History
A 56-year-old white female presented for an urgent visit with a chief complaint of a twitching eyelid. She had been seen in the past for seasonal ocular allergy and mild dry eye syndrome for which she was medicating with Pataday (olopatadine, Alcon) and artificial tears, as needed. She had no systemic history and denied any exposure to foreign body or harmful substances. She reported no allergies to any medication.  

Diagnostic Data
Her best-corrected visual acuity was 20/20 OU. External examination was normal with no evidence of afferent defect. Observation during the history revealed intermittent quivering and twitching of the temporal aspect of the right superior eyelid. 

Refraction uncovered mild hyperopia with negligible changes to her habitual spectacle prescription. Biomicroscopy revealed normal lids and lashes OU with normal anterior segment structure. 

Intraocular pressure (IOP) was measured at 16mm Hg. A dilated funduscopic examination found quiet grounds and normal posterior poles in both eyes. 

Your Diagnosis
Does this case require any additional tests? What does this patient’s history and clinical findings tell you about her likely diagnosis? How would you manage this patient? 

This 56-year-old patient suffers from seasonal allergies and mild dry eye symptoms, but her chief complaint is an annoying eyelid twitch. Can you identify her diagnosis?

Additional Testing
Additional testing might include lid eversion to rule out an undiscovered foreign body or conjunctival changes such as papillae or follicles constent with exposure to an allergen.  Sodium fluorescein staining could be used to insure an absence of occult corneal insult. 

Diagnosis
The diagnosis in this issue, by exclusion is eyelid myokymia. Eyelid myokymia is a general term connoting complex, involuntary, repetitive electrical discharges surrounding any motor unit (muscle) within the body.¹ With respect to the eye, it is known to primarily affect two structures, the superior oblique muscle, producing a jerk vertical nystagmus, ocillopsia (the perception that the world is moving) and transient diplopia and the eyelid.^2-5 

Myokymia of the eyelid results when repetitive bursts of discharges stimulate the muscle of muller and the ciliary portion of the orbicularis oculi to “oscillate,” “vibrate,” “flicker,” “quiver,” “twitch” or other similar descriptor.⁵ While most patients perceive the unexpected quiverings as an annoyance, the seizures are not painful nor are they so exaggerated that the layman can identify an episode without being within three feet and directly looking at the moving area. Myokymia occurs cyclically seemingly arising at times of increased stress. Patients may be aware or unaware of their body’s emotional fluctuations, physical fatigue or illness. The episodes are transient, lasting from one to 10 minutes and can occur one time or multiple times during the day for weeks to months. As the individuals return to homeostasis, the episodes cease and the phenomenon moves into “hibernation,” waiting for the next opportunistic trigger.²

Traditionally, involuntary, spastic twitching of muscles has been attributable to either tissues recovering from injury, demyelinating disease, neural response to compression or neural response to irritation.^1,4-7 In a study that examined acute unilateral facial paralysis, transient long-lasting motor dysfunction, featuring disorders of voluntary and involuntary movement was observed.⁷ It seems that after an injury (in this instance the insulted muscles that were studied were around the face) some patients exhibited an increase in their spontaneous blink rate as well as a sustained low-level contraction of the muscles of the nonparalyzed side.^6,7 This occasionally lead to full blepharospasm.⁷ The finding was hypothesized to be due to increased excitability of the facial motor neurons and brainstem interneurons mediating reflexes.^6,7 As one recognized mechanism of occurrence, full-blown “postparalytic” facial syndrome has been described as levels of muscular synkinesis (muscles responding together), myokymia (involuntary muscular spasm) and unwanted hemifacial contractions accompanying normal facial movements.^6,7 Pathophysiological mechanisms include abnormal axonal branching after injury with aberrant axonal regeneration and enhanced motoneuronal excitability.^6,7

Myokymia of the of the eyelid can also be a benign, self-limited disorder, with no relation to injury or paralysis.^2,3 In a study of 15 patients examined between 1983 and 2002 with a diagnosis of isolated eyelid myokymia where the patients in the study 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 were cleared of the any manifestation of neurologic disease.² Thirteen of the 15 patients (86.7%) underwent neuroimaging demonstrating negative results.² In the grouping of 13 patients, the myokymia resolved spontaneously in 4 and 8 were treated with botulinum toxin injection at regular intervals, with most reporting improvement.²

Patients who pose the question in passing, “Why does my eyelid twitch sometimes,” are more than likely experiencing benign eyelid myokymia. The diagnosis can be solidified by confirming the presence of the classic clinical features; episodic, limited to the eyelid, painless, no effect on functioning, comes and goes during the day, seems to come in a cyclic monthly pattern, recollection of other previous symptoms with a repeatable profile. Patients should be educated that the condition has a name and they should be reassured that in almost all instances it is harmless. They should be counseled regarding signs which indicate the need for additional work up. Treatment may include modalities as simple as observation rest, cold compresses, tonic water with quinine (anecdotal), removal of the inciting stress and progress to medicinal solutions such as topical beta blockers, anticonvulsants such as carbamazepine 100-200 mgs PO BID-QID as tolerated (minimum medicine to desired effect), gabapentine 100 mgs PO BID building to 300-600 mgs per day or local injections of botulinum toxin.^2-7

Chronic isolated eyelid myokymia is generally considered a benign condition. It tends not to progress to other facial muscles nor elaborate into other facial movements or disorders. Excessive benign eyelid myokymia responds well to botulinum toxin injection. Eyelid myokymia is rarely associated with other neurologic disease. Unfortunately, eyelid twitching can be a localized manifestation of underlying brainstem disease making persistent cases of myokymia a diagnosis of exclusion. Finally, Postparalytic facial dysfunction" may occur following idiopathic facial nerve palsy (Bell’s palsy). It seems to be the result of increased background muscle activity and enhance motor neuron recruitment.

This patient was educated to the facts regarding eyelid myokymia and advised to use cold compresses to quell the focal activity. The patient was also advised the that tonic water with quinine also has had some positive anecdotal responses and that it could be located at any grocery store in the carbonated beverage isle.

1. Mancias P, Butler IJ. Trigeminal myokymia in a young girl. J Child Neurol. 2003; 18(8):572-4.
2. Banik R, Miller NR. Chronic myokymia limited to the eyelid is a benign condition. J Neuroophthalmol. 2004;24(4):290-2.
3. Rubin M, Root JD. Electrophysiologic investigation of benign eyelid twitching. Electromyogr Clin Neurophysiol. 1991;31(6):377-81.
4. Straube A. Therapeutic considerations for eye movement disorders. Dev Ophthalmol. 2007;40:175-92.
5. Foroozan R, Buono LM, Sergott RC et al. Jumping Jack Flash. Surv Ophthalmol. 2006;51(1):63-7.
6 Valls-Solé J, Montero J. Movement disorders in patients with peripheral facial palsy. Mov Disord. 2003;18(12):1424-35.
7. 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.