📚 Reference: Acute Dystonia High-Yield Facts
- Mechanism Acute dystonia is caused by strong D2 receptor blockade leading to a relative excess of cholinergic (M1) activity in the striatum.
- Risk Factors Highest risk with high-potency, first-generation antipsychotics (e.g., Haloperidol).
- Timing Presents abruptly, typically within 4 hours to 4 days of initiation.
- Clinical Presentation Oculogyric crisis (upward eye deviation), Opisthotonus (back arching), Torticollis (neck spasm), Laryngospasm.
- Treatment Re-establish balance using M1 receptor antagonists (Benztropine, Diphenhydramine).
- Differential Distinguish from Akathisia (subjective restlessness), which is not a muscle spasm.