Atypical parkinsonism: Case-based learning on progressive supranuclear palsy.

A man aged 88 years was referred to a geriatric clinic for falls evaluation. He had worsening postural instability over the past three years with multiple unprovoked falls. His medical history included benign prostate hypertrophy and hypertension with no other vascular risk factors. He described his falls as if being pulled backwards by a magnetic force. On examination, he had a flat affect with monotonous voice. He also had bilateral bradykinesia and cogwheel rigidity with significant axial rigidity. Pull test was positive. He had presence of primitive reflexes including a positive glabella tap and palmomental reflex. His vertical gaze was restricted, particularly his downward gaze. This was overcome by oculocephalic manoeuvre. Executive dysfunction was evident on cognitive assessment. Relevant negative findings included absence of tremor, autonomic dysfunction and cerebellar signs. Speech and language were preserved. There was no behavioural disturbance. The patient had not been taking antidopaminergic medications. Cerebral magnetic resonance imaging (MRI) revealed midbrain atrophy (Figure 1). There was no significant vascular disease, iron deposition in the substantia nigra nor hydrocephalus. A diagnosis of probable progressive supranuclear palsy (PSP) with predominant parkinsonism was made on the basis of the Movement Disorder Society (MDS) criteria.1 Given the clinical suspicion of PSP, the decision was made against a trial of levodopa as the risk of harm secondary to orthostatic hypotension outweighed potential benefit. Over the next year, the patient had repeated hospitalisations for falls and was deemed unsafe to return home.