Overview and Facts about Hemifacial Spasms
Hemifacial spasm is a neuromuscular disorder that causes involuntary facial muscle twitching or spasms. This condition typically occurs on only one side of the face (hemi), but in rare cases, it can affect both sides of the face. This disorder affects men and women but is most common in middle-aged and older women.
If left untreated, symptoms may ultimately worsen, affecting all the muscles on one side of the face. Although the disorder is not life-threatening, individuals may become distressed by their condition, causing them to increasingly withdraw socially.
Signs and Symptoms of Hemifacial Spasms
The severity of this condition can vary widely. Initially, patients may notice a small twitching of the eyelid, which may force the eye to shut; as the disorder progresses, patients experience more noticeable symptoms, including:
- Pronounced spasms of the cheek and mouth
- Pain behind the ear
- Hearing changes
- Larger spasms affecting the entire one side of the face, from the eye to the chin
Causes and Risk Factors of Hemifacial Spasms
Hemifacial spasm is most commonly caused by a small blood vessel compressing the facial nerve at the brainstem, known as the seventh cranial nerve. Also known as CN VII, this nerve carries both motor and sensory fibers and is responsible for facial expressions. In rare cases, this disorder may be caused by an injury to the nerve, a vascular malformation, multiple sclerosis, or a benign tumor pressing on the nerve.
In some cases, the cause is unknown.
Tests and Diagnosis of Hemifacial Spasms
A test called an electromyography (EMG) may be performed to measure muscle response or electrical activity into a nerve’s stimulation of the muscle.
A magnetic resonance imaging (MRI) scan can help look for a blood vessel compressing the nerve and to rule out other structural abnormalities and also to look for a tumor that may be causing the facial spasms.
Treatment and Care for Hemifacial Spasms
Several treatment options are available to help manage symptoms, including injections of botulinum toxin (botox). Injecting botox into the affected muscles of the patient’s face temporarily paralyzes those muscles, relieving the spasms. The effects are temporary and must be repeated every three to six months. Oral medications may also be prescribed but may come with unwanted side effects.
When conservative treatments are unsuccessful, surgery may be recommended. The most common procedure is called microvascular decompression (MVD). During this procedure, a neurosurgeon lifts the blood vessel off the nerve it’s compressing, then inserts a small pad between the vessel and the nerve to relieve the pressure.