The role of exercise in facilitating basal ganglia function in Parkinson's disease

Recovery of motor function is associated with rescue of glutamate biomarkers in the striatum and motor cortex following treatment with Mucuna pruriens in a murine model of Parkinsons disease

There is growing interest in the use of natural products for the treatment of Parkinson's disease (PD). Mucuna pruriens has been used in the treatment of humans with PD. The goal of this study was to determine if daily oral treatment with an extract of Mucuna pruriens, starting after the MPTP-induced loss of nigrostriatal dopamine in male mice, would result in recovery/restoration of motor function, tyrosine hydroxylase (TH) protein expression in the nigrostriatal pathway, or glutamate biomarkers in both the striatum and motor cortex. Following MPTP administration, resulting in an 80 % loss of striatal TH, treatment with Mucuna pruriens failed to rescue either striatal TH or the dopamine transporter back to the control levels, but there was restoration of gait/motor function. There was an MPTP-induced loss of TH-labeled neurons in the substantia nigra pars compacta and in the number of striatal dendritic spines, both of which failed to be recovered following treatment with Mucuna pruriens. This Mucuna pruriens-induced locomotor recovery following MPTP was associated with restoration of two striatal glutamate transporter proteins, GLAST (EAAT1) and EAAC1 (EAAT3), and the vesicular glutamate transporter 2 (Vglut2) within the motor cortex. Post-MPTP treatment with Mucuna pruriens, results in locomotor improvement that is associated with recovery of striatal and motor cortex glutamate transporters but is independent of nigrostriatal TH restoration.

Exercise Intervention in Individuals at Clinical High Risk for Psychosis: Benefits to Fitness, Symptoms, Hippocampal Volumes, and Functional Connectivity

BACKGROUND AND HYPOTHESIS

Individuals at clinical high risk for psychosis (CHR-p) are less fit than nonclinical peers and show hippocampal abnormalities that relate to clinical symptoms. Exercise generates hippocampal neurogenesis that may ameliorate these hippocampal abnormalities and related cognitive/clinical symptoms. This study examines the impact of exercise on deficits in fitness, cognitive deficits, attenuated psychotic symptoms, hippocampal volumes, and hippocampal connectivity in individuals at CHR-p.

STUDY DESIGN

In a randomized controlled trial, 32 individuals at CHR-p participated in either an exercise (n = 17) or waitlist (no exercise) (n = 15) condition. All participants were sedentary at use and absent of current antipsychotic medication, psychosis diagnoses, or a substance use disorder. The participants completed a series of fitness, cognitive tasks, clinical assessments, and an MRI session preintervention and postintervention. The exercise intervention included a high-intensity interval exercise (80% of VO2max) with 1-minute high-intensity intervals (95% of VO2max) every 10 minutes) protocol twice a week over 3 months.

STUDY RESULTS

The exercise intervention was well tolerated (83.78% retention; 81.25% completion). The exercising CHR-p group showed that improved fitness (pre/post-d = 0.53), increased in cognitive performance (pre/post-d = 0.49), decrease in positive symptoms (pre/post-d = 1.12) compared with the waitlist group. Exercising individuals showed stable hippocampal volumes; waitlist CHR-p individuals showed 3.57% decreased hippocampal subfield volume. Exercising individuals showed that increased exercise-related hippocampal connectivity compared to the waitlist individuals.

CONCLUSIONS

The exercise intervention had excellent adherence, and there were clear signs of mechanism engagement. Taken together, evidence suggests that high-intensity exercise can be a beneficial therapeutic tool in the psychosis risk period.

From Exercise to Cognitive Performance: Role of Irisin

The beneficial effects of exercise on the brain are well known. In general, exercise offers an effective way to improve cognitive function in all ages, particularly in the elderly, who are considered the most vulnerable to neurodegenerative disorders. In this regard, myokines, hormones secreted by muscle in response to exercise, have recently gained attention as beneficial mediators. Irisin is a novel exercise-induced myokine, that modulates several bodily processes, such as glucose homeostasis, and reduces systemic inflammation. Irisin is cleaved from fibronectin type III domain containing 5 (FNDC5), a transmembrane precursor protein expressed in muscle under the control of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). The FNDC5/irisin system is also expressed in the hippocampus, where it stimulates the expression of the neurotrophin brain-derived neurotrophic factor in this area that is associated with learning and memory. In this review, we aimed to discuss the role of irisin as a key mediator of the beneficial effects of exercise on synaptic plasticity and memory in the elderly, suggesting its roles within the main promoters of the beneficial effects of exercise on the brain.

