Inferring the long duration response to levodopa in Parkinson's disease.

Introduction: The long duration response to levodopa in Parkinson's disease outlasts drug elimination by days to weeks. Though a substantive part of anti-parkinsonian motor benefit, it cannot easily be observed.

Objectives: To infer the magnitude of the long duration response during the first decade of Parkinson's disease and identify factors that influence it.

Disturbances of automatic gait control mechanisms in higher level gait disorder.

The underlying mechanisms responsible for the gait changes in frontal gait disorder (FGD), a form of higher level gait disorders, are poorly understood. We investigated the relationship between stride length and cadence (SLCrel) in people with FGD (n=15) in comparison to healthy older adults (n=21) to improve our understanding of the changes to gait in FGD. Gait data was captured using an electronic walkway system as participants walked at five self-selected speed conditions: preferred, very slow, slow, fast and very fast.

Study of levodopa response in Parkinson's disease: Observations on rates of motor progression.

Introduction: It is important to understand how the rate of motor progression in PD relates to dopaminergic treatment.

Methods: The methods for this study comprised prospective defined off state measurements of the levodopa response at 3-year intervals over a mean 13.3-year period in 34 patients enrolled before treatment initiation.

Longitudinal study of levodopa in Parkinson's disease: effects of the advanced disease phase.

Thirty-four patients have been studied from the time of initiation of pharmacological treatment in a long-term prospective study of levodopa effects and disease progression in Parkinson's disease. Objective motor scoring of the response to levodopa in defined off states was performed every 3 years. The mean time from the initiation of levodopa treatment to the most recent measurements was 18.