Factors influencing the level of stigma in Parkinson's disease in western Turkey.

Background and purpose:

Stigma is a widespread phenomenon in Parkinson’s disease (PD) and has been shown to affect the quality of life of individuals. This study aims to assess the level of stigma and identify the factors contributing to stigma in patients with PD in Turkey.

A total of 142 patients diagno­sed with PD between June 2022 and March 2023 were included in the study. Sociodemographic data including age, gender, marital status, education level, and duration of PD were collected using a sociodemographic information form. Motor symptom severity was assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS part III). The disease stage was determined using the Hoehn and Yahr scale. Participants were classified as PIGD (postural instability/gait difficulty) or TD (tremor dominant) based on the UPDRS score. Patients with a UPDRS ratio greater than or equal to 1.5 were classified as TD, while subjects with a ratio less than or equal to 1.0 were classified as PIGD. Ratios between 1.0 and 1.5 were classified as mixed type. Depression was assessed using the Hamilton Depression Rating Scale (HAM-D), while stigma was measured using the Chronic Illness Anticipated Stigma Scale (CIASS) and the stigma sub-scale of the 39-item Parkinson’s Disease Questionnaire (PDQ-39 stigma sub-scale).

The mean score on the stigma sub-scale of the PDQ-39 was 7.60±4.39, while the mean total stigma score on the CIASS was 1.37±0.39. Our results indicated that stigma was more prevalent among patients with PD with the TD motor subtype, younger age, shorter disease duration, higher level of disability, and presence of depression symptoms.

Our study highlights the association between stigma and disease progression, duration, and depressive symptoms in patients with PD in western Turkey.

Clinical Factors Predicting Voluntary Driving Cessation among Patients with Parkinson's Disease.

Factors that influence the decision of voluntary driving cessation in patients living with Parkinson's disease (PD) are still unclear. We aimed to reveal the factors affecting the decision of voluntary driving cessation in patients with PD. This hospital-based cross-sectional study recruited consecutive outpatients with PD. Data on sociodemographic and clinical characteristics and medication use were collected from the patients using semistructured interviews. Cognitive function was evaluated using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). We excluded patients with dementia or motor impairment (Hoehn - Yahr stage > 3). We divided the patients into two groups, with and without voluntary driving cessation (D: driver; RD: retired driver), and conducted investigations using multivariate logistic regression analyses. Of the 40 patients, 8 (20.0%) voluntarily retired from driving. Patients who decided on driving cessation had a higher prevalence of freezing of gait (FOG) (D vs. RD, 25.0% vs. 87.5%; P = 0.001) and tended to have lower scores for attention in the MoCA-J (D vs. RD, 5.0 ± 1.2 vs. 4.1 ± 1.4; P = 0.086). Multivariable analysis showed that FOG was independently associated with driving cessation (odds ratio: 14.46, 95% confidence interval: 1.91-303.74). FOG was associated with voluntary driving cessation in patients with PD without dementia or severe motor impairment. Physicians should consider providing extensive social support to maintain patients' mobility and independence, especially if the patients have these clinical factors.

Postural and gait symptoms in de novo Parkinson's disease patients correlate with cholinergic white matter pathology.

INTRODUCTION: The postural instability gait difficulty motor subtype of patients with Parkinson's disease (PIGD-PD) has been associated with more severe cognitive pathology and a higher risk on dementia compared to the tremor-dominant subtype (TD-PD). Here, we investigated whether the microstructural integrity of the cholinergic projections from the nucleus basalis of Meynert (NBM) was different between these clinical subtypes. METHODS: Diffusion-weighted imaging data of 98 newly-diagnosed unmedicated PD patients (44 TD-PD and 54 PIGD-PD subjects) and 10 healthy controls, were analysed using diffusion tensor imaging, focusing on the white matter tracts associated with cholinergic projections from the NBM (NBM-WM) as the tract-of-interest. Quantitative tract-based and voxel-based analyses were performed using FA and MD as the estimates of white matter integrity. RESULTS: Voxel-based analyses indicated significantly lower FA in the frontal part of the medial and lateral NBM-WM tract of both hemispheres of PIGD-PD compared to TD-PD. Relative to healthy control, several clusters with significantly lower FA were observed in the frontolateral NBM-WM tract of both disease groups. Furthermore, significant correlations between the severity of the axial and gait impairment and NBM-WM FA and MD were found, which were partially mediated by NBM-WM state on subjects' attentional performance. CONCLUSIONS: The PIGD-PD subtype shows a loss of microstructural integrity of the NBM-WM tract, which suggests that a loss of cholinergic projections in this PD subtype already presents in de novo PD patients.

