Idiopathic Parkinson’s disease (IPD) is typically insidious in onset and gradually progressive. Acute onset Parkinsonism is, conversely, a rare entity. It may be attributable to rapid onset dystonia parkinsonism; post-encephalitic sequelae; vascular lesions, such as stroke or subdural haematoma; acute metabolic disturbance; central and extra-pontine myelinolysis; drug side effects, including neuroleptic malignant syndrome; and toxins, ranging from cadmium to carbon monoxide and organophosphate poisoning.

We report two cases of clinically confirmed IPD (followed up over 7 months and 2 years, respectively), which presented atypically with abrupt onset Parkinsonism in the context of significant psychosocial stress. A comprehensive blood panel (including ATP1A3 in Patient B) and brain magnetic resonance imaging (MRI) were unremarkable. (123)I-FP-CIT SPECT (single photon emission computed tomography) confirmed a marked presynaptic dopaminergic deficit in the basal ganglia for both patients, consistent with degenerative Parkinsonism. Both had asymmetrical parkinsonism (without dystonia or functional signs) and progressed as expected for IPD, with typical motor fluctuations in one patient. Patient B, who was commenced on drug therapy, exhibited a significant Levodopa response consistent with IPD. These cases highlight the potential for IPD to present atypically with rapid symptom evolution in the presence of significant psychological stress.