Electroclinical patterns and evolution of epilepsy in the 4p- syndrome

Wolf-Hirschhorn syndrome (WHS) is a well-known clinical entity caused by partial deletion of the short arm of one chromosome 4 (4p- syndrome). Seizures occur in almost all the cases, but studies on the electroclinical disorder and its evolution are still scarce. We present a longitudinal study of the electroclinical features in 10 children with WHS.

Ten patients (five boys and five girls) underwent a detailed clinical assessment and a prolonged EEG study. Six of the 10 also had video-polygraphy.

Nine of the 10 patients had seizures; they were generalized or unilateral clonic and tonic-clonic, and atypical absences associated with myoclonic jerks. Age at onset of seizures varied from 1 day to 2.5 years. In all the patients, including the only one without seizures, two stereotyped EEG patterns were observed, consisting of (a) bursts of rhythmic (3-5 Hz), high-voltage slow waves located in the posterior regions and increased by sleep, or bursts of rapid spike-wave complexes in the centroparietal and parietooccipital regions; and (b) repetitive rapid posterior spikes. Sleep organization was constantly absent or very poor. The evolution of epilepsy was frequently good, with four seizure-free cases at the end of follow-up, two of them weaned from antiepileptic drugs (AEDs).

Seizure onset in WHS also can occur at neonatal age. At least two electrical stereotyped patterns of the epileptic disorder are associated with a relevant disorganization of the sleep states. Prognosis of epilepsy is generally good both for the seizure control and for its evolution.