Acute akinetic collapse in Parkinson's disease: A retrospective study of sustained immobilization and clinical outcomes

AbstractBackground Acute deterioration in Parkinson's disease (PD) often results in emergency hospitalization. While parkinsonism–hyperpyrexia syndrome (PHS) represents the most severe malignant form, acute motor worsening without hyperthermia is frequently encountered. Objective To characterize the clinical features and outcomes of acute sustained immobilization in PD requiring emergency hospitalization. Methods We conducted a retrospective observational study of PD patients who developed acute immobilization lasting ≥12 h and required emergency transportation and hospitalization. Clinical characteristics, precipitating factors, laboratory findings, and outcomes were analyzed. Results Forty patients were included (mean age 76.5 ± 8.6 years; 42.5% female). Most patients were alert at admission (median Glasgow Coma Scale 15 IQR 14–15) and lacked hyperthermia or overt autonomic instability. Falls were the most frequent precipitating event (45%). The mean duration of immobilization before hospital arrival was 24 h (IQR 16–38). Laboratory findings indicated dehydration and muscle injury (median creatine kinase 1638 IU/L, IQR 431–4543). Mean hospital stay was 31.9 ± 22.1 days. Functional status worsened significantly, with modified Rankin Scale scores increasing from 2.5 ± 0.8 to 3.2 ± 1.0 (p Conclusions Acute sustained immobilization without classical malignant features such as hyperpyrexia or autonomic instability represents a clinically significant pattern of acute motor deterioration in PD, associated with prolonged hospitalization and functional decline. We propose the term acute akinetic collapse (AAC) to describe this underrecognized clinical presentation. Recognition of AAC may facilitate earlier intervention and preventive strategies.