BASICS

DESCRIPTION

• Involuntary closure of both eyelids (blepharospasm) or muscles innervated by facial nerve unilaterally (hemifacial spasm):

– Blepharospasm:

– Essential (without associated disease)

– Blepharospasm-oromandibular dystonia or Meige syndrome (dystonia of face, jaw, and neck)

– Secondary – due to ocular irritation

– Hemifacial spasm

• System(s) affected: Nervous; musculoskeletal

EPIDEMIOLOGY

• Predominant age: Middle age (40–60 years)

• Predominant sex: Female > Male (2–4:1)

Incidence

2000 cases of blepharospasm diagnosed annually in the USA (1)

Prevalence

• 1.6–13.3/100,000 for blepharospasm

• 7.4–14.5/100,000 for hemifacial spasm

RISK FACTORS

• Blepharospasm:

– Head or facial trauma

– Specific eye disease, e.g., blepharitis and keratoconjunctivitis

– Family history of dystonia or tremor (2)

– Cigarette smoking was considered a negative risk factor earlier, but not in recent studies (3,4).

• Hemifacial spasm has no known risk factors.

Genetics

• Most sporadic, yet familial variety with autosomal dominance and incomplete penetrance in blepharospasm

• No genetic relationships known with hemifacial spasm

PATHOPHYSIOLOGY

• Blepharospasm:

– Two opposing muscle groups, protractors (orbicularis, corrugator, and procerus) and retractors (levator palpebra superioris and frontalis), fire at the same time.

– Sensitization of the trigeminal system via photophobia (2)

– Theory of ion channelopathy (5)

• Hemifacial spasm:

– Ephaptic transmission

ETIOLOGY

• Hemifacial spasm:

– Vascular compression of the facial nerve by an abnormal artery

– Rarely tumors of the posterior fossa compressing the facial nerve (6)

COMMONLY ASSOCIATED CONDITIONS

• Blepharospasm:

– Dry eyes

– Movement disorders, strokes

DIAGNOSIS

HISTORY

• Blepharospasm (1)[C]

– Increase blinking progresses to involuntary spasms of eyelids, initially unilateral:

Increases in severity and frequency

Often has ocular irritation

• History of drug use with tardive dyskinesia

• Hemifacial spasm:

– Involuntary eye closure that progresses over months to years to other facial muscles on the same side

PHYSICAL EXAM

• Blepharospasm:

– Nonvolitional contraction of multiple muscles (both protractors and retractors), not just orbicularis

– Careful exclusion of ocular causes

– Observation for other tics which are more brief, may involve winking

• Hemifacial spasm:

– Synchronous spasm of multiple facial muscle ipsilaterally

DIAGNOSTIC TESTS & INTERPRETATION

Lab

• MRI brain

• MRI/MRA brain with attention to the posterior fossa

Pathological Findings

Abnormal blood vessels: aneurysms, dolichoectasia, etc.

DIFFERENTIAL DIAGNOSIS

• Blepharospasm:

– Ocular myokymia

– Associated with lesions of brainstem and basal ganglia (Parkinson disease, Huntington disease, Wilson disease, Creutzfeldt–Jakob disease, progressive external ophthalmoplegia)

– Reflex (due to temporoparietal strokes)

– Ocular (irritative ocular disease, e.g., entropion)

– Tardive dyskinesia

– Facial tics (Tourette syndrome)

– Functional

– Focal seizures

• Hemifacial spasm:

– Tardive dyskinesia

– Myokymia

– Tics

– Dystonia

– Functional

TREATMENT

MEDICATION

First Line

• Treat underlying etiology in secondary etiologies.

• Botulinum toxin injection (7)[B], (8)[A]:

– Every 3–4 months

Second Line

• Oral medications (carbamazepine, anticholinergics, baclofen, clonazepam, haloperidol):

– Often sedating and not helpful

ADDITIONAL TREATMENT

Issues for Referral

Socially upsetting to sight impairment

SURGERY/OTHER PROCEDURES

• Blepharospasm:

– Orbicularis myectomy

– Differential section of the facial nerve

– Superior cervical ganglion block

• Hemifacial spasm:

– Microvascular decompression

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

• 1 month after botulinum injections

• If well reinjection every 3 months or longer

PATIENT EDUCATION

• Benign Essential Blepharospasm Research Foundation found to be helpful and other therapies

• Patient and family fact sheet (9)

• Reduce coffee intake

PROGNOSIS

90% improve with botulinum injections

COMPLICATIONS

With microvascular surgery can have facial weakness and hearing loss.

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