Sensory reweighting of postural control requires distinct rambling and trembling sway adaptations.

BACKGROUND: Implementation of the Sensory Organization Test (SOT) under the rambling-trembling (RM-TR) framework allows for an examination of both individual sensory contributions and compensatory mechanisms, a valuable insight in research and clinical settings. Such investigation could substantially improve our ability to assess and treat fall risk in older adults and people living with neurological disorders. RESEARCH QUESTION: How are RM and TR components of sway influenced by SOT-induced challenges in healthy adults? METHODS: Twenty-three healthy adults (27.4±8 years; 10 male) volunteered to participate in this cross-sectional study. Each participant completed a VR-based SOT program, which included six conditions with varied visual environments (normal, blacked-out, conflict) and support surfaces (stable, unstable foam), while a force plate captured forces at the plantar surface. Center of pressure (COP) was calculated and decomposed into RM-TR components. For each time series, range, root-mean-square (RMS) and sample entropy (SampEn) were extracted. Individual contributions of somatosensation, vision, and vestibular sense, as well as the preference ratio, were calculated. Repeated measures ANOVA were used to compare the effects of time series type (COP, RM, TR) and SOT condition. Paired t-tests were used to assess the difference in preference ratio between RM and TR components. RESULTS AND SIGNIFICANCE: TR sway behavior was impacted significantly by the sensory challenges induced by the SOT procedure, while RM was largely unaffected. Such findings are characteristic of healthy individuals, capable of competently re-weighting sensory input, but still facing challenge-based adaptations. Additionally, the mediolateral SampEn preference ratio was higher in TR compared to RM, indicating potential differences in compensation strategies between supraspinal and spinal/peripheral control mechanisms. These findings serve as a foundation for future RM-TR analyses using SOT procedures, aiding in our ability to implement targeted diagnostic and treatment methods, ultimately reducing the incidence of falls in aging and individuals with neurological conditions.

Full integration of highly stretchable inorganic transistors and circuits within molecular-tailored elastic substrates on a large scale.

The emergence of high-form-factor electronics has led to a demand for high-density integration of inorganic thin-film devices and circuits with full stretchability. However, the intrinsic stiffness and brittleness of inorganic materials have impeded their utilization in free-form electronics. Here, we demonstrate highly integrated strain-insensitive stretchable metal-oxide transistors and circuitry (442 transistors/cm2) via a photolithography-based bottom-up approach, where transistors with fluidic liquid metal interconnection are embedded in large-area molecular-tailored heterogeneous elastic substrates (5 × 5 cm2). Amorphous indium-gallium-zinc-oxide transistor arrays (7 × 7), various logic gates, and ring-oscillator circuits exhibited strain-resilient properties with performance variation less than 20% when stretched up to 50% and 30% strain (10,000 cycles) for unit transistor and circuits, respectively. The transistors operate with an average mobility of 12.7 ( ± 1.7) cm2 V-1s-1, on/off current ratio of > 107, and the inverter, NAND, NOR circuits operate quite logically. Moreover, a ring oscillator comprising 14 cross-wired transistors validated the cascading of the multiple stages and device uniformity, indicating an oscillation frequency of ~70 kHz.

Effects of walking training on risk markers of cardiovascular disease in individuals with chronic spinal cord injury.

