Blepharospasm
What is Blepharospasm?
Blepharospasm is a type of focal dystonia in which there is involuntary
contraction of the muscles of the eyelids causing closure of the lids.
This does not have any effect on a person's vision or mental faculties.
The only time vision would be affected is if the contractions become so
extreme that they force the eyelids closed. Symptoms include frequent
blinking and irritation of the eye. Dry eye has also been noted to be
present with blepharospasm. Other involuntary movements can occur in addition
to blepharospasm such as forceful opening of the jaw, retraction of the
lips, or protrusion of the tongue.
The cause is unknown, though
patients should be evaluated for diseases that may also have blepharospasm
as a symptom. Although the cause of blepharospasm is unknown, it is possibly
due to abnormal function of the basal ganglia of the brain. The job of
the basal ganglia is to help with the start and continuation of movement.
What is unknown about this is what makes the basal ganglia function incorrectly.
Who Gets Blepharospasm?
The cause of blepharospasm is unknown although there are likely genetic
factors. Diet, exercise, or similar events cause it. Most often individuals
with blepharospasm are seemingly randomly afflicted. It is possible for
it to be inherited, but this is rare. Those that are inherited also usually
have a generalized dystonia. Blepharospasm is not fatal but is usually
a life-long condition.
How is Blepharospasm Diagnosed?
Blepharospasm is diagnosed by the clinical evaluation by a physician,
usually a neurologist or ophthalmologist. It may occasionally be difficult
to diagnose. Usually it is necessary for the doctor to evaluate the information
provided from the patient, and the physical and neurological examinations
to provide the diagnosis. Electrodiagnosis is an important tool in the
diagnosis of blepharospasm.
How is Blepharospasm
Treated?
Treatment includes three areas of focus: oral medications, botulinum toxin
injections (which work the best), and surgery. Each of these can be used
separately, or in combination with the others to provide the best treatment.
Botulinum toxin injections are given to weaken the muscles that close
the eyes. This slight weakening allows patients with blepharospasm to
have more control opening their eyes. The injection of botulinum toxin
may be performed using electromyographic (EMG) guidance. An injectable
electrode attached to an EMG machine allows the muscle to be identified
and the toxin injected precisely into the muscle.
To Find a Specialist
To find a physician board-certified to conduct needle EMGs and nerve conduction
studies click here: www.abemexam.org
For More Information
Dystonia Medical Research Foundation:
www.dystonia-foundation.org
Benign Essential Belpharospasm Research Foundation, Inc: www.blepharospasm.org
National Institute of Neurological Disorders and Stroke: www.ninds.nih.gov
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