Blepharospasm is a neurological disorder characterized by intermittent, involuntary spasms and contractions of the
orbicularis oculi (eyelid) muscles around both eyes.
These result in abnormal twitching or blinking, and in the extreme, sustained eyelid closure resulting in functional blindness.
The word blepharospasm is derived from the Greek: βλέφαρον / blepharon, eyelid, and σπασμός / spasmos, ''
spasm
A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder.
A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a musc ...
,'' an uncontrolled muscle contraction. The condition should be distinguished from the more common, and milder, involuntary quivering of an eyelid, known as
myokymia or
fasciculation
A fasciculation, or muscle twitch, is a spontaneous, involuntary muscle contraction and relaxation, involving fine muscle fibers. They are common, with as many as 70% of people experiencing them. They can be benign, or associated with more seriou ...
.
Blepharospasm is one form of a group of movement disorders called
dystonia
Dystonia is a neurology, neurological Hyperkinesia, hyperkinetic Movement disorders, movement disorder in which sustained or repetitive muscle contractions occur involuntarily, resulting in twisting and repetitive movements or abnormal fixed po ...
.
It may be a primary or secondary disorder. The primary disorder is benign essential blepharospasm, in which term the qualifier ''essential'' indicates that the
cause is unknown. Blepharospasm may occur as secondary to conditions including dry eyes and other specific ocular disease or conditions,
Meige's syndrome and other forms of dystonia, and
Parkinson's disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
and other movement disorders.
Blepharospasm occurs in middle age and is more frequent among women than men. The most common treatments are medication and periodic injections of
botulinum toxin
Botulinum toxin, or botulinum neurotoxin (commonly called botox), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon en ...
into the eyelid muscles.
Epidemiology
Blepharospasm is a fairly rare disease. Estimates of incidence and prevalence vary, tending to be higher in population studies than service studies, likely because of delays in diagnosis.
In the United States, approximately 2,000 new cases of blepharospasm are diagnosed each year.
Estimates of incidence per million persons-years range from 14.5 in Northern California
to 100 in Taiwan.
Estimates of prevalence per million range from 12 in Olmsted County, Minnesota to 133 in Puglia, Southern Italy.
The onset of blepharospasm tends to be during the ages 40–60.
The condition is roughly more than twice as frequent among females than males,
which may be related to menopause and hormone treatments.
In Taiwan, the condition is more frequent among white- than blue-collar workers.
Signs and symptoms
Blepharospasm usually begins with occasional twitches of both eyelids, which progress over time to forceful and frequent spasms and contractions of the eyelids. In severe episodes, the patient cannot open their eyelids (apraxia), which severely limits their daily activities. Prolonged closure of the eyelids may result in functional blindness.
Patients suffering from blepharospasm also report sensory symptoms including sensitivity to light, dry eyes,
and burning sensation and grittiness in the eyes.
Although such symptoms tend to precede the onset of the blepharospasm, they may both be due to a common third factor.
Typically, the symptoms—spasms and contractions of the eyelids—tend to worsen when the patient relaxes but abate during sleep.
The symptoms may be temporarily alleviated by sensory tricks (geste antagoniste) including stretching or rubbing the eyebrows, eyelids, or forehead, and singing, talking, or humming. Blepharospasm is aggravated by fatigue, stress, and environmental factors such as wind or air pollution.
Although blepharospasm is defined as a bilaterally symmetric disorder that affects both eyes, some research has reported unilateral onset.
Causes
Historically, it was believed that blepharospasm was due to the abnormal functioning of the brain's
basal ganglia
The basal ganglia (BG) or basal nuclei are a group of subcortical Nucleus (neuroanatomy), nuclei found in the brains of vertebrates. In humans and other primates, differences exist, primarily in the division of the globus pallidus into externa ...
. The basal ganglia are structures in the brain that are involved in the regulation of motor and reward functions.
However, blepharospasm is now known to involve several regions of the brain and to be a multifactorial condition in which "one or several as yet unknown genes together with epigenetic and environmental factors combine to reach the threshold that induces the disease".
Blepharospasm is often associated with dry eyes, but the causal mechanism is still not clear.
Research in New York and Italy suggests that increased blinking (which may be triggered by dry eyes) leads to blepharospasm.
A case control study in China found that blepharospasm aggravated dry eyes.
Blepharospasm may be associated with dystonia in other parts of the body, particularly
Meige's Syndrome.
Blepharospasm may be associated with
Parkinson's Disease
Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...
, but the causal mechanism is still not clear. In rare cases, blepharospasm is associated with
multiple sclerosis
Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...
.
Some drugs can induce blepharospasm, including those used to treat depression
and Parkinson's disease.
Hormone replacement therapy
Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. Effects of menopause can include symptoms such ...
for women going through menopause has been found to be associated with dry eyes,
which in turn is associated with blepharospasm.
Blepharospasm can be caused by
concussion
A concussion, also known as a mild traumatic brain injury (mTBI), is a head injury that temporarily affects brain functioning. Symptoms may include headache, dizziness, difficulty with thinking and concentration, sleep disturbances, a brief ...
s in some rare cases, when a blow to the back of the head damages the basal ganglia.
Blepharospasm is associated with exposure to the sun.
