Benign Essential Blepharospasm

Excerpt

Blepharospasm is a disease that results in an increased rate of bilateral eyelid closure, mainly attributed to the involuntary contraction of the orbicularis oculi muscles. Blepharospasm is a type of dystonia. Dystonia falls under the classification of movement disorders and is characterized by either sustained or intermittent contraction of a muscle. This leads to abnormal repetitive movements or postures, which tend to have a certain pattern and may be twisting or tremulous. In most dystonias, voluntary action typically leads to exacerbation of dystonia due to overactivation of muscles.

Dystonia can potentially affect any part of the body and can present at a wide range of ages.

Dystonia can be classified according to its distribution across the body:

1. Focal dystonia refers to dystonia that affects only one isolated region of the body.

2. Segmental dystonia refers to dystonia that affects 2 or more contiguous regions of the body.

3. Multifocal dystonia refers to dystonia which affects 2 or more non-contiguous regions.

4. Hemidystonia refers to dystonia, which affects half of the body.

5. Generalized dystonia refers to dystonia, which affects the trunk along with 3 other sites.

Dystonia can have a static or progressive course of the disease. Furthermore, the variability of symptoms can be classified according to how often they occur:

1. Persistent dystonia refers to dystonia that persists to the same extent throughout the day.

2. Action-specific dystonia refers to dystonia that only occurs when performing a certain activity.

3. Diurnal fluctuation refers to dystonia, which fluctuates throughout the day with a circadian variation in severity.

4. Paroxysmal dystonia refers to sudden episodes of dystonia typically induced by a trigger.

Examples of focal dystonia include blepharospasm, oromandibular dystonia, writer's cramp, spasmodic dysphonia, and torticollis.

Blepharospasm is a focal dystonia characterized by the simultaneous contraction of agonist and antagonist muscles, resulting in involuntary eyelid closure; the first report of patients with blepharospasm comes from a description of 10 patients, made by Henri Meige in 1910: these patients had involuntary eyelid closure in association with contraction of the muscles of the jaw. In his paper, Meige named this phenomenon "Convulsions de la Face" (convulsions of the face).

This article will review the etiology, epidemiology, history, evaluation, and management of blepharospasm.