OBJECTIVE: To investigate the effects of an 8-week walking training program on glycemic control, lipid profile, and inflammatory markers in individuals with chronic spinal cord injury (SCI). DESIGN: A pilot, single-group, pretest-posttest study. SETTING: A neuromuscular research laboratory. PARTICIPANTS: Eleven participants with chronic SCI. INTERVENTION: An 8-week walking training program using a treadmill, a body weight-supported system, and an assistive gait training device. OUTCOME MEASURES: Levels of glycated hemoglobin (HbA1c), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), C-reactive protein (CRP), and interleukin-6 were assessed before and after the walking training. RESULTS: Following the walking training, there was a statistically significant decrease in HbA1c level (P<0.01) of uncertain clinical significance. The lipid profile improved after training, as shown by a statistically and clinically significant increase in HDL-C level (P<0.01) and a statistically significant decrease in LDL-C level (P<0.1) of no clinical significance. The ratio of LDL-C to HDL-C was significantly reduced (P<0.01). In regard to inflammatory markers, concentrations of IL-6 showed a significant reduction after training (P=0.05) of unknown clinical significance, while those of CRP trended to decrease (P=0.13). CONCLUSION: The findings of this pilot study suggest that an 8-week walking training program may produce favorable changes in risk markers of cardiovascular disease in individuals with chronic SCI as shown by clinically meaningful improvements in HDL-C, and small changes in the right direction, but uncertain clinical significance, in HbA1c, LDL-C and IL-6. A randomized controlled trial is needed to compare the effects of walking training on these outcome measures with those of other exercise modalities suitable for this population, and to see if more prolonged exercise exposure leads to favorable parameters of significant size to justify the exercise modality.

Proof-of-Concept of the Virtual Reality Comprehensive Balance Assessment and Training for Sensory Organization of Dynamic Postural Control.

Accurate quantification of the impact of visual, somatosensory, and vestibular systems on postural control may inform tailor-made balance intervention strategies. The aim of this proof-of-concept study was to determine the safety, sense of presence, system usability, and face validity of a newly developed Virtual Reality Comprehensive Balance Assessment and Training (VR-ComBAT) in healthy young individuals. The VR-ComBAT included six balance condition: (1) stable surface with fixed virtual reality (VR) surroundings; (2) stable surface with blacked out VR surroundings; (3) stable surface with VR visual conflict; (4) unstable surface with fixed VR surroundings; (5) unstable surface with blacked out VR surroundings; and (6) unstable surface with VR visual conflict. Safety was evaluated using the number of adverse events, including scores on the Simulator Sickness Questionnaire. Sense of presence was evaluated using the igroup Presence Questionnaire (iPQ). System usability was assessed using the Systems Usability Scale (SUS). Friedman analyses with post hoc Wilcoxon Signed Rank tests were employed to demonstrate face validity by quantifying center of pressure (COP) changes in mean distance, mean velocity, and mean frequency in the anteroposterior (AP) and mediolateral (ML) direction across the six conditions. Twenty-three participants (27.4 ± 8.0 years old; 13 women) reported no adverse events. Participants scores on average 44.9 ± 9.6 on the iPQ and 79.7 ± 9.9 on the SUS. Post hoc analyses showed significant changes in COP-based measures when compared to baseline. The mean frequency change of COP showed direction-dependence in which increased frequency change in AP was observed while decreased change in ML was noted. The VR-ComBAT provides a safe, feasible, and cost-effective VR environment that demonstrates consistent sensory re-weighting between visual, somatosensory, and vestibular systems. Future studies should investigate whether VR-ComBAT can be used to inform precision rehabilitation of balance and fall prevention in older adults without and with neurological conditions.

Conformally Gated Surface Conducting Behaviors of Single-Walled Carbon Nanotube Thin-Film-Transistors.

Semiconducting single-walled carbon nanotubes (s-SWCNTs) have gathered significant interest in various emerging electronics due to their outstanding electrical and mechanical properties. Although large-area and low-cost fabrication of s-SWCNT field effect transistors (FETs) can be easily achieved via solution processing, the electrical performance of the solution-based s-SWCNT FETs is often limited by the charge transport in the s-SWCNT networks and interface between the s-SWCNT and the dielectrics depending on both s-SWCNT solution synthesis and device architecture. Here, we investigate the surface and interfacial electro-chemical behaviors of s-SWCNTs. In addition, we propose a cost-effective and straightforward process capable of minimizing polymers bound to s-SWCNT surfaces acting as an interfering element for the charge carrier transport via a heat-assisted purification (HAP). With the HAP treated s-SWCNTs, we introduced conformal dielectric configuration for s-SWCNT FETs, which are explored by a carefully designed wide array of electrical and chemical characterizations with finite-element analysis (FEA) computer simulation. For more favorable gate-field-induced surface and interfacial behaviors of s-SWCNT, we implemented conformally gated highly capacitive s-SWCNT FETs with ion-gel dielectrics, demonstrating field-effect mobility of ~8.19 cm2/V⋅s and on/off current ratio of ~105 along with negligible hysteresis.