Executive function and dopamine response in Parkinson's disease freezing of gait.

BACKGROUND: This investigation examined whether aspects of attention and executive functioning differed between Parkinson's Disease (PD) patients with freezing of gait (FOG) based on responsiveness to dopamine. We also explored association of cognition with FOG severity and gait metrics. METHODS: Fifty-four individuals with PD completed the study protocol: 17 without freezing (PDC), 23 with dopa-responsive FOG (RFOG), and 14 with dopa-unresponsive (URFOG). Standardized neuropsychological tests assessed attention (focused and sustained), psychomotor speed, and set-switching (time and errors). FOG severity was measured using the new FOG Questionnaire (nFOG-Q). Metrics from timed up and go (TUG) tasks were obtained while "on" and "off" dopamine, with and without dual cognitive tasks. RESULTS: After controlling for clinical and demographic factors, analysis of covariance revealed a significant between-group difference for set-switching errors; planned contrasts revealed increased set-switching errors in URFOG relative to RFOG and PD control groups. Groups were not different in other cognitive domains. FOG severity was modestly associated with set-switching errors in RFOG but not URFOG. TUG performances while "on" were associated with set-switching errors in PD controls, and with focused attention in RFOG. CONCLUSION: PD patients with dopa-unresponsive FOG are more prone to set-switching errors than those who respond to treatment. Furthermore, executive function appears relevant to FOG severity only in patients who show dopamine response. Together, these findings suggest disruption of a common dopamine-mediated pathway for FOG and ability to monitor rules while alternating cognitive processes. Consideration of dopa-response could be useful in characterizing cohorts and treating FOG in PD.

A pilot randomized controlled trial examining the benefits of an adjuvant psycho-behavioural intervention in comparison to a health education program, on psychological well-being and freezing-of-gait in patients with Parkinson's disease.

This study investigated the effectiveness of a psycho-behavioural intervention (PBI) for freezing of gait (FOG) management in people with Parkinson's disease, through a double-blind randomized controlled pilot trial conducted with nineteen participants. Though no significant between-group differences were found, PBI was feasible, well-tolerated by participants, and exhibited a trend towards improvement for FOG and depression, thereby warranting further longitudinal investigations.

Beyond Physical Capacity: Factors Associated With Real-world Walking Activity After Stroke.

OBJECTIVE: To identify homogeneous subsets of survivors of chronic stroke who share similar characteristics across several domains and test if these groups differ in real-world walking activity. We hypothesized that variables representing the domains of walking ability, psychosocial, environment, and cognition would be important contributors in differentiating real-world walking activity in survivors of chronic stroke. DESIGN: Cross-sectional, secondary data analysis. SETTING: University/laboratory. PARTICIPANTS: A total of 283 individuals with chronic (≥6mo) stroke (N=238). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Thirteen variables representing 5 domains were included: (1) walking ability: 6-minute walk test (6MWT), self-selected speed (SSS) of gait; (2) psychosocial: Patient Health Questionnaire-9, Activities-specific Balance Confidence (ABC) scale; (3) physical health: low-density lipoprotein cholesterol, body mass index, Charlson Comorbidity Index (CCI); (4) cognition: Montreal Cognitive Assessment (MoCA); and (5) environment: living situation and marital status, work status, Area Deprivation Index (ADI), Walk Score. Mixture modeling was used to identify latent classes of survivors of stroke. After identifying the latent classes, walking activity, measured as steps per day (SPD), was included as a distal outcome to understand if classes were meaningfully different in their real-world walking RESULTS: A model with 3 latent classes was selected. The 6MWT, SSS, ABC scale, and Walk Score were significantly different among all 3 classes. Differences were also seen for the MoCA, ADI, and CCI between 2 of the 3 classes. Importantly, the distal outcome of SPD was significantly different in all classes, indicating that real-world walking activity differs among the groups identified by the mixture model. CONCLUSIONS: Survivors of stroke with lower walking ability, lower self-efficacy, lower cognitive abilities, and greater area deprivation had lower SPD. These results demonstrate that the physical and social environment (including socioeconomic factors) and cognitive function should also be considered when developing interventions to improve real-world walking activity after stroke.

