Negative myoclonus in Lafora disease (video-EEG)

This 17-year-old boy had at age 14 years generalized convulsive seizures and simple focal occipital seizures with elementary visual hallucinations. Progressive and severe cognitive deterioration started soon after onset of the epileptic seizures. Valproate, piracetam, and clobazam had only a transient beneficial effect on seizures. Background EEG activity quickly deteriorated. Lafora disease was confirmed with axillar biopsy, which showed Lafora bodies. The video-EEG is recorded while the patient is holding his hands outstretched in front of his chest. There are frequent drops of the fingers and hands with suppression of the EMG activity (negative myoclonus). The EEG is diffusely slow with frequent, nearly continuous brief bursts of polyspikes. (Courtesy of Professor Pierre Thomas from: The Educational Kit on Epilepsies. Volume 2: Idiopathic Generalised Epilepsies With Myoclonic Jerks. Oxford: Medicinae, 2007.)