Benign Essential Blepharospasm

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Background

Blepharospasm is a focal cranial dystonia characterized by increased blinking and involuntary eyelid closure. A dystonia is a movement disorder that causes the muscles to contract and spasm involuntarily.

The first record of blepharospasm and lower facial spasm was found in the 16th century in a painting titled De Gaper. At that time, and for several ensuing centuries, patients with such spasms were regarded as being mentally unstable and often were institutionalized in insane asylums. Little progress was made in the diagnosis or treatment of blepharospasm until the early 20th century, when Henry Meige (pronounced "mehzh"), a French neurologist, described a patient with eyelid and midface spasms, spasm facial median, a disorder now known as Meige syndrome.[1] At about the same time, the first medical treatments became available, including alcohol injections into the facial nerve, facial nerve avulsion, neurotomy, and neurectomy. The adverse effects of these treatments, including loss of facial expression and movements, functional and cosmetic deformities of ptosis, and eyelid malposition, were often as bad as the disease.

Pathophysiology

Blepharospasm is now recognized as a neuropathologic disorder, rather than psychopathologic, as was once believed. The cause of blepharospasm is multifactorial. Although it is likely that a central control center for coordination and regulation of blink activity exists, somewhere in the basal ganglia, midbrain, and/or brain stem, it is unlikely that a single defect in this elusive control center is the primary cause of this disease.[2, 3, 4, 5, 6, 7, 8, 9]

Blepharospasm is a network defect in dynamic circuit activity, rather than a defect at a specific locus.[10, 11] Fayers et al have found a decrease in corneal sensitivity in patients with blepharospasm, implying an impairment in cortical processing of sensory input, with a resultant loss of blink reflex inhibition.[12]

If the central control center fails to regulate blinking in blepharospasm, it is believed to be only one component of an overloaded, defective circuit. This circuit forms a blepharospasm vicious cycle, which has a sensory limb, a central control center located in the midbrain, and a motor limb. The sensory limb responds to multifactorial stimuli, including light, corneal or eyelid irritation, pain, emotion, stress, or various other trigeminal stimulants. These stimuli are transmitted to the central control center, which may be genetically predisposed or weakened by injury or age. This abnormal central control center fails to regulate the positive feedback circuit. The motor pathway is composed of the facial nucleus, facial nerve, and orbicularis oculi, corrugator, and procerus muscles. Other facial muscles also may be involved.

The photophobia associated with blepharospasm may be related to dry eyes and the melanopsin-containing intrinsically photosensitive retinal ganglion cells.

Epidemiology

Frequency

United States

It is estimated that there are at least 50,000 cases of blepharospasm in the United States, with up to 2000 new cases diagnosed annually. The prevalence of blepharospasm in the general population is approximately 5 in 100,000.

Mortality/Morbidity

At one end of the clinical spectrum, essential blepharospasm is manifested by simple increased blink rate and intermittent eyelid spasms, while at the other end of the spectrum, blepharospasm is a disabling condition with ocular pain and functional blindness. Patients may report that they are disabled to the point where they have stopped watching television, reading, driving, and/or walking. Patients may develop anxiety, avoid social contact, become depressed, become occupationally disabled, and become suicidal.[13, 14, 15]

Sex

Blepharospasm has a female-to-male preponderance of 1.8:1.

Age

The mean age of onset of blepharospasm is 56 years, and two thirds of patients are age 60 years or older.[16]

Prognosis

Botulinum toxin and myectomy help to control blepharospasm but may not cure it.

Botulinum toxin A is a safe, long-term treatment for patients with benign essential blepharospasm, but sustained treatment efficacy may require higher doses in later stages of the disease.[17]

Botulinum toxin injections are sometimes still required following myectomy of the eyelid protractors.

Patient Education

Inform patient and family of the BEBRF.

For excellent patient education resources, see eMedicineHealth's patient education article BOTOX® Injections.

