Predictors of Motor Progression in Parkinson's Disease

Treatment resistant motor features, such as postural instability and freezing of gait are
common in people with Parkinson's disease and major contributors to morbidity and mortality.
This project will use sleep studies, quantitative motor assessments and magnetic resonance
imaging to examine the relationship between abnormally increased muscle activity during rapid
eye movement sleep and the development and progression of treatment-resistant postural
instability and gait disturbances. Specifically, the investigators will test the hypothesis
that anticipatory postural adjustments (weight and pressure shifts) during gait initiation
are significantly reduced in people with Parkinson's disease who have abnormally elevated
muscle activity during rapid eye movement (REM) sleep compared to individuals will
Parkinson's disease whose REM sleep muscle activity is normal. In addition, the investigators
will test the hypothesis that the level of RSWA at baseline is predictive of measures of
motor decline (postural stability and gait) and alterations in the structure and function of
locomotor brainstem networks. Since sleep disorders can emerge years before a diagnosis of
Parkinson's disease, establishment of a link between sleep and treatment-resistant posture
and gait disorders will help identify individuals at risk of developing these disabling motor
features of disease.