repetitive nerve stimulation
Also written as: RNS — repetitive nerve stimulation
A technique testing neuromuscular junction function by delivering repeated electrical stimuli.
Full Definition
Repetitive nerve stimulation (RNS) is an electrophysiological test used to evaluate neuromuscular junction disorders by applying trains of electrical stimuli to peripheral nerves while recording muscle responses. The test typically involves stimulation at rates of 2-3 Hz and 20-50 Hz to assess for decremental or incremental responses. A decremental response of greater than 10% between the first and fourth compound muscle action potential amplitudes suggests neuromuscular junction dysfunction, as seen in myasthenia gravis. High-frequency stimulation may reveal incremental responses characteristic of Lambert-Eaton myasthenic syndrome. The test is often performed on facial, spinal accessory, and median nerves.
Usage
Usage note: Specify stimulation frequency when reporting results.
In Context
- "Repetitive nerve stimulation of the facial nerve showed a 15% decremental response, supporting the diagnosis of myasthenia gravis." — EMG/NCS report
- "RNS testing should be performed before administration of cholinesterase inhibitors." — Pre-procedure note