Executive Functioning, Muscle Power and Reactive Balance Are Major Contributors to Gait Adaptability in People With Parkinson's Disease

Assessing acute effects of two motor-cognitive training modalities on cognitive functions, postural control, and gait stability in older adults: a randomized crossover study

Background

The process of aging often accompanies a decline in cognitive function, postural control, and gait stability, consequently increasing the susceptibility to falls among older individuals. In response to these challenges, motor-cognitive training has emerged as a potential intervention to mitigate age-related declines.

Objective

This study aims to assess the acute effects of two distinct motor-cognitive training modalities, treadmill dual-task training (TMDT) and interactive motor-cognitive training (IMCT), on cognitive function, postural control, walking ability, and dual-task performance in the elderly population.

Method

In this randomized crossover study, 35 healthy elderly individuals (aged 60-75) participated in three acute training sessions involving TMDT, IMCT, and a control reading condition. Assessments of executive function, postural control, gait performance, and cognitive accuracy were conducted both before and after each session.

Results

Both TMDT and IMCT improved executive functions. Notably, IMCT resulted in a significant enhancement in correct response rates and a reduction in reaction times in the Stroop task (p < 0.05) compared to TMDT and the control condition. IMCT also led to an increase in dual-task gait speed (p < 0.001) and showed a trend towards improved cognitive accuracy (p = 0.07). Conversely, TMDT increased postural sway with eyes open (p = 0.013), indicating a potential detriment to postural control.

Conclusion

The findings suggest that IMCT holds greater immediate efficacy in enhancing cognitive function and gait stability among older adults compared to TMDT, with a lesser adverse impact on postural control. This underscores the potential of IMCT as a preferred approach for mitigating fall risk and enhancing both cognitive and physical functions in the elderly population.

Association between executive and physical functions in people with Parkinson's disease

PURPOSE

People with Parkinson's disease (PD) can develop cognitive and physical impairments. There is limited evidence on the association between executive function and physical function in people with PD.

OBJECTIVE

We aimed to investigate the association between the executive and physical functions in people with Parkinson's disease (PD) by comparing healthy controls.

METHOD

Thirty-three patients diagnosed with PD and 33 healthy controls were included in the study. PD group was divided into two subgroups according to their scores on executive tests as high performers (PD-HPs; n = 17) and low performers (PD-LPs; n = 16). The severity of motor symptoms disease severity, executive function, global cognitive function, reaction time, hand function, functional capacity, physical activity, and balance confidence was assessed by the validated instruments.

RESULTS

The PD group had less physical function and executive function compared to healthy controls (p < 0.05). The PD-LPs group had less physical and cognitive function than the PD-HPs group (p < 0.05). The executive functions were significantly correlated with almost all variables in both people with PD and healthy people, and correlations were moderate to strong (p < 0.05). However, the correlation coefficients were relatively higher in people with PD compared to healthy controls.

CONCLUSION

There was a significant association between executive and physical function in people with PD. Future studies should be conducted to determine whether the treatment of one of these dysfunctions affects the other.

Sex-related differences in the posture and vertical perception of gait function in patients with Parkinson's disease

BACKGROUND

Although several factors, such as sex and body schema, contribute to gait function, factors for gait dysfunction in Parkinson's disease (PD) have not been elucidated. Postural verticality, a higher-order neural mechanism of gait, is involved in generation of a gait program in healthy individuals; however, its role in patients with PD is unclear. Although subjective postural vertical (SPV), which denotes cognitive information about posture with verticality as the reference axis, is anteriorly and laterally shifted in patients with PD, the presence of sex-related differences in SPV and effect of SPV on gait function remain unclear. Since SPV affects the degree of flexion and lateral bending posture and long-term prognosis of PD, factors affecting SPV in patients with PD should be clarified to improve gait function.

RESEARCH QUESTION

Is vertical perception of posture (i.e., SPV) related to gait function in patients with PD? Are there any sex-related differences?

