Benign adult familial myoclonic epilepsy (clinical vignette)

Electroclinical and MRI features in a patient with BAFME. (A) Free-hand drawing showing cortical tremor; the drawing is perturbed by sudden, brisk jerks, highly suggestive of myoclonus. (B) Polygraphic recording showing mild, generalized paroxysmal activity and irregular, short-lasting electromyographic bursts, indicative of cortical myoclonus in the reciprocally antagonist muscles. (C) Jerk-locked averaging analysis shows a positive-negative potential, recognizable over the left centroparietal electrodes, preceding myoclonus about 30 ms (right wrist extensor muscle; number of triggers = 100). Somatosensory evoked potential (SEP) and C-reflex following electric stimulation of the right median nerve at wrist showing large N20 component and the complex N20-P25 of the left centro-parietal region (upper trace) followed from C-reflex in right flexor radialis carpi muscle (lower trace). (D) 1H-MR spectroscopy using a PRESS sequence (TR 1500 ms, TE 144 ms) showing abnormal spectral peak areas at 3.22 ppm corresponding to choline (location of the 8 cm3 voxel: right cerebellar hemisphere). (Contributed by Dr. Pasquale Striano.)