Blepharospasm is a focal dystonia characterized by increased blinking and involuntary closing of the eyes. This form may be primary or secondary. People with blepharospasm have normal vision.

Terms used to describe blepharospasm include: eye dystonia, cranial dystonia, adult onset focal dystonia. When blepharospasm occurs with dystonia in the face, the term Meige's syndrome may be used.

Symptoms

Blepharospasm affects the eye muscles and usually begins gradually with excessive blinking and/or eye irritation. In the early stages it may only occur with specific precipitating stressors such as bright lights, fatigue, and emotional tension.

As the condition progresses, symptoms may occur frequently during the day. The spasms disappear in sleep, and some people find that after a good night's sleep, spasms do not appear for several hours after waking. In a few cases, spasms may intensify so that the eyelids remain forcefully closed for several hours at a time.

When blepharospasm and oromandibular dystonia occur together, the condition may be referred to as Meige's syndrome. In such cases, spasms of the eyelids are accompanied by jaw clenching or mouth opening, grimacing, and tongue protrusion.

Cause

Blepharospasm may develop spontaneously with no known precipitating factor or be inherited. Some people with blepharospasm have family members with dystonia affecting different body areas.

Blepharospasm may be secondary due to drug exposure or occur in association with disorders such as parkinsonian syndromes and Wilson's disease.

Diagnosis

Diagnosis of blepharospasm is based on information from the affected individual and the physical and neurological examination. At this time, there is no test to confirm diagnosis of blepharospasm.

Blepharospasm should not be confused with:

Ptosis- drooping of the eyelids caused by weakness or paralysis of a levator muscle of the upper eyelid.

Blepharitis- an inflammatory condition of the lids due to infection or allergies.

Hemifacial spasm- a non-dystonic condition involving various muscles on one side of the face, often including the eyelid, and caused by irritation of the facial nerve. The muscle contractions are more rapid and transient than those of blepharospasm, and the condition is always confined to one side.

Treatment

One of the most effective treatments for blepharospasm is regular botulinum toxin injections to the affected muscles. Medications—including clonazepam, lorazepam, and trihexyphenidyl—are helpful in some cases. If botulinum toxin injections and medications are not effective, myectomy surgery in which portions of muscle are removed may also alleviate symptoms.

Sources Dystonia medical research foundation