The Time Course of Changes in Prefrontal Cortex Activity During Walking in People With Parkinson's Disease.

BACKGROUND: Walking abnormalities in people with Parkinson's disease (PD) are characterized by a shift in locomotor control from healthy automaticity to compensatory, executive control, mainly located in the prefrontal cortex (PFC). Although PFC activity during walking increases in people with PD, the time course of PFC activity during walking and its relationship to clinical or gait characteristics is unknown. OBJECTIVE: To identify the time course of PFC activity during walking in people with PD. To investigate whether clinical or gait variables would explain the PFC activity changes. METHODS: Thirty-eight people with PD tested OFF medication wore a portable, functional near-infrared spectroscopy (fNIRS) system to record relative PFC activity while walking. Wearable inertial sensors recorded spatiotemporal gait characteristics. Based on the PFC activity (fNIRS) in the late phase of the walking task (final 40 seconds), compared to the early phase (initial 40 seconds), participants were separated into 2 groups: reduced or sustained PFC activity. RESULTS: People with PD who reduced PFC activity during walking had less impaired gait (eg, faster gait speed) than those who had a sustained increase in PFC activity (P < .05). Cognitive set-shifting ability explained 18% of the PFC activation in the group with a sustained increase in PFC activity (P = .033). CONCLUSIONS: The time course of reduction in PFC activity corresponds to less impaired gait performance in people with PD, while a sustained increase in PFC activity is related to worse cognitive flexibility. Reduction in PFC activity while walking may indicate a less impaired, automatic control of walking.

Telerehabilitation by Videoconferencing for Balance and Gait in People with Parkinson's Disease: A Scoping Review.

Although supervised and real-time telerehabilitation by videoconferencing is now becoming common for people with Parkinson's disease (PD), its efficacy for balance and gait is still unclear. This paper uses a scoping approach to review the current evidence on the effects of telerehabilitation by videoconferencing on balance and gait for patients with PD. We also explored whether studies have used wearable technology during telerehabilitation to assess and treat balance and gait via videoconferencing. Literature searches were conducted using PubMed, ISI's Web of Knowledge, Cochrane's Library, and Embase. The data were extracted for study design, treatment, and outcomes. Fourteen studies were included in this review. Of these, seven studies investigated the effects of telerehabilitation (e.g., tele-yoga and adapted physiotherapy exercises) on balance and gait measures (e.g., self-reported balance, balance scale, walking speed, mobility, and motor symptoms) using videoconferencing in both assessment and treatment. The telerehabilitation programs by videoconferencing were feasible and safe for people with PD; however, the efficacy still needs to be determined, as only four studies had a parallel group. In addition, no study used wearable technology. Robust evidence of the effects of telerehabilitation by videoconferencing on balance and gait for patients with PD was not found, suggesting that future powered, prospective, and robust clinical trials are needed.

Factors Associated With Physical Activity and Sedentary Behavior in People With Parkinson Disease: A Systematic Review and Meta-Analysis.

OBJECTIVE: The goal of this review was to investigate factors associated with physical activity and sedentary behavior in people with Parkinson disease (PD). The magnitude of these associations were investigated in line with the International Classification of Functioning, Disability and Health components. METHODS: A systematic literature review was conducted until February 2023, searching 4 databases (PubMed, EMBASE, Web of Science, and Scopus) for original articles investigating associations with physical activity or sedentary behavior in people with PD. Two independent researchers performed data extraction, and the risk of bias in the included studies was assessed using the Quality in Prognosis Studies tool. Meta-analyses were conducted to determine the magnitude of the associations, and significant regression models from the included studies were described. RESULTS: Forty-two studies were included. Twenty-one factors associated with overall physical activity were identified. Higher levels of physical activity had small association with cognition and body mass index, and fair association with 17 factors related to self-efficacy, physical function, mobility, quality of life, age, PD symptoms, and more. Better manual dexterity and functional gait had moderate to good association with higher levels of physical activity. The regression model with the higher magnitude was composed mostly of contextual factors, except for the body max index. The magnitude of factors associated with physical activity intensity or sedentary behavior could not be identified. CONCLUSION: Functional gait and manual dexterity were the strongest factors related to physical activity in people with PD. Further investigation is needed to understand the factors associated with physical activity intensity and sedentary behavior. IMPACT: This study emphasizes the significance of considering contextual factors alongside body function and structure, activity and participation, and the health condition to enhance physical activity improvement during the rehabilitation process. By adopting such holistic approach, rehabilitation professionals can optimize the overall health and wellbeing of individuals with Parkinson disease.