METHODS

The gait and SPV were evaluated in 59 adult outpatients with PD (31 men and 28 women) using five gait (step length, walking speed, coefficient of variation of step time [step CV], cadence, and mean gait acceleration [acceleration]) and two SPV (SPV in the sagittal and coronal planes) assessments and compared between the sexes.

RESULTS

No sex-related differences were observed in the SPV in patients with PD. The SPV and gait assessments demonstrated no association in men. Walking speed and SPV in the sagittal plane (p = 0.029), and step CV and SPV in the coronal (p = 0.018) and sagittal planes (p = 0.032) were correlated in women.

SIGNIFICANCE

Although no sex-related differences in the SPV were observed, our results demonstrated that the SPV is involved in gait function in women but not in men with PD.

Effects of motor and cognitive complex training on obstacle walking and brain activity in people with Parkinson's disease: a randomized controlled trial

BACKGROUND

The difficulties in obstacle walking are significant in people with Parkinson's disease (PD) leading to an increased fall risk. Effective interventions to improve obstacle walking with possible training-related neuroplasticity changes are needed. We developed two different exercise programs, complex walking training and motor-cognitive training, both challenging motor and cognitive function for people with PD to improve obstacle walking.

AIM

To investigate the effects of these two novel training programs on obstacle walking and brain activities in PD.

DESIGN

A single-center randomized, single-blind controlled study.

SETTING

University laboratory; outpatient.

POPULATION

Individuals with idiopathic PD.

METHODS

Thirty-two participants were randomly assigned to the complex walking training group (N.=11), motor-cognitive training group (N.=11) or control group (N.=10). Participants in training groups received exercises for 40 minutes/session, with a total of 12-session over 6 weeks. Control group did not receive additional training. Primary outcomes included obstacle walking, and brain activities (prefrontal cortex (PFC), premotor cortex (PMC), and supplementary motor area (SMA)) during obstacle walking by using functional near-infrared spectroscopy. Secondary outcomes included obstacle crossing, timed up and go test (TUG), cognitive function in different domains, and fall efficacy scale (FES-I).

RESULTS

The motor-cognitive training group demonstrated greater improvements in obstacle walking speed and stride length, SMA activity, obstacle crossing velocity and stride length, digit span test, and TUG than the control group. The complex walking training did not show significant improvement in obstacle walking or change in brain activation compared with control group. However, the complex walking training resulted in greater improvements in Rey-Osterrieth Complex Figure test, TUG and FES-I compared with the control group.

CONCLUSIONS

Our 12-session of the cognitive-motor training improved obstacle walking performance with increased SMA activities in people with PD. However, the complex walking training did not lead such beneficial effects as the cognitive-motor training.

CLINICAL REHABILITATION IMPACT

The cognitive-motor training is suggested as an effective rehabilitation program to improve obstacle walking ability in individuals with PD.

Changes in postural stability after cerebrospinal fluid tap test in patients with idiopathic normal pressure hydrocephalus

Introduction

In patients with idiopathic normal pressure hydrocephalus (iNPH), the characteristics of balance disturbance are not as well understood as those related to gait. This study examined changes in postural stability in quiet standing after the cerebrospinal fluid tap test (CSFTT) in these patients. Furthermore, the study explored the relationship between the amount of spontaneous body sway and both gait and executive function.

Materials and methods

All patients diagnosed with iNPH underwent CSFTT. We evaluated their center of pressure (COP) measurements on a force plate during quiet standing, both pre- and post-CSFTT. Following the COP measurements, we calculated COP parameters using time and frequency domain analysis and assessed changes in these parameters after CSFTT. At pre-CSFTT, we assessed the Timed Up and Go (TUG) and the Frontal Assessment Battery (FAB). We investigated the relationship between COP parameters and the TUG and FAB scores at pre-CSFTT.

