Melvin D. Yahr

TL;DR: Controversy over the effectiveness of therapeutic measures for parkinsonism is due partially to this wide variability and to the paucity of clinical information about the natural history of the syndrome.

TL;DR: The Movement Disorder Society Task Force for Rating Scales for Parkinson's disease (PD) prepared a critique of the Hoehn and Yahr scale, which recommends that it be used in its original form for demographic presentation of patient groups and in research settings, the HY scale is useful primarily for defining inclusion/exclusion criteria.

TL;DR: Under the most optimal circumstances, the best that can be expected from their judicious administration is a 20% reduction in the severity of symptoms with a modest improvement of functional capacity.

TL;DR: In 5 patients the latency became less prolonged on levodopa therapy, suggesting that catecholaminergic pathways have either indirect or direct effects on the generation of visual evoked potentials.

TL;DR: In this paper, a total of 99 patients with Parkinson's disease (PD) were examined and the results showed that the spatial contrast sensitivity function switches in parallel with motor symptoms of the disease.