fasciculation potential
Spontaneous muscle fiber activity recorded during EMG, appearing as irregular firing motor unit potentials.
Full Definition
Fasciculation potentials are spontaneous discharges of motor units that occur irregularly and represent the firing of an entire motor unit. They appear on EMG as motor unit action potentials with variable morphology and firing patterns. Fasciculations can be visible as muscle twitches on clinical examination and may be benign or pathological. When associated with neurogenic disease, particularly motor neuron disorders like ALS, they often accompany other abnormal findings such as fibrillation potentials and positive sharp waves. The irregular, unpredictable nature distinguishes fasciculation potentials from other repetitive discharges.
Usage
Usage note: Distinguish clearly from 'fibrillation potentials' which represent single muscle fiber activity.
In Context
- "Abundant fasciculation potentials were recorded from the first dorsal interosseous muscle." — EMG findings documentation
- "The presence of fasciculation potentials in multiple muscles raised concern for motor neuron disease." — Electrodiagnostic consultation