Hemifacial Spasm

What hemifacial spasm looks like

• twitching that usually starts in the muscle around one eye, especially the lower eyelid
• over months to years, spreading to the cheek, the corner of the mouth, the chin and the neck muscle (platysma) on the same side
• the eye may close forcefully while the mouth pulls sideways
• spasms come in bursts, sometimes almost continuous
• worse with stress, fatigue, talking or eating
• spasms often continue during sleep
• some people hear a clicking sound in the ear during spasms

Both sides are affected only very rarely, and then not at the same moment.

Hemifacial spasm vs other facial twitches

Causes

• Blood vessel compression: the most common cause. An artery, often the anterior inferior cerebellar artery, presses on the facial nerve as it leaves the brainstem, damaging its insulation and causing the nerve to fire abnormally.
• Tumors: rarely, an acoustic neuroma, meningioma or other mass.
• After Bell's palsy or facial nerve injury.
• Multiple sclerosis and other brainstem lesions (rare).

High blood pressure may be a risk factor.

Diagnosis

Diagnosis is based on the typical appearance. A neurologist will examine facial strength and other cranial nerves. MRI of the brain with detailed views of the facial nerve is recommended to look for vessel compression and rule out tumors. Electromyography (EMG) can help in unclear cases.

Treatment

Botulinum toxin injections

Small injections of botulinum toxin into the affected muscles weaken them enough to stop the spasms. This is the first-line treatment.

• improvement starts in 3 to 7 days
• effects last about 3 to 4 months, so injections are repeated
• helps most people
• side effects include temporary eyelid droop, facial weakness, dry eye or double vision, which wear off

Medicines

Anti-seizure medicines (carbamazepine, gabapentin) or muscle relaxants (baclofen, clonazepam) help some people with mild symptoms, but are generally less effective than Botox.

Microvascular decompression surgery

A neurosurgeon makes a small opening behind the ear and places a tiny Teflon cushion between the artery and the facial nerve. It can cure hemifacial spasm, with success in most people, often improving over weeks to months after surgery. Risks include hearing loss on that side, facial weakness, spinal fluid leak and, rarely, stroke. It is considered for people who want a permanent solution or do not respond well to Botox.

Outlook

Hemifacial spasm is usually lifelong without treatment and tends to slowly worsen. It does not cause paralysis or threaten life. With regular Botox or successful surgery, most people have good control.

Frequently asked questions

What causes hemifacial spasm?

In most people, a blood vessel presses on the facial nerve where it exits the brainstem, causing it to misfire. Rarely, a tumor, multiple sclerosis or a previous facial nerve injury such as Bell's palsy is responsible.

Is hemifacial spasm serious?

It is not life-threatening and does not lead to stroke or paralysis. However, it can affect vision, sleep and confidence. An MRI is recommended to rule out rare causes such as a tumor.

Does Botox work for hemifacial spasm?

Yes. Botulinum toxin injections are the main treatment and control spasms in most people. Effects begin within a week and last about 3 to 4 months, so injections are repeated regularly.

Will my eyelid twitch turn into hemifacial spasm?

Most eyelid twitching is harmless myokymia that comes and goes with stress, caffeine or tiredness and never spreads. See a doctor if twitching persists for weeks, spreads to the cheek or mouth, or causes the eye to close.