History

At onset, blepharospasm is characterized by increased frequency of blinking, particularly in response to various common stimuli, including wind, air pollution, sunlight, noise, movements of the head or eyes, and in response to stress or the environment.[18, 19, 20, 21, 22] Patients may complain of photophobia and ocular surface discomfort, and especially of dry eye symptoms.[23] These symptoms progress over a variable period to include involuntary unilateral spasms, which later become bilateral.[24]

Patients may report that they are disabled to the point where they have stopped watching television, reading, driving, and/or walking. A family history positive for dystonia or blepharospasm further aids in the diagnosis.[25]

Blepharospasm commonly is associated with dystonic movements of other facial muscles. Anatomic changes associated with long-standing blepharospasm include eyelid and brow ptosis, dermatochalasis, entropion, and canthal tendon abnormalities.

The early symptoms of blepharospasm include increased blink rate (77%), eyelid spasms (66%), eye irritation (55%), midfacial or lower facial spasm (59%), brow spasm (24%), and eyelid tic (22%).

Symptoms commonly preceding diagnosis include tearing, eye irritation, photophobia, and vague ocular pain. While these complaints are common in the average ophthalmology practice, awareness of this disorder and proper suspicion may aid in early diagnosis.

Conditions relieving blepharospasm included sleep (75%), relaxation (55%), inferior gaze (27%), artificial tears (24%), traction on eyelids (22%), talking (22%), singing (20%), and humming (19%).

Comorbid diagnoses include dry eyes (49%) and other neurologic disease (8%).[26, 27]

Physical

In normal blinking, eyelid closure is the result of activity and co-inhibition of 2 groups of muscles, the protractors of the eyelids (ie, orbicularis oculi, corrugator superciliaris, procerus muscles) and the voluntary retractors of the eyelids (ie, levator palpebrae superioris, frontalis muscles). During the normal blink, the protractors and retractors have co-inhibition and function only at separate times. In patients with blepharospasm, this inhibition between the protractors and retractors is lost.

Causes

A specific etiology for blepharospasm has yet to be identified. Some patients with blepharospasm report a familial occurrence of the affliction. In families with autosomal dominant familial dystonia, affected members may have a generalized or segmental dystonia, while other members have various focal dystonias, such as isolated blepharospasm.

A study by DeFazio et al examined the first-degree relatives of 122 patients with primary blepharospasm. The study investigated genetic and environmental connections regarding the disorder and found no major difference between familial and sporadic cases with regard to coffee drinking and existing eye diseases. These findings suggest that sporadic and familial blepharospasm most likely has a commonality in etiologic background and influences of environmental factors.[28]

Wabbels has reported a single case of congenital blepharospasm.[29]

Zhou et al used functional MRI (fMRI) to identify abnormal neurological pathways in 9 patients with benign essential blepharospasm compared with controls.[30]

Complications

Complications of benign essential blepharospasm may include the following:

Laboratory Studies

No laboratory studies are required to diagnose, evaluate, or treat blepharospasm.

Imaging Studies

No imaging study is necessary to diagnose, evaluate, or treat blepharospasm.[32, 33]

MRI of postcranial fossa for hemifacial spasm may need to be performed.

Staging

No staging classification has been described for blepharospasm.

Medical Care

Blepharospasm is a chronic condition, which too often progressively worsens. Although no cure currently exists, patients have excellent treatment options. Since the disease frequently progresses despite treatment, patients may become frustrated and resort to unconventional remedies, sometimes becoming the victims of charlatans.[13]

The most effective of today's conventional treatments include botulinum toxin injections, education, and support provided by the Benign Essential Blepharospasm Research Foundation (BEBRF), pharmacotherapy, and surgical intervention. Unconventional treatments have included faith healing, herbal remedies, hypnosis, and acupuncture.

The first line of treatment for all patients should address the sensory limb of the blepharospasm vicious cycle circuit. Such measures include wearing tinted sunglasses with ultraviolet blocking to decrease the poorly understood cause of painful light sensitivity (photo-oculodynia).[34] Adams et al (2006) showed improved light sensitivity with gray and FL-41 tinted lenses,[35] and Blackburn et al (2009) showed the FL-41 tint improves blink frequency, light sensitivity, and functional limitations in patients with benign essential blepharospasm[36] .

Taping up the eyelids and ptosis crutches may be tried but are often not tolerated as a long-term treatment. Lid hygiene to decrease irritation and blepharitis should be encouraged. Frequent applications of artificial tears and punctal occlusion to alleviate dry eyes often improve symptoms.

