Thirty-three outpatient epileptics with normal CT scans (group 1) and 31 patients with cerebellar and brain stem (CBS) atrophy (group 2) were randomly included in this study. There were no significant statistical differences between the groups with regard to age, education, and number of grand mal and other seizures. Statistical analyses showed that group 2 had a longer history of epilepsy with a consequently longer duration of phenytoin (PHT) consumption. Neuropsychological assessment revealed lower performance by this group on the following measures: full I.Q. scale, verbal I.Q. scale, performance I.Q. scale, information, arithmetic, block design, object assembly, digit symbol, Stroop test forms I and II, the B-M dexterity test, and the simple visual and auditory reaction time. No significant differences were observed between the two groups for the remaining 5 subtests from the WAIS scale, for the immediate recall and the delayed recall subtests belonging to Wechsler memory scale as well as for visual and auditory movement time. Analysis of the composite scores of neuropsychological performance showed that the cerebellum interferes with the following complex behavioral functions: (i) visuo-spatial organization for a concrete task, a function related to the cerebello-parietal loops' (ii) planning and programming of daily activities, a function related to the cerebello-frontal loops; and (iii) the speed of information processing, a mainly subcortical function.

Reversible chronic cerebellar ataxia followed phenytoin treatment in two epileptic women. Cerebellar ataxia in both patients and axonal polyneuropathy in one patient were improved after administration of thiamine alone or with folate. In one patient, some specific behavioral functions improved. However, recovery could have been spontaneous.

High-resolution CT scans of the brain and posterior fossa were performed on 106 phenytoin (PHT)treated epileptics, 28 de novo epileptics and 43 control subjects. A higher incidence of cerebellar and brainstem (CBS) atrophy was observed in chronic PHT-or PHT+ phenobarbital-treated epileptics compared to the two other groups. Some control subjects and de novo epileptics presented mild CBS atrophy, whereas moderate to severe atrophy was noted exclusively in chronically-treated patients. In attempting to delineate the etiology of CBS atrophy, epileptic patients were divided in three groups: 55 subjects with normal CT scans, 30 with both cerebral and CBS atrophy, and 49 with pure CBS atrophy. Their ages, length of illness, number of generalized seizures, number of other seizures, and amount of PHT received during their lifetime were assessed. Statistical analysis revealed that posterior fossa atrophy in epileptics was significantly correlated with both the length of the illness and the amount of PHT ingested during the patient's lifetime. The number of seizures appears to not be related to CBS atrophy. RESUME: L'atrophie cerebelleuse chez les epileptiques. On a pratique la tomodensitometrie du cerveau avec haute resolution pour la fosse posterieure chez 106 epileptiques chroniques traites a la phenytoine (PHT), chez 28 Epileptiques chroniques traites a la PHT, chez 28 epileptiques de novo et chez 43 sujets-controles. Nous avons retrouve une fr6quence significativement elevee de l'atrophie cerebelleuse et du tronc cerebral (ACTC) chez les epileptiques chroniques par rapport aux deux autres groupes. Certains sujets controles et epileptiques de novo ont presente une atrophic ponto-c6r£belleuse legere tandis que les atrophies moderees ou severes ont ete observees en exclusivite chez les epileptiques. En essayant de preciser retiologie de l'ACTC, 134 patients traites sur base externe ont ete divises en trois groupes: 55 sujets avec une tomodensitometrie du cerveau normale, 30 patients avec ACTC et avec atrophies cerebrales et 49 epileptiques avec des ACTC pures. Les parametres etudies ont ete l'age, la duree de la maladie, le nombre de crises de grand-mal, le nombre d'autres crises et la quantite de PHT ingeree pendant la vie du malade. Les analyses statistiques ont demontre que l'ACTC est correlee avec la duree de la maladie et avec la quantite totale de PHT ingeree pendant la vie du malade. Le nombre de crises n'etait pas apparemment relie avec la frequence de l'atrophie des formations de la fosse posterieure.