Postictal serum creatine kinase in the diagnosis of seizure disorders.

We prospectively correlated daily serum creatine kinase (CK) levels with the occurrence of different types of epileptic and nonepileptic seizures documented by video EEG recording in 22 hospitalized patients. Prolonged postictal CK elevations, 8.0 to 19.2 times baseline, were seen following six (15%) of 41 generalized tonoclonic seizures. No CK elevations were seen following 147 complex partial, focal motor, absence, and tonic seizures or 55 psychogenic seizures, 89% of which involved vigorous muscular activity. Six of 12 patients with generalized tonoclonic seizures had postictal CK elevations compared with none of six patients with psychogenic seizures and none of 15 patients with complex partial, focal motor, absence, and tonic seizures. Thus, postictal CK determination can serve as an adjunctive test for differentiation between psychogenic and epileptic generalized tonoclonic seizures.