Results

A total of 72 patients with iNPH were initially enrolled, and 56 patients who responded positively to CSFTT were finally included. Post-CSFTT, significant improvements were observed in COP parameters through time domain analysis. These included the velocity of COP (vCOP), root-mean-square of COP (rmsCOP), turn index, torque, and base of support (BOS), compared to the pre-CSFTT values (p < 0.05). In the frequency domain analysis of COP parameters post-CSFTT, there was a decrease in both the peak and average of power spectral density (PSD) values in both the anteroposterior (AP) and mediolateral (ML) directions below 0.5 Hz (p < 0.05). In addition, the TUG scores showed a positive correlation with vCOP, rmsCOP, turn index, torque, BOS, and both the peak and average PSD values in the AP and ML directions below 0.5 Hz (p < 0.05). The FAB scores demonstrated a negative correlation with vCOP, rmsCOP, turns index, BOS, and both peak and average PSD values in the AP direction below 0.5 Hz (p < 0.05).

Conclusion

In patients with iNPH who responded to CSFTT, there was an improvement in spontaneous body sway during quiet standing after CSFTT. Increased spontaneous sway is associated with impaired gait and frontal lobe function. This may be linked to impaired cortico-cortical and cortico-subcortical circuits in patients with iNPH.

Two-year course of walking adaptability in persons living with late effects of polio

OBJECTIVE

To evaluate the 2-year course of walking adaptability in persons with late effects of polio.

DESIGN

Prospective cohort study.

PATIENTS

A total of 48 persons with late effects of polio (69% female, mean age 63.1 years) with a fall history and/or fear of falling.

METHODS

Walking adaptability (i.e. variable target-stepping and reactive obstacle-avoidance) was assessed on an interactive treadmill at baseline, 1 year and 2 years. Further, leg-muscle strength and balance were assessed at baseline. The course of walking adaptability was analysed with linear mixed models. Based on median values, subgroups were defined for low vs high baseline walking-adaptability and for clinical characteristics. Tme by subgroup interactions were analysed.

RESULTS

Variable target-stepping and reactive obstacle-avoidance did not change (p > 0.285). Reactive obstacle-avoidance improved for persons with a high balance score at baseline (p = 0.037), but not for those with lower scores (p = 0.531). No other time by subgroup interactions were found (p > 0.126).

CONCLUSION

Walking adaptability did not change in persons with late effects of polio over 2 years, and walking adaptability course did not differ between subgroups stratified for walking adaptability determinants, except for balance. Since falls are a major problem among persons with late effects of polio, future studies should investigate whether walking adaptability declines over a longer time and which persons are most at risk.

Role of exercise in modulating prefrontal cortical activation for improved gait and cognition in Parkinson's disease patients

PURPOSE

This narrative review evaluated the impact of exercise on gait and cognitive functions in patients with Parkinson's disease (PD), focusing on prefrontal cortical (PFC) activation assessed using near-infrared spectroscopy (NIRS).

METHODS

A literature search was conducted in the PubMed and Web of Science databases using keywords such as "Parkinson's disease," "gait," "cognitive functions," "exercise," and "NIRS," focusing on publications from the last decade. Studies measuring PFC activity using NIRS during gait tasks in patients with PD were selected.

RESULTS

The review indicated that patients with PD demonstrate increased PFC activity during gait tasks compared to healthy controls, suggesting a greater cognitive demand for movement control. Exercise has been shown to enhance neural efficiency, thus improving gait and cognitive functions.

CONCLUSION

Exercise is crucial for improving gait and cognitive functions in patients with PD through increased PFC activation. This emphasizes the importance of incorporating exercise into PD management plans and highlights the need for further studies on its long-term effects and the neurobiological mechanisms underlying its benefits, with the aim of optimizing therapeutic strategies and improving patients' quality of life.

