Somatostatin and beta-endorphin levels in cerebrospinal fluid of nonmedicated and medicated patients with epileptic seizures.

Neuropeptides have been proposed to play a role in regulation of the seizure threshold and interictal behavior in experimental models of epilepsy, but there are few studies concerning neuropeptides in human epilepsy. We compared the levels of two peptides, somatostatin (SLI) and beta-endorphin (BEP) in lumbar cerebrospinal fluid (CSF) of unmedicated (N = 18) and medicated (n = 24) epileptic patients with the levels of these peptides in control (n = 20). Peptide levels in the CSF of patients with panic disorder (8) were also evaluated. Patients with chronic medicated epilepsy had a SLl level 80% (p = 0.003, Mann-Whitney U-test) that of the controls, 76% (p = 0.011) that of unmedicated patients, and 84% (p = 0.028) that of the panic group. BEP in the CSF did not differ in unmedicated, medicated and control patients. On the other hand, patients with panic disorder had higher levels of BEP in CSF than did the controls (117%, p = 0.041). In panic patients SLl was at control level. The present study indicates that the peptidergic systems are affected differentially in epilepsy and in panic disorder. Furthermore, there seems to be selectivity in the affect on peptidergic systems during the period when the epilepsy becomes chronic.