Cognitive workload during verbal abstract reasoning in Parkinson's disease: a pilot study.

BACKGROUND: Pupillary response reflects cognitive workload during processing speed, working memory, and arithmetic tasks in Parkinson's disease (PD). Abstract reasoning, a higher-order cognitive function that relates different objects, events, or thoughts in a similar manner, may also be compromised in PD. The aim of this study was to compare pupillary response as a measure of cognitive workload while completing a verbal abstract reasoning test between patients with PD and age-matched controls. METHODS: Nineteen non-demented individuals with PD (66.6 ± 8.9 years) and 10 healthy controls (65.3 ± 7.3 years) were recruited. A remote eye tracker recorded the pupillary response at 60 Hz, while the participants were performing the Similarities test of Wechsler Adult Intelligence Scale-IV. Outcome measures included pupillary response, evaluated by the Index of Cognitive Activity (ICA), and behavioral responses of the Similarities test. RESULTS: The PD group (scaled scores = 8.9 ± 2.2) did not show impairment in behavioral performance on Similarities test compared with healthy controls (scaled scores = 8.8 ± 2.3; p = .91). However, the PD group (ICA = .32 ± .09) demonstrated significantly greater cognitive workload during the Similarities test compared to controls (ICA = .24 ± .08; p = .03). CONCLUSIONS: Non-demented individuals with PD exerted greater cognitive workload to complete a verbal abstract reasoning task despite similar behavioral performance compared to healthy controls. Clinical utilities of pupillary response to detect and monitor early impairment in higher-order executive function will be the subject of further study in the PD population.

Highly Scalable and Robust Mesa-Island-Structure Metal-Oxide Thin-Film Transistors and Integrated Circuits Enabled by Stress-Diffusive Manipulation.

The increasing interest in flexible and wearable electronics has demanded a dramatic improvement of mechanical robustness in electronic devices along with high-resolution implemented architectures. In this study, a site-specific stress-diffusive manipulation is demonstrated to fulfill highly robust and ultraflexible amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) and integrated circuits. The photochemically activated combustion sol-gel a-IGZO TFTs on a mesa-structured polyimide show an average saturation mobility of 6.06 cm2 V-1 s-1 and a threshold voltage of -0.99 V with less than 9% variation, followed by 10 000 bending cycles with a radius of 125 µm. More importantly, the site-specific monolithic formation of mesa pillar-structured devices can provide fully integrated logic circuits such as seven-stage ring-oscillators, meeting the industrially needed device density and scalability. To exploit the underlying stress-diffusive mechanism, a physical model is provided by using a variety of chemical, structural, and electrical characterizations along with multidomain finite-element analysis simulation. The physical models reveal that a highly scalable and robust device can be achieved via the site-specific mesa architecture, by enabling generation of multineutral layers and fine-tuning the accumulated stresses on specific element of devices with their diffusion out into the boundary of the mesa regions.

Classification of Parkinson's disease and essential tremor based on balance and gait characteristics from wearable motion sensors via machine learning techniques: a data-driven approach.