Age-related effects of repeated task switching in a novel voluntary gait adaptability task

Age-related effects of task switching have been extensively studied based on cognitive tasks and simple motor tasks, but less on complex cognitive-motor tasks involving dynamic balance control while walking. The latter tasks may especially be difficult and relevant for older adults in terms of safe mobility in daily life. The aim of the present study was, therefore, to examine age-related changes in task-switching adaptability using a novel voluntary gait adaptability test protocol. Fifteen healthy young (27.5 ± 2.9 years) and 16 healthy old (70.9 ± 7.6 years) adults carried out 2 different visual target stepping tasks (either target avoidance or stepping) twice in a block (A-B-A-B, 2 min per task; three blocks in total) without any intrablock breaks. Our results showed that old adults showed significantly more step errors both in Tasks A and B as well as more interference effects than young adults. Age-related differences in step accuracy were significant in the anterior-posterior direction both in Task A and B but not in the mediolateral direction. Both in step errors and accuracy, no interaction effects of age and trial were shown. Our results suggest that old adults could not cope with rapid and direct task changes in our voluntary gait adaptability task as young adults. Since the significant main effect of trial for Task B, but not Task A appears to be due to different task complexity, further studies may determine the effect of task complexity or task switch timing.

Muscle shape changes in Parkinson's disease impair function during rapid contractions

AIM

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized, among the others, by muscle weakness. PD patients reach lower values of peak torque during maximal voluntary contractions but also slower rates of torque development (RTD) during explosive contractions. The aim of this study was to better understand how an impairment in structural/mechanical (peripheral) factors could explain the difficulty of PD patients to raise torque rapidly.

METHODS

Participants (PD patients and healthy matched controls) performed maximum voluntary explosive fixed-end contraction of the knee extensor muscles during which dynamic muscle shape changes (in muscle thickness, pennation angle, and belly gearing: the ratio between muscle belly velocity and fascicle velocity), muscle-tendon unit (MTU) stiffness and EMG activity of the vastus lateralis (VL) were investigated. Both the affected (PDA) and less affected limb (PDNA) were investigated in patients.

RESULTS

Control participants reached higher values of peak torque and showed a better capacity to express force rapidly compared to patients (PDA and PDNA). EMG activity was observed to differ between patients (PDA) and controls, but not between controls and PDNA. This suggests a specific neural/nervous effect on the most affected side. On the contrary, MTU stiffness and dynamic muscle shape changes were found to differ between controls and patients, but not between PDA and PDNA. Both sides are thus similarly affected by the pathology.

CONCLUSION

The higher MTU stiffness in PD patients is likely responsible for the impaired muscle capability to change in shape which, in turn, negatively affects the torque rise.

Intra-individual variability in cognitive performance predicts functional decline in Parkinson's disease

BACKGROUND

Cognitive deficits contribute to disability in Parkinson's disease (PD). Cognitive intra-individual variability (IIV) is associated with cognitive decline in age-related disorders, but IIV has not been related to functional ability in PD. We examined IIV in predicting functional ability in participants with PD.

METHODS

De-identified National Alzheimer's Coordinating Center data (N = 1,228) from baseline and follow-up visits included participants with PD propensity score matched to control participants at baseline on age (M = 72), education (M = 15), and gender (28% female). PD symptom duration averaged 6 years. Outcome measures included the Functional Ability Questionnaire (FAQ), overall test battery mean (OTBM) of ten cognitive variables, IIV calculated as the standard deviation of cognitive data for each participant, Geriatric Depression Scale (GDS), and Unified PD Rating Scale gait and posture items. Baseline FAQ status in the PD group was predicted using logistic regression with age, education, cognition, GDS, and motor function as predictors. We compared baseline characteristics of PD participants with and without functional impairment at follow up.

RESULTS

PD participants showed lower OTBM and greater IIV, GDS, and motor dysfunction than controls (p < .0001). Education, OTBM, IIV, GDS, and gait predicted functional status (77% overall classification; AUC = .84). PD participants with functional impairment at follow up showed significantly lower OTBM and greater IIV, GDS, and motor dysfunction at baseline (p < .001).

CONCLUSION

IIV independently predicts functional status in participants with PD while controlling for other variables. PD participants with functional impairment at follow up showed greater IIV than those without functional impairment at follow up.

