Electroclinical Patterns and Evolution of Epilepsy in the 4p– Syndrome

Summary: Background: 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.

Methods: 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.

Results: 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).

Conclusions: 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.