Blepharospasm

Frequent, Uncontrollable Blinking

What is blepharospasm?

Blepharospasm is a term used to describe involuntary contraction of the eyelid muscles that leads to frequent, uncontrollable blinking. Blepharospasm often affects both eyelids, making it difficult to open the eyelids. In severe cases, this debilitating condition can lead to what is known as "functional blindness" because the patient is unable to open, or keep open, the eyelids for any significant period of time.

Approximately 75% of patients with blepharospasm are female and the average age at onset is 56 years. Although the exact cause of this disorder is unknown, experts believe that it may be caused by an inappropriate signal within the part of the brain known as the basal ganglia.

What are the symptoms of blepharospasm?

In the early stages of blepharospasm, symptoms include irritation and discomfort of the eyelids as well as an increase in blinking often associated with light and glare. There may be a feeling of dryness or a sensation of grittiness in the eyes.

Symptoms may progress to more sustained eyelid closure that interferes with normal activities such as reading, walking and socialising.

The degree of incapacity may vary from day to day. Some activities, such as driving a car, can become quite hazardous because of the inability to keep the eyelids open at will. Bright, dazzling or flickering lights, dusty or smoky air, or high-speed travel by train or car can make the symptoms worse.

What is the long-term outlook for blepharospasm?

The initial stages of sensitivity to glare and uncontrollable blinking may eventually disappear over the course of a few months. If the blepharospasm progresses, blinking usually becomes more frequent, forceful and uncontrollable. Sustained eyelid closure may develop. Symptoms fluctuate in severity so there may be periods when the symptoms are less troublesome.

What is hemifacial spasm?

Related to blepharospasm, hemifacial spasm is a neuromuscular disorder characterised by frequent involuntary contractions of the muscles on one side of the face. Hemifacial spasm is rare, affecting around 8 out of 100,000 men and 15 out of 100,000 women. Spasm affecting the left side is slightly more common than right-sided spasm.

What are the symptoms of hemifacial spasm?

The earliest symptom is usually an intermittent twitching of the eyelid muscle that can lead to forced closure of the eye. The spasm can spread gradually to involve the muscles of the lower face, which may cause the mouth to be pulled to one side. Eventually the spasms involve all of the muscles on one side of the face almost continuously. In some severe cases, the spasms may cause the mouth to become clamped shut, making speaking, eating, and swallowing difficult.

What causes hemifacial spasm?

In most people, there is no apparent cause for hemifacial spasm. Occasionally, it can be attributed to a facial nerve injury, pressure on the VIIth facial nerve or a tumour. Hemifacial spasm can also follow Bell's palsy (an inflammation of the facial nerve resulting in temporary facial weakness) due to incorrect regeneration of the facial nerve.