Identification and diagnosis of anti-Parkinson drug-induced respiratory dyskinesia: A case report in a patient with long-term antipsychotic treatment

Background Diagnosing respiratory dyskinesia (RD) in Parkinson's disease (PD) patients with long-term antipsychotic use is challenging, requiring differentiation between levodopa-induced dyskinesia (LID) and tardive dyskinesia (TD). Case description A 70-year-old female with PD and a 30-year history of schizophrenia on chlorpromazine presented with aggravated limb tremor and new-onset abnormal breathing. Following a switch to quetiapine and intensification of her PD medication (Madopar increased to 0.25 g tid), she developed perioral/shoulder chorea and irregular respirations. Symptoms occurred synchronously with peak Madopar doses. Reducing Madopar to 0.125 g tid led to significant resolution of both motor and respiratory symptoms within two weeks. Conclusion This case highlights the diagnostic challenge of dyskinesia in patients with complex medication histories. A detailed symptom-medication timing analysis and a cautious drug adjustment trial were crucial for diagnosis and management. The atypical respiratory phenotype may be influenced by long-term antipsychotic exposure.