BACKGROUND: Parkinson's disease (PD) and essential tremor (ET) are movement disorders that can have similar clinical characteristics including tremor and gait difficulty. These disorders can be misdiagnosed leading to delay in appropriate treatment. The aim of the study was to determine whether balance and gait variables obtained with wearable inertial motion sensors can be utilized to differentiate between PD and ET using machine learning. Additionally, we compared classification performances of several machine learning models. METHODS: This retrospective study included balance and gait variables collected during the instrumented stand and walk test from people with PD (n = 524) and with ET (n = 43). Performance of several machine learning techniques including neural networks, support vector machine, k-nearest neighbor, decision tree, random forest, and gradient boosting, were compared with a dummy model or logistic regression using F1-scores. RESULTS: Machine learning models classified PD and ET based on balance and gait characteristics better than the dummy model (F1-score = 0.48) or logistic regression (F1-score = 0.53). The highest F1-score was 0.61 of neural network, followed by 0.59 of gradient boosting, 0.56 of random forest, 0.55 of support vector machine, 0.53 of decision tree, and 0.49 of k-nearest neighbor. CONCLUSIONS: This study demonstrated the utility of machine learning models to classify different movement disorders based on balance and gait characteristics collected from wearable sensors. Future studies using a well-balanced data set are needed to confirm the potential clinical utility of machine learning models to discern between PD and ET.

In-Plane Amorphous Oxide Ionotronic Devices and Circuits with Photochemically Enabled Favorable Interfaces.

Here, we demonstrate a side-gated in-plane structure of solution-processed amorphous oxide semiconductor ionotronic devices and logic circuits enabled by ion gel gate dielectrics with a monolithically integrated nanoscale passivation architecture. The large capacitance of the electric double layer (EDL) in the ion gel allows a device structure to be a side gate geometry, forming an in-plane structured amorphous In-Ga-Zn-O (a-IGZO) ionotronic transistor, which can be translated into a simplified logic gate configuration with a low operation voltage. Particularly, the monolithic passivation of the coplanar electrodes offers advantages over conventional inhomogeneous passivation, mitigating unintentional parasitic leakage current through the ion gel dielectric layer. More importantly, the monolithically integrated passivation over electrodes was readily obtained with a complementary metal-oxide semiconductor-compatible photochemical process by employing a controlled ultraviolet light manipulation under ozone ambient, which introduced not only much enhanced electrical characteristics but also a scalable device architecture. We investigated various electrical behaviors of the side-gated a-IGZO ionotronic transistor based on EDL, which is called an electric double layer transistor (EDLT), and logic circuits enabled by photochemically realized monolithic aluminum oxide (AlOX) passivation comparing to the native or polymerized passivation layer, which reveals that the photoassisted AlOX secures high-performance a-IGZO EDLTs with a low off current (<5.23 × 10-8 A), high on/off ratio (>1.87 × 105), and exceptional high carrier mobility (>14.5 cm2 V-1 s-1). Owing to the significantly improved electrical characteristics, an inverter circuit was successfully achieved with broad operation voltages from an ultralow VDD of 1 mV to 1.5 V, showing a fully logical voltage transfer characteristic with a gain of more than 4 V V-1.

Can Qigong improve non-motor symptoms in people with Parkinson's disease - A pilot randomized controlled trial?

Non-motor symptoms (NMS) including sleep disorders, anxiety, depression, fatigue, and cognitive decline can significantly impact quality of life in people with PD. Qigong exercise is a mind-body exercise that shows a wide range of benefits in various medical conditions. The purpose of this study was to investigate the effect of Qigong exercise on NMS with a focus on sleep quality. Seventeen participants completed a 12-week intervention of Qigong (n = 8) or sham Qigong (n = 9). Disease severity, anxiety and depression levels, fatigue, cognition, quality of life, and other NMS of the participants were evaluated prior to the intervention and at the end of the 12-week intervention. After the intervention, both Qigong and sham-Qigong group showed significant improvement in sleep quality (p < 0.05) and overall NMS (p < 0.05). No significant difference was found between groups. Qigong exercise has the potential as a rehabilitation method for people with PD, specifically alleviating NMS in PD. However, this finding needs to be carefully considered due to the small sample size and potentially low intervention fidelity of this study.

