Serotonin metabolism with idiopathic grand mal seizures.

Serotonin was determined in platelets of 140 patients with idiopathic mal seizures. According to anticonvulsive therapy these patients were divided into the following five groups: no medication, Diphenylhydantoin, Diphenylhydantoin calcium, Primidon, and combination of various of the anticonvulsants mentioned. The results obtained in the entire group of patients as well as in the various subgroups were compared with those of a group of healthy persons without therapy. In addition the various subgroups were compared to each other. There were significantly reduced serotonin values in the patients with idiopathic grand mal seizures as well as in each of its various groups as compared with the values obtained in healthy persons. Furthermore, significantly higher values were observed in the patients receiving primidone as compared with those receiving no anticonvulsants, Diphenylhydantoin, and a combination of various anticonvulsants. Our results taken together with those reported in the literature point to the possibility that a special imbalance in the cerebral neurotransmitter system, including a deficiency of serotonin, may represent a pathogenetic factor for idiopathic grand mal seizures. In addition, this investigation indicates that primidone elevates serotonin in platelets of patients with grand mal seizures.