The impact of sleep quality on cognitive functioning in Parkinson's disease

In healthy individuals and those with insomnia, poor sleep quality is associated with decrements in performance on tests of cognition, especially executive function. Sleep disturbances and cognitive deficits are both prevalent in Parkinson's disease (PD). Sleep problems occur in over 75% of patients, with sleep fragmentation and decreased sleep efficiency being the most common sleep complaints, but their relation to cognition is unknown. We examined the association between sleep quality and cognition in PD. In 35 non-demented individuals with PD and 18 normal control adults (NC), sleep was measured using 24-hr wrist actigraphy over 7 days. Cognitive domains tested included attention and executive function, memory and psychomotor function. In both groups, poor sleep was associated with worse performance on tests of attention/executive function but not memory or psychomotor function. In the PD group, attention/executive function was predicted by sleep efficiency, whereas memory and psychomotor function were not predicted by sleep quality. Psychomotor and memory function were predicted by motor symptom severity. This study is the first to demonstrate that sleep quality in PD is significantly correlated with cognition and that it differentially impacts attention and executive function, thereby furthering our understanding of the link between sleep and cognition.Published versio

The impact of sleep quality on cognitive functioning in Parkinson's disease

In healthy individuals and those with insomnia, poor sleep quality is associated with decrements in performance on tests of cognition, especially executive function. Sleep disturbances and cognitive deficits are both prevalent in Parkinson's disease (PD). Sleep problems occur in over 75% of patients, with sleep fragmentation and decreased sleep efficiency being the most common sleep complaints, but their relation to cognition is unknown. We examined the association between sleep quality and cognition in PD. In 35 non-demented individuals with PD and 18 normal control adults (NC), sleep was measured using 24-hr wrist actigraphy over 7 days. Cognitive domains tested included attention and executive function, memory and psychomotor function. In both groups, poor sleep was associated with worse performance on tests of attention/executive function but not memory or psychomotor function. In the PD group, attention/executive function was predicted by sleep efficiency, whereas memory and psychomotor function were not predicted by sleep quality. Psychomotor and memory function were predicted by motor symptom severity. This study is the first to demonstrate that sleep quality in PD is significantly correlated with cognition and that it differentially impacts attention and executive function, thereby furthering our understanding of the link between sleep and cognition.Published versio

Parkinson's disease dementia: a neural networks perspective.

In the long-term, with progression of the illness, Parkinson's disease dementia affects up to 90% of patients with Parkinson's disease. With increasing life expectancy in western countries, Parkinson's disease dementia is set to become even more prevalent in the future. However, current treatments only give modest symptomatic benefit at best. New treatments are slow in development because unlike the pathological processes underlying the motor deficits of Parkinson's disease, the neural mechanisms underlying the dementing process and its associated cognitive deficits are still poorly understood. Recent insights from neuroscience research have begun to unravel the heterogeneous involvement of several distinct neural networks underlying the cognitive deficits in Parkinson's disease dementia, and their modulation by both dopaminergic and non-dopaminergic transmitter systems in the brain. In this review we collate emerging evidence regarding these distinct brain networks to give a novel perspective on the pathological mechanisms underlying Parkinson's disease dementia, and discuss how this may offer new therapeutic opportunities

Cognitive Rehabilitation for Executive Dysfunction in Parkinson's Disease: Application and Current Directions

Cognitive dysfunction in Parkinson's disease contributes to disability, caregiver strain, and diminished quality of life. Cognitive rehabilitation, a behavioral approach to improve cognitive skills, has potential as a treatment option to improve and maintain cognitive skills and increase quality of life for those with Parkinson's disease-related cognitive dysfunction. Four cognitive rehabilitation programs in individuals with PD are identified from the literature. Characteristics of the programs and outcomes are reviewed and critiqued. Current studies on cognitive rehabilitation in PD demonstrate feasibility and acceptability of a cognitive rehabilitation program for patients with PD, but are limited by their small sample size and data regarding generalization of effects over the long term. Because PD involves progressive heterogeneous physical, neurological, and affective difficulties, future cognitive rehabilitation programs should aim for flexibility and individualization, according to each patient's strengths and deficits

Metadoxine in the treatment of acute and chronic alcoholism: a review.

Alcohol abuse and alcoholism are responsible for a wide variety of medical problems. The pharmacotherapeutic aspect of alcoholism includes the use of drugs, with different actions and objectives. Among them, metadoxine seems to be of interest. Metadoxine is able to accelerate the elimination of alcohol from the blood and tissues, to help restore the functional structure of the liver and to relieve neuro-psychological disorders associated with alcohol intoxication. Metadoxine also seems to be safe; in more than 15 years of post-marketing surveillance only minor aspecific and reversible events were monitored in patients exposed to the treatment. In this review the preclinical and clinical results obtained using metadoxine in acute and chronic alcohol intoxication are reported

Cognitive training modifies disease symptoms in a mouse model of Huntington's disease

Huntington's disease (HD) is an incurable neurodegenerative disorder which causes a triad of motor, cognitive and psychiatric disturbances. Cognitive disruptions are a core feature of the disease, which significantly affect daily activities and quality of life, therefore cognitive training interventions present an exciting therapeutic intervention possibility for HD. We aimed to determine if specific cognitive training, in an operant task of attention, modifies the subsequent behavioural and neuropathological phenotype of the Hdh(Q111) mouse model of HD. Three testing groups comprising both Hdh(Q111) mice and wildtype controls were used. The first group received cognitive training in an operant task of attention at 4 months of age. The second group received cognitive training in a comparable non-attentional operant task at 4 months of age, and the third group were control animals that did not receive cognitive training. All groups were then tested in an operant task of attention at 12 months of age. Relative to naïve untrained mice, both wildtype and Hdh(Q111) mice that received cognitive training in the operant task of attention demonstrated an increased number of trials initiated, greater accuracy, and fewer ‘time out’ errors. A specific improvement in response time performance was observed in Hdh(Q111) mice, relative to naïve untrained Hdh(Q111) mice. Relative to the group that received comparable training in a non-attentional task, both wildtype and Hdh(Q111) mice that received attentional training demonstrated superior accuracy in the task and made fewer ‘time out’ errors. Despite significant behavioural change, in both wildtype and Hdh(Q111) mice that had received cognitive training, no significant changes in neuropathology were observed between any of the testing groups. These results demonstrate that attentional cognitive training implemented at a young age significantly improves attentional performance, at an older age, in both wildtype and Hdh(Q111) mice. Attentional cognitive training also improved motor performance in Hdh(Q111) mice, thus leading to the conclusion that cognitive training can improve disease symptoms in a mouse model of HD