Benign Essential Blepharospasm Research Foundation, formed in 1981, is a foundation established to undertake, promote, develop, and search for a cure for benign essential blepharospasm (BEB), Meige syndrome, and related disorders. This organization is located in Beaumont, Texas, and promotes awareness of these conditions to both physicians and the general public, organizes support groups throughout the world, and obtains funding for research and education.[37, 38, 39]

Pharmacotherapy

Since the central control center for blepharospasm is unknown, drug therapy directed against this as of yet unidentified center tends to follow a "shotgun approach." Historically, an extensive list of drugs has been used to treat blepharospasm, in part because blepharospasm initially was considered a manifestation of psychiatric illness, and because no one drug was demonstrably more efficacious than another. Recently, these psychoactive medicines have been used not for their psychotropic action but for their motor system action.

Most patients respond incompletely or not at all to pharmacotherapy. At best, pharmacotherapy provides only partial, transient relief. Patients react differently to the various pharmacologic agents, and there is no way to predict which patient may respond to any particular agent. Tricyclic antidepressants do not directly help blepharospasm but are useful if there is depression exacerbating the symptoms. Drugs with the highest percentages of favorable patient responses include lorazepam (67% of patients), clonazepam (42%), and Artane (41%). The relief provided by these agents is variable.

Although drugs from a variety of different classes have demonstrated some effectiveness in blepharospasm, drug therapy for blepharospasm and facial dystonias usually are based upon the following 3 unproven pharmacologic hypotheses: (1) cholinergic excess, (2) GABA hypofunction, and (3) dopamine excess. Pharmacotherapy is generally less effective than botulinum toxin injections and, thus, is reserved as second-line treatment for spasms that poorly respond to botulinum toxin, such as in mid-face and lower-face spasm.

Botulinum toxin

Botulinum A toxin is regarded as the most effective treatment of choice for the rapid but temporary treatment of orbicularis spasm.[40, 41, 42, 43, 44, 45, 46, 47, 48, 49] More than 95% of patients with blepharospasm report significant improvement with use of the toxin. The toxin interferes with acetylcholine (ACh) release from nerve terminals, causing temporary paralysis of the associated muscles. Botulinum A toxin is the product of the bacteria, Clostridium botulinum (a large anaerobic, gram-positive, rod-shaped organism). Two of the commercially available botulinum A preparations include onabotulinumtoxinA (Botox) and incobotulinumtoxinA (Xeomin). AbobotulinumtoxinA (Dysport) may also be effective.[50]

Once injected, the toxin rapidly and firmly binds at receptor sites on cholinergic nerve terminals in a saturable fashion. The toxin is internalized through the synaptic recycling process. Paralysis of muscle is a result of the inhibition of the release of vesicular ACh from the nerve terminal. It is assumed that the toxin attaches to the ACh-containing vesicles in the nerve terminal and prevents calcium-dependent exocytosis.

The paralytic effect is dose related, with a peak of effect at 5-7 days after injection. Patients typically note the onset of relief 2.5 days after injection, with a mean duration of relief from symptoms of 3 months. More than 5% of treated patients have sustained relief for more than 6 months, although some patients require injections as often as monthly. It takes as much as 6-9 months for the injected muscles to recover from the effects of the toxin, and, occasionally, muscles do not fully return to their preinjection level of function. Some have suggested that the development of antitoxin antibodies or the progressive atrophy of muscle may account for variations in the dose response curve, but no studies have supported these findings.

Tear breakup time (TBUT), lissamine green staining, and Ocular Surface Disease Index (OSDI) scores have all been shown to be improved after botulinum toxin injection.[51]

Complications of botulinum toxin injections include ptosis (7-11%), corneal exposure/lagophthalmos (5-12%), symptomatic dry eye (7.5%), entropion, ectropion, epiphora, photophobia (2.5%), diplopia (< 1%), ecchymosis, and lower facial weakness.[52, 53] One of the more common adverse effects, ptosis, is due to diffusion of toxin from the upper eyelid injection sites to the exquisitely sensitive levator muscle. The incidence of ptosis has been reported as high as 50% of patients treated more than 4 times. In the hands of experienced injectors, the rate of complications such as ptosis is presumably less. Injection of botulinum toxin into the medial and lateral pretarsal orbicularis is usually sufficient to stop spasms for the duration of effect; avoiding central injections to the preseptal and preorbital orbicularis should help reduce the risk of ptosis.