Effect of Cognitive Function on Balance and Posture Control after Stroke.

Hemiplegic gait is the most common sequela of stroke. Patients with hemiplegic gait are at a risk of falling because of poor balance. The theory of cognitive-motor networks paved the way for a new field of research. However, the mechanism of the relationship of cognition with gait or posture control networks is unclear because of the dynamic characteristics of walking and changing postures. To explore differences in the balance function and fall risk between patients with and without cognitive impairment after stroke, we utilized the Berg balance scale, Timed "Up and Go" test, and 10 m walking test. Patients were divided into two groups: the observation group (16 patients, female 6 and male 10), comprising patients with cognitive impairment after stroke, and the control group (16 patients, female 7 and male 9), comprising patients without cognitive impairment after stroke. We found that patients with cognitive impairment had worse balance function and a higher risk of falls. They needed a longer time to turn around or sit down. Our findings indicated that posture control in turning around and sitting down required more cognitive resources in daily life.

Poor sleep quality is associated with cognitive, mobility, and anxiety disability that underlie freezing of gait in Parkinson's disease.

BACKGROUND: Individuals with Parkinson's disease (PD) who report freezing of gait (FOG) have poorer sleep quality than those without FOG. Cognitive, anxiety, and mobility disability are components of the FOG phenotype, however, no study has investigated if poor sleep quality is associated with all three components that underlie FOG in PD. RESEARCH QUESTION: Are there associations among sleep quality and all three components of the FOG phenotype? METHODS: Forty and 39 individuals with and without FOG (PD + FOG and PD-FOG), respectively, and 31 age-matched healthy controls (HC) participated in this study. Self-reported FOG (new-FOG questionnaire-NFOGQ), sleep quality (Pittsburgh Sleep Quality Index-PSQI), cognitive function (Montreal Cognitive Assessment-MoCA), anxiety (subscale from Hospital Anxiety and Depression Scale-HADS-A), and mobility (timed-up-and-go test-TUG) were assessed. RESULTS AND SIGNIFICANCE: PSQI scores were correlated with the scores of NFOGQ, MoCA, HADS-A, and TUG time in PD + FOG (P ≤ 0.0038). The multiple regression analysis identified the PSQI scores as the only predictor of the variance of the NFOGQ scores (R2 = 0.46, P < .0001). The variance in the PSQI scores were explained (69 %) by MoCA scores, NFOGQ scores, TUG time, and HADS-A scores (P ≤ 0.05). Although PD + FOG had a higher disease severity compared to PD-FOG (P < 0.001), disease severity did not enter in the regression model to explain PSQI scores and NFOGQ scores. We also observed associations of PSQI scores with the MoCA scores and TUG time for HC (P ≤ 0.0038), whereas there was no association between PSQI scores and any variable in PD-FOG (P > 0.05). Finally, PD + FOG presented worse scores of PSQI, MoCA, HADS-A, and TUG time than PD-FOG and HC (P < 0.05). Thus, poor sleep quality is associated with FOG and all three components that underlie FOG, regardless of the disease severity. Therefore, treatments useful to decrease FOG should be targeted to ameliorate sleep quality, cognition, anxiety, and mobility.

Relationships Between Sensorimotor Inhibition and Mobility in Older Adults With and Without Parkinson's Disease.

