E Roze, E Apartis, F Clot, N Dorison, S Thobois, L Guyant-Marechal, C Tranchant, P Damier, D Doummar, N Bahi-Buisson, N André-Obadia, D Maltete, A Echaniz-Laguna, Y Pereon, Y Beaugendre, S Dupont, T De Greslan, C P Jedynak, G Ponsot, J C Dussaule, A Brice, A Dürr, M Vidailhet
OBJECTIVE: To clarify the clinical and neurophysiologic spectrum of myoclonus-dystonia patients with mutations of the SGCE gene. METHODS: We prospectively studied 41 consecutive patients from 22 families with documented mutations of the SGCE gene. The patients had a standardized interview, neurologic examination, and detailed neurophysiologic examination, including surface polymyography, long-loop C-reflex studies, and EEG jerk-locked back averaging. RESULTS: We noted a homogeneous electrophysiologic pattern of myoclonus of subcortical origin with short jerks (mean 95 msec, range 25 to 256 msec) at rest, during action, and during posture; there were no features of cortical hyperexcitability (specifically no abnormal C-reflex response and no short-latency premyoclonic potential on back-averaging studies)...
March 25, 2008: Neurology