoma8 tology EEG findings Normal EEG 5 Focal paroxysms 11 “Secondary bisynchronism” 10 Coma-sleep pattern 1 (;TAT findings Normal 4 Focal lesion 19 Diffuse lesion 4
7%
FIG. 1. Left: An expansive process appearing as a dense zone 2.5 cm in diameter, in contact with the posterior portion of the roof of the left lateral ventricle, which is not deformed or displaced. The tumor is surrounded by an area of low density, i.e., edema. Right: In a supraventricular plane the tumor, which appeared to affect only the centrum ovale, is here seen to be in contact with cerebral cortex and to include a focus of calcification. In both cases the surgical sequelae can be seen.
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H . GASTAUT AND J. L . GASTAUT
FIG. 2. In these three planes the extensive posttraumatic lesions of the right temporo-parieto-occipital areas are seen. The grades of density represent either loss of matter or scar tissue. The highest plane shows bony lesions secondary to fracture and neurosurgery; just beneath the bone an area shaped like a biconvex lens corresponds to a calcified hematoma.
cases), is seen at all ages but particularly in patients over 6 1 years. In this age group they comprise 13%, whereas we (Gastaut and Gastaut, 1974) and Courjon et al. (1970) found only 7% on electroclinical examination. CTAT showed parenchymal changes in the whole superficial and/or deep Sylvian area, with or without cysts. For example, in the case of a 33-year-old man with left hemiplegia due t o cervicocranial trauma and epilepsy due to subsequent carotid thrombosis as shown by
angiography, CTAT showed damage limited to the territory served by the right Sylvian artery (Fig. 4). Epilepsy after occlusion of the posterior cerebral artery, at birth or due to a brain insult in infancy, is a characteristic syndrome of postischemic epilepsy. Although it is fairly frequent, it has not hitherto been recognized. We found 9 patients younger than 20 years old, often mentally retarded, often with hemiplegia and/or hemianopsia or quadrantanopsia, who
CTAT IN EPILEPSY
331
occupied the occipital lobe and sometimes also the parietal or temporal lobe supplied by the posterior cerebral artery. This type of lesion has been described pathologically but has not been studied systematically. It was not even mentioned in the study of 69 autopsies of patients with cerebral palsy, although porencephaly was found in 14 (Christensen and Melchior, 1967). Only Remillard et al. (1974) reported eight similar lesions in patients with temporal lobe epilepsy and with hemianopsia or quadrantanopsia. That such lesions have not been recognized more often is explained by the large volume of the porencephaly and the small amount of air injected in fractionated pneumoencephalography. This is exemplified by the case history of an 11-year-old mentally retarded girl who had a generalized clonic seizure at the age of 7 months. She had right hemiparesis, FIG. 3. A large area of low density in which was probably congenital and which the right frontal lobe shows loss of brain matter secondary to head injury became apparent when she learned t o walk. and neurosurgery. Note the enlargeFrom the age of 2, she had “drop” attacks due ment of the left Sylvian fossa and the to right-sided hypotonia. When she was 10 she Iow density at the tip of the left had atypical absence attacks with loss of temporal lobe, which is a contrecoup postural tone. EEGs have always shown slow lesion. spike-and-wave discharges particularly in the left hemisphere but possibly involving both had secondary generalized epilepsy or, more sides of the brain. In 1970, on the basis of often, partial epilepsy with complex symptoma- X-ray findings, tumor of the thalamic region tology of the temporal lobe. CTAT demon- was diagnosed and radiotherapy was recomstrated smooth porencephalic cysts communi- mended. Another examination in 1974 showed cating with the lateral ventricle; the cysts “extensive, cerebral atrophy of the left side
FIG. 4 The triangular zone of low density corresponds t o postischemic loss of tissue in the territory supplied by the right Sylvian artery.
332
H. GASTAUT AND J. L . GASTAUT
FIG. 5. In these four planes, note a huge porencephalic cavity communicating directly with the lateral ventricle. Note also the drain in the anterior-external portion of the cavity. Artifacts are due to struggling of the child.
with displacement and bulging of the Sylvian artery and its branches suggesting the existence of a cyst.” Exploratory surgery was undertaken, which established left Rolandotemporal atrophy with arachnoiditis in the Sylvian fossa: exploration of the ventricular cavity revealed no tumor and the foramen of Monro was clear. In January, 1975, radioisotope cisternal examination suggested hydrocephalus with normal pressure, and a ventriculoperitoneal drain was inserted from the left lateral ventricle. CTAT revealed neither tumor nor hydrocephalus but
rather a large left parieto-occipital porencephalic cavity (Fig. 5). Postinfectious epilepsy. There were only 7 such patients, and CTAT showed parenchymal change after purulent meningitis or presuppurative meningoencephalitis due to otitis media in 5 and empyema in 1 patient. The remaining patient had an abscess. She was a 44-year-old woman who had focal motor seizures of the right arm and leg followed by right hemiplegia. CTAT showed a large abscess of the left parietal lobe (Fig. 6).
CTAT IN EPILEPSY
333
FIG. 6. Left parietal abscess: round area of low density surrounded by a ring of high density (after i.v. injection of a contrast medium containing iodine) corresponding to the capsule of the abscess.
Edema in front of and behind the lesion.
