EYELID MYOKYMIA

Signs and Symptoms

The word myokymia is derived from the Greek words myo, meaning muscle, and kyma, meaning wave. It is defined by complex, involuntary, repetitive electrical discharges involving any muscle within the body.1 With respect to the eye, it is known to primarily affect two structures: the eyelid and the superior oblique muscle.1-3 Patients with superior oblique myokymia present with a vertical jerk nystagmus, oscillopsia (the perception that the world is moving) and transient diplopia.3-6 In contrast, patients with myokymia of the eyelid present with a chief complaint of intermittent “oscillating,” “vibrating,” “flickering,” “quivering” or “twitching” eyelid.3

Eyelid myokymia is the result of repetitive bursts of electrical discharge that stimulate the Muscle of Müller and the ciliary portion of the orbicularis oculi.1,7 While most patients perceive the unexpected quivering as an annoyance, the spasms are not painful, nor are they so exaggerated that an observer could identify an episode without being within a three-foot distance, directly looking at the affected area. In contrast, benign essential blepharospasm is a disorder involving involuntary and sustained contractions of the muscles around the eyes, often with forced closure.

Myokymia occurs cyclically and seems to arise at times of increased stress. Patients may be aware or unaware of their body’s emotional fluctuations, physical fatigue or illness. The episodes may also be connected to increased sympathetic tone, which can be voluntarily or unknowingly altered by cigarette smoking (nicotine), caffeinated drinks (coffee, tea, sports drinks, and energy-boosting supplements or drinks) and some medicines.8 The episodes are transient, lasting from one to 10 minutes, and can occur just once or multiple times during the day for weeks to months. During normal physical and emotional periods, the episodes cease and the phenomenon moves into “hibernation,” often recurring during or following a trigger.2

Pathophysiology

Traditionally, involuntary spastic twitching of muscles has been attributable to either (1) tissues recovering from injury, (2) demyelinating disease and neural response to compression, or (3) irritation.1,3,6,9 In a study that examined acute unilateral facial paralysis, transient long-lasting motor dysfunction featuring disorders of voluntary and involuntary movement was observed.10 It seems that, after an injury, some patients exhibit an increase in their spontaneous blink rate as well as a sustained low-level contraction of the muscles of the non-paralyzed side.9,10 This occasionally leads to full blepharospasm.10 The finding was hypothesized by the authors to be due to increased excitability of the facial motor neurons and brainstem interneurons mediating reflexes.9,10

As one recognized mechanism of occurrence, full-blown “postparalytic facial syndrome” has been described as levels of muscular synkinesis (muscles responding together), myokymia and unwanted hemifacial contractions accompanying normal facial movements.9,10 Pathophysiological mechanisms include abnormal axonal branching after injury with aberrant axonal regeneration and enhanced motor neuronal excitability.9,10

Myokymia of the eyelid is generally considered to be a benign, self-limiting disorder, with no relation to injury or paralysis.2 In a study of 15 patients with a diagnosis of isolated eyelid myokymia where the patients had at least 12 months of follow-up, all patients whose symptoms began as unilateral, weekly or biweekly intermittent eyelid spasms with progression to daily spasms over several months demonstrated no manifestation of serious neurologic disease.2 Thirteen of the 15 patients (86.7%) underwent neuroimaging and no abnormalities were found; in this group of 13 patients, the myokymia resolved spontaneously in four individuals, with eight of the remaining nine opting to be treated with botulinum toxin injection at regular intervals. Most patients who elected to receive injections reported improvement.

Recently, several reports have suggested that eyelid myokymia may, in very rare instances, be a presenting sign of multiple sclerosis.7,8 The described patients were young and seemingly healthy individuals with no relevant medical history or known drug use. In one case, the eyelid myokymia gave way after several weeks to facial myokymia involving the ipsilateral brow and cheek; in another, the eyelid twitching persisted and became continuous, prompting neuroradiologic investigation. In both instances, periventricular white matter lesions were noted on MRI of the brain.7,8

Management

Patients who pose the question in passing, “Why does my eyelid twitch sometimes?” are most likely experiencing benign eyelid myokymia. The diagnosis can be solidified by confirming the presence of these classic clinical features in their history if they are described as: (1) episodic, (2) limited to the eyelid, (3) painless, (4) not affecting visual function, (5) intermittent throughout the day, (6) cyclical and (7) repeatable, in that the symptoms have occurred previously and that recurrences may happen when stress levels increase.