Meticulous technique in the administration of botulinum toxin helps ensure reliable and consistent results. BOTOX® should be hydrated with 0.9% nonpreserved saline, which should be introduced slowly into the vacuum-sealed vial to prevent frothing. If there is no vacuum in the BOTOX® bottle, it should not be used. Once reconstituted, the solution should be used immediately or kept refrigerated.

At the first treatment, use of a total dose of no more than 25 units per eye, divided among 4-6 periocular injection sites is recommended to avoid adverse effects. Subsequent treatments should be adjusted depending on patient response to the initial doses.[54] At each site, inject 2.5-10 units of BOTOX®. Use of lower volumes (higher concentrations) is suggested to avoid the risk of spread to adjacent areas. The solution should be injected subcutaneously over the orbicularis oculi and intramuscularly over the thicker corrugator and procerus muscles. Patients may return home without restrictions of activity. Most patients require repeated treatment every 3 months, but this ranges from 1-5 months.

Chundury et al found that patients who preferred treatment with incotulinumtoxinA felt that it was more effective, while those who preferred treatment with onabotulinumtoxinA felt that it had a longer duration.[55]

However, Saad and Gourdeau found in a “split-face” technique study that no difference was noted in either subjective or objective measures between the two toxins.[56]

Surgical Care

In patients with blepharospasm who do not develop sufficient improvement with an adequate trial of botulinum toxin injections, surgical intervention may be considered. The mainstay of surgical treatment of spasm of the orbicularis oculi is myectomy.[57, 58, 59, 60, 61, 62] An older procedure, neurectomy, has almost completely been abandoned because of a higher complication rate than seen with myectomy. Many patients with BEB have a component of apraxia of eyelid opening.[63, 64] It is estimated that almost 50% of patients who are considered failures of BOTOX® treatment have apraxia of eyelid opening. Frontalis suspension and limited myectomy with complete removal of the pretarsal orbicularis should be considered for patients who are visually disabled by apraxia of eyelid opening.

Patients may fail botulinum toxin therapy because they have eyelid malposition, aesthetic concerns, apraxia of eyelid opening, or photo-oculodynia. These conditions require surgeries in addition to or in place of myectomy.

Myectomy

Limited myectomy involves surgical extirpation of protractors of the eyelids, including the pretarsal, preseptal, and orbital portions of the upper and lower eyelid orbicularis oculi muscle. Extended myectomy includes removal of the procerus and corrugator muscles. Myectomy is a staged procedure with upper eyelid surgery typically performed first, followed by lower eyelid surgery if symptoms persist. Simultaneous upper and lower eyelid myectomy is avoided because it typically leads to chronic lymphedema.

Many patients with BEB have aesthetic concerns about eyebrow ptosis or forehead rhytids, which can be addressed safely at the time of myectomy by sculpting or repositioning of the retro-orbicularis oculi fat pad or by endoscopic forehead lift surgery.

Frontalis suspension

Karapantzou et al found that, in patients with blepharospasm, frontalis suspension was effective in patients in whom botulinum toxin injections alone were ineffective.[65]

Superior cervical ganglion block

Treatment of BEB focuses heavily on reducing the motor component of the disease. Remember that there is also a sensory loop of the disease, which is harder to quantify because it involves the patient's subjective complaints of ocular surface irritation and photosensitivity. In some patients in which BOTOX® treatment fails, a careful history and examination reveals that BOTOX® does reduce spasm and weaken the orbicularis muscle but does not relieve the sensory symptoms of the disease. For patients who complain of debilitating light sensitivity (photo-oculodynia) intervention by a pain clinic may benefit the patient.

Two reports have demonstrated reduction of photo-oculodynia after superior cervical ganglion blocks to chemodenervate the orbital sympathetics. These preliminary studies suggest that the sympathetic nervous system may play a role in maintaining the afferent loop of the disease.[66]

Interventions involving the globus pallidus

Deep brain stimulation of the globus pallidus internus and pallidotomy have been described for Meige syndrome.[67]

Long-Term Monitoring

Treatments such as botulinum toxin injections usually provide temporary relief from blepharospasm, and long-term follow-up care is needed.

