Blepharospasm is a focal dystonia that is characterized by excessive blinking and involuntary closing of the eyes. This form can be either primary or secondary.
People who are living with blepharospasm usually have a normal vision. When vision is impaired, it is solely due to the forced closure of the eyelids.
Blepharospasm can also be referred to as a 'cranial dystonia.' Cranial dystonia is a wide description of dystonia that affects any part of the head.
Cause of Blepharospasm
Blepharospasm may develop spontaneously with no known precipitating factor or be inherited. Some of the 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 of Blepharospasm
The diagnosis of blepharospasm depends on information from the affected individual and the physical and neurological examination. At this time, there is no test to confirm diagnosis of blepharospasm, and, in most cases, assorted laboratory tests are normal.
Symptoms of Blepharospasm
Blepharospasm affects the eye muscles and usually begins gradually with over blinking or eye irritation.
At initial stages of the condition, it may only occur with specific precipitating stressors such as bright lights, fatigue, and emotional tension. It is almost always present in both eyes.
As the condition progresses, symptoms may happen 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.
Blepharospasm can occur with dystonia that affects the mouth or jaw (oromandibular dystonia). 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.
Treatment of Blepharospasm
One of the most effective treatments for blepharospasm is to give 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. Botulinum toxin injections can or cannot be required after the myectomy surgery.