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.

Jaw tremor in Parkinson's disease (PD) may not respond well to conventional treatment. It causes embarrassment and social handicap. We piloted the use of botulinum toxin (BTX) injections in three patients with PD jaw tremor. BTX A (Dysport; mean, 53 U; range, 30-100 U) was given into each masseter muscle. Outcome was assessed by subjective and clinical improvement and by video recording before and 4 to 9 weeks after injections. There was an excellent response in all without side effects. BTX injections into the masseter may effectively improve jaw tremor and be useful in PD and other conditions.

Serial peripheral nerve conduction studies are reported on a case of acute ophthalmoplegia and ataxia with areflexia (Miller Fisher syndrome). These tests showed abnormalities identical to those found in the Guillain-Barré syndrome.

No abstract

No abstract