Myokymia

An involuntary, spontaneous, localized rippling or quivering of skeletal muscle fibers involving small motor units, producing visible fine contractions that are generally insufficient to cause joint movement or displacement of the affected limb.

Causes

• Physiological and lifestyle causes

  • Stress

  • Anxiety

  • Fatigue

  • Physical exhaustion

  • Sleep deprivation

  • Excessive caffeine intake

  • Excessive alcohol consumption

• Ocular causes (for eyelid involvement)

  • Eye strain due to prolonged screen time

  • Dry eye disease

  • Ocular surface irritation

  • Prolonged visual concentration

• Electrolyte and metabolic causes

  • Hypokalemia

  • Hypomagnesemia

  • Hypocalcemia

  • Dehydration

• Neurological causes

  • Peripheral nerve hyperexcitability syndromes

  • Multiple sclerosis

  • Brainstem tumor

  • Radiation-induced nerve damage

  • Peripheral nerve injury

  • Motor neuron disease (rare)

• Medication and substances increasing neuromuscular excitability

  • Stimulant medications

  • Sympathomimetic agents

  • Drug withdrawal states

• Other causes

  • Benign fasciculation syndrome

  • Hyperthyroidism

  • Vitamin B12 deficiency

  • Idiopathic fasciculations