Large fasciculation can clinically manifest as spinal myoclonus; electromyographic and dynamic echomyographic studies of four cases with motor neuron disease

Abstract

HighlightsFour cases with motor neuron disease were studied by surface EMG and dynamic Echo.Fasciculation manifesting as myoclonus involved contraction of more muscle fibers.Large fasciculation can be a cause of spinal myoclonus.

Minipolymyoclonus: A Critical Appraisal

“…However, in later stages with significant muscle atrophy, denervation-reinnervation with axonal sprouting and the formation of unstable motor units, ectopic activity of peripheral motor axonal generators is primarily responsible for complex fasciculation. Studies by Inoue et al [ 7 ] and Bhat et al [ 8 ] have both shown that fasciculation in motor neuron disease (MND) can give rise to small-amplitude, jerky “twitches” in the fingers (especially with the hands outstretched and fingers extended), a phenomenon known as ‘minipolymyoclonus,’ or it can present with large amplitude “shock-like” movements mimicking spinal myoclonus [ 7 ].…”

Differentiating fasciculations from myoclonus in motor neuron disease

“…In this issue of Clinical Neurophysiology Practice, Inoue and colleagues report on the ultrasound and surface electromyography (EMG) findings of four patients with motor neuron disease (MND) with abnormal involuntary limb movements ( Inoue et al, 2018 ). In two patients, the movements were “twitches” affecting the fingers of both hands and in the other two patients larger “shock-like” movements, which clinically resembled myoclonus.…”