Acute dystonias
Acute dystonia is a sudden-onset movement disorder characterised by sustained or repetitive involuntary muscle contractions producing abnormal postures, twisting movements or cramps.
In the Emergency Department (ED) it is most commonly drug‑induced and can range from a distressing focal spasm to a life‑threatening pharyngeal or laryngeal crisis. Rapid recognition and prompt reversal of the neurotransmitter imbalance are the priorities.
Definition
- Sudden, sustained or repetitive involuntary muscle contractions producing abnormal postures or movements.
- Commonly affects head, neck, face, eyes and mouth; may involve trunk, limbs or respiratory muscles.
Epidemiology and risk factors
- More frequent in younger patients (especially <35 years) and in males.
- Drug‑induced dystonia typically occurs within minutes-days (often within 7 days) of starting or increasing a dopamine‑blocking drug.
- Common risk factors:
- Recent initiation or dose increase of dopamine‑blocking agents (high‑potency first‑generation antipsychotics, some antiemetics).
- Male sex, young age, prior dystonia or family history.
- Stimulant use (e.g. cocaine).
- Physiological stressors (dehydration, fatigue, intercurrent viral illness).
- Metabolic disturbances (hypocalcaemia, hypomagnesaemia). (MHRA; GOV.UK)