Blepharospasm

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Blepharospasm
Classification and external resources
ICD-10 [1]24.5
ICD-9 333.81
DiseasesDB 15748


Blepharospasm is abnormal contraction of the eyelid muscles. It often refers to benign essential blepharospasm (BEB) which is a bilateral condition and a form of focal dystonia leading to episodic closure of the eyelids. The exact cause of BEB is unknown and, by definition, it is not associated with another disease entity or syndrome. Symptoms usually begin as mild and infrequent spasms that progress over time to forceful and frequent contractures of the eyelids, in advanced cases causing functional blindness from inability to temporarily open the eyes. The treatment of choice for BEB is periodic injection of botulinum toxin into the orbicularis oculi muscle. BEB is a clinical diagnosis and must be distinguished from secondary blepharospasm, which can occur in association with a syndrome, movement disorder, or a specific ocular disease such as in reflex blepharospasm secondary to ocular irritation.  

Disease Entity

Blepharospasm ICD9 333.81

Disease

Blepharospasm is involuntary closure of both eyelids. Benign essential blepharospasm (BEB) is a bilateral condition and a form of focal dystonia characterized by episodic contraction of the eyelid protractor muscles (orbicularis oculi, procerus, and corrugator superciliaris) and is not associated with another disease. BEB needs to be differentiated from blepharospasm that can exist as part of a specific syndrome (ie Meige syndrome) or systemic disease (ie extrapyramidal disorders) and that which occurs secondary to ocular irritation and medication.

Epidemiology

  • Age: onset most commonly occurs during years 40-60
  • Gender: Female > Male (2-4:1)
  • Incidence: 2,000 cases diagnosed annually in the U.S.
  • Prevalence: 1.6-30/100,000

Etiology

The exact cause of benign essential blepharospasm is unknown. Some evidence using functional neuroimaging suggests dysfunction within the basal ganglia. In rare cases, genetics have been reported to play a role.

Risk Factors

Variable risk factors for blepharospasm have been reported:

  • Head or facial trauma.
  • Family history of dystonia or tremor.
  • Reflex blepharospasm is reportedly triggered by severely dry eyes and blepharitis, intraocular inflammation, meningeal irritation, light sensitivity.
  • Stress may exacerbate benign essential blepharospasm.
  • Medications, such as those used to treat Parkinson's disease, have been associated with blepharospasm.
  • Earlier studies suggested that cigarette smoking was a negative risk factor, but more recent studies no longer support this.

Pathophysiology

The mechanism underlying benign essential blepharospasm is not yet clearly understood. Basal ganglia dysfunction, overactivity of the seventh nerve leading to simultaneous forceful contractions of the eyelid protractors and retractors, ion channelopathy, and sensitization of the trigeminal system by photophobia are some of the proposed mechanisms.

Primary prevention

There is no known method to prevent benign essential blepharospam. In cases of secondary blepharospasm, avoiding the inciting irritant (ie bright light), treating the underlying disease (ie blepharitis, dry eye), decreasing stress or the dose of the causal medication may reduce symptoms.

Diagnosis

Diagnosis of benign essential blepharospasm is made clinically and it is a diagnosis of exclusion, having ruled out the presence of associated conditions. Neuroimaging is generally unrevealing and of limited use in the workup.

History

History is very important in making the diagnosis, and it also allows the clinician to distinguish between primary (essential) and secondary blepharospasm. In BEB, excessive blinking, which may start as unilateral and mild twitches, progresses to bilateral frequent and more forceful spasms. During severe episodes a patient may report the inability to pry the eyelids open. Episodes may interfere with the patient’s daily activities, such as reading and driving. The spasms disappear during sleep and may be reduced when concentrating on a specific task. In secondary etiologies, the patient may offer a history of drug use as with tardive dyskinesia, of ocular irritation from light or dry eye as in reflex blepharospasm, of associated facial grimacing as in Meige syndrome, or a history of  other abnormal movements such as tics or cogwheeling of the neck and extremities in extrapyramidal disease states.

Physical examination

The physician may observe involuntary contraction of multiple eyelid muscles (both protractors and retractors) during a spasm episode. Careful slit lamp examination for ocular causes and inspection for other twitches in the face or extremities must be undertaken.

Symptoms and Signs

Signs and symptoms in benign essential blepharospasm are limited to the bilateral eyelids. They usually begin as mild and infrequent twitches that progress over time to forceful and frequent spasms of the eyelids, which abate during periods of sleep. In advanced cases, these episodes can cause functional blindness from periodic inability to open the eyes. This can severely limit the patient's ability to preform activities of daily living and impart psychological stress. When blepharospasm is part of Meige's syndrome, it is associated with facial grimacing. Reflex blepharospasm may be accompanied by photophobia and ocular signs of blepharitis and surface disease.

Clinical diagnosis

The diagnosis of blepharospasm is clinical and is made by careful history taking and physical exam.

Diagnostic procedures

Benign essential blepharospasm is a clinical diagnosis and a diagnosis of exclusion. Neuroradiologic studies are generally unrevealing and rarely indicated in the workup.

Laboratory test

Laboratory tests have no utility in the diagnosis and workup of blepharospasm.

