Repeater F waves: a comparison of sensitivity with sensory antidromic wrist-to-palm latency and distal motor latency in the diagnosis of carpal tunnel syndrome.
Thirty-five thousand six hundred supramaximal shocks were applied to 209 healthy and 147 entrapped median nerves (carpal tunnel syndrome--CTS) to characterize the backfiring behavior of the alpha motor neuron pool of abductor pollicis brevis in health and the modifying effect of a compressive neuropathy. A contraction of the normal subpopulation of active F-wave generators was found in CTS, while active neurons backfired at higher than normal frequencies (p less than 0.001). These modifications in spinal behavior are reflected in the % Repeater F-wave value, whose sensitivity in the detection of CTS approaches that of sensory wrist-to-palm latency estimation. This technique offers an alternative to latency measurement in the diagnosis of CTS. An economical strategy for the electrodiagnosis of CTS is proposed.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D004576:Electromyography; D005071:Evoked Potentials; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D011930:Reaction Time; D014953:Wrist