Benign essential blepharospasm (BEB) is a chronic neurological condition that affects the muscles responsible for blinking. The disease causes an abnormal, sustained, and involuntary contraction of the eyelids. Symptoms usually begin as mild twitching that progress over time to uncontrollable, forced spasms of the upper and lower eyelids. The spasms may expand to affect the brow depressors and, in some cases, the upper cheek muscles.
The onset of this condition is most common between 40 to 60 years of age, and is extremely rare among young people. The cause is unknown, although it may be related to an abnormal misfiring of the basal ganglia, the structures of the brain involved in coordination of movement. Vision is seldom impaired in patients with blepharospasm, although patients with severe cases may have a hard time opening their eyes. The condition is usually present in both eyes at the same time. However, if the twitching affects only one eye, the spasms usually progresses and the other eye may become involved.
The most effective treatment of blepharospasm is the application of botulinum toxins, such as Botox, Xeomin or Dysport, to the spastic muscles. The application is an in-office procedure. The effect may last from 2 to 6 months, depending on the dose utilized and the severity of the disease. Botulinum toxin has revolutionized the treatment of BEB because it has replaced mutilating surgical procedures used in the past. Some patients may also need to take medications such as clonazepam or lorazepam to control the spasms. Surgical intervention is now seldom required.
Hemifacial spasm (HS) is another neurologic disease that causes involuntary contraction of specific muscles in the face. The spasms begin as infrequent, random movements which later become generalized and constant. These involuntary movements are only present on one side of the face, hence the term hemifacial (hemi means half). The spasms may be a manifestation of a vessel in the brainstem compressing the facial nerve or the presence of a tumor in that area. Therefore, it is important to perform an MRI in these patients. If the MRI is normal, the symptoms of the disease can be treated without surgery.
Hemifacial spasm responds very well to treatment with botulinum toxin injections. This is done in the office every two to four months, depending on the product used and the response to treatment. Botulinum toxin helps to relax the muscles and make the spasms disappear or improve significantly. The doses that are necessary to reduce the spasms are much larger than those utilized for aesthetic purposes.