The therapeutic efficacy of Qigong exercise on the main symptoms of fibromyalgia: A pilot randomized clinical trial.

BACKGROUND: Some of the most debilitating symptoms of fibromyalgia (FM) include widespread chronic pain, sleep disturbances, chronic fatigue, anxiety, and depression. Yet, there is a lack of effective self-management exercise interventions capable of alleviating FM symptoms. The objective of this study is to examine the efficacy of a 10-week daily Qigong, a mind-body intervention program, on FM symptoms. METHODS: 20 participants with FM were randomly assigned to Qigong (experimental) or sham-Qigong (control) groups, with participants blinded to the intervention allocation. The Qigong group practiced mild body movements synchronized with deep diaphragmatic breathing and meditation. The sham-Qigong group practiced only mild body movements. Both groups practiced the interventions two times per day at home, plus one weekly group practice session with a Qigong instructor. Primary outcomes were: pain changes measured by the Short-Form McGill Pain Questionnaire, a visual analog scale for pain, pressure pain threshold measured by a dolorimeter. Secondary outcomes were: the Revised Fibromyalgia Impact Questionnaire the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale and the Quality of Life Scale. RESULTS: The experimental group experienced greater clinical improvements when compared to the control group on the mean score differences of pain, sleep quality, chronic fatigue, anxiety, depression, and fibromyalgia impact, all being statistically significant at p < 0.05. CONCLUSION: Daily practice of Qigong appears to have a positive impact on the main fibromyalgia symptoms that is beyond group interaction. TRIAL REGISTRATION: ClinicalTrials.gov NCT03441997.

Artificial neural networks in neurorehabilitation: A scoping review.

BACKGROUND: Advances in medical technology produce highly complex datasets in neurorehabilitation clinics and research laboratories. Artificial neural networks (ANNs) have been utilized to analyze big and complex datasets in various fields, but the use of ANNs in neurorehabilitation is limited. OBJECTIVE: To explore the current use of ANNs in neurorehabilitation. METHODS: PubMed, CINAHL, and Web of Science were used for the literature search. Studies in the scoping review (1) utilized ANNs, (2) examined populations with neurological conditions, and (3) focused on rehabilitation outcomes. The initial search identified 1,136 articles. A total of 19 articles were included. RESULTS: ANNs were used for prediction of functional outcomes and mortality (n = 11) and classification of motor symptoms and cognitive status (n = 8). Most ANN-based models outperformed regression or other machine learning models (n = 11) and showed accurate performance (n = 6; no comparison with other models) in predicting clinical outcomes and accurately classifying different neurological impairments. CONCLUSIONS: This scoping review provides encouraging evidence to use ANNs for clinical decision-making of complex datasets in neurorehabilitation. However, more research is needed to establish the clinical utility of ANNs in diagnosing, monitoring, and rehabilitation of individuals with neurological conditions.

Pilot Feasibility Study Examining Pupillary Response During Driving Simulation as a Measure of Cognitive Load in Breast Cancer Survivors.

OBJECTIVES: To test the feasibility of adding driving simulation tasks to measure visuospatial ability and processing speed to an existing neurocognitive battery for breast cancer survivors (BCSs). SAMPLE & SETTING: 38 BCSs and 17 healthy controls from a cross-sectional pilot study conducted at the University of Kansas Medical Center. METHODS & VARIABLES: Exploratory substudy measuring pupillary response, visuospatial ability, and processing speed during two 10-minute driving simulations (with or without n-back testing) in a sample of BCSs with self-reported cognitive complaints and healthy controls. RESULTS: Feasibility of measurement of pupillary response during driving simulation was demonstrated. No between-group differences were noted for pupillary response during driving simulation. BCSs had greater visuospatial ability and processing speed performance difficulties than healthy controls during driving simulation without n-back testing and slower n-back response time. IMPLICATIONS FOR NURSING: Preliminary evidence showed a possible link between cancer/treatment on visuospatial ability and processing speed in BCSs.