Mesencephalic Locomotor Region and Presynaptic Inhibition during Anticipatory Postural Adjustments in People with Parkinson's Disease.

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) have a loss of presynaptic inhibition (PSI) during anticipatory postural adjustments (APAs) for step initiation. The mesencephalic locomotor region (MLR) has connections to the reticulospinal tract that mediates inhibitory interneurons responsible for modulating PSI and APAs. Here, we hypothesized that MLR activity during step initiation would explain the loss of PSI during APAs for step initiation in FOG (freezers). Freezers (n = 34) were assessed in the ON-medication state. We assessed the beta of blood oxygenation level-dependent signal change of areas known to initiate and pace gait (e.g., MLR) during a functional magnetic resonance imaging protocol of an APA task. In addition, we assessed the PSI of the soleus muscle during APA for step initiation, and clinical (e.g., disease duration) and behavioral (e.g., FOG severity and APA amplitude for step initiation) variables. A linear multiple regression model showed that MLR activity (R2 = 0.32, p = 0.0006) and APA amplitude (R2 = 0.13, p = 0.0097) explained together 45% of the loss of PSI during step initiation in freezers. Decreased MLR activity during a simulated APA task is related to a higher loss of PSI during APA for step initiation. Deficits in central and spinal inhibitions during APA may be related to FOG pathophysiology.

Effects of resistance training on metabolic and cardiovascular responses to a maximal cardiopulmonary exercise test in Parkinson`s disease / Efeitos do treinamento resistido sobre as respostas metabólicas e cardiovasculares ao teste de esforço cardiopulmonar máximo na doença de Parkinson

ABSTRACT: Objective: To evaluate the effects of resistance training on metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson's disease. Methods: Twenty-four patients with Parkinson's disease (modified Hoehn and Yahr stages 2 to 3) were randomly assigned to one of two groups: Control or Resistance Training. Patients in the Resistance Training Group completed an exercise program consisting of five resistance exercises (two to four sets of six to 12 repetitions maximum per set) twice a week. Patients in the Control Group maintained their usual lifestyle. Oxygen uptake, systolic blood pressure and heart rate were assessed at rest and during cycle ergometer-based maximal cardiopulmonary exercise testing at baseline and at 12 weeks. Assessments during exercise were conducted at absolute submaximal intensity (slope of the linear regression line between physiological variables and absolute workloads), at relative submaximal intensity (anaerobic threshold and respiratory compensation point) and at maximal intensity (maximal exercise). Muscle strength was also evaluated. Results: Both groups had similar increase in peak oxygen uptake after 12 weeks of training. Heart rate and systolic blood pressure measured at absolute and relative submaximal intensities and at maximal exercise intensity did not change in any of the groups. Muscle strength increased in the Resistance Training but not in the Control Group after 12 weeks. Conclusion: Resistance training increases muscle strength but does not change metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson's disease without cardiovascular comorbidities.

RESUMO Objetivo: Avaliar os efeitos do treinamento resistido nas respostas metabólicas e cardiovasculares ao teste de esforço cardiopulmonar máximo em pacientes com doença de Parkinson. Métodos: Vinte e quarto pacientes com doença de Parkinson (estágios 2 a 3 de Hoehn e Yahr modificado) foram aleatoriamente randomizados em dois grupos: Controle e Treinamento Resistido. O Grupo Treinamento Resistido realizou, duas vezes por semana, cinco exercícios resistidos, duas a quatro séries, seis a 12 repetições máximas por série. O Grupo Controle manteve seu estilo de vida. No início e após 12 semanas, consumo de oxigênio, pressão arterial sistólica e frequência cardíaca foram avaliados em repouso e durante um teste de esforço cardiopulmonar máximo realizado em um cicloergômetro. As avaliações durante o exercício foram realizadas nas intensidades submáximas (a inclinação da regressão linear entre as variáveis fisiológicas e as cargas absolutas), nas intensidades submáximas relativas (limiar anaeróbico e ponto de compensação respiratória) e na intensidade máxima (pico do exercício). Adicionalmente, foi avaliada a força muscular. Resultados: Comparado com o início, o consumo de oxigênio pico aumentou, de forma semelhante, em ambos os grupos após 12 semanas. A frequência cardíaca e a pressão arterial sistólica avaliadas nas intensidades submáximas absolutas e relativas, assim como no pico do exercício, não se modificaram em nenhum dos grupos. Finalmente, diferente do Grupo Controle, a força muscular aumentou no Grupo Treinamento Resistido após 12 semanas. Conclusão: Em pacientes com doença de Parkinson sem comorbidades cardiovasculares, o treinamento resistido aumenta a força muscular, mas não modifica as respostas metabólicas e cardiovasculares ao teste de esforço cardiopulmonar máximo.

