Pathophysiology of hemifacial spasm: III. Effects of facial nerve decompression.
We studied 59 patients with hemifacial spasm before decompression of the facial nerve in the cerebellopontine angle. Fifty-three patients were reexamined 1 week later, and 30 patients after 2 to 8 months. Within 1 week, ephaptic transmission disappeared in 23% and changed from bidirectional to unidirectional in 45%. After-discharges disappeared in 64% and were mild in 34%. Synkinesis after supraorbital nerve stimulation disappeared in 53%, and the blink reflex amplitude became normal. After 2 to 8 months, ephaptic transmission was abolished in 73% and unidirectional in 17%. After-discharges and synkinesis disappeared in 90%, and the latency of the blink reflex decreased. It is concluded that decompression stops ectopic/ ephaptic excitation due to decrease in the interstitial resistance, and enables remyelination.
D000328:Adult; D000368:Aged; D004594:Electrophysiology; D005154:Facial Nerve / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000150:complications; D013035:Spasm / Q000503:physiopathology* / Q000601:surgery; D009435:Synaptic Transmission