Long-Term Wu Qin Xi Exercise on Response Inhibition and Cortical Connectivity in Parkinson's Disease: Design and Implementation of a Randomized Controlled Clinical Trial

Background: Motor symptom disorders in patients with Parkinson disease (PD) are closely related to reduced inhibitory ability. Although exercise has been shown to improve this ability in patients with PD, its effects on proactive and reactive inhibition have not been determined. Most previous studies of inhibitory control disorder in people with PD have been behavioral, and little attention has been paid to functional cortical connectivity. Wu Qin Xi, a low–medium-intensity qigong exercise that is safe and easy to do for elderly individuals, can support physical well-being and help prevent and alleviate disease. In this study, our aims were to explore the effects of a long-term Wu Qin Xi intervention on response inhibition and to examine how improved inhibition control relates to cortical connectivity using dual-site paired-pulse transcranial magnetic stimulation (ppTMS), in patients with mild–moderate PD.

Methods: A single-blind randomized controlled trial will be conducted. A total of 90 elderly subjects will be recruited and allocated randomly to Wu Qin Xi, balance exercise, and healthy control groups. The exercise interventions will be implemented in three 90-min sessions per week for 24 weeks; the healthy control group will receive no intervention. The primary assessments will be response inhibition metrics and task-based ppTMS. The secondary outcomes will include motor symptom severity, mobility, balance, emotional state, and quality of life. Assessments will be conducted at baseline, at the conclusion of the intervention period (week 24), and a few months after the intervention (week 36 follow-up).

Discussion: This study is designed to provide insights into the effects of practicing Wu Qin Xi on response inhibition function in people with PD. The results will provide evidence on the value of traditional Chinese exercise as a therapeutic rehabilitation option for these patients. They will also provide data addressing how brain function–related cortical connectivity is related to reactive vs. proactive inhibition in people with PD participating in an exercise intervention.

Clinical Trial Registration: This study has been registered prospectively in the Chinese Clinical Trial Registry (ChiCTR2000038517, 18 January 2021).

Motor-cognitive approach and aerobic training: a synergism for rehabilitative intervention in Parkinson's disease

Parkinson's disease (PD) results in a complex deterioration of motor behavior. Effective pharmacological or surgical treatments addressing the whole spectrum of both motor and cognitive symptoms are lacking. The cumulative functional impairment may have devastating socio-economic consequences on both patients and caregivers. Comprehensive models of care based on multidisciplinary approaches may succeed in better addressing the overall complexity of PD. Neurorehabilitation is a highly promising non-pharmacological intervention for managing PD. The scientific rationale beyond rehabilitation and its practical applicability remain to be established. In the present perspective, we aim to discuss the current evidence supporting integrated motor-cognitive and aerobic rehabilitation approaches for patients with PD while suggesting a practical framework to optimize this intervention in the next future.

Multimodal Training Reduces Fall Frequency as Physical Activity Increases in Individuals With Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) results in a global decrease in information processing, ultimately resulting in dysfunction executing motor-cognitive tasks. Motor-cognitive impairments contribute to postural instability, often leading to falls and decreased physical activity. The aim of this study was to determine the effects of a multimodal training (MMT) versus single-modal (SMT) training on motor symptoms, fall frequency, and physical activity in patients with PD classified as fallers.

METHODS

Individuals with PD were randomized into SMT (n = 11) or MMT (n = 10) and completed training 3 times per week for 8 weeks. The SMT completed gait and cognitive training separately, whereas MMT completed gait and cognitive training simultaneously during each 45-minute session. Physical activity, 30-day fall frequency, and PD motor symptoms were assessed at baseline, posttreatment, and during a 4-week follow-up.

RESULTS

Both groups exhibited significant (P < .05) improvements in clinical ratings of motor function, as symptoms improved by 8% and 15% for SMT and MMT, respectively. Physical activity significantly increased (P < .05) for both groups from baseline (mean steps 4942 [4415]) to posttreatment (mean steps 5914 [5425]). The MMT resulted in a significant 60% reduction in falls.

