Clinical and electroencephalographic correlates of the multiple independent spike foci pattern in children

The multiple independent spike foci (MISF) pattern on electroencephalograms occurred in 4.2% of 1,500 recordings obtained from patients between the ages of 6 months and 15 years. Among the 63 patients with MISF, 53 (84%) had a seizure disorder and 48 (76%) had generalized motor seizures. Half the study group had daily seizures and half had more than one type of attack. Sixty-eight percent of MISF patients were intellectually subnormal. The intellectual status varied according to age at seizure onset, findings on clinical neurological examination, incidence of spikes in the recording, number of spike foci, and presence of excessive delta activity.