Electrical and transcranial magnetic stimulation of the facial nerve: diagnostic relevance in acute isolated facial nerve palsy.
Unilateral facial weakness is common. Transcranial magnetic stimulation (TMS) allows identification of a conduction failure at the level of the canalicular portion of the facial nerve and may help to confirm the diagnosis.


METHODS
We retrospectively analyzed 216 patients with the diagnosis of peripheral facial palsy. The electrophysiological investigations included the blink reflex, preauricular electrical stimulation and the response to TMS at the labyrinthine part of the canalicular proportion of the facial nerve within 3 days after symptom onset.


RESULTS
A similar reduction or loss of the TMS amplitude (p < 0.005) of the affected side was seen in each patient group. Of the 216 patients (107 female, mean age 49.7 ± 18.0 years), 193 were diagnosed with Bell's palsy. Test results of the remaining patients led to the diagnosis of infectious [including herpes simplex, varicella zoster infection and borreliosis (n = 13)] and noninfectious [including diabetes and neoplasma (n = 10)] etiology.


CONCLUSIONS
A conduction block in TMS supports the diagnosis of peripheral facial palsy without being specific for Bell's palsy.


CONCLUSIONS
These data shed light on the TMS-based diagnosis of peripheral facial palsy, an ability to localize the site of lesion within the Fallopian channel regardless of the underlying pathology.
Department of Clinical Neurophysiology, Klinikum Bremen-Ost, University of Göttingen, Bremen, Germany. Svenja.Happe@klinikum-bremem-ost.de
Svenja
S
Happe
Sabine
S
Bunten
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004558:Electric Stimulation; D005154:Facial Nerve / Q000503:physiopathology*; D005155:Facial Nerve Diseases / Q000175:diagnosis* / Q000503:physiopathology; D005158:Facial Paralysis / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult