High-resolution ultrasound in the evaluation and prognosis of Bell's palsy.
BACKGROUND
Bell's palsy is a commonly encountered paralysis of the facial nerve occurring worldwide. Prognosis for Bell's palsy is good, but the proportion of patients with poor outcomes may reach 30%. Ultrasound (US) may provide a novel approach for evaluating and prognosticating Bell's palsy, in comparison with known electrophysiological techniques.


METHODS
In this study, we measured the diameter of the distal facial (VII) nerve using US in patients with Bell's palsy treated with prednisolone, in comparison with healthy controls. Blink reflex and VII nerve conduction studies were also performed. Studies were prospective and performed within 1 week of disease onset.


RESULTS
Our results have shown that diameter of the distal VII nerve is a good predictor of favorable (positive predictive value: 100%) and bad outcomes (negative predictive value: 77%) in Bell's palsy at 3 months after clinical presentation. Furthermore, we also noted the lack of correlation of VII diameter with conventional VII nerve conduction studies (NCS) and blink reflex studies. US was superior to VII nerve conduction and blink reflex studies in outcome prediction.


CONCLUSIONS
This first study utilizing US in Bell's palsy highlights its role in outcome prediction and contributes to our understanding of recovery processes in this common neurological disorder.
Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore. gnrlyl@sgh.com.sg
Y L
YL
Lo
S
S
Fook-Chong
T H
TH
Leoh
Y F
YF
Dan
M P
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Lee
H Y
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Gan
L L
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Chan
D000328:Adult; D000368:Aged; D020330:Bell Palsy / Q000000981:diagnostic imaging* / Q000473:pathology; D005154:Facial Nerve / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D014463:Ultrasonography; D055815:Young Adult