Epilepsy of other etiology. Several case reports are presented t o illustrate the fact that CTAT provided the diagnosis. (1) CTAT demonstrated lesions with moderate calcium deposits which had not been picked up by X-ray in: (a) 4 patients with the syndrome of Bourneville; (b) 1 patient with the SturgeWeber-Krabbe syndrome; (c) 2 patients with
Fahr’s syndrome. (2) CTAT showed intraparenchymal leucoblastic infiltration in a patient with acute lymphoblastic leukemia complicated by epilepsy. (3) CTAT showed external hydrocephalus and frontotemporal hydroma in a patient with Menke’s syndrome; triventricular hydrocephalus due to benign stenosis of the aqueduct of Sylvius in 2 patients, with epilepsy
FIG. 7. An enormous hydrocephalus, so pronounced that only the interhemispheric septum differentiates the picture of hydrocephalus from hydranencephaly. On the right, note the drain.
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FIG. 8. The right frontal triangular zone of low density at the operative site represents postoperative tissue repair secondary to an ischemic process.
of epilepsy. In the past, when such a diagnosis was made on the basis of the patient's history, clinical findings, and the methods available (EEG, scintigraphy, angiography, and pneumoencephalography), the proportion of established organic lesions was at most 30% (30%, Juul-Jensen, 1965; 30%, Roger and Brichler, 1965; 17%, Gundmundsson, 1966). In the study reported here, the usual methods were supplemented by CTAT and the proportion of organic lesions was nearly 55%. Indeed, in 81 of our 401 patients, i.e., in 20%,CTAT revealed a cerebral lesion which had been missed in the other examinations and which had merely been suspected from the history. We now perform CTAT in all patients with epilepsy, and we find tumor in 11% of patients of all ages and in 16% of patients over 20 years of age. G. Wortzman @ersonal communication) also found an 11% incidence of tumor in 431 patients of all ages, a considerably higher incidence than that reported before CTAT became available (2%, Lennox, 1960; 1%, Krohn, 1961; 2%, Roger and Brichler, 1965; 4%, Juul-Jensen, 1965; 5%, Gundmundsson, 1966; 7%, Oller-Daurella, 1974, in patients over 20 years of age). It is therefore likely that physicians who DISCUSSION AND CONCLUSIONS handle epilepsy will request CTAT as often as Computerized transverse axial tomography EEG. After examination of the patient, they (CTAT) is of prime importance in the diagnosis will request an EEG to try to establish a
as the only symptom in 1 patient, so pronounced as to simulate hydranencephaly in the other patient; 2 postoperative epileptogenic lesions; agenesis of the corpus callosum in' 2 patients with the West syndrome. Two examples are described briefly below. A 6-month-old child had a head diameter of 45 cm. Pneumoencephalography had shown triventricular hydrocephalus due to stenosis of the aqueduct. When the child was 5 months old, ventriculoatrial derivation was done. After that time, the infant developed clonic seizures of the left arm, and. the EEG, previously normal, was very slow over the right hemisphere. CTAT revealed an enormous hydrocephalus which would have been hydranencephaly had the septum media not been present (Fig. 7). A 31-year-old woman underwent surgery at the age of 10 for tuberculoma of the right optic nerve; 1 year later the optic chiasm was explored again. The first grand mal occurred in 1975. The EEG showed a right frontal spike focus, which CTAT showed to be scar tissue, undoubtedly postoperative (Fig. 8).
CTAT IN EPILEPSY positive diagnosis, to classify the patient according to the International Classification of the Epilepsies (Gastaut, 1969), and to identify those patients with primary generalized epilepsy that are mainly functional. They will then request CTAT to ascertain or rule out an organic lesion. Other methods of examination will be reserved for such special problems as demonstrating vascular malformations by angiography. CTAT is also of theoretical interest as it permits anatomical study of the brain in living persons and thus opens a new era in the study of epilepsy. One may even suppose that the present-day electroclinical classification of the epilepsies will become an anatomoelectroclinical classification because of the use of CTAT. ACKNOWLEDGMENTS
We are indebted to the World Health Organization for their interest and moral support in the teaching and research of epilepsy. We express our appreciation to the EM1 Ltd. Company (London) for putting an EMI-scan apparatus at our disposal in the EEG Laboratory for a trial period of 6 months, and to the Hospital for buying the EMI-scanner and for placing it with us permanently.
