Abstracts

In patients with temporal lobe epilepsy (TLE), psychotic symptoms can be observed both in the ictal and interictal periods. Some patients with refractory TLE, candidates to the epilepsy surgery, presented psychotic episodes during their hospitalization. We therefore decided to study them with the objective of identifying the possible causes of those events. The purpose of this study was to evaluate the relationship between dysfunction of mesial temporal structures and psychotic episodes in patients with refractory TLE.
Sixteen adult patients with clinically refractory temporal lobe epilepsy and candidates to epilepsy surgery that presented psychotic symptoms during the hospitalization were undergone neuropsychological evaluation including WAIS-R, WMS-R, RAVLT, RVDLT and the Sodium amobarbital test (SAT). None of the patients showed dementia, and Intelligence Quotient was equal or more than 80. The diagnosis of psychosis was based on the DSM-IV, satisfying the criteria for short psychotic disorder. The characterization of patients with refractory temporal lobe epilepsy was performed through diagnostic methods that consisted on prolonged monitoring with video-EEG, with scalp and sphenoidal electrodes and with the magnetic resonance imaging.
69% of patients presented bilateral interictal epileptogenic discharges and the remainings presented right mesotemporal interictal epileptogenic discharges. Hippocampal atrophy were found in 87.5% of patients (6 in the left and 8 in the right). Six patients (37.5%) had already psychiatric symptoms previously to the hospitalization, including severe depression, affective lability, visual hallucinations and paranoid ideas. Regarding the neuropsychological evaluation, 10 patients (62,5%) had impaired memory functions. Of these, 6 presented bilateral deficit and 4 unilateral (two in the right and two in the left). According to the moment in that the psychotic episode was observed, the patients were distributed in 3 groups:
-After SAT: Four patients presented psychotic symptoms a few hours after the SAT, when the hemisphere contralateral to the hippocampal atrophy was anesthetized.
-After epileptic seizures: Psychotic symptoms were verified after several seizures starting in the temporal lobe contralateral to the hippocampal atrophy in 3 patients, and after bitemporal seizures in two patients, without hippocampal atrophy.
-After surgical procedure: In six patients, we observed psychotic manifestations in the first days after the surgery.
These findings suggest that psychotic episodes occur after bilateral dysfunction of the hippocampus, reinforcing the idea that abnormalities of the hippocampus can be part of the cerebral substratum of psychotic diseases.
[Supported by: FAPERGS]