Basics
- Characterized by repetitive, involuntary contractions of the face (supplied by the Facial Nerve- Cranial Nerve VII)
- Normally starts with the muscles around the eye and then progresses to the cheek and lips
- Brief twitches but increase in duration as the disease progresses
- Often caused by a abnormal blood vessel compressing the facial nerve inside the skull
- Treatment consist of medication and surgery in refractory cases
Symptoms and Signs
- Involuntary muscle contractions on one side of the face
- Contractions may be initiated by voluntary movement of the muscles of facial expression
- Muscle weakness in the face
- Normally painless
Demographics
- 8 (men) to 15 (women) out of 100,000
- Affects Women > Men, normally in the 50s and 60s
- slightly more common on the left than the right
Diagnosis
- EMG
- MRI / CT
- Clinical exam
Treatment
- Medications: Carbamazepine (Tegretol), baclofen, gabapentin (Neurontin), and Phenytoin (Dilantin)
- Injection of Botox– works for about 5 months and then the injections need to be repeated
- Surgery: Microvascular decompression (aka MVD) with insertion of a pledget (like a piece of felt) between the nerve and the abnormal blood vessel- the definitive treatment in medically refractory cases
Prognosis
- According to several studies, 2/3 of patients will achieve some relief with medication but the traditional thinking still views oral medications as being generally ineffective
- Botox injections- typically provide relief for 5months
- Surgery offers the definitive treatment of hemifacial spasm caused by an aberrant blood vessel: 86% of patients are spasm free at 10 years
Differential Diagnosis
- Basilar artery aneurysm
- Acoustic nerve tumor
- Meningioma
- Multiple sclerosis
- Bell’s palsy- can actually later result in hemifacial spasm
References
- Adam’s and Victor Neurology
- Handbook of Neurosurgery: Greenberg
- Harper, RL et al. “Microvascular decompression for hemifacial spasm: long term results of 114 operations” Journal of Neurosurgery