fasciculation potential
Spontaneous electrical activity recorded during needle EMG representing the firing of individual motor units, typically indicating lower motor neuron pathology.
Full Definition
Fasciculation potentials are spontaneous motor unit action potentials that fire irregularly and represent the pathological activation of motor units in denervated or diseased muscle. These potentials have the same morphology as voluntary motor unit action potentials but occur without conscious muscle contraction. They are commonly associated with anterior horn cell diseases such as amyotrophic lateral sclerosis, but can also occur in peripheral neuropathies, radiculopathies, and benign fasciculation syndrome. The presence and firing pattern of fasciculation potentials provide important diagnostic information about the location and severity of motor neuron dysfunction. In EMG reports, the frequency, morphology, and distribution of fasciculations are carefully documented.
Usage
Usage note: Use singular 'fasciculation potential' when referring to individual discharges; use plural 'fasciculation potentials' when describing the general phenomenon or multiple occurrences.
In Context
- "Abundant fasciculation potentials were observed in the first dorsal interosseous muscle, consistent with anterior horn cell disease." — EMG report
- "The neurologist noted that fasciculation potentials in this distribution pattern strongly suggested a diagnosis of motor neuron disease." — Neurology consultation report