Fitness-to-drive agreements after stroke: medical versus practical recommendations.

BACKGROUND AND PURPOSE: Physicians often struggle to screen out patients who are no longer fit to drive after stroke. The agreement between the recommendations of physicians and on-road assessors with regard to fitness to drive after stroke was investigated. METHODS: In this retrospective study, 735 patients with stroke underwent medical, visual and road tests at an official fitness-to-drive center of the Belgian Road Safety Institute. Physicians provided medical fitness-to-drive recommendations using one of three categories (favorable, reserved or unfavorable). On-road assessors used the same three categories to make practical fitness-to-drive recommendations. Agreement between the medical and practical fitness-to-drive recommendations was calculated using the percentage of agreement and prevalence and bias adjusted kappa (PABAK). Area under the curve (AUC) was used to predict the medical and practical recommendations after stepwise logistic regression analyses. RESULTS: The percentage of agreement was 73% and the PABAK was 0.60 (P < 0.0001). Physicians disagreed on 92% of patients classified as unfavorable and 80% of those classified as reserved by the on-road assessor. Previous visits to the driving center and number of comorbidities predicted medical fitness-to-drive recommendations (AUC = 0.68). Age, previous visits to the center, binocular acuity and driving experience constituted the best model to predict practical fitness-to-drive recommendations (AUC = 0.70). CONCLUSIONS: Although there was a moderate agreement between the medical and practical fitness-to-drive recommendations, physicians were less likely to screen out those patients who may pose an actual risk on the road. Demographic, clinical and driving factors differently affected the medical and practical fitness-to-drive recommendations.

Between-sessions test-retest reliability of prefrontal cortical activity during usual walking in patients with Parkinson's Disease: A fNIRS study.

BACKGROUND: Examining between-sessions test-retest reliability of functional near-infrared spectroscopy (fNIRS) data is crucial to better interpret rehabilitation-related changes in the hemodynamic response. RESEARCH QUESTION: This study investigated test-retest reliability of prefrontal activity during usual walking in 14 patients with Parkinson's Disease with a fixed retest intervals of five weeks. METHODS: Fourteen patients performed usual walking in two sessions (T0 and T1). Relative changes in cortical activity (oxy and deoxyhemoglobin: ∆HbO2 and ∆HbR, respectively) in the dorsolateral prefrontal cortex (DLPFC) using fNIRS system and gait performance were measured. Test-retest reliability of mean ∆HbO2 for the total DLPFC and for each hemisphere were measured using paired t-test, intraclass correlation coefficient (ICC), and Bland-Altman plots with 95% agreement. Pearson correlations between cortical activity and gait performance were also performed. RESULTS: Moderate reliability was found for ∆HbO2 in the total DLPFC (mean difference of ∆HbO2 between T1 and T0 = -0.005 µmol, p = 0.93; ICC average = 0.72). However, test-retest reliability of ∆HbO2 was poorer when considering each hemisphere. SIGNIFICANCE: Findings suggest that fNIRS may be used as a reliable tool for rehabilitation studies in patients with PD. Test-retest reliability of fNIRS data between 2 sessions during walking tasks should be interpreted respectively of gait performance.

Increased prefrontal activity during usual walking in aging.

Executive functions are important for successful accomplishment of walking tasks, particularly during a dual task. Over the past few years, several studies investigated prefrontal cortex activity under different walking conditions in older adults with functional near infrared spectroscopy (fNIRS). However, little is known about changes in dorsolateral prefrontal cortex (DLPFC) activity during walking in the early stages of aging. The main objective of this study was to compare changes in DLPFC activity during simple and dual task walking across three different age groups. Twenty-five young (age range = 18-37), twenty-five youngest-old (age range = 55-65), and twenty-five older adults (age range = 67-87) participated in this study. Main results showed that, during simple task walking, older adults had increased DLPFC activity with equivalent walking performance. This increased mainly concerned the right hemisphere. During dual task walking, older adults had increased right DLPFC activity but seemed to have enough resources to maintain their performance during DT walking. This result supports the idea that compensation mechanisms, due to loss of automaticity of walking in aging, appear already during simple task walking. Measuring cortical activity with fNIRS during a simple task walking might be used as valuable indicator for identifying individuals at risk of falling.