Diagnosis
No laboratory tests exist with which to definitively diagnose blepharospasm. Historically, the condition was frequently misdiagnosed,
often as a psychiatric condition.
Diagnosis of blepharospasm has been enhanced by the proposal of objective diagnostic criteria that start from "stereotyped, bilateral and synchronous orbicularis oculi spasms" and proceed to the identification of a "sensory trick" or "increased blinking". The criteria have been validated across multiple ethnicities in multiple centers.
Treatment
Standard first line treatments of blepharospasm are conservative therapies, oral medication, and periodic injections of
botulinum toxin
Botulinum toxin, or botulinum neurotoxin (commonly called botox), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon en ...
.
Particularly when associated with dry eyes, blepharospasm may be relieved with warm compresses, eye drops, and eye wipes. A Japanese study showed that warm compresses containing menthol were more effective in increasing tear film.
Drugs used to treat blepharospasm are
anticholinergic
Anticholinergics (anticholinergic agents) are substances that block the action of the acetylcholine (ACh) neurotransmitter at synapses in the central nervous system, central and peripheral nervous system.
These agents inhibit the parasympatheti ...
s,
benzodiazepine
Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...
s,
baclofen, and
tetrabenazine.
The proportion of patients who benefited from anticholinergics ranged from 1 in 9 in Oregon to 1 in 5 in England.
Besides failing to resolve the blepharospasm, some drugs present the risk of side effects. In Japan, use of etizolam and benzodiazepine was associated with the development of blepharospasm.
A case report from Sri Lanka suggests treatment with
Mosapride
Mosapride is a gastroprokinetic agent that acts as a selective 5HT4 agonist. The major active metabolite of mosapride, known as M1, additionally acts as a 5HT3 antagonist, which accelerates emptying throughout the whole of the gastrointestinal ...
.
The main first-line therapy is periodic injections of botulinum toxin type A to induce localized, partial paralysis of the eyelid muscles.
Injections are generally administered at intervals of around 10 weeks, with variations based on patient response and usually give fairly quick relief from the muscle spasms. An English study reported that 118 (78%) of 151 patients experienced significant relief of symptoms for a mean duration of 9.2 weeks.
However, in a minority of patients, the injections do not provide any symptomatic relief. Injections of botulinum toxin may diminish in effectiveness with prolonged use and require increased dosage. Injections of botulinum toxin increase the risk of visual complaints and
''ptosis'' (eyelid droop).
Patients who do not respond well to medication or botulinum toxin injections are candidates for surgical therapy. The most effective surgical treatment has been ''protractor myectomy'', the removal of muscles responsible for eyelid closure. Myectomy is more effective than distal neurectomy.
A case report from California suggests the use of intense pulsed light therapy to relieve blepharospasm. Patients suffering from blepharospasm may get relief by wearing spectacles fitted to lift the upper eyelid.
Among complementary therapies, two simulate sensory tricks: Attaching a device to spectacle frames to press on the patient's temple, and applying thin cosmetic tapes to the forehead and eyebrows. Another complementary therapy is retraining the brain to "rewire" itself and eliminate dystonic movements. Associated wit
Joaquin Farias sensorimotor retraining activities and proprioceptive stimulation aim to induce
neuroplasticity
Neuroplasticity, also known as neural plasticity or just plasticity, is the ability of neural networks in the brain to change through neurogenesis, growth and reorganization. Neuroplasticity refers to the brain's ability to reorganize and rewir ...
, making it possible for patients to recover substantial function that was lost due to blepharospasm.
[Farias, J., Sarti-Martínez, MA. Title: "Elite musicians treated by specific fingers motion program to stimulate propiceptive sense", ''Congreso Nacional De La Sociedad Anatómica Española'', Alicante (España), ''European Journal of Anatomy'', p. 110] Complementary therapies lack evidence of the highest quality (
Level 1 Level 1 may refer to:
Technology and standards
* Level 1 (National Qualifications Framework)
* level 1 cache, a type of CPU cache (Computer Memory)
* A Level I trauma center
* Level 1, a level of automation in a self-driving car (see Autonomous ...
).
Research
The U.S. National Library of Medicine maintains a register of clinical trials of therapies to trea
blepharospasm
Multimedia
Blepharospasm Research Foundation
* Victoria S. Pelak
Relationships of Blepharospasm to Ophthalmic Conditions such as Dry Eye BEBRF Symposium, August 6, 2016.
* Charles N.S. Soparkar
Blepharospasm and dry eyes BEBRF Symposium, September 9, 2017.
Complementary/alternative therapies Philadelphia, October 9, 2021
Neuroplasticity training
* Federico Bitti
"Dystonia. Rewiring the brain through movement and dance", TEDxNapoli* Joaquin Farias
"How your movements can heal your brain", TEDxNapolih1>
References
External links
American Academy of Ophthalmology: EyeWikiBenign Essential Blepharospasm Research FoundationClinicalTrials.govInternetmedicin (Swedish source for licensed doctors)National Eye InstituteNational Organization for Rare Disorders
{{CNS diseases of the nervous system
Extrapyramidal and movement disorders
Dystonia
Disorders of eyelid, lacrimal system and orbit