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du Troisi&me Age. Dausse edit., Paris, pp
53-69,1974. Gundmundsson G. Epilepsy in Iceland. Acta Neurol Scand 43, Suppl. 25, 1966. Juul-Jensen P. Epilepsy. A clinical and social analysis of 1,020 adult patients with epileptic seizures. Acta Neurol Scand 41, Suppl. 13,1965. Krohn WA. A study of epilepsy in Northern Norway. Acta Psychiatr Scand Suppl. 150, pp 215-227,1961. Lennox WG. Epilepsy and Related Disorders. Little, Brown and Co., Boston, 1960, 1,168 PPOller-Daurella L. Limites y vision de conjuto de las epilepsias tardias. In “Epilepsia Tardia,” I1 Congreso Nacional de Neurologia, TipoLinea, S.A. Dr. Casas, 12 Zaragoza, 1974. Payan J and Gawler J. E.E.G. and E.M.I. scan: Early results of a comparative study. Electroencephalogr Clin Neurophysiol 38:212,1975. Remillard GM, Ethier R, and Andermann F. Temporal lobe epilepsy and perinatal occlusion of the posterior cerebral artery. Neurology 24:lOOl-1009,1974. Roger J and Brichler C. In: C. Brichler, Contribution a l’fitude d u Pronostic filoigne d e l’gpilepsie, Thesis. Rennes, 1965. SUMMARY
Computerized transverse axial tomography (CTAT) of the brain has been used routinely, as well as the EEG, to study patients with epilepsy. In patients with the various electroclinical types of epilepsy - primary, secondary, REFERENCES and partial - it gave accurate information Christensen E and Melchior J. Cerebral Palsy. A about the frequency, topography, and severity Clinical and Neuropathological Study. The Lavenham Press, Suffolk, England, 1967, of morphological abnormalities. In the various types of organic lesion - tumor, posttraumatic, 134 pp. Courjon J, Artru F, and Zeskov P. A propos des postischemic, postinfectious, etc. - it markedly crises d’epilepsie apparaissant aprils 60 ans, increased the ability to establish etiology. observees en clientele de neurologie dans un Especially notable was the finding of (1) tumor service de neurochirurgie. Sem Hop Paris 46, in 16% of patients over 20 years of age, and (2) 48:3129-3132,1970. Courville CB. Pathology of the Central Nervous the determination of a type of pathology that System. Pacific Press Pub. Assoc., Mountain has received little attention - postischemic View, California, 1945,450 pp. occipital porencephaly probably due to occluGastaut H. Classification of the epilepsies. sion of the posterior cerebral artery, either at Proposal for an international classification. birth or in early infancy Epilepsia Suppl. 10,pp 514-521,1969. Gastaut H. Die Diagnose der Epilepsien. Munch Med Wochenschr 116:1977-1980,1974. RESUME Gastaut H, Gastaut JL, Goncalves e Silva GE, La tomographie axiale commandee ordinaand Fernandez-Sanchez GR. Relative frequency of different types of epilepsy. teur (TACOgraphie) du cerveau a 6th utilisbe, ainsi que l’E.E.G., pour etudier 500 malades Epilepsia 16:457-461, 1975. Gastaut H and Gastaut JL. Les epilepsies du Bpileptiques. Cette Nouvelle mdthode donne troisiilme Bse dans le cadre des crises des informations exactes sur la nature, le s i a e cerhbrales pfopres ii cet tge. In: Le Cerveau et l’importance des lesions cerdbrales qui sont
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observBes dans 63%des cas lorsqu’il s’agit d’une Bpilepsie partielle, dans 61% des cas lorsqu’il s’agit d’une Bpilepsie gBnBralisBe secondaire et dans 10% des cas seulement lorsqu’il s’agit d’une Bpilepsie gBnBralisBe primaire. La tacographie cBrBbrale facilite donc considerablement le diagnostic Ctiologique des Bpilepsies. Elle met en Bvidence une Btiologie tumorale chez 11%des Bpileptiques de tous tges et chez 16% d e ceux qui sont tgBs d e plus de 20 ans. Elle permet de d6couvrir des Btiologies jusque 11 mhconnues, par exemple une porenckphalie occipitale post-isch6-mique chez des enfants hBmipliigiques etlou hemianopsiques souffrant d’une Bpilepsie partielle. (C.A. Tassinari, Marseilles)
ZUSAMMENFASSUNG Die computergesteuerte transversale axiale Tomographie (CTAT) des Gehirns wurde zu
Untersuchungen von Patienten mit Epilepsie routinemassig wie das EEG eingesetzt. Bei Patienten mit den verschiedenen elektro-klinischen Typen der Epilepsie - primare, sekundare, partielle - lieferte die Methode genaue Information uber die Frequenz, Lokalisation und Schwere morphologischer Abnormitaten. Sie erhohte die Moglichkeit einer atiologischen Klarung bei verschiedenen Arten organischer Liisionen: tumoros, posttraumatisch, postischamisch, postinfektios usw. Besonders erwahnt werden sollen folgende Befunde : (1) Tumoren bei 16% der Patienten, die alter als 20 Jahre waren, (2) die postischamische occipitale Porencephalie wahrscheinlich als Folge eines Verschlusses der A. cerebri posterior bei Geburt und in der friihen Kindheit, ein pathologischer Mechanismus, der bisher wenig Aufmerksamkeit gefunden hat. (D. Scheffner, Heidelberg)
Computerized Transverse Axial Tomography in Epilepsy””’ H. Gastaut and J. L. Gastaut Groupe Hospitalier de la Timone, 13385 Marseilles, Cedex 4, France (Received June 4 , 1976)
We are reporting findings with computerized transverse axial tomography (CTAT) in 401 of 500 consecutive patients with epilepsy seen in the past 6 months. All patients had been examined neurologically and by EEG, and the seizures of 401 were classified according to the Classification of the International League against Epilepsy (Gastaut, 1969) (Table 1).The findings on CTAT are correlated with the electroclinical form of epilepsy and with etiology. Electroclinical Forms of Epilepsy Primary generalized epilepsy (corresponding roughly to essential or idiopathic epilepsy) (Table 2). Since 90% of patients had a normal CTAT, the conclusions can be drawn that (1) this form of epilepsy is usually not caused by a cerebral lesion but is due to a constitutional predisposition to epilepsy, either acquired or genetic; (2) tonic-clonic seizures of primary generalized epilepsy (grand mal) and absence seizures (petit mal) do not cause deterioration even though they recur frequently over years or decades (more than 1,000 grand ma1 attacks in 59 years in one case). Secondary generalized epilepsy (Table 3). This form of epilepsy is often due to encephalopathy in childhood. A cerebral lesion
Key words: Computerized axial tomography-Epilepsy (classification)-Brain tumorPorencephaly (in epilepsy) *Presented at the 21st European Congress of Electroencephalography and Epilepsy, Marseilles, France, September 8-11, 1975.
