neuromyotonia
Pronunciation: new-roh-my-oh-TOH-nee-ah
Continuous muscle fiber activity originating from peripheral nerve hyperexcitability, producing characteristic EMG patterns.
Full Definition
Neuromyotonia is a disorder of peripheral nerve hyperexcitability characterized by spontaneous, continuous muscle fiber activity that persists during sleep and general anesthesia. EMG findings include continuous motor unit discharges with characteristic doublet, triplet, or multiplet patterns firing at high frequencies (150-300 Hz). The activity originates from the terminal portions of motor axons and creates a distinctive 'ping of raindrops on a tin roof' sound. This condition may be acquired (autoimmune) or hereditary and can be associated with voltage-gated potassium channel antibodies.
Usage
Usage note: Distinguish from myokymia by frequency and persistence of discharges.
In Context
- "The EMG demonstrated neuromyotonia with characteristic high-frequency multiplet discharges that persisted despite attempts at muscle relaxation." — EMG diagnostic report