BACKGROUND: Reduced cortical sensorimotor inhibition is associated with mobility and cognitive impairments in people with Parkinson's disease (PD) and older adults (OAs). However, there is a lack of clarity regarding the relationships among sensorimotor, cognitive, and mobility impairments. The purpose of this study was to determine how cortical sensorimotor inhibition relates to impairments in mobility and cognition in people with PD and OAs. METHOD: Cortical sensorimotor inhibition was characterized with short-latency afferent inhibition (SAI) in 81 people with PD and 69 OAs. Six inertial sensors recorded single- and dual-task gait and postural sway characteristics during a 2-minute walk and a 1-minute quiet stance. Cognition was assessed across the memory, visuospatial, executive function, attention, and language domains. RESULTS: SAI was significantly impaired in the PD compared to the OA group. The PD group preformed significantly worse across all gait and postural sway tasks. In PD, SAI significantly correlated with single-task foot strike angle and stride length variability, sway area, and jerkiness of sway in the coronal and sagittal planes. In OAs, SAI significantly related to single-task gait speed and stride length, dual-task stride length, and immediate recall (memory domain). No relationship among mobility, cognition, and SAI was observed. CONCLUSIONS: Impaired SAI related to slower gait in OA and to increased gait variability and postural sway in people with PD, all of which have been shown to be related to increased fall risk.

Impact of depression on gait variability in Parkinson's disease.

OBJECTIVE: The goal of this study was to analyze how depression associated with Parkinson's disease (PD) affected gait variability in these patients using a dual-task paradigm. Additionally, the dependency of the executive functions and the impact of depression on gait variability were analyzed. PATIENTS AND METHODS: Three subject groups were included: patients with PD, but no depression (PD-NonDep; 14 patients), patients with both PD and depression (PD-Dep; 16 patients) and healthy controls (HC; 15 subjects). Gait was recorded using the wireless sensors. The participants walked under four conditions: single-task, motor dual- task, cognitive dual-task, and combined dual-task. Variability of stride length, stride duration, and swing time was calculated and analyzed using the statistical methods. RESULTS: Variability of stride duration and stride length were not significantly different between PD-Dep and PD-NonDep patients. The linear mixed model showed that swing time variability was statistically significantly higher in PD-Dep patients compared to controls (p = 0.001). Hamilton Disease Rating Scale scores were significantly correlated with the swing time variability (p = 0.01). Variability of all three parameters of gait was significantly higher while performing combined or cognitive task and this effect was more pronounced in PD-Dep group of patients. CONCLUSIONS: Depression in PD was associated with swing time variability, and this effect was more prominent while performing a dual-task. SIGNIFICANCE: Diagnosing and treating depression might be important for gait improvement and fall reduction in PD patients.

LL-00066471, a novel positive allosteric modulator of α7 nicotinic acetylcholine receptor ameliorates cognitive and sensorimotor gating deficits in animal models: Discovery and preclinical characterization.

α7 nicotinic acetylcholine receptor (α7 nAChR) is an extensively validated target for several neurological and psychiatric conditions namely, dementia and schizophrenia, owing to its vital roles in cognition and sensorimotor gating. Positive allosteric modulation (PAM) of α7 nAChR represents an innovative approach to amplify endogenous cholinergic signaling in a temporally restricted manner in learning and memory centers of brain. α7 nAChR PAMs are anticipated to side-step burgeoning issues observed with several clinical-stage orthosteric α7 nAChR agonists, related to selectivity, tolerance/tachyphylaxis, thus providing a novel dimension in therapeutic strategy and pharmacology of α7 nAChR ion-channel. Here we describe a novel α7 nAChR PAM, LL-00066471, which potently amplified agonist-induced Ca2+ fluxes in neuronal IMR-32 neuroblastoma cells in a α-bungarotoxin (α-BTX) sensitive manner. LL-00066471 showed excellent oral bioavailability across species (mouse, rat and dog), low clearance and good brain penetration (B/P ratio > 1). In vivo, LL-00066471 robustly attenuated cognitive deficits in both procognitive and antiamnesic paradigms of short-term episodic and recognition memory in novel object recognition task (NORT) and social recognition task (SRT), respectively. Additionally, LL-00066471 mitigated apomorphine-induced sensorimotor gating deficits in acoustic startle reflex (ASR) and enhanced antipsychotic efficacy of olanzapine in conditioned avoidance response (CAR) task. Further, LL-00066471 corrected redox-imbalances and reduced cortico-striatal infarcts in stroke model. These finding together suggest that LL-00066471 has potential to symptomatically alleviate cognitive deficits associated with dementias, attenuate sensorimotor gating deficits in schizophrenia and correct redox-imbalances in cerebrovascular disorders. Therefore, LL-00066471 presents potential for management of cognitive impairments associated with neurological and psychiatric conditions.

