Twenty-one patients with Parkinson's disease were studied before and 2 h after the administration of a single dose of 20 mg of methylphenidate. In response to methylphenidate, attention significantly improved, whereas memory and visual-spatial performance were unchanged. Gait speed, stride time variability, and Timed Up and Go times (demonstrated measures of fall risk) significantly improved. These findings suggest a new potential pharmacologic means of enhancing mobility and decreasing fall risk in Parkinson's disease.
"halamus with primary motor cortex and hippocampus ( Xia et al . , 2012 ) . Patients with Parkinson ' s disease ( PD ) demonstrate altered cortical and subcortical activation and functional connectivity ( Eidelberg et al . , 1994 ; Huang et al . , 2007 ; Ma and Eidelberg , 2007 ) . Low doses of methylphenidate improved gait and voluntary movement ( Auriel et al . , 2006 ; Devos et al . , 2007 ; Kwak et al . , 2010 ) , and along with levodopa improved performance on complex hand movements ( Nutt et al . , 2004 ) in patients with PD . In an earlier study , adding methylphenidate to levodopa treatment increased peak hand tapping speed in patients with PD compared to levodopa alone Table 2 . Summary of sig"
[Show abstract][Hide abstract] ABSTRACT: By blocking dopamine and norepinephrine transporters, methylphenidate affects cognitive performance and regional brain activation in healthy individuals as well as those with neuropsychiatric disorders. Resting-state connectivity evaluates the functional integrity of a network of brain regions. Here, we examined how methylphenidate effects resting-state functional connectivity of the dorsal striatum and thalamus, areas each with dense dopaminergic and noradrenergic innervations, as well as global cerebral connectivity. We administered a single, oral dose (45 mg) to 24 healthy adults and compared resting-state connectivity to 24 demographically matched adults who did not receive any medication. The results showed that methylphenidate alters seed-based and global connectivity between the thalamus/dorsal striatum with primary motor cortex, amygdala/hippocampus and frontal executive areas (p < 0.05, corrected). Specifically, while methylphenidate at this dosage enhances connectivity to the motor cortex and memory circuits, it dampens prefrontal cortical connectivity perhaps by increasing catecholaminergic signalling past the 'optimal' level. These findings advance our understanding of a critical aspect of the multifaceted effects of methylphenidate on brain functions. The results may also facilitate future studies of the aetiology and treatment of neurological and psychiatric disorders that implicate catecholaminergic dysfunction.
The International Journal of Neuropsychopharmacology 05/2014; 17(08):1-15. DOI:10.1017/S1461145714000674 · 4.01 Impact Factor
"Alternatively, perhaps, the magnitude of the cognitive change needed to affect on the TUG and straight line walking are not the same. In a previous study that examined the effects of methylphenidate in PD, gait speed, TUG and executive function all significantly improved . Perhaps the pharmacologic intervention had a more widespread or more potent effect. "
[Show abstract][Hide abstract] ABSTRACT: Background: Patients with Parkinson's disease (PD) suffer from impaired gait and mobility. These changes in motor function have been associated with cognitive deficits that also commonly co-occur in PD, especially executive function (EF) and attention. Objective: We hypothesized that a cognitive remediation program would enhance gait and mobility. Methods: The 18 PD patients in this study were assessed at baseline and again at one and four weeks after completion of a 12 week long, home-based computerized cognitive training program. Subjects were asked to "play" computer games designed to improve EF and attention for 30 minutes a day, three times per week for 12 weeks, while seated. The Timed Up and Go (TUG), gait speed, and stride time variability quantified mobility. A previously validated, computerized neuropsychology battery quantified global cognitive function and its sub-domains. Results: Compared to pre-training values, global cognitive scores and time to complete the TUG significantly improved after the training. TUG components of turning speed and duration also improved. Other TUG components, gait speed, and variability did not change after training. Conclusions: These initial findings suggest that computerized cognitive training can improve cognitive function and has a beneficial carryover effect to certain aspects of mobility in patients with PD. Additional studies are required to replicate these findings and more fully assess the underlying mechanisms. Nonetheless, the present results underscore the motor-cognitive link in PD and suggest that computerized cognitive training may be applied as a therapeutic option to enhance mobility in patients with PD.
"The Timed Up and Go test assessed functional mobility [45,46] (standard instructions were followed; there was no dual task during this test). A computerized neuropsychological test battery (Mindstreams®, NeuroTrax Corp., NJ), previously validated in patients with PD [15,47] quantified executive function, memory and attention (largely sustained attention) [48,49]. The executive function battery included computerized versions of the Go-No-Go and the Stroop interference tests. "
[Show abstract][Hide abstract] ABSTRACT: Background
The beneficial effects of bilateral sub-thalamic nucleus deep brain stimulation on motor function and gait in advanced Parkinson’s disease are established. Less is known about the effect of stimulation on cognitive function and the capacity to walk while dual tasking, an ability that has been related to fall risk. Everyday walking takes place in complex environments that often require multi-tasking. Hence, dual tasking gait performance reflects everyday ambulation as well as gait automaticity. The purpose of this study was to examine the impact of sub-thalamic nucleus deep brain stimulation on dual task walking in patients with advanced Parkinson’s disease.
Gait was assessed using a performance-based test and by quantifying single-task and dual task walking conditions in 28 patients with advanced Parkinson’s disease. These tests were conducted in 4 conditions: “OFF” medication, with the stimulator turned on and off, and “ON” medication, with the stimulator turned on and off. A previously validated, computerized neuro-psychological battery assessed executive function, attention and memory “OFF” and “ON” deep brain stimulation, after subjects took their anti-Parkinsonian medications.
Stimulation improved motor function and the spatiotemporal parameters of gait (e.g., gait speed) during both single-task and dual task walking conditions. Attention improved, but executive function did not. The dual task effect on gait did not change in response to stimulation. For example, during serial 3 subtractions, gait speed was reduced by -0.20 ± 0.14 m/sec while OFF DBS and OFF meds and by -0.22 ± 0.14 m/sec when the DBS was turned on (p = 0.648). Similarly, ON medication, serial 3 subtractions reduced gait speed by -0.20 ± 0.16 m/sec OFF DBS and by -0.22 ± 0.09 m/sec ON DBS (p = 0.543).
Bilateral sub-thalamic nucleus deep brain stimulation improves motor symptoms, certain features of gait and even some aspects of cognitive function. However, stimulation apparently fails to reduce the negative impact of a dual task on walking abilities. These findings provide new insight into the effects of deep brain stimulation on gait during cognitively challenging conditions and everyday walking.
Journal of NeuroEngineering and Rehabilitation 04/2013; 10(1):38. DOI:10.1186/1743-0003-10-38 · 2.74 Impact Factor
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