側頭骨内顔面神経麻ひの誘発筋電図における患側大振幅について

Abstract

In the very acute phase of Bell's palsy and Ramsay Hunt's syndrome, the amplitudes of evoked electromyograms of the orbicularis oculi and oris muscles not rarely appear to extend beyond the upper limit of normal. This abnormally large amplitude declinedvery sharply, and in the second week of the diseases, the amplitude returned to normal or even decreased below normal in 6 patients, 4 out of the 76 patients with Bell's palsyand 2 of the 16 with Hunt's examined in our clinic. In these 6 patients, there was noevidence of denervation, and the facial palsy continued to be incomplete throughout thecourse of the disease. Thus, the abnormally large amplitude was a sign of favorableprognosis of the facial palsy. The results suggest that the facial nerve becomes transiently hyperexitable after moderate damage of the intratemporal area.