Cortical activation during gait adaptability in people with Parkinson's disease

BACKGROUND

People with Parkinson's disease (PD) have difficulties adapting their gait. While underlying neural mechanisms involving the prefrontal cortex (PFC) have been studied across various complex walking tasks, less is known about the premotor cortex (PMC) and supplementary motor area (SMA), key cortical regions for motor planning. This study compared frontal cortical regions activation patterns using functional near-infrared spectroscopy (fNIRS), between people with PD and healthy controls (HC) during gait adaptability tasks.

METHODS

Forty-nine people with PD (mean (SD) age: 69.5 (7.9) years) and 21 HC (69.0 (5.9) years) completed a simple walk and three randomly presented gait adaptability tasks: (i) stepping on targets, (ii) avoiding obstacles and (iii) negotiating both targets and obstacles. Cortical activity in the dorsolateral PFC (DLPFC), SMA and PMC were recorded using fNIRS. Step length, velocity and accuracy and cortical activity were contrasted between the groups and walking conditions.

RESULTS

Compared with the HC, the PD group exhibited greater PMC activation and walked significantly slower and took shorter steps in all conditions. A statistically significant group by condition interaction indicated an increase in DLPFC cortical activation in the HC participants when undertaking the obstacle avoidance task compared with the simple walk but no increase in cortical activation in the PD group when undergoing this more challenging gait task.

CONCLUSIONS

Our findings suggest people with PD have little or no DLPFC, SMA and PMC capacity beyond what they need for simple walking and in consequence need to slow their gait velocity to meet the demands of target stepping and obstacle avoidance tasks. Such behavioral and neural patterns appear consistent with concepts of compensatory over-activation and capacity limitation.

The Added Value of Combined Timed Up and Go Test, Walking Speed, and Grip Strength on Predicting Recurrent Falls in Chinese Community-dwelling Elderly

Purpose

To determine whether combined performance-based models could exert better predictive values toward discriminating community-dwelling elderly with high risk of any-falls or recurrent-falls.

Participants and Methods

This prospective cohort study included a total of 875 elderly participants (mean age: 67.10±5.94 years) with 513 females and 362 males, recruited from Hangu suburb area of Tianjin, China. All participants completed comprehensive assessments.

Methods

We documented information about sociodemographic information, behavioral characteristics and medical conditions. Three functional tests—timed up and go test (TUGT), walking speed (WS), and grip strength (GS) were used to create combined models. New onsets of any-falls and recurrent-falls were ascertained at one-year follow-up appointment.

Results

In total 200 individuals experienced falls over a one-year period, in which 66 individuals belonged to the recurrent-falls group (33%). According to the receiver operating characteristic curve (ROC), the cutoff points of TUGT, WS, and GS toward recurrent-falls were 10.31 s, 0.9467 m/s and 0.3742 kg/kg respectively. We evaluated good performance as “+” while poor performance as “–”. After multivariate adjustment, we found “TUGT >10.31 s” showed a strong correlation with both any-falls (adjusted odds ratio (OR)=2.025; 95% confidence interval (CI)=1.425–2.877) and recurrent-falls (adjusted OR=2.150; 95%CI=1.169–3.954). Among combined functional models, “TUGT >10.31 s, GS <0.3742 kg/kg, WS >0.9467 m/s” showed strongest correlation with both any-falls (adjusted OR=5.499; 95%CI=2.982–10.140) and recurrent-falls (adjusted OR=8.260; 95%CI=3.880–17.585). And this combined functional model significantly increased discriminating abilities on screening recurrent-fallers than a single test (C-statistics=0.815, 95%CI=0.782–0.884, P<0.001), while not better than a single test in predicting any-fallers (P=0.083).

Conclusion

Elderly people with poor TUGT performance, weaker GS but quicker WS need to be given high priority toward fall prevention strategies for higher risks and frequencies. Meanwhile, the combined “TUGT–, GS–, WS+” model presents increased discriminating ability and could be used as a conventional tool to discriminate recurrent-fallers in clinical practice.

