Abstract

A 36-year-old female artist presented with bradykinesia of left arm and left leg, slight tremor, decreased voice volume, loss of facial expression and bradyphrenia. Her father had developed parkinsonism aged 36 and died aged 52. Examination revealed hypomimia, hypophonia, square wave jerks and subtle left-sided bradykinesia. Cognitive assessment was normal. Following multiple neurological opinions, she was diagnosed with familial idiopathic Parkinson's disease (PD). Initial treatment with l-dopa was of limited benefit and caused orofacial dystonia. She became progressively more bradykinetic, fell frequently, and apraxia of eyelid opening, aphonia and dysphagia ensued. T2-weighted MRI revealed high signal in the mesiotemporal regions bilaterally. Genetic studies detected an N279K mutation of the microtubule-associated protein tau (MAPT) gene on chromosome 17, prompting a diagnosis of pallidopontonigral degeneration (PPND). PPND was first described in 1992 as a rapidly progressive autosomal dominant syndrome of parkinsonism and dementia. It falls within the frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) spectrum of disorders. PPND mimics idiopathic PD early in the disease course and can be associated with near-normal cognition as in this patient. Recent studies suggest a potential biomarker role for MRI. This case, illustrated with sequential videos, delineates the natural history of this entity.