Brain activity during dual task gait and balance in aging and age-related neurodegenerative conditions: A systematic review.

The aims of this systematic review were to investigate (1) real-time brain activity during DT gait and balance, (2) whether changes in brain activity correlate with changes in behavioral outcomes in older adults and people with age-related neurodegenerative conditions. PubMed, PsycINFO, and Web of Science were searched from 2009 to 2019 using the keywords dual task, brain activity, gait, balance, aging, neurodegeneration, and other related search terms. A total of 15 articles were included in this review. Functional near-infrared spectroscopy and electroencephalogram measures demonstrated that older adults had higher brain activity, particularly in the prefrontal cortex (PFC), compared to young adults during dual task gait and balance. Similar neurophysiological results were observed in people with age-related neurodegenerative conditions. Few studies demonstrated a relationship between increased brain activity and better behavioral outcomes. This systematic review supports the notion that aging and age-related neurodegenerative conditions are associated with neuronal network changes, resulting in increased brain activity specifically in the PFC. Further studies are warranted to assess the relationship between increased PFC activation during dual task gait and balance and behavioral outcomes to better optimize the rehabilitation interventions.

Effects of Qigong Exercise on Non-Motor Symptoms and Inflammatory Status in Parkinson's Disease: A Protocol for a Randomized Controlled Trial.

Background: Non-motor symptoms such as sleep disturbance, cognitive decline, fatigue, anxiety, and depression in Parkinson's disease (PD) impact quality of life. Increased levels of pro-inflammatory cytokines in individuals with PD have been reported, which may contribute to non-motor symptoms. A mind-body exercise, Qigong, has demonstrated benefits across different medical conditions. However, a lack of evidence causes clinicians and patients to be uncertain about the effects of Qigong in individuals with PD. This study will examine the effects of Qigong on non-motor symptoms and inflammatory status in individuals with PD. Methods: Sixty individuals with PD will be recruited. Qigong and sham Qigong group (n = 30 for each) will receive a 12-week intervention. Participants will practice their assigned exercise at home (2×/day) and attend routinely group exercise meetings. Results: Clinical questionnaires and neuropsychological tests will measure non-motor symptoms including sleep quality (primary outcome). Biomarker assays will measure inflammatory status. A two-way mixed-design analysis of variance (ANOVA) will be utilized. Conclusions: This study may generate evidence for the benefits of Qigong on non-motor symptoms of PD and the effect on inflammatory status. Findings may lead to the development of a novel, safe, and cost-effective rehabilitation approach for individuals with PD.

Pupillary response: cognitive effort for breast cancer survivors.

PURPOSE: The purpose of this cross-sectional comparative pilot study was to evaluate cognitive effort, indexed by pupillary response (PR), for breast cancer survivors (BCS) with complaints of cognitive dysfunction following chemotherapy. STUDY AIMS: Compare the cognitive effort employed by BCS to healthy controls (HC) during neuropsychological tests (NPT) for memory, sustained attention, verbal fluency, visuospatial ability, processing speed and executive function; and Investigate the relationship between PR-indexed cognitive effort and participants' self-report of cognitive function. METHODS: Self-report of cognitive function was collected from 23 BCS and 23 HC. PR was measured during NPT. Independent two-sample t tests or Wilcoxon rank sum tests were used to compare group scores. Between-group effect size (Cohen's d) was calculated for each outcome. Correlation between mean self-report scores and PR values, as well as 95% confidence intervals, was calculated. RESULTS: No group differences were demonstrated for NPT performance. BCS reported more issues with cognitive function than HC (p < .0001). A group effect for BCS was seen with PR-indexed cognitive effort for components of most NPT (p < .05). PR was correlated with most self-report measures of cognitive function (r = 0.33-0.45). CONCLUSIONS: PR sensitivity to cognitive effort across a variety of NPT and correlation with self-report of cognitive function was demonstrated. The portability, affordability, and "real-time" aspects of PR are attractive for potential use in the clinic setting to assess cognitive function. A larger study is needed to confirm these results. Prospective investigation of PR in BCS is needed to demonstrate sensitivity to cognitive function changes over time.

