Epilepsy and EEG findings in 18 males with fragile X syndrome

Of the 24 males identified as having fragile X syndrome in the Northeast Essex screening programme, 25% had epilepsy. Epilepsy in individuals with fragile X syndrome is known to follow a benign course with seizures disappearing before the age of 20. However, half of our sample with a history of epilepsy continued to have seizures after the age of 20. We reviewed the EEG reports of 18 of the 24 individuals (aged between 13 and 63 years) including all six individuals with epilepsy. We had 32 EEG recordings from 18 subjects, with nine people having more than one recording at different points. The EEG showed a definite improvement in only five individuals. Three individuals who had serial recordings (one with epilepsy) showed no significant changes over time and the EEG of one subject with epilepsy deteriorated. The most common abnormal EEG findings were rhythmic theta activity (50%) and a slowing of background activity (28%). There were no characteristic features in the sleep EEGs performed on four subjects. The possible implications of these preliminary findings are discussed.