Blepharospasm

Blepharospasm, characterized by recurrent spasm of the orbicularis oculi muscle, is a disease where patients demonstrate uncontrolled blinking, twitching, or closure of the eyelids. Symptoms are most commonly bilaterally found, and usually manifest in the fifth to seventh decades. Women are more affected than men, with a 3:1 ratio. The high incidence of movement disorders among first-degree relatives of patients with blepharospasm suggests that the condition is genetically transmitted. Patients often display a grimacing expression with involuntary closure of the eyes, and symptoms often disappear in sleep. Blepharospasm is usually idiopathic, or may be secondary to ocular irritation, such as corneal or conjunctival foreign body, trichiasis, blepharitis, or dry eye syndrome. It is speculated that the condition is related to basal ganglia dysfunction, and is exacerbated by fatigue or stress, suggesting that there may be a psychological component to the condition. Severe blepharospasm may lead to functional blindness.

Meige syndrome is blepharospasm with uncontrollable facial, head, and neck involvement. Hemifacial spasm should be considered in the differential diagnosis for blepharospasm; patients with this manifest unilateral facial spasms that involve both the upper and lower face. This condition is usually idiopathic but may be secondary to the compression of the facial nerve by an artery or by a posterior fossa tumor.

Magnetic resonance imaging (MRI) should be obtained in all patients where this is a suspicion to rule out malignancy. Other conditions to be considered in the differential diagnosis include Tourette syndrome, trigeminal neuralgia, tardive dyskinesia, and eyelid myokymia. Eyelid myokymia usually involves the lower eyelid, and is unilateral in nature. The twitches are commonly triggered by stress or caffeine.

While some cases of blepharospasm spontaneously resolve, most cases require some form of treatment. Any underlying disorder contributing to ocular irritation should be appropriately treated. If an underlying disorder causing ocular irritation has been ruled out, treatment of blepharospasm includes psychotherapy, neuroleptic pharmacological therapy, biofeedback training, hypnosis, and botulinum toxin. Haloperidol, clonazepam, bromocriptine, and baclofen have all shown limited success. Botulinum toxin, the current first-line therapy, can be injected into the orbicularis muscles. This type of treatment is often reserved for severe cases of blepharospasm. Injections are usually repeated [Page 268]every 12 weeks, indefinitely. Side effects include transient ptosis and diplopia. If the patient is unresponsive or intolerant to these therapies, surgical ablation of the facial nerve or extirpation of the orbicularis muscles may be considered.