Myokmia

Overview
Myokmia is an involuntary and continuous Myoclonus (muscle twitch) that affects the muscles of the face, particularly the eyelids, as a result of the random firing of neurons leading into the muscle fibres.

Differential diagnosis of causes of myokmia
It is mainly caused by a lack of sleep, or increased intake of nicotine, caffeine, or by stress. However, Myokmia can also or rare occasions be a pathognomonic symptom of lesions on the brain stem, multiple sclerosis or pontine glioma.

However, these causes are extremely rare, with only 2 out of 132 cases of Myokmia diagnosed at Seth G.s. Medical College in Bombay being caused by such lesions.