Facial reflex myoclonus induced by language: a neuropsychological and neurophysiological study

We studied a 53 year old right-handed patient who presented isolated myoclo nus of right facial muscles induced exclusively by language. Twitching sign ificantly hindered speaking and reading performance. MRI and CT-scan reveal ed no brain lesion. Conventional EEG showed a few spike-waves predominantly in the left hemisphere. Spike-waves increased during drowsiness. An EEG-EM G polygraphic study was performed during stimulation tests which included l inguistic tasks and non-verbal/non-linguistic tests. Myoclonus was triggere d by speaking and writing but not by non-linguistic tasks. The severity of myoclonus was dependent on the complexity of the language task. Back-averag ing of right facial EMG bursts failed to show a reliable EEG-EMG correlatio n. However, the facial reflex myoclonus might have originated from the left rolandic-opercular cortex, as it was triggered by complex language activit ies. Findings in this case are compared with those reported for other forms of reflex seizure and myoclonus. (C) Elsevier, Paris.