Medication Summary

The goals of pharmacotherapy are to reduce morbidity and to prevent complications.

OnabotulinumtoxinA (Botox)

Clinical Context:  Treats excessive, abnormal contractions associated with blepharospasm. Binds to receptor sites on motor nerve terminals and inhibits release of ACh, which, in turn, inhibits transmission of impulses in neuromuscular tissue. It is indicated for the treatment of blepharospasm associated with dystonia in patients aged 12 years or older.

IncobotulinumtoxinA (Xeomin)

Clinical Context:  Botulinum toxin type A that is free of complexing proteins found in natural toxin from Clostridium botulinum. Acetylcholine release inhibitor and neuromuscular blocking agent. Indicated as first-line treatment for blepharospasm in adults.

Class Summary

Botulinum toxins help produce symptomatic improvement of orbicularis spasm and autonomic symptoms. The various botulinum toxins possess individual potencies, and care is required to ensure proper use and avoid medication errors, since they are not interchangeable. OnabotulinumtoxinA and incobotulinumtoxinA are both approved by the FDA for the treatment of blepharospasm.

What is benign essential blepharospasm (BEB)?What is the pathophysiology of benign essential blepharospasm (BEB)?What is the prevalence of benign essential blepharospasm (BEB) in the US?What is the morbidity associated with benign essential blepharospasm (BEB)?What is the sexual predilection of benign essential blepharospasm (BEB)?Which age groups have the highest prevalence of benign essential blepharospasm (BEB)?What is the prognosis of benign essential blepharospasm (BEB)?Which clinical history findings are characteristic of benign essential blepharospasm (BEB)?Which physical findings are characteristic of benign essential blepharospasm (BEB)?What causes benign essential blepharospasm (BEB)?What are the possible complications of benign essential blepharospasm (BEB)?Which conditions should be included in the differential diagnoses of benign essential blepharospasm (BEB)?What are the differential diagnoses for Benign Essential Blepharospasm?What is the role of lab testing in the workup of benign essential blepharospasm (BEB)?What is the role of imaging studies in the workup of benign essential blepharospasm (BEB)?How is benign essential blepharospasm (BEB) staged?How is benign essential blepharospasm (BEB) treated?What is the role of drug treatment for benign essential blepharospasm (BEB)?What is the role of botulinum A toxin in the treatment of benign essential blepharospasm (BEB)?What are the possible complications of botulinum A toxin in the treatment of benign essential blepharospasm (BEB)?How is botulinum A toxin administered in the treatment of benign essential blepharospasm (BEB)?What is the efficacy of botulinum A toxin for treatment of benign essential blepharospasm (BEB)?What is the role of surgery in the treatment of benign essential blepharospasm (BEB)?What is the role of myectomy in the treatment of benign essential blepharospasm (BEB)?What is the role of frontalis suspension in the treatment of benign essential blepharospasm (BEB)?What is the role of a superior cervical ganglion block in the treatment of benign essential blepharospasm (BEB)?What is the role of deep brain stimulation in the treatment of benign essential blepharospasm (BEB)?What is included in the long-term monitoring of patients with benign essential blepharospasm (BEB)?Which medications in the drug class Botulinum toxins are used in the treatment of Benign Essential Blepharospasm?

Author

Robert H Graham, MD, Consultant, Department of Ophthalmology, Mayo Clinic, Scottsdale, Arizona

Disclosure: Partner received salary from Medscape/WebMD for employment.

Specialty Editors

Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Chief Editor

Edsel Ing, MD, MPH, FRCSC, Associate Professor, Department of Ophthalmology and Vision Sciences, University of Toronto Faculty of Medicine; Active Staff, Michael Garron Hospital (Toronto East Health Network); Consulting Staff, Hospital for Sick Children and Sunnybrook Hospital, Canada

Disclosure: Nothing to disclose.

Additional Contributors

Ron W Pelton, MD, PhD, Private Practice, Colorado Springs, Colorado

Disclosure: Nothing to disclose.

Acknowledgements

The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous coauthor, Stanley M Saulny, MD, to the development and writing of this article.

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