Benign essential blepharospasm

Synonyms

2

Overview

Benign essential blepharospasm (BEB) is a progressive neurological disorder characterized by abnormal blinking or spasms of the eyelids. It is a form of dystonia, a group of movement disorders involving uncontrolled tensing of the muscles (contractions), rhythmic shaking (tremors), and other involuntary movements. BEB occurs in both men and women, although it is especially common in middle-aged women.

Initial symptoms include an increased frequency of blinking, dry eyes, and eye irritation. As the condition progresses, spasms of the muscles surrounding the eyes cause involuntary winking or squinting and increasing difficulty keeping eyes open, which can lead to vision impairment. In more than half of all people with BEB, the symptoms affect other facial muscles and muscles in other areas of the body. When people with BEB also experience involuntary muscle spasms affecting the tongue and jaw, this is known as Meige syndrome. The cause of BEB is unknown; however, some cases appear to run through families. Although there is no cure for BEB, symptoms can be treated using various methods including botulinum toxin injections.

Symptoms

Sign and symptoms may include:

  • Progressive worsening of eyelid spasms
  • Occasional eye blinking
  • Occasional eye irritation
  • Involuntary winking
  • Involuntary squinting
  • Increasing difficulty keeping eyes open
  • Light sensitivity
  • Longer eyelid spasms 
  • Uncontrollable eyelid closing
  • Involuntary eye muscle contraction
  • Eye muscle spasms
  • Inability to open eyes
  • Forceful blinking

Causes

The exact cause is unknown. 

Prevention

Management should be under medical supervision. Currently, there is no cure or way to prevent BEB as the disease frequently progresses despite treatment.

  • Sunglasses: Wearing tinted sunglasses with ultraviolet blocking may help in decreasing painful light sensitivity in those who show significant photosensitivity.
  • Lid hygiene: Lid hygiene may decrease eye irritation. Those having blepharitis also show improvement.
  • Artificial tears: Application of artificial tears and punctal occlusion to alleviate dry eyes may improve blepharospasm.

Diagnosis

Diagnosis of BEB is made clinically (based on history and physical examination) and it is a diagnosis of exclusion by ruling out the presence of associated conditions.

Clinical features of benign essential blepharospasm:

At onset of BEB, there is increased frequency of blinking precipitated by stimuli such as wind, sunlight, noise, air pollution, reading, watching television, stress, or movement of eye or head. Patients may develop sensory tricks ( geste antagoniste ) to relieve symptoms such as tics and movements of other muscles innervated by facial nerve e.g. whistling, coughing, eating, picking teeth, yawning or chewing gum.

Eyelid spasm, a characteristic feature of blepharospasm, sets in a few months to years after early features. Blepharospasm is unilateral to begin with but usually eventually evolves into a bilateral condition. Blepharospasm usually lasts for minutes to hours together. Blepharospasm has a variable course and may be intermittent or continuous. It is slowly progressive in most of the patients. 

Excessive blinking may lead to unilateral mild twitches, but may progress to bilateral, frequent and forceful spasms. During severe episodes, patient is unable to open the eyelids which may be associated with severe pain and functional blindness and may interfere with daily routine activities. Severe blepharospasm may cause high level of distress and psychosocial impairment causing anxiety, depression, avoidance of social contact and occupational problems. Blepharospasm reduces while concentrating on a specific task or during sleep.

Blepharospasm may be associated with apraxia (loss of ability to perform activity) of eyelid opening i.e. inhibition of proper functioning of levator palpebrae superioris muscle. Apraxia is especially common in parkinsonian disorders.

Prognosis

With botulinum toxin treatment most individuals with BEB have substantial relief of symptoms. Although some may experience side effects such as drooping eyelids, blurred or double vision, and eye dryness, these side effects are usually only temporary. 

Treatment

In most cases of BEB the treatment of choice is botulinum toxin injections (there are several formulations; the most commonly used is Botox), which relax the muscles and stop the spasms.

Approved therapies:

Botulinum toxin type A (Botox) - FDA-approved indication: Treatment of cervical dystonia in adults to decrease the severity of abnormal head position and neck pain associated with cervical dystonia. Treatment of blepharospasm or strabismus associated with dystonia in adults (patients 12 years of age and above).

Resources

Refer to research Publications.