Acute dystonia occurs in 10% of patients treated with anti psychotics (dopamine receptor antagonist). It is most common in young adults and develops abruptly within days of starting treatment and is accompanied by anxiety.

Presents with abnormal positioning of head and neck (retrocollis, torticollis), abnormal positioning of limbs or trunk, spasms of jaw muscles (trismus, gaping, grimacing), tongue dysfunction (dysarthria, protrusion), dysphagia, laryngo-pharyngeal spasm, dysphonia, eye deviated up, down or sideways (oculogyric crisis).

Drug-Induced Movement Disorders. Twycross R, Wilcock A (Ed). Palliative Care Formulary. Third Edition,. Palliativedrugs.com Ltd, United Kingdom. 2007, pp. 545-548.