Midline Spikes: EEG and Clinical Features

Clinical features of 40 patients with midline spikes on EEG were compared with those of age- and sex-matched controls. Seizure incidence was significantly greater in the study group than in the controls (85% v 45%). Tonic-clonic seizures were the most frequent type. Eighteen patients from the study group had additional focal or generalized epileptiform abnormalities. This subgroup had a significantly greater incidence of seizures than patients with only midline spikes (100% v 73%). Midline spikes are more common in children and markedly activated with sleep. They must be distinguished from normal sleep transients.