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Hemifacial spasm and posterior auricular muscle
1University of Istanbul, Cerrahpasa Medical Faculty, Department of Neurology, Istanbul, Turkey.
Electromyography and Clinical Neurophysiology
|October 25, 2006
Summary
Posterior auricular muscle (PAM) activity is linked to hemifacial spasm (HFS). Botulinum toxin treatment targeting PAM improved symptoms in most patients with auricular involvement, suggesting PAM as a treatment target.
Area of Science:
- Neurology
- Ophthalmology
- Otorhinolaryngology
Background:
- Hemifacial spasm (HFS) is characterized by involuntary facial muscle contractions.
- The involvement of the posterior auricular muscle (PAM) in HFS reflex activity is not well understood.
- Auricular symptoms like tinnitus or clicking sounds can occur in HFS patients.
Purpose of the Study:
- To determine the extent of posterior auricular muscle (PAM) involvement in hemifacial spasm (HFS).
- To investigate if PAM contributes to the reflex activity observed in HFS.
- To evaluate the efficacy of botulinum toxin treatment targeting PAM in HFS patients with auricular symptoms.
Main Methods:
- Recorded spasm activity from facial muscles and synchronously from the posterior auricular muscle (PAM) on the symptomatic side in 19 HFS patients.
- Assessed lateral spread of blink reflex to orbicularis oris and PAMs.
- Administered botulinum toxin injections into the PAM for 14 patients with specific auricular symptoms.
Main Results:
- Spasm activity was recorded in the PAM of all HFS patients studied.
- Lateral spread of blink reflex to PAMs was observed in most patients.
- 9 out of 14 patients with auricular symptoms showed symptomatic improvement after botulinum toxin treatment targeting PAM.
Conclusions:
- Posterior auricular muscle (PAM) activity is affected in hemifacial spasm (HFS) and contributes to reflex activity.
- HFS patients with auricular symptoms and PAM spasm activity are potential candidates for botulinum toxin treatment.
- Targeting PAM with botulinum toxin offers a promising therapeutic option for select HFS patients.
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