Does overground robotic gait training improve non-motor outcomes in patients with chronic stroke? Findings from a pilot study.

Stroke is the leading cause of disability among the elderly in the industrialized world. No more than 40% of stroke survivors walk independently, and only after receiving appropriate rehabilitation treatment; many stroke patients have also non-motor symptoms. The aim of this pilot study is to evaluate the effects of Ekso-training on non-motor outcomes, including gastrointestinal function and psychological well-being, in post stroke patients. We enrolled 30 post-stroke subjects, which were randomized into two groups in order of recruitment: 15 patients were trained with the overground exoskeleton Ekso-GT (experimental group, EG), whereas 15 patients were submitted to a standard gait training (control group, CG). Both the groups underwent the same amount of physiotherapy. At the end of the training, only in the EG we observed a significant improvement in constipation, mood, and coping strategies, with regard to social support, as well as in the perception of quality of life (as per SF-12). According to these preliminary data, overground robotic gait training can be considered a valuable tool in improving non-motor symptoms, including constipation and behavioral disorders in patients with chronic stroke.

The effect of tactile feedback on gait initiation in people with Parkinson's disease: A pilot study.

BACKGROUND: Gait initiation and turning are common triggers for Freezing of Gait (FOG) in people with Parkinson's disease (PD). Recently, it has been shown that closed-loop tactile feedback (CLTF) can be effective to improve turning performance in people with FOG. RESEARCH QUESTION: Does CLTF change the preparation and execution of the first step during gait initiation? METHODS: People (n = 36) with PD with FOG (PD + FOG) (n = 18) and without FOG (PD-FOG) (n = 18) were included in the study and performed self-initiated gait with or without CLTF under single and dual task conditions. Anticipatory postural adjustments (APAs) and step kinematics were quantified with inertial measurement units (IMUs). Muscle activity of the right and left tensor fasciae latae (TFL) was measured via EMG recordings. RESULTS: PD + FOG and PD-FOG did not differ in age, gender and disease duration and severity (p > 0.05). PD + FOG performed smaller APAs (F = 4.559, p = 0.04) with a higher amount of TFL co-contraction (F = 6.034, p = 0.02) compared to PD-FOG. CLTF had no effect on APAs but led to an increase in first step duration (F = 7.921, p = 0.008). CONCLUSIONS: PD + FOG had smaller APAs and higher left and right TFL co-contraction during gait initiation. CLTF did not impact preparation of the first step but led to a slower execution of the first step. We speculate that, similarly to findings from turning, CLTF might result in the participant attending more closely to the first step compared to without CLTF. Whether increased attention on gait initiation is beneficial in diminishing FOG should be investigated in more detail.

Analysis of non-invasive gait recording under free-living conditions in patients with Parkinson's disease: relationship with global cognitive function and motor abnormalities.

BACKGROUND: We investigated the gait characteristics of patients with Parkinson's disease (PD), under free-living conditions, using a wearable device, and assessed their relationships with global cognitive function and motor abnormalities. METHODS: The study subjects comprised patients with PD aged < 80 years, with a Mini-Mental State Examination (MMSE) score of ≥20, free of any motor complications. A wearable sensor with a built-in tri-axial accelerometer was waist-mounted on each patient, and continuous, 24-h records were obtained. The mean gait cycle duration and mean gait acceleration amplitude, under free-living conditions, were computed and analyzed to determine their relationship with disease duration, MMSE score, Unified Parkinson's Disease Rating Scale (UPDRS) Part III score, and postural instability and gait difficulty (PIGD) score. RESULTS: The study included 106 consecutive patients with PD. The mean gait cycle duration was 1.18 ± 0.12 s, which was similar to that of the normal controls. However, the mean gait acceleration amplitude of PD patients (1.83 ± 0.36 m/s2) was significantly lower than that of the control (p < 0.001). In PD patients, the mean gait acceleration amplitude correlated with the MMSE (ß = 0.197, p = 0.028), UPDRS Part III (ß = - 0.327, p < 0.001), and PIGD (ß = - 0.235, p = 0.008) scores. CONCLUSIONS: The gait rhythm of PD patients is preserved at levels similar to those of normal subjects. However, the mean gait acceleration amplitude was significantly reduced in patients with PD. The results indicate that gait acceleration amplitude correlates with the severity of motor disorders and global cognitive function.