was found on CTAT in 61% of patients, confirming the “secondary” nature of this type of epilepsy, which is usually accompanied by mental retardation. Secondary generalized epilepsies have two major forms according to whether they are dependent upon a nonspecific encephalopathy (the West syndrome, LennoxGastaut syndrome, other syndromes not yet identified clearly), or upon a specific encephalopathy. Of the nonspecific encephalopathies (Table 3), all patients with the West syndrome had abnormal findings on CTAT. Two had global atrophy of unknown etiology, 1 had atrophy with Mongolism, 2 had agenesis of the corpus callosum, and 1 had a tumor. Of 42 patients with the Lennox-Gastaut syndrome, 25 (60%) had lesions, either widespread atrophy or focal lesions, including one tumor (Table 4). Of other nonspecific encephalopathies (Table 3), atrophy was diffuse in 4, with or without hydrocephalus; it was lobar or porencephaly in 2 patients. There were 13 patients with specific encephalopathies (Table 3), including 5 who were normal on CTAT: 2 with the LundborgUnverricht syndrome, 1 Ramsey-Hunt, 1 subacute sclerosing panencephalitis, and 1 patient with leucodystrophy. Those 8 patients who had lesions on CTAT were: 1 SturgeWeber-Krabbe syndrome, 1 Menke’s syndrome, 2 trisomia-21, 2 spinocerebellar degeneration, and 2 patients with tuberous sclerosis (Bourneville). Because the lesions were focal (“small area” atrophy usually posttraumatic, postinfectious or postischemic, tumors, etc.). in nearly half the
325
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H . GASTAUT AND J. L. GASTAUT TABLE 1. The patients
Types of epilepsy
No. of patients
Nonclassifiable epilepsies Classifiable epilepsies Generalized Primary Secondary Partial Elementary symptomatology (motor or sensory) Complex symptomatology ( psychosensorimotor) Apparently generalized at the onset Other types Benign with Rolandic spikes Unilateral seizures Grand ma1 of late onset
6,000 (1974)b 1,409 4,591 1,731 1,306 425 2,860
500 (1975)Q 99 40 1 147 73 74 198
(24%) (77%) (38%) (28%) (9%) (62%)
459
(10%)
69
(17%)
1,821
(40%)
84
(22%)
580
(13%)
45
(11%)
15 16 25
( 4%) ( 4%) ( 6%)
(20%) (80%) (37%) (18%) (19%) (49%)
Assessment of the epilepsies in this =(1975) and in a previous b(1974) study (Gastaut. 1974; Gastaut et al.. 1975) according to the International Classification (Gastaut. 1969).
patients (Table 3), we may assume that the generalized clinical and EEG symptoms of such epilepsies are not due to the lesion per se but to some secondary factor (metabolic, immunological, viral) into which W.H.O. recommends research. Partial epilepsy (Table 5). A cerebral lesion was found on CTAT in 63% of these patients, the same proportion as in secondary generalized epilepsy. The lesions, however, were mainly focal (78%). The diffuse lesions (22%) were due in part t o the relatively few focal lesions in patients with seizures of complex symptoma-
TABLE 2 . Findings o n computerized transverse axial tomography (CTAT) in 7 3 patients with primary generalized epilepsy
Seizures Grand ma1 (with or without myoclonia) CTAT normal Petit ma1 (typical absences) CTAT normal Both petit and grand ma1 CTAT normal Other forms CTAT normal Total CTAT normal CTAT abnormal
No. of Datients 25 24 ( 9 6 % ) 20 18 ( 9 0 % ) 22 17 ( 7 7 % ) 6 6 (100%) 73 65 (89%) 8 (11%)
tology. Either CTAT is not reliable in demonstrating temporal lobe pathology, or some diffuse lesions cause partial attacks because temporolimbic structures have a low convulsive threshold. Epilepsy with symptoms due to Rolandic discharges (somatomotor and somatosensory) had the highest proportion of focal lesions, although the lesions affected Rolandic cortex in only half the cases. The mechanism by which subcortical (central grey matter) or cortical lesions that do not impinge on the Rolandic area cause Rolandic symptoms is not known. Apart from these three types of epilepsy, the characteristics of which are well described in the International Classification of the Epilepsies (Gastaut, 1969), we have studied the following groups. (1) All 15 children with benign epilepsy with Rolandic EEG paroxysms had a normal CTAT, confirming other evidence that this syndrome is not organic but rather a functional epilepsy similar to generalized primary epilepsy. (2) Of 25 patients with grand ma1 seizures of late onset (the clinical and EEG findings did not justify including them in the group of primary grand mal or of partial epilepsy with secondary generalized seizures), 1 0 were normal on CTAT and 15 had diffuse lesions. Such findings confirm the existence (which we suspected in 1974) of secondary generalized
CTAT IN EPILEPSY
TABLE 3. Findings on computerized transverse axial tomoDaPhY (CTAT) in 74 Patients with secondary generalized epilepsy
32 7