Assessment of Force Production in Parkinson's Disease Subtypes

Muscle weakness is a secondary motor symptom of Parkinson's disease (PD), especially in the subtype characterized by postural instability and gait difficulty (PIGD). Since the PIGD subtype also presents worse bradykinesia, we hypothesized that it also shows a decreased rate of force development, which is linked to an increased risk of falling in PD. Therefore, we investigated the effects of PD and PD subtypes on a force production profile and correlated the force production outcomes with clinical symptoms for each PD subtype. We assessed three groups of participants: 14 healthy older adults (OA), 10 people with PD composing the PIGD group, and 14 people with PD composing the tremor-dominant group. Three knee extension maximum voluntary isometric contractions were performed in a leg extension machine equipped with a load cell to assess the force production. The outcome measures were: peak force and rate of force development (RFD) at 50 ms (RFD50), 100 ms (RFD100), and 200 ms (RFD200). We observed lower peak force, RFD50, RFD100, and RFD200 in people with PD, regardless of subtypes, compared with the OA group (p < 0.05 for all comparisons). Together, our results indicated that PD affects the capacity to produce maximal and rapid force. Therefore, future interventions should consider rehabilitation programs for people with PD based on muscle power and fast-force production, and consequently reduce the likelihood of people with PD falling from balance-related events, such as from an unsuccessful attempt to avoid a tripping hazard or a poor and slower stepping response.

The Four Square Step Test for Assessing Cognitively Demanding Dynamic Balance in Parkinson's Disease Patients

Objective

The Four Square Step Test (FSST) is a tool that assesses dynamic balance during obstacle step-over. To date, few studies have used the FSST to measure balance in patients with Parkinson’s disease (PD). This study aimed to verify that patients with PD, even at the de novo early stage, take more time to perform the FSST and identify which factors, cognitive status or cardinal motor symptoms, are related most to FSST scores.

Methods

Thirty-five newly diagnosed drug-naïve patients with PD and 17 controls completed the FSST. The Unified Parkinson’s Disease Rating Scale (UPDRS), Hoehn and Yahr (H&Y) stage, spatiotemporal gait parameters, and neuropsychological test battery were also assessed in the PD group.

Results

Mean FSST performance time was 8.20 ± 1.61 seconds in patients with PD, which was significantly more than the control group (7.13 ± 1.10 seconds, p = 0.018). UPDRS part III total score and H&Y stage were not significantly associated with FSST, but among the UPDRS subscores, only the postural instability/gait disturbance subscore showed a significant association. Regarding the association between FSST and cognition, the Trail Making Test-B and the Color Word Stroop Test showed strongly inverse correlations with FSST (rho = -0.598 and -0.590, respectively). With respect to gait parameters, double support time was significantly associated with FSST score (rho = 0.342, p = 0.044); however, other parameters, including velocity and step length, were not associated with the FSST.

Conclusion

The FSST can be used in the clinic to assess dynamic balance with cognitive demands even in the early stages of PD.

Predictors of physical activity levels in individuals with Parkinson's disease: a cross-sectional study

BACKGROUND

To investigate whether modifiable predictors (depressive symptoms, impairment in behavior and mood, balance impairments, and knee extensor muscle strength) are determinants of the physical activity level in Parkinson's disease.

MATERIALS AND METHODS

A cross-sectional study with individuals diagnosed with idiopathic Parkinson's disease. Regression analysis of the data was used to investigate whether depressive symptoms, impairments in behavior and mood, balance impairments, or dominant knee extensor muscle strength are predictors of physical activity levels in Parkinson's disease.

RESULTS

A total of 50 individuals with mild to moderate Parkinson's disease participated in this study, with a mean age of 67 ± 8 years and 68% male. Balance impairments explained 29% of the variation in the physical activity levels. The explained variance increased to 34% when depressive symptoms were included in the model.