The effects of dual-task cognitive interference on gait and turning in Huntington's disease.

Huntington's disease (HD) is characterized by motor, cognitive, and psychiatric dysfunction. HD progression causes loss of automaticity, such that previously automatic tasks require greater attentional resources. Dual-task (DT) paradigms and fast-paced gait may stress the locomotor system, revealing deficits not seen under single-task (ST). However, the impact of gait "stress tests" on HD individuals needs further investigation. Therefore, the aims of this study were to investigate whether: 1) fast-paced and dual-task walking uncover deficits in gait and turning not seen under single-task, 2) cognitive and gait outcomes relate to fall incidence, and 3) gait deficits measured with wearable inertial sensors correlate with motor symptom severity in HD as measured by the Unified Huntington's disease Rating Scale-total motor score (UHDRS-TMS). Seventeen HD (55 ± 9.7 years) and 17 age-matched controls (56.5 ± 9.3 years) underwent quantitative gait testing via a 25m, two-minute walk test with APDMTM inertial sensors. Gait was assessed under a 1) ST, self-selected pace, 2) fast-as-possible (FAP) pace, and 3) verbal fluency DT. The UHDRS-TMS and a cognitive test battery were administered, and a retrospective fall history was obtained. During ST, DT, and FAP conditions, HD participants demonstrated slower gait, shorter stride length, and greater lateral step and stride length variability compared to controls (p<0.00001 to 0.034). Significant dual-task costs (DTC) were observed for turns; HD participants took more time (p = 0.013) and steps (p = 0.028) to complete a turn under DT compared to controls. Higher UHDRS-TMS correlated with greater stride length variability, less double-support, and more swing-phase time under all conditions. Decreased processing speed was associated with increased gait variability under ST and FAP conditions. Unexpectedly, participant's self-reported falls did not correlate with any gait or turn parameters. HD participants demonstrated significantly greater DTC for turning, which is less automatic than straight walking, requiring coordination of body segments, anticipatory control, and cortical regulation. Turn complexity likely makes it more susceptible to cognitive interference in HD.

A botanical drug composed of three herbal materials attenuates the sensorimotor gating deficit and cognitive impairment induced by MK-801 in mice.

OBJECTIVES: A botanical drug derived from the ethanolic extract composed of Clematis chinensis Osbeck (Ranunculaceae), Trichosanthes kirilowii Maximowicz (Cucurbitaceae) and Prunella vulgaris Linné (Lamiaceae) has been used to ameliorate rheumatoid arthritis as an ethical drug in Korea. In our study, we investigated the effect of this herbal complex extract (HCE) on schizophrenia-like behaviours induced by MK-801. METHODS: HCE (30, 100 or 300 mg/kg, p.o) was orally administered to male ICR mice to a schizophrenia-like animal model induced by MK-801. We conducted an acoustic startle response task, an open-field task, a novel object recognition task and a social novelty preference task. KEY FINDINGS: We found that a single administration of HCE (100 or 300 mg/kg) ameliorated MK-801-induced abnormal behaviours including sensorimotor gating deficits and social or object recognition memory deficits. In addition, MK-801-induced increases in phosphorylated Akt and GSK-3ß expression levels in the prefrontal cortex were reversed by HCE (30, 100 or 300 mg/kg). CONCLUSIONS: These results imply that HCE ameliorates MK-801-induced dysfunctions in prepulse inhibition, social interactions and cognitive function, partly by regulating the Akt and GSK-3ß signalling pathways.

Context-Dependent Behavior in Parkinson's Disease With Freezing of Gait.

