[Frontal lobe dysfunction in patients with epilepsy and chronic psychosis]

Fifty patients diagnosed as having epileptic crises were given neuropsychological tests including the Wechsler Adult Intelligence Scale or WAIS, Luria's neuropsychological test and a quantitative EEG examination. Multivariate analysis was done of the following variables: presence or absence of inter-octal psychosis, onset of crises before the age of 10 years, frequency of crises or status epilepticus greater than 100, known cause or otherwise of epilepsy, and the presence of more than one type of crisis in a particular patient. The working hypothesis was to show that the association of epilepsy and psychosis causes alterations in superior psychic functions (SPF) particularly of the frontal lobes. The WAIS test, intelligence, verbal and executive quotients and the 11 subtests were evaluated using multivariate analysis (ANOVA) conditioned by the different variables studied. The broad band spectral measurements of the quantitative EEG (BBSM) were studied using a statistical programme (COMPARA) by which the groups of individuals were compared with a standard group, using the Student t and Fisher tests. The different BBSM variables studied were: absolute power, relative power and total dominant frequency.

Amongst the most important results were: reduction in the performance scale of epileptics with chronic psychosis, alterations on the verbal scale in epileptics with more than one type of crisis, presence of frontal and fronto-temporal dysfunction in epileptics with chronic psychosis and negative signs of schizophrenia. On the quantitative EEG in epileptics with psychosis there was abnormally slow activity predominantly in the frontal lobes.

From the overall results we may conclude that in patients with epilepsy and chronic psychosis there is cortical dysfunction of the frontal lobe.