CONCLUSION

Among the predictor variables investigated in our study, only balance impairments and depressive symptoms explained the variance in physical activity levels in individuals with Parkinson's disease.

People With Parkinson’s Disease Exhibit Reduced Cognitive and Motor Cortical Activity When Undertaking Complex Stepping Tasks Requiring Inhibitory Control

Background

People with Parkinson’s disease (PD) have difficulties generating quick and accurate steps in anticipation of and/or in response to environmental hazards. However, neural mechanisms underlying performance in cognitively demanding stepping tasks are unclear.

Objective

This study compared activation patterns in cognitive and motor cortical regions using functional near-infrared spectroscopy (fNIRS) between people with PD and age-matched healthy older adults (HOA) during stepping tasks.

Methods

Fifty-two people with PD and 95 HOA performed a simple choice stepping reaction time test (CSRT) and 2 cognitively demanding stepping tests (inhibitory CSRT [iCSRT] and Stroop stepping test [SST]) on a computerized step mat. Cortical activation in the dorsolateral prefrontal cortex (DLPFC), Broca’s area, supplementary motor area (SMA), and premotor cortex (PMC) were recorded using fNIRS. Stepping performance and cortical activity were contrasted between groups and between the CSRT and the iCSRT and SST.

Results

The PD group performed worse than the HOA in all 3 stepping tests. A consistent pattern of interactions indicated differential hemodynamic responses between the groups. Compared with the CSRT, the PD group exhibited reduced DLPFC activity in the iCSRT and reduced SMA and PMC activity in the SST. The HOA exhibited increased DLPFC, SMA, and PMC activity when performing the SST in comparison with the CSRT task.

Conclusions

In contrast to the HOA, the PD group demonstrated reduced cortical activity in the DLPFC, SMA, and PMC during the more complex stepping tasks requiring inhibitory control. This may reflect subcortical and/or multiple pathway damage with subsequent deficient use of cognitive and motor resources.

Timed Up and Go Test With a Cognitive Task: Correlations With Neuropsychological Measures in People With Parkinson's Disease

Background

The Timed Up and Go (TUG) test is a simple and widely used clinical test for the assessment of lower extremity function, balance, mobility, and fall risk in various populations. The TUG has been found as a valid and reliable measure in people with Parkinson’s disease (PD). Besides, the addition of a cognitive task to the TUG (TUG-cognitive) enhances predictive validity related to fall risk in people with PD. However, further investigation is needed about the correlations of the TUG-cognitive test with neuropsychological measures in people with PD.

Methods

Thirty-three people with PD [modified Hoehn and Yahr scale, median (min-max)=2.5 (1.0-3.0)] participated in this cross-sectional study. The TUG was administered in the traditional way and with a cognitive task (counting backward by three from any number between 20 and 100). Neuropsychological measures included the Montreal Cognitive Assessment (MoCA), Trail Making Test (TMT), and the Simple Reaction Time (SRT) test for stepping. The self-reported number of falls in the last six months was also recorded.

Results

The TUG-cognitive [13.1 (SD=8.5) seconds] was significantly longer than the TUG-traditional [12.2 (SD=8.1) seconds] (p<0.01). The TUG-cognitive significantly correlated with the MoCA [(rho=-0.712), TMT part A (TMT-A; rho=0.722), TMT part B (TMT-B; rho=0.694), SRT (rho=0.794), and number of falls (rho=0.960)] (p<0.01). The TUG-traditional also significantly correlated with the MoCA (rho=-0.682), TMT-A (rho=0.684), TMT-B (rho=0.746), SRT (rho=0.755), and number of falls (rho=0.702) (p<0.01).

Conclusion

Both the TUG-cognitive and TUG-traditional strongly correlated with neuropsychological measures; while the correlations were slightly stronger for the TUG-cognitive, the difference was not significant. The TUG-cognitive can be used in the clinical practice as a simple and more informative alternative to the TUG-traditional in people with PD.