Frequent contributing factors include: too much caffeine, high levels of anxiety, fatigue, dehydration, stress, overwork, and a lack of sleep. Use of certain drugs or alcohol may also be factors, as can magnesium deficiency. It can be also seen in patients with multiple sclerosis.
Myokymia
Euthymia 
Strephosymbolia
Kleptomania
Dysthymia
Klazomania
Congenital athymia
Cyclothymia