- Exhibit characteristic waxing and waning in frequency
- Involuntary rapid muscle twitches that can be felt
- Fasciculations without other neurologic findings are benign
- Indicate lower motor neuron disease when accompanied by weakness or atrophy
- Irregular, single discharges occurring on background of ongoing EMG activity
- Motor unit action potential bursts that are irregular in frequency
- May occur in singlet, doublet, triplet, or multiplet discharges
- Intra-burst frequency of discharge may be up to 200 Hz
Abnormal EMG Activity Types
Myotonic Discharges
Neuromyotonic Discharges
Fasciculations
Fibrillations
- Occur when a muscle fiber loses contact with its innervating axon, producing a spontaneous action potential
- No pathological significance if they have irregular potentials
