Hemifacial spasm (HFS) is an involuntary twitching of one side of the face. It usually starts around the eye and slowly progresses to involve the lower face. In some patients, it starts around the musculature of the mouth and progresses up the face towards the eye. The muscles in the forehead and neck are usually the last to be affected. Twitching can be observed during sleep and is rarely painful. Unfortunately, there is no medical treatment which is consistently effective for HFS. Botulinum toxin (Abotox@) injections are ineffective in producing long term control of the spasm and result in varying degrees of facial weakness. We have also learned that such injections may negatively impact on subsequent definitive surgical treatment.

Over 30 years ago Dr. Peter Jannetta noted a blood vessel pulsating against the facial nerve at the brainstem in a patient with HFS. Moving the vessel cured the spasms and since that time over 1000 patients have been treated at UPMC with microvascular decompression. The Minimally Invasive Cranial Base Center currently performs approximately 75 MVDs for HFS each year. Surgery has undergone significant evolution over the past 30 years with ability to monitor hearing and facial nerve function thus reducing the incidence of injury to less than 5%. The ability to monitor facial nerve irritability (lateral spread) optimizes our chance of identifying the pathologic vessels and achieving a cure.

Most recently, we have introduced the endoscope (telescope) to this procedure. This device allows us to look around corners thus minimizing brain retraction and maximizing identification of hidden blood vessels that might be causing the HFS. This advantage is maximized when the surgeon is able to fuse both images in the same set of binoculars and is referred to as "image fusion." This concept was pioneered at UPMC in collaboration with commercial industry. We have found this technology especially useful in cases of recurrences and repeat operations.

Image fusion with microscope image (A)
and endoscope image (B) displayed to surgeon
simultaneously to aid in vessel manipulation.

In addition to primary cases, UPMC surgeons currently undertake re-exploration in approximately 20 patients per year for recurrences of HFS. Most of these patients have had their surgery performed elsewhere and are referred to UPMC because of its clinical experience with this disease entity.

The following are photos from a reoperation on a patient unsuccessfully treated at another institution for hemifacial spasm.

A) Eighth cranial nerve, (B) area treated at another institution with pad, (C) vessel treated at another institution, (D) seventh cranial nerve at brainstem not treated by prior operation, (E) vessel compressing seventh nerve at brainstem; decompressed during second operation. Patient cured.

Benign essential blepharospasm can easily be confused with hemifacial spasm. The latter can be diagnosed through facial muscle EMG testing and treated with microvascular decompression.

Results

Approximately 90% of individuals who undergo MVD for HFS are completely relieved or dramatically improved following surgery. The same holds true for patients who undergo repeat operations following failed surgery or recurrence. In those patients who have never received botox the recurrence rate at 18 months following surgery is 15% while in those that have received botox the recurrence rate at 18 months is 30%. Significant complications are seen in fewer than 5% of cases.