Comparação de inibições medulares entre indivíduos com doença de Parkinson e saudáveis / Comparison of spinal inhibitions between parkisonian and helathy individuals

O objetivo do presente estudo foi comparar os níveis de inibição pré-sináptica (IPS) e inibição recíproca (IR) entre indivíduos com Doença de Parkinson e saudáveis e, a correlação entre essas inibições e a rigidez muscular e a severidade clínica de indivíduos com Doença de Parkinson (avaliadas através da Escala Unificada de Avaliação da Doença de Parkinson). Foram avaliados 11 indivíduos nos estágios 2 e 3 da doença e 13 indivíduos saudáveis pareados pela idade. A IPS foi menor em indivíduos com Doença de Parkinson (31,6%) do que em saudáveis (67,1%) (p = 0,02). A IR não diferiu entre indivíduos com Doença de Parkinson (26,9%) e saudáveis (27,6%) (p = 0,91). Adicionalmente, não foram detectadas correlações entre os níveis de IPS com a rigidez e a severidade clínica (p > 0,05). Portanto, mecanismos inibitórios não explicam totalmente a rigidez muscular e a severidade clinica da doença. Alterações entre ativação de músculos agonistas e antagonistas parecem estar relacionadas a influências supraespinhais anormais nos mecanismos espinhais decorrentes da doença...

The purposes of the present study were to compare presynaptic inhibition (PI) and disynaptic reciprocal inhibition (DRI) levels between parkinsonians and healthy individuals and to verify the correlation of such inhibitions with muscle rigidity and clinical severity (assessed by the Unified Parkinson Disease Rating Scale). We evaluated 11 parkinsonians in stages 2 and 3 of the disease and 13 healthy individuals matched for age. The PI was significant lower in parkinsonians (31.6%) than in healthy individuals (67.1%) (p = 0.02). The DRI did not differ between parkinsonians (26.9%) and healthy individuals (27.6%) (p = 0.91). Furthermore, no significant correlation was observed between PI with muscle rigidity and clinical severity (p > 0.05). Therefore, inhibitory mechanisms do not fully explain the cause of muscle rigidity and clinical severity of parkinsonians. Changes between the activation of agonist and antagonist muscles seem to be caused by abnormal supraspinal influence on spinal mechanisms...

Efeito da familiarização na estabilização dos valores e 1RM para homens e mulheres / Effect of familiarization on the stabilization of 1RM values for men and women

O objetivo deste estudo foi verificar o número de sessões de familiarização necessárias para estabilização da carga do teste de uma repetição máxima (1RM) no exercício agachamento em homens e mulheres. Oito homens (25 ± 4 anos) e oito mulheres (20 ± 1anos) foram submetidos a cinco sessões experimentais. ANOVA e plotagem de Bland-Altman foram utilizadas para comparar a carga de 1RM entre as sessões (p<0,05). A estabilização da carga ocorreu na quarta sessão para os homens e na terceira para as mulheres, com aumentos significantes da força absoluta e relativa da primeira à quarta (17kg e 19%) e da primeira à terceira (9kg e 14%) sessões, respectivamente. Porém, não houve diferença significante na força relativa entre os gêneros. De acordo com nossos resultados, indivíduos inexperientes em treinamento de força atingem alta reprodutibilidade ao teste de 1RM no exercício agachamento, após realizar três a quatro sessões de familiarização.

The purpose of this study was to determine the number of familiarization sessions for stabilizing the load of one repetition maximum (1RM) tests on the squat exercise in men and women. Eight men (25 ± 4 years) and eight women (20 ± 1 years) underwent five experimental sessions. ANOVA and Bland-Altman plotting were used to compare the 1RM load between the sessions (p<0.05). The stabilization of load occurred at the fourth session for men and at the third session for women, with significantly increased in relative and absolute strength from the first to the fourth (17kg and 19%) and from the first to the third (9kg and 14%) session, respectively. However, relative strength did not differ significantly between genders. According to our results, individuals not experienced with strength training can reach high reliability in the 1RM test in the squat exercise, after performing three or four familiarizations sessions.