Fitness-to-drive recommendations in post-stroke patients: a retrospective study.

BACKGROUND: Stroke sequelae can have an impact on daily life activities such as driving. French legislation stipulates that post-stroke patients should undergo a multi-professional fitness-to-drive assessment before being allowed to drive again. This retrospective study aims to explore the determinants of multi-professional fitness-to-drive recommendations. METHODS: Sixty-six post-stroke patients assessed for fitness to drive in the Kerpape Center, France in 2019 were included. Favorable or unfavorable driving recommendations were attributed to patients following a joint decision by a multi-professional team. Individual characteristics obtained from medical records were compared. RESULTS: Findings showed that 64% of stroke patients received a favorable fitness-to-drive recommendation. Across all demographic, clinical, and driving characteristics, the time interval between stroke and assessment was significantly longer for patients designated as unfit to drive than for those designated as fit to drive (P = .004). Furthermore, the proportion of instrumental sequelae was higher in patients designated as unfit to drive than in those designated as fit to drive (P = .022). Stepwise logistic regression showed that the presence of instrumental sequelae, mainly aphasia, was the best predictor of fitness-to-drive recommendations. CONCLUSIONS: The post-stroke time interval and the presence of instrumental sequelae explained the difference between patients recommended as fit-to-drive and unfit-to-drive. Furthermore, aphasia was found be the best predictor of a fitness-to-drive recommendation. It is possible that aphasia impacts the understanding of instructions during on-road testing. These findings emphasize the need for a standardized multi-professional fitness-to-drive assessment, since the determinants of fitness-to-drive recommendation differ between studies.

Interaction between pedestrians and automated vehicles: Perceived safety of yielding behaviors and benefits of an external human-machine interface for elderly people.

This study focuses on Automated Vehicles (AVs) interactions with pedestrians during road crossing situations. A dual-phase experiment was designed: one from the pedestrian's perspective and the other one from the AV passenger's point of view. Eight AV behaviors to yield were investigated. Participants' task was to assess the safety of each one of these yielding behaviors. Moreover, an external HMI (eHMI) was designed to support them in these interactions. 40 participants were involved in this experiment (50% females, 20 young versus 20 elderly). Results obtained show significant differences between old and young participants: elderly people have not the same way to perceive and assess the safety of the yielding behaviors from "the inside" and from "the outside" of the car. Conversely, young participants assessed AV behaviors similarly whether as pedestrians or as AV passengers. When considering benefits introduced by the eHMI, it significantly reduces differences between old and young participants and tends to harmonize their safety assessments: with to the eHMI, elderly people are more able to adequately perceive and assess the safety/dangerousness of the AV braking manoeuvers, and their safety judgments become at last quite similar to those of young participants. Moreover, the eHMI increases participants' Acceptance of AV and reduces their concerns about their future interactions with AV as a pedestrian, especially for elderly people.

Changes in Prefrontal Cortical Activity During Walking and Cognitive Functions Among Patients With Parkinson's Disease.

Background: Walking becomes more and more degraded as Parkinson's Disease (PD) progresses. Previous research examined factors contributing to this deterioration. Among them, changes in brain cortical activity during walking have been less studied in this clinical population. Objectives: This study aimed to: (1) investigate changes in dorsolateral prefrontal cortex (DLPFC) activation during usual walking and dual-task walking conditions in patients with PD; (2) examine the association between cortical activity and behavioral/cognitive outcomes; and (3) explore which factors best predict increased activation of the DLPFC during usual walking. Methods: Eighteen patients with early stage PD and 18 controls performed 4 conditions: (1) standing while subtracting, (2) usual walking, (3) walking while counting forward, and (4) walking while subtracting. Cortical activity in DLPFC, assessed by changes in oxy-hemoglobin (ΔHbO2) and deoxy-hemoglobin (ΔHbR), was measured using functional near infrared spectroscopy (fNIRS). Gait performance was recorded using wearables sensors. Cognition was also assessed using neuropsychological tests, including the Trail Making Test (TMT). Results: DLPFC activity was higher in patients compared to controls during both usual walking and walking while subtracting conditions. Patients had impaired walking performance compared to controls only during walking while subtracting task. Moderate-to-strong correlations between ΔHbO2 and coefficients of variation of all gait parameters were found for usual walking and during walking while counting forward conditions. Part-B of TMT predicted 21% of the variance of ΔHbO2 during usual walking after adjustment for group status. Conclusions: The increased DLPFC activity in patients during usual walking suggests a potential compensation for executive deficits. Understanding changes in DLPFC activity during walking may have implications for rehabilitation of gait in patients with PD.

Measuring the Cognitive Workload During Dual-Task Walking in Young Adults: A Combination of Neurophysiological and Subjective Measures.

Background: Walking while performing a secondary task (dual-task (DT) walking) increases cognitive workload in young adults. To date, few studies have used neurophysiological measures in combination to subjective measures to assess cognitive workload during a walking task. This combined approach can provide more insights into the amount of cognitive resources in relation with the perceived mental effort involving in a walking task. Research Question: The objective was to examine cognitive workload in young adults during walking conditions varying in complexity. Methods: Twenty-five young adults (mean = 24.4 ± 5.4) performed four conditions: (1) usual walking, (2) simple DT walking, (3) complex DT walking and (4) standing while subtracting. During the walking task, mean speed, cadence, stride time, stride length, and their respective coefficient of variation (CV) were recorded. Cognitive workload will be measured through changes in oxy- and deoxy-hemoglobin (ΔHbO2 and ΔHbR) during walking in the dorsolateral prefrontal cortex (DLPFC) and perceived mental demand score from NASA-TLX questionnaire. Results: In young adults, ΔHbO2 in the DLPFC increased from usual walking to both DT walking conditions and standing while subtracting condition. ΔHbO2 did not differ between the simple and complex DT and between the complex DT and standing while subtracting condition. Perceived mental demand gradually increased with walking task complexity. As expected, all mean values of gait parameters were altered according to task complexity. CV of speed, cadence and stride time were significantly higher during DT walking conditions than during usual walking whereas CV of stride length was only higher during complex DT walking than during usual walking. Significance: Young adults had greater cognitive workload in the two DT walking conditions compared to usual walking. However, only the mental demand score from NASA-TLX questionnaire discriminated simple from complex DT walking. Subjective measure provides complementary information to objective one on changes in cognitive workload during challenging walking tasks in young adults. These results may be useful to improve our understanding of cognitive workload during walking.