Slimmer's paralysis: electrophysiological evidence of compressive lesion.

A 14-year-old girl developed right peroneal nerve palsy following diet for weight reduction. Peroneal neuropathy started after sitting and leg-crossing. The main electrophysiologic findings showed a severe slowing of conduction velocity in the above-to-below capitulum fibulae segment and a striking reduction in the size of the compound motor action potential when the nerve was stimulated above the knee. These features are consistent with focal demyelination and conduction block of the nerve fibres. The left peroneal nerve showed the same results but less severe. There were no electrophysiological signs of subclinical polyneuropathy. Examination after 3 months was normal. The clinical and electrophysiological features in this case support the compressive origin of the peroneal neuropathy in slimmer's paralysis.