Speech characteristics of patients with pallido-ponto-nigral degeneration and their application to presymptomatic detection in at-risk relatives

Purpose: This report describes the speech characteristics of individuals with a neurodegenerative syndrome called pallido-ponto-nigral degeneration (PPND) and examines the speech samples of at-risk, but asymptomatic, relatives for possible preclinical detection. Method: Speech samples of 9 members of a PPND kindred were subjected to perceptual characterization. Speech deterioration patterns were reported for 2 participants followed longitudinally at 6-month intervals. Cross-sectional findings were reported for 3 participants at various stages of disease. Longitudinal and cross-sectional findings were used to guide the examination of 4 at-risk, but asymptomatic, participants. Results: Results revealed a progressive mixed dysarthria with hypokinetic, spastic, and flaccid features. It was characterized primarily by vocal tremor and high-frequency vocal flutter, speaking rate abnormalities most often in the direction of slowing, and a tendency toward monopitch. Dysarthria progression was marked by exacerbation and increasing severity of early features, progressive decrease in spontaneous speech output, verbal perseverations, and eventual mutism. Results for at-risk participants revealed preclinical speech abnormalities that preceded other motor signs. Speech results were examined in light of available autopsy findings for site of lesion associations. Conclusion: The dysarthria of PPND is an early harbinger of disease onset. It has a mixed presentation, with hypokinetic, spastic, and flaccid features.