Blepharospasm is defined as an abnormal, involuntary, sustained and forceful closure or twitching of the eyelids. It is derived from the Greek word ‘blepharon’ which means eyelid, and ‘spasm’ which is an uncontrolled muscle contraction. Blepharospasm is usually associated with headaches, eyebrow strain and occasionally loss of vision. Isolated blepharospasm is rare and represents a minority of patients presenting with blepharospasm. Blepharospasm is commonly associated with lower facial spasms as part of a syndrome or disease complex. Some examples are:
- Meige Syndrome – characterized by spasm of the eyelids and midface.
- Brueghel’s Syndrome – presents with blepharospasm and marked spasms in the lower face and neck.
- Segmental Cranial Dystonia – in addition to the usual spasms of the eyelids and facial muscles, this is associated with spasms along distribution of various cranial nerves, most often involving the facial nerve.
- Generalized Dystonia – presents with spasms across various body parts in addition to blepharospasm and facial spasms.
Blepharospasm has had a dismal past in terms of historical misadventure. The earliest record of blepharospasm and lower facial spasm is a 16th Century painting called ‘De Gaper’ and during that period it was common practice to institutionalize those suffering from blepharospasm and lower facial spasm in mental asylums. This unfortunate practice continued for various centuries until major breakthrough was made in its diagnosis and treatment by Henry Meige, a French neurologist in the early 20th century. For his contribution, the symptom complex of eyelid and midface spasms with dystonia is given the eponym, Meige Syndrome. Henderson’s classic article on bleparospasm was published in 1956 and exhaustively described the disability with various treatment options.
Various treatment modalities such as alcohol injections into the facial nerve, facial nerve avulsion, neurotomy and neurectomy were developed during the same period but their results were often even more dreadful than the disease itself. However, recent developments in the treatment have shown marked improvement in the outcome of the disease.
Types of Blepharospasm
Blepharospasm occurs in two forms:
- Essential or spontaneous blepharospasm is a rare focal dystonia without any known cause and affects individuals between 45 and 65 years of age. Although idiopathic in nature, essential blepharospasm is commonly associated with stress, fatigue or an irritant. The symptoms may possibly be benign and transient or might cause significant lifelong challenges to the individual and even cause functional blindness in those rare cases.
- Reflex blepharospasm is due to reflex sensory stimulation through branches of the trigeminal nerve and is common in conditions like phlyctenular conjunctivitis, interstitial keratitis, corneal foreign body, corneal ulcers and iridocyclitis. Excessive stimulation of the retina by dazzling light, stimulation of facial nerve due to central causes, and some hysterical patients also present with reflex blepharospasm. It is due to any pain in and around the eye.
Pathophysiology of Blepharospasm
It is understood that blepharospasm is a neuropathologic disorder and not due to some psychopathology as was believed in the past. The cause of blepharospasm is multifactorial cannot be pin-pointed to a central regulatory area somewhere in the basal ganglia, midbrain or brainstem.
The current view is that blepharospasm occurs due to a defective circuitry and not just a defective focus. To understand this better we need to understand the circuit that controls blinking. The circuit consists of a sensory limb, a control center located in the midbrain, and a motor limb:
- Various stimuli such as corneal or eyelid irritation, pain, emotion, stress and other nerve stimulants trigger the sensory limb of the circuit.
- Sensory stimuli are transmitted to a defective control center in the midbrain which is weakened by age, injury or genetics. This defective center results in a failure to regulate the positive feedback mechanism.
- The abnormal positive feedback signals are unregulated in the motor pathway which causes uncontrolled contractions of various muscles in the distribution of facial nerve and its nucleus. The muscles commonly involved are orbicularis oculi, corrugator superciliaris and procerus of the eyelids and other muscles of facial expression ultimately resulting in contortion of the face and blepharospasm.
Clinical Presentation of Blepharopasm
The onset of blepharospasm is marked by a gradually progressive increase of blinking in response to innocuous stimuli like wind, polluted air, sunlight, noise, movements of the head or eyes, or exposure to any stressful environment. They also present with dry eye symptoms such as photophobia and eye irritation. Initially, it starts in one eye but progresses gradually to involve both eyes and even the facial and neck muscles. Symptoms may include: dry eyes, increased rate of blinking, spasms of the eyelids, irritation of the eyes, eye pain, midfacial or lower facial spasms, brow spasms, and/or eyelid tics. The following anatomic changes are seen with long-standing blepharospasm:
- Ptosis or drooping of the brow and eyelids
- Dermatochalasis otherwise called as “baggy eyes” due to loose skin
- Entropion or inward turning of the eyelids
- Canthal tendon abnormalities
Due to its rarity and its similarities with other diseases, blepharospasm i is often misdiagnosed. Following conditions should be considered in the differential diagnosis while evaluating a suspected case of blepharospasm:
- Bells Palsy
- Allergic conjunctivitis
- Eyelid myokymia
- Keratoconjunctivitis sicca
- Non-granulomatous anterior uveitis
At Idaho Eyelid and Facial Plastic Surgery, we have a number of non-surgical options to treat blepharospasm, including Botox and Dysport injections. Botulinum toxin injections work by disrupting the communication between nerve and muscle, thereby relaxing the overactive muscles that cause blepharospasm.
- Ptosis: Ptosis is may also be called Blepharoptosis. It refers to an eyelid which is droopy. This may possibly cause a loss of vision, especially while reading, headaches, and eyebrow strain.
- Lagophthalmos: Patients with lagophthalmos have an inability to close eyelids. This may possibly occur, for instance, in patients with Thyroid eye disease.
- Ectropion: Ectropion is when the eyelid turns out.
- Epiphora: Patients with epiphora complain of watery eyes; it is when there is an imbalance between production and drainage of tears.