An intensive exercise-based training program reduces prefrontal activity during usual walking in patients with Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) leads to a progressive loss of locomotor automaticity. Consequently, PD patients rely more on executive resources for the control of gait, resulting in increased prefrontal activity while walking. Exercise-based training programs may improve automaticity of walking and reduce prefrontal activity in this population. This study aimed to assess the effect of an intensive multidisciplinary exercise-based training program on prefrontal activity and gait performance during usual walking in PD patients. METHOD: Fourteen patients (mean age: 67 ± 9; disease duration: 6 ± 5 years; Hoehn and Yahr score: 1.9 ± 0.6) were included in this study. They were assessed in ON stage at three different times at 5-week intervals: two times before the training program (T0 and T1) and once after the training program (T2). Gait performance (stride time, speed, stride length, cadence, and their respective coefficient of variation) and cortical activity in the dorsolateral prefrontal cortex (DLPFC) using functional near infrared spectroscopy (fNIRS) were measured during usual walking. RESULTS: Patients had reduced cortical activity of the DLPFC at T2 compared to T1 (p = 0.003). Patients had shorter stride time at T2 compared to T1 (p = 0.025) and tended to have longer stride length at T2 than at T1 (p = 0.056). CONCLUSION: The training program led to positive effects on prefrontal activity and gait performance. Reduced prefrontal activity during usual walking after training program suggests that patients may have a greater reserve capacity to face more challenging walking conditions. Further studies will investigate the effect of this training on cortical activity during dual-task walking..

Visual search and target detection during simulated driving in Parkinson's disease.

Patients with Parkinson's Disease (PD) often exhibit difficulties with visual search that may impede their ability to recognize landmarks and cars while driving. The main objective of this study was to investigate visual search performances of both billboards and cars in patients with PD using a driving simulator. A second objective was to examine the role of cognitive functions in performing the visual search task while driving. Nineteen patients with PD (age: 68 ±â€¯8yo, sex (Men/Women): 15/4) and 14 controls (age: 60 ±â€¯11yo, sex: 7/7) first performed a battery of cognitive tests. They then drove in a simulator and were instructed to follow a lead vehicle while searching for billboards with the letter A (stationary target) or red cars (moving target) among other distractors. Accuracy and response times of visual search were the main outcome variables. Standard deviation of lateral position (SDLP) was the secondary outcome. During driving, patients were less accurate in identifying the targets, particularly for the stationary billboards located in the outer periphery. Within the group of patients, significant correlations were found between several measures of cognitive tests and simulator-based visual search accuracy. By contrast, only the score on the MOCA test correlated significantly with visual search accuracy in controls. Findings suggest that patients with PD have impaired visual search for more eccentric stationary targets while driving a simulator, which is likely due to cognitive deficits. Difficulties identifying objects in the outer periphery may have implications for driving safety. Decreased functional field of view under increased cognitive load may have attributed to the difficulties identifying these landmarks. This may impact the ability to identify, anticipate, and respond to important information (e.g., pedestrians, navigation signs, landmarks), especially in complex driving situations (e.g. urban driving or intersections).Future studies should be conducted in a larger sample size to determine whether a visual search task on a driving simulator may predict on-road driving performances.

Pupillary response to cognitive workload during saccadic tasks in Parkinson's disease.

The relationship between cognitive workload and cognitive impairments in Parkinson's disease (PD) is currently not well known. This study compared cognitive workload during saccadic tasks between patients with PD and controls. Sixteen controls, 11 patients with no obvious cognitive impairment (PD-NCI) (MOCA score≥26), and 10 PD patients with cognitive impairment (PD-CI) (MOCA score<26) performed prosaccade and antisaccade tasks. Cognitive workload, extracted via pupil recording, and other eye metrics were compared between the three groups. PD-NCI patients exhibited greater cognitive workload than controls in the prosaccade task. PD-CI patients also showed more cognitive workload in the prosaccade task than PD-NCI patients and controls. No other differences in eye metrics were found between the three groups. Cognitive workload could be used to differentiate between different cognitive states in PD. The causal relationship between increased cognitive workload and cognitive decline in PD-NCI should be the focus of future studies.