Experimental Factor Ontology term EFO_1001381 (Nocturnal Paroxysmal Dystonia) is a parasomnia characterized by paroxysmal episodes of choreoathetotic, ballistic, dystonic movements, and semipurposeful activity. The episodes occur during non-rapid eye movement sleep and typically recur several times per night. (Neurology 1992 Jul;42(7 Suppl 6):61-67; Adams et al., Principles of Neurology, 6th ed, p391).