Objective: To assess acute akinesia in patients with Parkinson disease (PD) ("acute akinesia" defined as a sudden deterioration in motor performance that persists for > or =48 hours despite treatment).
Methods: The study population was a cohort of 675 patients followed regularly for 12 years in the authors' outpatient clinic. All patients were studied when acute akinesia led to hospitalization. Unified Parkinson's Disease Rating Scale (UPDRS) scores were rated during the akinetic state and compared with ratings obtained 1.6 +/- 0.9 months before the onset or after recovery.
Results: Twenty-six patients developed acute akinesia; in 17 of the 26 patients, new akinetic symptoms first manifested at the onset of an infectious disease or after surgery and appeared unrelated to changes in treatment or altered levodopa kinetics. In nine patients, acute akinesia developed concurrently with gastrointestinal diseases or drug manipulations showed features of neuroleptic malignant syndrome. Acute akinesia severe enough to increase the UPDRS Motor Subscale score by 31.4 +/- 12.8 appeared within 2 to 3 days and persisted for 11.2 +/- 6.2 days despite attempts to increase the dopaminergic drug dose or administer continuous subcutaneous apomorphine infusion. Symptomatic recovery began 4 to 26 days after the onset of acute akinesia and appeared incomplete in 10 patients. Four patients of 26 died despite treatment. Levodopa kinetics were normal in all patients without gastrointestinal disease and in one patient with gastric stasis.
Conclusions: Acute akinesia is a life-threatening complication of Parkinson disease (PD). It is unlike the "wearing-off" phenomenon that occurs when dopaminergic drug levels decline and responds to dopaminergic rescue drugs. Acute akinesia may be a clinical entity distinct from the previously described PD motor fluctuations.