[The prognostic role of electromyography in vocal cord paralysis].
OBJECTIVE
To predict the recovery of vocal cord paralysis (VCP) by using electromyography (EMG).


METHODS
The characteristics of EMG of 46 patients with unilateral VCP were assessed to determine the most useful factors in determining prognosis. The factors include the duration, amplitude, waveform morphology, root-mean-square, and time interval.


RESULTS
A positive prognosis for laryngeal recovery was indicated when the following EMG features were present in the immobile vocal fold during voluntary tasks if EMG was performed during 6 months of the onset of VCP: normal motor unit waveform morphology; no electrical silence. This predictive rate is 76%. When the root-mean-square value is greater than 26 microV, the predictive rate is 80%. On the basis of the criteria, all the prognostic rate is 84%.


CONCLUSIONS
The results support the concept that EMG record is valuable in determining prognosis performed during 6 months of the onset of VCP.
Chen
Shicai
S
Department of Otolaryngology, Changhai Hospital, Second Military Medical University, Shanghai 200433.
Zheng
Hongliang
H
Zhou
Shuimiao
S
Cui
Yi
Y
Li
Zhaoji
Z
Wen
Wu
W
Geng
Liping
L
D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D007821:Laryngeal Muscles / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D014826:Vocal Cord Paralysis / Q000503:physiopathology*