Directionality of corticomuscular coupling in essential tremor and cortical myoclonic tremor

A role of the motor cortex in tremor generation essential (ET) is assumed, yet directionality corticomuscular coupling unknown. Our aim to clarify cortex. To this end we also study ‘familial cortical myoclonic with epilepsy’ (FCMTE) and slow repetitive voluntary movements a known drive. Directionality (EEG-EMG) was studied renormalized partial directed coherence (rPDC) during 25 ET patients, healthy controls (mimicked) seven FCMTE patients; self-paced 2 Hz task eight patients controls. Efferent around frequency seen 33% 45.5% controls, all and, Hz, Ascending coupling, majority participants, weaker than 5–6 Hz. Possible explanations are that results from faulty subcortical output bypassing cortex; rate-dependent transmission similar rhythmic movements; and/or feedforward mechanism resulting decreased afferent (sensory) coupling. linear drive lacking patients.