in only 59% (indirect confirmation), whereas the nontraumatic CTAT method revealed the tumor directly in every case. An example of the superiority of computerLesions on CTAT ized tomography is the case of a 41-year-old None Focal Diffuse man who had seizures of the right hand and West synface with dysphasia for 10 years. EEG, 6 0 1 5 drome angiography, pneumoencephalography, and Lennox-Gasscintigraphy were normal at the onset. Repeat taut syndrome 42 17 13 12 angiography at the age of 32 suggested an Other nonexpansive lesion in the left temporal lobe, and specific therefore surgery was performed. No tumor was epileptofound, but the patient was left with some genic paresis, and his seizures increased. During the encephalopathies 13 7 2 4 next 8 years, angiography and six scintigraphies Specific were performed and were normal and the EEG epilepshowed a temporal focus, thought to be togenic postoperative. CTAT showed a left centroparieencephtal tumor (Fig. 1)just posterior t o the operative alopathies 13 5 3 5 - site. Total 74 29 19 2 6 , Posttraumatic epilepsy (Table 8). There were 45 (61%) 27 patients (7%) with posttraumatic epilepsy Etiology established by a history of prolonged coma, 38 known 9 29 (76%) depressed fracture, fracture of the base of the Etiology skull, or neuropsychiatric sequelae. In 23 20 16 (44%) unknown 36 patients (85%), CTAT revealed focal lesions in 19 and diffuse lesions in 4. The site of the focal epilepsy in adults and particularly in old lesion was frontal or temporal or both in 17, people, depending on involutional or arterio- Parieto-OcciPital in only 2 Patients. These lesions varied from simple, fairly focal cortical pathic encephalopathy. atrophy to parenchymal affection of a whole Computerized Transverse Axial Tomography lobe (or more) with ventricular dilatation and cortical atrophy. In most patients the latter (CTAT) and the Etiology of Epilepsy type of lesion, probably cortical scarring and Epilepsy secondary to brain tumor (Table subjacent demyelination, leads t o parenchymal 6). In 53 patients, CTAT showed an expansive resorption and to formation of an arachnoid intracranial lesion. The diagnosis had been cyst or to porencephaly, with or without established in 1 0 of these patients by X-ray or operation. In 20 patients clinical and EEG findings made tumor likely. In 1 7 patients who TABLE 4. Findings on computerized tmnsverse axial tomography (CTAT) in 42 patients with had infrequent seizures, most of late onset, the Lennox-Gastaut syndrome tumor was not suspected, and the diagnosis had even been excluded by X-ray in 6 patients. No. of Thus, CTAT is by far the best method of CTAT findings patients diagnosing brain tumor in patients with ~~~~~l 17 epilepsy since the tumor was found in all our Global cort./subcort. atrophy 10 2 patients, and in 2 3 of the 24 in the series of Hemispheric cort./subcort. atrophy Payan and Gawler (1975). In our study, ~ ~ ~ ~ ~ atrophy ~ ~ b c o r t2 . 4 evidence of a tumor was found by clinical Parietooccipital tumor 1 examination in only 21% of patients (progres- B l & , o m & (Bourneville) 2 sive neurological deficit or increased intra- Leucoblastic infiltrate 1 cranial pressure) (Table 7), by EEG (focal or Of 1 Focal lesion-type unknown 2 projected delta rhythm) in only 30%, by X-ray
328
H. GASTAUT AND J. L . GASTAUT TABLE 5. Findings o n computerized transverse axial tomography (CTAT) in 198 patients with the three forms of partial seizures
Form of partial seizures
Lesions on CTAT Focal
None With elementary symptomatology (motor or sensory) With complex symptomatology (psychosensorimotor ) With apparently generalized symptomatology Total
Diffuse
69
23
41
5
84
34
30
20
45
16
26
3
73 (37%)
97 (49%)
198
communication to the ventricle. A good example of these lesions was the CTAT (Fig. 2) of a 22-year-old man who had a severe head injury at the age of 14 with a right parieto-occipital depressed fracture. He was in a coma for 3 weeks. The surgical report described “laceration of the dura, retro-Rolandic contusion, laceration of the brain and evacuation of a great deal of cerebral matter.” The only neurological sequelae of the trauma were nocturnal seizures, adversive and left-sided at the onset. The psychological sequela was discrete intellectual deficit. Contrecoup lesions are also seen clearly by CTAT. In the case of a 20-year-old man who had an open right frontal fracture, the patient developed right-sided hemiplegia and somatomotor seizures after surgical resection of the right frontal pole. The EEG showed a right
28 (14%)
frontal spike focus. CTAT (Fig. 3) showed not only an enormous right frontal lesion, responsible for the EEG focus, but also a smaller atrophic lesion in the left centrotemporal region caused by contrecoup and responsible for the hemiplegia and the right-sided seizures. Almost exclusively fronto-orbital and temporal posttraumatic lesions have long been recognized by pathologists (Courville, 1945) and can be confirmed by CTAT. This precise visualization of a posttraumatic lesion can be extremely important for forensic medicine. For instance, the first patient cited above (Fig. 2) sued for damages, and the consultant for the defendant contested the surgical evidence. He said “evacuation of large amount of cerebral matter” was incompatible with the neurological condition of the patient; its existence, however, was confirmed by CTAT.
TABLE 6 . Findings o n computerized transverse axial tomography (CTAT) and seizures of 53 patients with brain tumor Epilepsy secondary to tumor Number Previously diagnosed Previously undiagnosed Incidence in epilepsya All 401 patients 222 patients with late onset Partial epilepsy With elementary symptomatology (motor or sensory) With complex symptomatology (psychosensorimotor ) With apparently generalized symptomatology Generalized epilepsy Unilateral epilepsy
No.
