The differential diagnosis for acute dystonias is:
- Dislocated mandible
- Hyperventilation
- Hypocalcaemia and hypomagnesaemia
- Primary neurological cause: temporal lobe epilepsy, meningitis, stroke, Wilson’s disease
- Tetanus
- Toxicity:
- Strychnine poisoning (spontaneous tonic-clonic contractions as well as extensor thrust provoked by external stimuli)
- Anti-cholinergic agents (agitation and restlessness)
- Drug seeking behaviour: there are reports of patients who misuse anticholinergics and present to the ED feigning a dystonic reaction to obtain their drug of abuse.