Skull Base Institute

Hemifacial Spasm

Hemifacial Spasm: Managing Complex Facial Disorders

The complexity of managing facial disorders requires a dedicated, multidisciplinary approach. Patients can find this special expertise at the Facial Pain, Spasm and Paralysis Center (Facial PSP Center) at The Skull Base Institute.

This joint venture brings together Dr. Shahinian and several renowned pain specialists, including Dr. Robert Merrill, Director of UCLA’s Orofacial Pain Center, and Dr. Ronald Young, Medical Director of California Neuroscience Institute. The Facial PSP Center offers a comprehensive approach to the diagnosis and treatment of facial pain, spasm and paralysis. Treatment alternatives include medical, surgical, radiosurgical, psychological and pharmacological management – each customized to the patient’s needs. Pain experts, surgeons, neurologists, psychologists and a full-time social worker closely collaborate to provide the most appropriate care. Endoscopic “keyhole approach” for microvascular nerve compression syndromes The endoscope is being used at the Skull Base Institute to treat hemifacial spasm, trigeminal neuralgia, or severe facial pain.

Patients with neurovascular problems such as trigeminal neuralgia, hemifacial spasm, intractable vertigo and spasmodic torticollis benefit from the Skull Base Institute’s innovative endoscopic “keyhole” approach to these disorders.

At the Institute, surgeons perform this delicate microvascular decompression procedure through a dime-size opening behind the ear. Through this opening, surgeons insert a 2.7 mm endoscope. They can then identify the problem and perform the procedure – meticulously separating the nerve and blood vessel, and inserting a Teflon disk between them. Once the pressure has been relieved, patients often report immediate and complete relief from the pain.

In many cases, the endoscopic “keyhole” surgery is the preferred approach to traditional methods, in which instruments are inserted in a larger opening behind the ear, and the brain pushed aside to reach the nerve compression area.

Hemifacial spasm (HFS) is a neuromuscular disorder that is characterized by paroxysmal bursts of involuntary tonic or clonic activity occurring in the muscles innervated by the facial nerve (the seventh cranial nerve). The contractions are frequent, involuntary, intermittent or continuous, and involve the facial musculature on the side of the affected facial nerve. The disorder presents almost always unilaterally, although bilateral involvement may occur rarely in severe cases. Although primary HFS is an indolent disorder and untreated cases of HFS generally do not have dire consequences, patients often bare the emotional burden of the society’s response to unusual facial movements and therefore they often seek a definitive medical or surgical treatment.

Hemifacial spasm may occur in both men and women, but a slight female preponderance exists. It most frequently affects women in their fifth or sixth decade, with no racial or ethnic predilection.

In essentially all cases, HFS is caused by an ectatic blood vessel that irritates the facial nerve (or nucleus) by compressing or forming a loop around the nerve at the cerebellopontine angle at its exit from the brainstem. Most instances of HFS previously thought to be idiopathic were probably caused by one of those aberrant blood vessels. Rarely, the condition may be secondary to facial nerve injury or facial nerve compression by certain tumors such as acoustic neuromas or other tumors of the cerebellopontine angle. Hemifacial spasms can also occur with regeneration of the facial nerve following facial palsy (Bell’s palsy).

Hemifacial spasm typically begins with brief unilateral intermittent clonic movements or twitching of the eyelid muscle (orbicularis oculi ) which can lead to forced closure of the eye on the affected side. As the disease progresses the disorder spreads to other facial muscles (corrugator, frontalis, orbicularis oris, platysma, zygomaticus) to involve the whole middle and lower face on one side. Emotional stress, fatigue, anxiety, or minor activities such as reading or coughing may precipitate or worsen the facial spasms. At a later stage, clonic movements progress to sustained tonic contractions of the involved facial musculature. Eventually, the spasms involve all the muscles on one side of the face and become almost continuous. HFS is usually a painless condition, but it can be associated with ipsilateral facial pain.

A wide variety of other entities that are characterized by or associated with craniofacial movement disorders may mimic but should not be confused with HFS. For instance, craniofacial tremors that may occur in Parkinson disease or thyroid dysfunction or essential blepharospasm, which is bilateral twitching confined to the eyelid and the forehead.

Medical history and neurological examination are usually suggestive. To further confirm the diagnosis an electromyography (EMG) is performed with special equipment that allows stimulation and recording of the activity of selected facial nerve branches. An MRI/MRA is performed to exclude the small but definite probability of a mass lesion in the region of the cerebellopontine angle and to identify the blood vessel irritating the facial nerve.

In mild and early cases, twitching can be controlled through the use of some anti-seizure drugs or minor tranquillizers, such as tegretol, clonazepam and diazepam, these drugs need to be taken on a long-term basis, and it is not always a successful form of treatment. Botulinum toxin injection directly into the affected muscles can ablate the muscular spasm for several months but its effect is temporary and the sensation of spasm often persists. The response to the latter two treatment modalities varies and their effects often attenuate over time, necessitating a surgical treatment.

The definitive procedure is Microvascular Decompression (MVD), which allows the surgeon to explore the posterior cranial fossa and directly visualize the facial nerve as it exits the brainstem. The offending blood vessel is then moved away from the nerve which is padded with a small piece of Teflon. The advantage is spasm relief in the majority of patients and usually lasts indefinitely.

Hemifacial spasm generally persists throughout life, gradually worsening over the years; however, the condition almost always responds well to treatment, and surgical decompression of the offending blood vessels can yield excellent results.

If you or someone you love has questions about Hemifacial Spasm, please Contact Us and we will be happy to help you.