end-plate noise
Characteristic EMG activity recorded near neuromuscular junctions, producing irregular, low-amplitude potentials that sound like static or frying.
Full Definition
End-plate noise refers to the characteristic electromyographic activity recorded when the needle electrode is positioned near the neuromuscular junction (motor end-plate region). This activity appears as irregular, low-amplitude (10-50 microvolts) potentials with variable morphology and produces a distinctive sound resembling static electricity or frying on the audio monitor. End-plate noise results from spontaneous acetylcholine release and is a normal finding that helps identify the motor point during EMG examination. It must be distinguished from pathological spontaneous activity such as fibrillation potentials or positive sharp waves.
Usage
Usage note: Normal finding that should not be reported as abnormal spontaneous activity.
In Context
- "End-plate noise was encountered during needle placement, indicating proximity to the neuromuscular junction." — EMG procedure note
- "The irregular potentials were identified as benign end-plate noise rather than pathological spontaneous activity." — Electromyography interpretation