Percent
53 10 43
19 81
43 36 47
11 16
26
49
12
23
9 4 2
17 8 4
“Those 10 patients are not included whose tumor had probably already been diagnosed.
CTAT IN EPILEPSY TABLE 7 . Diagnostic yield of various methods in 47patients with epilepsy secondary to tumor Method No. of patients Clinical Progressive neurological deficit or intracranial hypertension suggesting tumor 10 (21%) EEG Continuous focal or “projected” delta waves suggesting tumor 14 (30%) Neuroradiology (in only 32 patients) Arteriogram or pneumoencephalogram 19 (59%) Computerized transaxial tomography Tumor visualized 47 (100%)
Postischemic Epilepsy The 20 patients in this category (5% of our patients) form two groups with different lesions on CTAT. Epilepsy after occlusion of the Sylvian artery or its branches, although rare (only 11
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TABLE 8. Findings in 27 patients with posttmumatic epilepsy Incidence 271401 Clinical findings Primary generalized epilepsy 0 Secondary generalized epilepsy 4 Partial epilepsy 23 Seizures with Elementary symptomatology (motor or sensory) 7 Complex symptomatology (psycho8 sensorimotor) Apparently generalized symptoma8 tology EEG findings Normal EEG 5 Focal paroxysms 11 “Secondary bisynchronism” 10 Coma-sleep pattern 1 (;TAT findings Normal 4 Focal lesion 19 Diffuse lesion 4
7%
FIG. 1. Left: An expansive process appearing as a dense zone 2.5 cm in diameter, in contact with the posterior portion of the roof of the left lateral ventricle, which is not deformed or displaced. The tumor is surrounded by an area of low density, i.e., edema. Right: In a supraventricular plane the tumor, which appeared to affect only the centrum ovale, is here seen to be in contact with cerebral cortex and to include a focus of calcification. In both cases the surgical sequelae can be seen.
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H . GASTAUT AND J. L . GASTAUT
FIG. 2. In these three planes the extensive posttraumatic lesions of the right temporo-parieto-occipital areas are seen. The grades of density represent either loss of matter or scar tissue. The highest plane shows bony lesions secondary to fracture and neurosurgery; just beneath the bone an area shaped like a biconvex lens corresponds to a calcified hematoma.
cases), is seen at all ages but particularly in patients over 6 1 years. In this age group they comprise 13%, whereas we (Gastaut and Gastaut, 1974) and Courjon et al. (1970) found only 7% on electroclinical examination. CTAT showed parenchymal changes in the whole superficial and/or deep Sylvian area, with or without cysts. For example, in the case of a 33-year-old man with left hemiplegia due t o cervicocranial trauma and epilepsy due to subsequent carotid thrombosis as shown by
angiography, CTAT showed damage limited to the territory served by the right Sylvian artery (Fig. 4). Epilepsy after occlusion of the posterior cerebral artery, at birth or due to a brain insult in infancy, is a characteristic syndrome of postischemic epilepsy. Although it is fairly frequent, it has not hitherto been recognized. We found 9 patients younger than 20 years old, often mentally retarded, often with hemiplegia and/or hemianopsia or quadrantanopsia, who
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331
occupied the occipital lobe and sometimes also the parietal or temporal lobe supplied by the posterior cerebral artery. This type of lesion has been described pathologically but has not been studied systematically. It was not even mentioned in the study of 69 autopsies of patients with cerebral palsy, although porencephaly was found in 14 (Christensen and Melchior, 1967). Only Remillard et al. (1974) reported eight similar lesions in patients with temporal lobe epilepsy and with hemianopsia or quadrantanopsia. That such lesions have not been recognized more often is explained by the large volume of the porencephaly and the small amount of air injected in fractionated pneumoencephalography. This is exemplified by the case history of an 11-year-old mentally retarded girl who had a generalized clonic seizure at the age of 7 months. She had right hemiparesis, FIG. 3. A large area of low density in which was probably congenital and which the right frontal lobe shows loss of brain matter secondary to head injury became apparent when she learned t o walk. and neurosurgery. Note the enlargeFrom the age of 2, she had “drop” attacks due ment of the left Sylvian fossa and the to right-sided hypotonia. When she was 10 she Iow density at the tip of the left had atypical absence attacks with loss of temporal lobe, which is a contrecoup postural tone. EEGs have always shown slow lesion. spike-and-wave discharges particularly in the left hemisphere but possibly involving both had secondary generalized epilepsy or, more sides of the brain. In 1970, on the basis of often, partial epilepsy with complex symptoma- X-ray findings, tumor of the thalamic region tology of the temporal lobe. CTAT demon- was diagnosed and radiotherapy was recomstrated smooth porencephalic cysts communi- mended. Another examination in 1974 showed cating with the lateral ventricle; the cysts “extensive, cerebral atrophy of the left side
FIG. 4 The triangular zone of low density corresponds t o postischemic loss of tissue in the territory supplied by the right Sylvian artery.