Pupillary Response to Cognitive Demand in Parkinson's Disease: A Pilot Study.

Previous studies have shown that pupillary response, a physiological measure of cognitive workload, reflects cognitive demand in healthy younger and older adults. However, the relationship between cognitive workload and cognitive demand in Parkinson's disease (PD) remains unclear. The aim of this pilot study was to examine the pupillary response to cognitive demand in a letter-number sequencing (LNS) task between 16 non-demented individuals with PD (age, median (Q1-Q3): 68 (62-72); 10 males) and 10 control participants (age: 63 (59-67); 2 males), matched for age, education, and Montreal Cognitive Assessment (MOCA) scores. A mixed model analysis was employed to investigate cognitive workload changes as a result of incremental cognitive demand for both groups. As expected, no differences were found in cognitive scores on the LNS between groups. Cognitive workload, exemplified by greater pupil dilation, increased with incremental cognitive demand in both groups (p = 0.003). No significant between-group (p = 0.23) or interaction effects were found (p = 0.45). In addition, individuals who achieved to complete the task at higher letter-number (LN) load responded differently to increased cognitive demand compared with those who completed at lower LN load (p < 0.001), regardless of disease status. Overall, the findings indicated that pupillary response reflects incremental cognitive demand in non-demented people with PD and healthy controls. Further research is needed to investigate the pupillary response to incremental cognitive demand of PD patients with dementia compared to non-demented PD and healthy controls. Highlights -Pupillary response reflects cognitive demand in both non-demented people with PD and healthy controls-Although not significant due to insufficient power, non-demented individuals with PD had increased cognitive workload compared to the healthy controls throughout the testing-Pupillary response may be a valid measure of cognitive demand in non-demented individuals with PD-In future, pupillary response might be used to detect cognitive impairment in individuals with PD.

The Impact of Advanced Age on Driving Safety in Adults with Medical Conditions.

BACKGROUND: Adults aged 85 and older, often referred to as the oldest-old, are the fastest-growing segment of the population. The rapidly increasing number of older adults with chronic and multiple medical conditions poses challenges regarding their driving safety. OBJECTIVE: To investigate the effect of advanced age on driving safety in drivers with medical conditions. METHODS: We categorized 3,425 drivers with preexisting medical conditions into four age groups: middle-aged (55-64 years, n = 1,386), young-old (65-74 years, n = 1,013), old-old (75-84 years, n = 803), or oldest-old (85 years and older, n = 223). All underwent a formal driving evaluation. The outcome measures included fitness to drive recommendation by the referring physician, comprehensive fitness to drive decision from an official driving evaluation center, history of motor vehicle crashes (MVCs), and history of traffic violations. RESULTS: The oldest-old reported more cardiopulmonary and visual conditions, but less neurological conditions than the old-old. Compared to the middle-aged, the oldest-old were more likely to be considered unfit to drive by the referring physicians (odds ratio [OR] = 4.47, 95% confidence interval [CI] 2.20-9.10) and by the official driving evaluation center (OR = 2.74, 95% CI 1.87-4.03). The oldest-old reported more MVCs (OR = 2.79, 95% CI 1.88-4.12) compared to the middle-aged. CONCLUSION: Advanced age adversely affected driving safety outcomes. The oldest-old are a unique age group with medical conditions known to interfere with safe driving. Driving safety strategies should particularly target the oldest-old since they are the fastest-growing group and their increased frailty is associated with severe or fatal injuries due to MVCs.