Myokymia — Simple Condition, Complicated Treatment
BY LEO SEMES, OD, FAAO
As one who is occasionally afflicted with myokymia, or lid twitching, I thought that I would share my experiences with managing this condition. Myokymia can result in significant self-consciousness. Although of minimal significance to a casual observer, the patient (victim) typically sees a different picture.
Myokymia is spontaneous contracture of the eyelid muscles, typically the orbicularis. The condition is usually unilateral and more frequently involves the lower lid. It is usually benign and self-limiting. Rarely it can be a precursor to blepharospasm or hemi-facial paresis.
A history of stress, fatigue, and excessive caffeine or alcohol intake may be present. Minimizing or eliminating these potential triggers may be a first step.
Problems With a Common Treatment
One previously available remedy for symptomatic patients was an over-the-counter medication containing quinine. Unfortunately, the FDA removed such medications from OTC distribution on Dec. 11, 2006 for reasons including the fine distinction between therapeutic and potentially lethal doses. In addition, its use in treating leg cramps had resulted in such adverse effects as cardiac arrhythmia, renal failure, and vision and hearing loss as well as blood disorders including thrombotic thrombocytopenia purpura and thrombocytopenia. The FDA had recorded 655 adverse events from 1969 to 2006, among which were 93 deaths thought to be attributable to quinine dosing. While these are rare events, the outcomes can be significant.
The FDA now relegates quinine usage to malaria treatment. Qualaquin (324mg quinine sulfate capsule, AR Scientific) is FDA-approved for the treatment (not the prophylaxis) of malaria. There are specific disclaimers in the package insert for its use for leg camps, which have a similar mechanism to lid twitch. It is available only by prescription.
Until the FDA order in 2006, generic quinine sulfate tablets were available in 230mg doses. These could be prescribed for half-dose administration, which I recommended at bedtime as a one-time solution, for example.
Alternative sources include quinine water (50mg to 75mg per liter) and some so-called energy drinks (variable). The latter typically contain caffeine and have a high sugar content, so recommending this as a quinine source may be counterproductive. Toxic doses are generally in the rage of above 2g/day.
Alternative Treatment Options
Topical antihistamines have been recommended, but no controlled studies are available that have shown predictable, positive results. The theoretical mechanism is to prolong the refractory period or to reduce the excitability of the orbicularis muscle endplates. The effect typically occurs about 20-to-30 minutes following topical administration to the inferior conjunctival cul-de-sac.
One case report in the literature suggests the use of betaxolol 0.25% drops (Betoptic-S, Alcon) administered twice per day for the rare condition of superior oblique myokymia. Extension to eyelid myokymia application may be worthy of exploration. The caveat would be that all beta-blockers have some systemic absorption and are contraindicated in patients who have cardiopulmonary prohibitions.
Botulinum toxin (Botox, Allergan) administered by subcutaneous injection is an alternative when facial spasm is diagnosed and may be an alternative of last resort when “tincture of time, reassurance, rest, and relaxation“ are insufficient to quell symptoms and signs. CLS
Dr. Semes is a professor of optometry at the University of Alabama at Birmingham School of Optometry.