Clinical manifestations in children with occipital spike-wave paroxysms.

ABSTRACT

The pattern of occipital-posterotemporal spike-wave paroxysms (O-PT SWPs), is a distinctive EEG abnormality observed primarily with occipital epilepsy of childhood and basilar artery migraine. We studied EEG and clinical features in 30 children and young adults with this EEG pattern. Prolonged and brief O-PT SWPs were observed. Prolonged discharges (greater than 6 s) were observed only in children with seizures (p less than 0.001), and brief discharges (1-6 s) were observed immediately after eye closure. Generalized SWPs (11 patients, 37%) and background abnormalities (17 patients, 57%) were common. Photic activation of O-PT SWPs was not observed. Twenty-four patients (80%) manifested paroxysmal phenomena-seizures (20 patients, 67%) and migraine (12 patients, 40%, 4 alone and 8 with seizures). Fifteen patients (75%) had partial seizures, and 5 (25%) had absence seizures. In 7 patients with partial seizures, an etiology was evident. Neurologic examination was more often abnormal in patients with secondary partial seizures than in those with idiopathic partial seizures (p less than 0.05) and absence seizures. Conversely, migraine was more often associated with idiopathic partial seizures than with secondary partial seizures (p less than 0.05) and absence seizures. Six children (20%) had no paroxysmal events. Generalized SWPs were uncommon in patients with idiopathic partial seizures. We conclude that O-PT SWPs is a nonspecific epileptiform abnormality that may occur in children with (a) idiopathic partial, (b) symptomatic partial, and (c) absence epilepsies, but it may also occur in patients with no evidence of seizures.