Differential diagnosis

  • Ocular myokymia
  • Secondary to ocular irritation (ie dry eyes, blepharitis, entropion, intraocular inflammation, photosensitivity)
  • Secondary to meningeal irritation (ie temporoparietal strokes)
  • Tardive dyskinesia (secondary to neuroleptic and antipsychotic drugs)
  • Meige syndrome (blepharospasm-oromandibular dystonia)
  • A symptom of systemic disease associated with lesions of the brainstem and basal ganglia (Parkinson's, Huntington's, Wilson's, progressive external ophthalmoplegia, progressive supranuclear palsy.)
  • Facial tics (Tourette syndrome)
  • Hemifacial spasm (contraction of the entire one side of the face)
  • Cerebral palsy
  • Functional (Focal brain injury or tumor)
  • Infections (viral encephalitis, Reye's syndrome, subacute sclerosing panencephalitis, Jakob-Creutzfeldt disease, AIDS, tuberculosis, tetanus).
  • Focal seizures


Management

Medical or surgical, with oral medications having limited usefulness. In secondary causes of blepharospasm, treat the underlying etiology.

  • Artificial tears should be recommended, as often the patients have dry eyes as well which can cause ocular irritation and additional reflexive blepharospasm.
  • Eyelid scrubs with baby shampoo or other non-irritating soap can minimize any blepharitis that can also aggravate blepharospasms.
  • Dark sunglasses (FL-41 tinted) can also minimize light sensitivity (photophobia)/ bright light triggers, and thus minimize spasms.

Medical therapy

First line

  • Periodic injection of a botulinum toxin A (onabotulinumtoxinA - Botox, Allergan), incobotulinumtoxinA (Xeomin, Merz Pharmaceuticals), or abobotulinumtoxinA (Dysport, Tercica) is the treatment of choice for BEB
  • Botulinum toxin injection is directed into or adjacent to the orbicularis oculi muscle, every 3-4 months.
  • The dosage varies from 2.5 to 5 units per injection site and 4 to 8 sites per eye.
  • Average onset of action is in 2-3 days and average peak effect occurs at about 7-10 days, with duration of 3-4 months, at which time need for reinjection is anticipated.

Second line

  • Oral medications such as muscle relaxants and sedatives are rarely effective in the treatment of BEB. They may dampen symptoms of mild BEB or possibly prolong intervals between injections, but their side effects must be considered alongside their benefits.
  • Use of FL-41 tinted glasses (rose-colored) may also be helpful in those patients who have significant photosensitivity.
  • Some studies have suggested improvement of spasms with methylphenidate (ritalin), although additional controlled studies are needed.
  • Reduce stress
  • Some patients note benefits with acupuncture or herbal supplements

Medical follow up

1 month after botulinum injections, and if no complications observed, then every 3-4 months for reinjection.

Surgery

Surgery is reserved for patients who are poorly responsive to botulinum therapy and are disabled by their symptoms. Patients with apraxia of eyelid opening may often proceed to surgery as chemodenervation with botulinum toxin is less effective. Surgical myectomy of the orbital and palpebral orbicularis muscle in the upper (and sometimes lower) eyelids as well as surgical ablation of the facial nerve are effective in treating BEB. However, the latter procedure has been mostly abandoned owing to high recurrence rates incidence of hemifacial paralysis.    
Surgery in patients with apraxia of eyelid opening may require a frontalis sling rather than a levator repair to help elevated the eyelids.

Complications

Complications associated with botulinum toxin injection include:

  • Bruising, blepharoptosis, ectropion, epiphora, diplopia, lagophthalmos, and corneal exposure.
  • These are all usually transient and related to spread of the toxin to adjacent muscles.
  • The central portion of the pretarsal orbicularis is avoided to minimize the chance of inducing ptosis.

Prognosis

90% improve symptomatically with botulinum injections, although continued injections are necessary.
Patients with apraxia of eyelid opening often do not respond as well to injections.

Other considerations

Symptoms of BEB can progress to render a person incapable of activities of daily living, such as reading and driving, and cause an unwanted cosmetic effect. The psychological distress is a real part of the disease and patient education, counseling, and support is as valuable as medical treatment.

Additional Resources

References

  1. Orbit, Eyelids, and Lacrimal System, Section 7. Basic and Clinical Science Course, AAO, 2011-2012.
  2. Neuro-Ophthalmology, Section 5. Basic and Clinical Science Course, AAO, 2011-2012.
  3. Ben Simon GJ, McCann JD. Benign essential blepharospasm. Int Ophthalmol Clin. 2005;45(3):49-75.
  4. Anderson RL, Patel BC, Holds JB, Jordan DR. Blepharospasm: past, present, and future. Ophthal Plast Reconstr Surg. 1998;14(5):305-317.
  5. Hallett M, Evionger C, Jankovic J, Stacy M. Update on blepharospasm. Report from the BEBRF International Workshop. Neurology.2008;71(16):1275-1282.
  6. Defazio G, Martino D, Abbruzzese G, et al. Influence of cigarette smoking and coffee drinking on the risk of primary late onset blepharospasm: evidence from a multicenter case control study. J Neurol Neurosurg Psychiatry. 2007;78(8):877-879.
  7. Hall TA, McGwin G, Searcey K, et al. Benign essential blepharospasm: risk factors with reference to hemifacial spasm. J Neuroophthalmol. 2005;25(4):280-285.
  8. Dutton JJ, Fowler AM. Botulinim toxin in ophthalmology. Surv Ophthalmol. 2007;52(1):13-31.
  9. Georgescu D, Vagefi MR, McMullan TF, McCann JD, Anderson RL. Upper eyelid myectomy in blepharospasm with associated apraxia of lid opening. Am J Ophthalmol. 2008;145(3):541-547.
  10. Whitney CM. Benign essential blepharospasm. The Neurologist.2005;11(3):193-194.
  11. Blackburn MK, Lamb RD, Digre KB, et al. FL-41 tint improves blink frequency, light sensitivity, and functional limitations in patients with benign essential blepharospasm. Ophthalmology. 2009 May;116(5):997-1001