Hemifacial spasm: an electrophysiological evidence of facial motorneurons hyperexcitability.
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Date
1994-12-01
Authors
Eksantivongs, S
Poungvarin, N
Viriyavejakul, A
Punyamee, J
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Abstract
Twenty patients with primary hemifacial spasm and ten patients with Parkinson's disease were studied by means of paired stimuli blink reflex. The second stimuli were delivered at a varying time interval between 50-900 ms. The R2 response's absolute refractory periods were compared between patients and twenty one age-matched normal controls as well as between hemifacial spasm and Parkinson's disease. In normal subjects, the mean absolute refractory period was found to be 271.42 +/- 64.36 ms, in hemifacial spasm 160.00 +/- 50.62 ms and in Parkinson's disease 157.14 +/- 53.45 ms. The absolute refractory periods obtained from patients were significantly shorter than in normal controls (p < 0.05). However the values between patients with hemifacial spasm and Parkinson's disease were not (p > 0.05). This result strongly supports bilateral facial motoneurons hyperexcitability as the underlying mechanism of hemifacial spasm.
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Chotmaihet Thangphaet.
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Citation
Eksantivongs S, Poungvarin N, Viriyavejakul A, Punyamee J. Hemifacial spasm: an electrophysiological evidence of facial motorneurons hyperexcitability. Journal of the Medical Association of Thailand. 1994 Dec; 77(12): 627-32