2023 American Academy of Neurology Abstract Website

Objective:

This is a case-based review of clinical manifestations and electroencephalogram findings of Mowat-Wilson Syndrome (MWS)

Background:

MWS is a rare multisystem disorder due to ZEB2 gene defects. The main feature of MWS is epilepsy; 75-80% prevalence was noted in prior case series.

Design/Methods:

Children with known diagnoses of MWS were identified in the Pediatric Epilepsy Clinic attached to a tertiary-care pediatric hospital through retrospective chart review. Literature was searched with keywords ‘Mowat-Wilson Syndrome’ and ‘EEG features’

Results:

Three children with MWS were identified. All cases were heterozygous for ZEB2 gene mutations and had brain imaging and electroencephalograms available for review.

Patient A (11 year-old): Semiology was generalized and focal (oral automatisms and left-hand flapping). On electroencephalogram there was continuous 2-3 Hz spike-and-wave activity during sleep with left predominance (left frontal at first, but then involving the entire left hemisphere over the years), and intermittent 2.5-3 Hz high-voltage generalized spike-and-wave bursts during wakefulness

Patient B (7 year-old): Semiology was generalized and focal (right-sided hypotonia and leftwards gaze). On electroencephalogram there were frequent 2-3 Hz poly-spike-and-wave discharges with left frontal-central predominance during sleep, and seizures stemming from right temporal and parieto-occipital areas during status epilepticus

Patient C (4 year-old): Semiology was generalized. On electroencephalogram there were frequent bi-occipital sharp-and-slow-wave discharges as well as infrequent bursts of high-amplitude generalized 1-2 Hz spike-and-waves

Conclusions:

Electroencephalograms of 2 of 3 patients had continuous spike-waves in sleep (CSWS), even as seizure burden and semiology differed. While there was no CSWS in Patient C, there were sharp-and-slow-wave discharges during wakefulness. It is possible that due to Patient C’s younger age, the EEG has not progressed to develop full CSWS. Indeed, in Patient A, there was a clear progression of EEG abnormalities as the child grew older. This leads these authors to believe that CSWS seems to be distinctly common among Mowat-Wilson.