Patients should be educated that the condition has a name, and should be reassured that in almost all instances it is benign. They should be counseled regarding signs that would indicate the need for additional testing or consultation, such as persistence, worsening or involvement of other facial muscle groups. Since increased sympathetic tone, worsened from exogenous sources, can exaggerate or even instigate the problem, patients should be reminded that during stressful situations they often consciously or unconsciously increase energy drink, coffee, soda pop, tea and nicotine consumption, which can exacerbate the phenomenon. If a new medication has recently been introduced, it should be investigated for side effects.

Treatment for eyelid myokymia typically consists of behavior modification in the form of stress reduction, elimination of nicotine and/or caffeine, and rest. Direct forms of intervention may include discontinuation of provoking medications (where feasible), use of cold compresses or consumption of tonic water with quinine (based on anecdotal reports). In more severe or intolerable cases, pharmacologic intervention may be attempted with topical beta blockers, anticonvulsants such as carbamazepine (100mg to 200mg PO BID-QID) or gabapentin (100mg PO BID building to 300mg to 600mg per day), or local eyelid injections of botulinum toxin.2,3,6,10

Clinical Pearls

Chronic isolated eyelid myokymia is generally considered a benign condition. It tends not to progress to other facial muscles, nor to evolve into other facial movements or disorders. When these complications occur, the practitioner needs to be suspicious for more significant systemic disorders such as multiple sclerosis or neoplastic disease.

Excessive benign eyelid myokymia responds well to botulinum toxin injection.

Isolated eyelid myokymia is rarely associated with other neurologic disease. However, eyelid twitching can be a localized manifestation of underlying brainstem disease, making cases of persistent myokymia a diagnosis of exclusion.

Postparalytic facial dysfunction may occur following idiopathic facial nerve palsy (Bell’s palsy) and seems to be the result of increased background muscle activity and enhanced motor neuron recruitment.11

1. Banik R, Miller NR. Chronic myokymia limited to the eyelid is a benign condition. J Neuroophthalmol. 2004;24(4):290-2.

2. Mancias P, Butler IJ. Trigeminal myokymia in a young girl. J Child Neurol. 2003; 18(8):572-4.

3. Straube A. Therapeutic considerations for eye movement disorders. Dev Ophthalmol. 2007;40:175-92.

4. Williams PE, Purvin VA, Kawasaki A. Superior oblique myokymia: efficacy of medical treatment. J AAPOS. 2007;11(3):254-7.

5. Ruttum MS1, Harris GJ. Superior oblique myectomy and trochlear resection for superior oblique myokymia. Am J Ophthalmol. 2009;148(4):563-5.

6. Foroozan R, Buono LM, Sergott RC et al. Jumping Jack Flash. Surv Ophthalmol. 2006;51(1):63-7.

7. Palasí A, Martínez-Sánchez N, Bau L, Campdelacreu J. Unilateral eyelid myokymia as a form of presentation of multiple sclerosis. Neurologia. 2013;28(3):187-9.

8. Barmettler A, Dinkin MJ, Lelli GJ. Eyelid myokymia: not always benign. Orbit. 2011;30(6):289-90.

9. Valls-Solé J, Montero J. Movement disorders in patients with peripheral facial palsy. Mov Disord. 2003;18(12):1424-35.

10. Valls-Sole J, Tolosa ES, Pujol M. Myokymic discharges and enhanced facial nerve reflex responses after recovery from idiopathic facial palsy. Muscle Nerve. 1992;15(1):37-42.

11. Valls-Solé J. Facial nerve palsy and hemifacial spasm. Handb Clin Neurol. 2013;115:367-80.