Background. Context-dependent behavior is a phenomenon in which people demonstrate superior performance in the context where a motor task was originally learned, but show poorer performance in an unfamiliar context. Previous studies found that people with Parkinson's disease (PD) demonstrated greater context-dependency than nondisabled adults. Moreover, the frontostriatal circuit appeared to play a role in mediating context-dependent behavior. Neuroimaging studies showed that people with PD and freezing of gait (FoG) had difficulty recruiting the frontostriatal circuit when performing a set-shifting task, known to be mediated by this neural network. Objective. This study aimed to investigate whether individuals with PD and FoG (PD + FoG) would be more context-dependent than those without FoG (PD - FoG). Furthermore, the association between context-dependent behavior and set-shifting ability would be determined. Methods. Sixteen individuals with PD + FoG, 15 participants with PD - FoG, and 15 nondisabled adults (Control) were recruited. The participants practiced 3 numerical sequences, each associated with a specific context. One day following practice, the participants were tested under 2 conditions: the sequence-context associations remained the same as practice or were changed. Set-shifting ability was measured by the Trail Making Test (TMT). Results. Compared to the PD - FoG group, the PD + FoG group showed a greater decrement in normalized motor performance when the sequence-context associations were changed. Context-dependency correlated with the TMT in the PD - FoG group but not in the PD + FoG or Control groups. Conclusion. While people with PD + FoG appeared to be more context-dependent than individuals without FoG, a relationship between context-dependent behavior and set-shifting existed only in those without FoG.

Dual-Task Obstacle Crossing Training Could Immediately Improve Ability to Control a Complex Motor Task and Cognitive Activity in Chronic Ambulatory Individuals With Spinal Cord Injury.

Background: The effectiveness of dual-task training has been reported in individuals with cognitive impairments. To date, there is no clear evidence on the incorporation of dual-task training in ambulatory individuals with spinal cord injury (SCI) who have intact cognitive functions but have various degrees of sensorimotor dysfunction. Objectives: To compare the immediate effects of dual-task obstacle crossing (DTOC) and single-task obstacle crossing (STOC) training on functional and cognitive abilities in chronic ambulatory participants with SCI. Methods: This is a randomized 2 × 2 crossover design with blinded assessors. Twenty-two participants were randomly trained using a 30-minute DTOC and STOC training program with a 2-day washout period. Outcomes, including 10-Meter Walk Tests (single- and dual-task tests), percent of Stroop Color and Word Test task errors, Timed Up and Go Test (TUG), and five times sit-to-stand test, were measured immediately before and after each training program. Results: Participants showed significant improvement in all outcomes following both training programs (p < .05), except percent of Stroop Color and Word Test task errors after STOC training. Obvious differences between the training programs were found for the percent of Stroop task errors and TUG (ps = .014 and .06). Conclusion: Obstacle crossing is a demanding task, thus the obvious improvement was found immediately after both training programs in participants with long post-injury time (approximately 5 years). However, the findings primarily suggest the superior effects of DTOC over STOC on a complex motor task and cognitive activity. A further randomized control trial incorporating a complex dual-task test is needed to strengthen evidence for the benefit of DTOC for these individuals.

The Effect of Motor and Cognitive Tasks on Gait in People with Stroke.

OBJECTIVE: Gait of people with unilateral stroke is characterized by pronounced asymmetry. The aim of the study was to investigate the effect of cognitive and motor tasks on asymmetry of gait in people with stroke. MATERIALS AND METHODS: Nine individuals with stroke walked over the GAITRite walkway while performing motor (holding a cup with water) or cognitive (reciting the alphabet) tasks or walked with no additional task. Gait velocity, cadence, and symmetry indexes for the stance phase, swing phase, and single support phase of a gait cycle were calculated. RESULTS: The motor and cognitive tasks negatively affected gait velocity (P < .05) and cadence (P < .05). Walking and performing additional tasks resulted in the increase of the asymmetry of gait. The cognitive task had a greater effect on gait asymmetry than the motor task. CONCLUSIONS: The study outcome revealed that gait of individuals with stroke could be affected by simultaneous performance of additional tasks. The outcome provides a basis for future investigation of the ways of improving symmetry of gait in people with stroke.