Sleep "ON", sleep better! Positive effects of levodopa on sleep behaviour in people with Parkinson's disease.

People with Parkinson's disease experience reduced sleep quality compared with their peers. Levodopa may have a direct effect on sleep macrostructure or may improve sleep by enhancing nocturnal motor performance. Therefore, it is important to understand the acute effects of withdrawing levodopa on sleep measures in Parkinson's disease. The purpose of this study was to compare the estimated objective and subjective sleep measures of people with Parkinson's disease sleeping under (ON-night) versus without (OFF-night) the effects of the last daily dopaminergic medication before going to bed. A total of 23 people with Parkinson's disease were instructed to wear an actigraphy device for 4 consecutive nights to objectively measure the sleep behaviour. Subjective sleep measure was assessed each morning using a Likert scale. Participants slept for 3 nights on ON-night and 1 night on OFF-night. They were instructed not to take their last dose of levodopa before going to bed in OFF-night. Sleeping in ON- versus OFF-night increased total sleep time (7.8%, p = 0.032) and sleep efficiency (3.7%, p = 0.019), and decreased duration and number of wakes after sleep onset (22.3%, p = 0.050; and 29.2%, p = 0.013, respectively). However, subjective sleep analysis indicated no significant differences between the two conditions. From a clinical point of view, our results suggest that sleeping on ON-night resulted in an improvement in estimated objective sleep measures compared with sleeping on OFF-night. From a methodological point of view, our findings emphasize the importance of relying on objective sleep measurements to accurately assess OFF-night sleep behaviour in people with Parkinson's disease.

Obstacle Avoidance Increases Asymmetry of Crossing Step in Individuals With Parkinson's Disease and Neurologically Healthy Individuals.

The authors' aim was to investigate gait asymmetry of crossing step during obstacle avoidance while walking in people with Parkinson's disease (PD) under and without the effects of dopaminergic medication. Thirteen individuals with PD and 13 neurologically healthy individuals performed 5 trials of unobstructed gait and 10 trials of obstacle crossing during gait (5 trials with each leg) and spatiotemporal parameters were analyzed. Obstacle crossing increased step duration of the crossing step for the most-affected or nondominant limb compared to the crossing step with the least-affected or dominant limb. Individuals with PD without the effects of medication increased step duration for the step with the least-affected limb compared to the step with the most-affected limb during obstacle crossing.

Gaze and motor behavior of people with PD during obstacle circumvention.

The aim of this study was to analyze the motor and visual strategies used when walking around (circumvention) an obstacle in patients with Parkinson's disease (PD), in addition to the effects of dopaminergic medication on these strategies. To answer the study question, people with PD (15) and neurologically healthy individuals (15 - CG) performed the task of obstacle circumvention during walking (5 trials of unobstructed walking and obstacle circumvention). The following parameters were analyzed: body clearance (longer mediolateral distance during obstacle circumvention of the center of mass -CoM- to the obstacle), horizontal distance (distance of the CoM at the beginning of obstacle circumvention to the obstacle), circumvention strategy ("lead-out" or "lead-in" strategy), spatial-temporal of each step, and number of fixations, the mean duration of the fixations and time of fixations according to areas of interest. In addition, the variability of each parameter was calculated. The results indicated that people with PD and the CG presented similar obstacle circumvention strategies (no differences between groups for body clearance, horizontal distance to obstacle, or obstacle circumvention strategy), but the groups used different adjustments to perform these strategies (people with PD performed adjustments during both the approach and circumvention steps and presented greater visual dependence on the obstacle; the CG adjusted only the final step before obstacle circumvention). Moreover, without dopaminergic medication, people with PD reduced body clearance and increased the use of a "lead-out" strategy, variability in spatial-temporal parameters, and dependency on obstacle information, increasing the risk of contact with the obstacle during circumvention.