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FIG. 5. In these four planes, note a huge porencephalic cavity communicating directly with the lateral ventricle. Note also the drain in the anterior-external portion of the cavity. Artifacts are due to struggling of the child.
with displacement and bulging of the Sylvian artery and its branches suggesting the existence of a cyst.” Exploratory surgery was undertaken, which established left Rolandotemporal atrophy with arachnoiditis in the Sylvian fossa: exploration of the ventricular cavity revealed no tumor and the foramen of Monro was clear. In January, 1975, radioisotope cisternal examination suggested hydrocephalus with normal pressure, and a ventriculoperitoneal drain was inserted from the left lateral ventricle. CTAT revealed neither tumor nor hydrocephalus but
rather a large left parieto-occipital porencephalic cavity (Fig. 5). Postinfectious epilepsy. There were only 7 such patients, and CTAT showed parenchymal change after purulent meningitis or presuppurative meningoencephalitis due to otitis media in 5 and empyema in 1 patient. The remaining patient had an abscess. She was a 44-year-old woman who had focal motor seizures of the right arm and leg followed by right hemiplegia. CTAT showed a large abscess of the left parietal lobe (Fig. 6).
CTAT IN EPILEPSY
333
FIG. 6. Left parietal abscess: round area of low density surrounded by a ring of high density (after i.v. injection of a contrast medium containing iodine) corresponding to the capsule of the abscess.
Edema in front of and behind the lesion.
Epilepsy of other etiology. Several case reports are presented t o illustrate the fact that CTAT provided the diagnosis. (1) CTAT demonstrated lesions with moderate calcium deposits which had not been picked up by X-ray in: (a) 4 patients with the syndrome of Bourneville; (b) 1 patient with the SturgeWeber-Krabbe syndrome; (c) 2 patients with
Fahr’s syndrome. (2) CTAT showed intraparenchymal leucoblastic infiltration in a patient with acute lymphoblastic leukemia complicated by epilepsy. (3) CTAT showed external hydrocephalus and frontotemporal hydroma in a patient with Menke’s syndrome; triventricular hydrocephalus due to benign stenosis of the aqueduct of Sylvius in 2 patients, with epilepsy
FIG. 7. An enormous hydrocephalus, so pronounced that only the interhemispheric septum differentiates the picture of hydrocephalus from hydranencephaly. On the right, note the drain.
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FIG. 8. The right frontal triangular zone of low density at the operative site represents postoperative tissue repair secondary to an ischemic process.
of epilepsy. In the past, when such a diagnosis was made on the basis of the patient's history, clinical findings, and the methods available (EEG, scintigraphy, angiography, and pneumoencephalography), the proportion of established organic lesions was at most 30% (30%, Juul-Jensen, 1965; 30%, Roger and Brichler, 1965; 17%, Gundmundsson, 1966). In the study reported here, the usual methods were supplemented by CTAT and the proportion of organic lesions was nearly 55%. Indeed, in 81 of our 401 patients, i.e., in 20%,CTAT revealed a cerebral lesion which had been missed in the other examinations and which had merely been suspected from the history. We now perform CTAT in all patients with epilepsy, and we find tumor in 11% of patients of all ages and in 16% of patients over 20 years of age. G. Wortzman @ersonal communication) also found an 11% incidence of tumor in 431 patients of all ages, a considerably higher incidence than that reported before CTAT became available (2%, Lennox, 1960; 1%, Krohn, 1961; 2%, Roger and Brichler, 1965; 4%, Juul-Jensen, 1965; 5%, Gundmundsson, 1966; 7%, Oller-Daurella, 1974, in patients over 20 years of age). It is therefore likely that physicians who DISCUSSION AND CONCLUSIONS handle epilepsy will request CTAT as often as Computerized transverse axial tomography EEG. After examination of the patient, they (CTAT) is of prime importance in the diagnosis will request an EEG to try to establish a
as the only symptom in 1 patient, so pronounced as to simulate hydranencephaly in the other patient; 2 postoperative epileptogenic lesions; agenesis of the corpus callosum in' 2 patients with the West syndrome. Two examples are described briefly below. A 6-month-old child had a head diameter of 45 cm. Pneumoencephalography had shown triventricular hydrocephalus due to stenosis of the aqueduct. When the child was 5 months old, ventriculoatrial derivation was done. After that time, the infant developed clonic seizures of the left arm, and. the EEG, previously normal, was very slow over the right hemisphere. CTAT revealed an enormous hydrocephalus which would have been hydranencephaly had the septum media not been present (Fig. 7). A 31-year-old woman underwent surgery at the age of 10 for tuberculoma of the right optic nerve; 1 year later the optic chiasm was explored again. The first grand mal occurred in 1975. The EEG showed a right frontal spike focus, which CTAT showed to be scar tissue, undoubtedly postoperative (Fig. 8).
CTAT IN EPILEPSY positive diagnosis, to classify the patient according to the International Classification of the Epilepsies (Gastaut, 1969), and to identify those patients with primary generalized epilepsy that are mainly functional. They will then request CTAT to ascertain or rule out an organic lesion. Other methods of examination will be reserved for such special problems as demonstrating vascular malformations by angiography. CTAT is also of theoretical interest as it permits anatomical study of the brain in living persons and thus opens a new era in the study of epilepsy. One may even suppose that the present-day electroclinical classification of the epilepsies will become an anatomoelectroclinical classification because of the use of CTAT. ACKNOWLEDGMENTS
We are indebted to the World Health Organization for their interest and moral support in the teaching and research of epilepsy. We express our appreciation to the EM1 Ltd. Company (London) for putting an EMI-scan apparatus at our disposal in the EEG Laboratory for a trial period of 6 months, and to the Hospital for buying the EMI-scanner and for placing it with us permanently.