CONCLUSIONS

Although SMT and MMT approaches are both effective in improving physical activity and motor symptoms of PD, only MMT reduced fall frequency after the intervention.

Forced Aerobic Exercise Preceding Task Practice Improves Motor Recovery Poststroke

OBJECTIVE

To understand how two types of aerobic exercise affect upper-extremity motor recovery post-stroke. Our aims were to (1) evaluate the feasibility of having people who had a stroke complete an aerobic exercise intervention and (2) determine whether forced or voluntary exercise differentially facilitates upper-extremity recovery when paired with task practice.

METHOD

Seventeen participants with chronic stroke completed twenty-four 90-min sessions over 8 wk. Aerobic exercise was immediately followed by task practice. Participants were randomized to forced or voluntary aerobic exercise groups or to task practice only.

RESULTS

Improvement on the Fugl-Meyer Assessment exceeded the minimal clinically important difference: 12.3, 4.8, and 4.4 for the forced exercise, voluntary exercise, and repetitive task practice-only groups, respectively. Only the forced exercise group exhibited a statistically significant improvement.

CONCLUSION

People with chronic stroke can safely complete intensive aerobic exercise. Forced aerobic exercise may be optimal in facilitating motor recovery associated with task practice.

Influence of aerobic exercise training on the neural correlates of motor learning in Parkinson's disease individuals

BACKGROUND

Aerobic exercise training (AET) has been shown to provide general health benefits, and to improve motor behaviours in particular, in individuals with Parkinson's disease (PD). However, the influence of AET on their motor learning capacities, as well as the change in neural substrates mediating this effect remains to be explored.

OBJECTIVE

In the current study, we employed functional Magnetic Resonance Imaging (fMRI) to assess the effect of a 3-month AET program on the neural correlates of implicit motor sequence learning (MSL).

METHODS

20 healthy controls (HC) and 19 early PD individuals participated in a supervised, high-intensity, stationary recumbent bike training program (3 times/week for 12 weeks). Exercise prescription started at 20 min (+ 5 min/week up to 40 min) based on participant's maximal aerobic power. Before and after the AET program, participants' brain was scanned while performing an implicit version of the serial reaction time task.

RESULTS

Brain data revealed pre-post MSL-related increases in functional activity in the hippocampus, striatum and cerebellum in PD patients, as well as in the striatum in HC individuals. Importantly, the functional brain changes in PD individuals correlated with changes in aerobic fitness: a positive relationship was found with increased activity in the hippocampus and striatum, while a negative relationship was observed with the cerebellar activity.

CONCLUSION

Our results reveal, for the first time, that exercise training produces functional changes in known motor learning related brain structures that are consistent with improved behavioural performance observed in PD patients. As such, AET can be a valuable non-pharmacological intervention to promote, not only physical fitness in early PD, but also better motor learning capacity useful in day-to-day activities through increased plasticity in motor related structures.

Engaging cognitive circuits to promote motor recovery in degenerative disorders. exercise as a learning modality

Exercise and physical activity are fundamental components of a lifestyle essential in maintaining a healthy brain. This is primarily due to the fact that the adult brain maintains a high degree of plasticity and activity is essential for homeostasis throughout life. Plasticity is not lost even in the context of a neurodegenerative disorder, but could be maladaptive thus promoting disease onset and progression. A major breakthrough in treating brain disorders such as Parkinson's disease is to drive neuroplasticity in a direction to improve motor and cognitive dysfunction. The purpose of this short review is to present the evidence from our laboratories that supports neuroplasticity as a potential therapeutic target in treating brain disorders. We consider that the enhancement of motor recovery in both animal models of dopamine depletion and in patients with Parkinson's disease is optimized when cognitive circuits are engaged; in other words, the brain is engaged in a learning modality. Therefore, we propose that to be effective in treating Parkinson's disease, physical therapy must employ both skill-based exercise (to drive specific circuits) and aerobic exercise (to drive the expression of molecules required to strengthen synaptic connections) components to select those neuronal circuits, such as the corticostriatal pathway, necessary to restore proper motor and cognitive behaviors. In the wide spectrum of different forms of exercise, learning as the fundamental modality likely links interventions used to treat patients with Parkinson's disease and may be necessary to drive beneficial neuroplasticity resulting in symptomatic improvement and possible disease modification.