Do F-wave measurements detect changes in motor neuron excitability?
✍ Scribed by Jenny Z. Lin; Mary Kay Floeter
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 146 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0148-639X
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The use of F waves to assess motor neuron excitability in experimental paradigms has never been validated. Our objective was to determine whether F‐wave area, amplitude, and persistence measurements change in response to manipulations known to alter the excitability of motor neurons. The effects of muscle vibration, contraction of a remote muscle, and high‐intensity stimulation of ipsilateral or contralateral fingers were assessed in 12 healthy volunteers. F‐wave area, amplitude, and persistence all declined with ipsilateral cutaneous stimulation. The other maneuvers facilitated some, but not all, of the F‐wave measurements. Changes in F‐wave area and amplitude were correlated, but neither correlated with changes in persistence. A sample size of 50–75 F waves was needed to approximate amplitude and area results from 100 F waves with an accuracy of ±25%. We conclude that changes in F waves are better at detecting inhibition than facilitation of motor neurons. F waves reflect motor neuron excitability in a general way but do not allow for accurate measures of short‐term changes in excitability. Muscle Nerve 30: 289–294, 2004