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du Troisi&me Age. Dausse edit., Paris, pp
53-69,1974. Gundmundsson G. Epilepsy in Iceland. Acta Neurol Scand 43, Suppl. 25, 1966. Juul-Jensen P. Epilepsy. A clinical and social analysis of 1,020 adult patients with epileptic seizures. Acta Neurol Scand 41, Suppl. 13,1965. Krohn WA. A study of epilepsy in Northern Norway. Acta Psychiatr Scand Suppl. 150, pp 215-227,1961. Lennox WG. Epilepsy and Related Disorders. Little, Brown and Co., Boston, 1960, 1,168 PPOller-Daurella L. Limites y vision de conjuto de las epilepsias tardias. In “Epilepsia Tardia,” I1 Congreso Nacional de Neurologia, TipoLinea, S.A. Dr. Casas, 12 Zaragoza, 1974. Payan J and Gawler J. E.E.G. and E.M.I. scan: Early results of a comparative study. Electroencephalogr Clin Neurophysiol 38:212,1975. Remillard GM, Ethier R, and Andermann F. Temporal lobe epilepsy and perinatal occlusion of the posterior cerebral artery. Neurology 24:lOOl-1009,1974. Roger J and Brichler C. In: C. Brichler, Contribution a l’fitude d u Pronostic filoigne d e l’gpilepsie, Thesis. Rennes, 1965. SUMMARY
Computerized transverse axial tomography (CTAT) of the brain has been used routinely, as well as the EEG, to study patients with epilepsy. In patients with the various electroclinical types of epilepsy - primary, secondary, REFERENCES and partial - it gave accurate information Christensen E and Melchior J. Cerebral Palsy. A about the frequency, topography, and severity Clinical and Neuropathological Study. The Lavenham Press, Suffolk, England, 1967, of morphological abnormalities. In the various types of organic lesion - tumor, posttraumatic, 134 pp. Courjon J, Artru F, and Zeskov P. A propos des postischemic, postinfectious, etc. - it markedly crises d’epilepsie apparaissant aprils 60 ans, increased the ability to establish etiology. observees en clientele de neurologie dans un Especially notable was the finding of (1) tumor service de neurochirurgie. Sem Hop Paris 46, in 16% of patients over 20 years of age, and (2) 48:3129-3132,1970. Courville CB. Pathology of the Central Nervous the determination of a type of pathology that System. Pacific Press Pub. Assoc., Mountain has received little attention - postischemic View, California, 1945,450 pp. occipital porencephaly probably due to occluGastaut H. Classification of the epilepsies. sion of the posterior cerebral artery, either at Proposal for an international classification. birth or in early infancy Epilepsia Suppl. 10,pp 514-521,1969. Gastaut H. Die Diagnose der Epilepsien. Munch Med Wochenschr 116:1977-1980,1974. RESUME Gastaut H, Gastaut JL, Goncalves e Silva GE, La tomographie axiale commandee ordinaand Fernandez-Sanchez GR. Relative frequency of different types of epilepsy. teur (TACOgraphie) du cerveau a 6th utilisbe, ainsi que l’E.E.G., pour etudier 500 malades Epilepsia 16:457-461, 1975. Gastaut H and Gastaut JL. Les epilepsies du Bpileptiques. Cette Nouvelle mdthode donne troisiilme Bse dans le cadre des crises des informations exactes sur la nature, le s i a e cerhbrales pfopres ii cet tge. In: Le Cerveau et l’importance des lesions cerdbrales qui sont
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observBes dans 63%des cas lorsqu’il s’agit d’une Bpilepsie partielle, dans 61% des cas lorsqu’il s’agit d’une Bpilepsie gBnBralisBe secondaire et dans 10% des cas seulement lorsqu’il s’agit d’une Bpilepsie gBnBralisBe primaire. La tacographie cBrBbrale facilite donc considerablement le diagnostic Ctiologique des Bpilepsies. Elle met en Bvidence une Btiologie tumorale chez 11%des Bpileptiques de tous tges et chez 16% d e ceux qui sont tgBs d e plus de 20 ans. Elle permet de d6couvrir des Btiologies jusque 11 mhconnues, par exemple une porenckphalie occipitale post-isch6-mique chez des enfants hBmipliigiques etlou hemianopsiques souffrant d’une Bpilepsie partielle. (C.A. Tassinari, Marseilles)
ZUSAMMENFASSUNG Die computergesteuerte transversale axiale Tomographie (CTAT) des Gehirns wurde zu
Untersuchungen von Patienten mit Epilepsie routinemassig wie das EEG eingesetzt. Bei Patienten mit den verschiedenen elektro-klinischen Typen der Epilepsie - primare, sekundare, partielle - lieferte die Methode genaue Information uber die Frequenz, Lokalisation und Schwere morphologischer Abnormitaten. Sie erhohte die Moglichkeit einer atiologischen Klarung bei verschiedenen Arten organischer Liisionen: tumoros, posttraumatisch, postischamisch, postinfektios usw. Besonders erwahnt werden sollen folgende Befunde : (1) Tumoren bei 16% der Patienten, die alter als 20 Jahre waren, (2) die postischamische occipitale Porencephalie wahrscheinlich als Folge eines Verschlusses der A. cerebri posterior bei Geburt und in der friihen Kindheit, ein pathologischer Mechanismus, der bisher wenig Aufmerksamkeit gefunden hat. (D. Scheffner, Heidelberg)
