Neurológia pre prax 4/2020

Needle electromyography

During the investigation of muscle with EMG electrode the spontaneous activity is evaluated at first – fibrillations, positive sharp waves, fasciculations, myotonic discharges etc. This pathological activity at rest may be characteristic for certain types of disorders. The investigation of voluntary activity with evaluation of motor unit action potentials (MUP) follows. There is necessary to assess not only a form of MUP (amplitude, duration, number of phases), but also their stability, recruitment, firing rate, interferential curve. A needle EMG owns a potential to respond to many logical questions of a clinician, but it has also its restricions, that clinician should have knowledge of.

Keywords: a needle electrode, fibrillation, positive sharp waves, myotonic discharges, motor unit action potentials