U-Rate-UE; Measuring Perceived Recovery of the Affected Upper Extremity in Adults Post-stroke.

OBJECTIVE: To establish initial validity of "U-Rate-UE", a single-question scale regarding perceived recovery of the stroke affected upper extremity (UE). DESIGN: A retrospective longitudinal study of data collected at rehabilitation admission, 6 weeks, and 6 months since stroke. SETTING: Stroke rehabilitation and community-based. PARTICIPANTS: A convenience sample of 87 individuals, median (interquartile range) age 71.5 (65-80) years, 15.0 (12-20) days post-stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The affected UE was assessed using the Fugl-Meyer Motor Assessment, grip strength, Action Research Arm Test, the Box and Block Test (BBT), and The Rating of Everyday Arm-Use in the Community and Home. Participants also rated how much they perceive that their affected UE recovered from the stroke using U-Rate-UE; 0-100 (no to full recovery). Longitudinal changes in U-Rate-UE ratings were assessed. In addition, at 6 weeks and 6 months post-stroke, the change in BBT was calculated and participants were grouped into achieved/did not achieve the minimal detectable change (MDC). Correlations between U-Rate-UE to the other UE assessments were assessed at all 3 timepoints. RESULTS: Significant changes in U-Rate-UE were seen over time (P<.05). At 6 weeks and 6 months, participants who achieved BBT-MDC rated their recovery significantly higher than participants who did not. U-Rate-UE was moderately-strongly significantly correlated to UE assessments (rho=.61-.85, P<.001). CONCLUSIONS: The U-Rate-UE is supported for use with UE assessments contributing to comprehensive clinical understanding of the recovery of the affected UE in adults post-stroke.

Performance in complex life situations: effects of age, cognition, and walking speed in virtual versus real life environments.

BACKGROUND: Virtual reality (VR) enables objective and accurate measurement of behavior in ecologically valid and safe environments, while controlling the delivery of stimuli and maintaining standardized measurement protocols. Despite this potential, studies that compare virtual and real-world performance of complex daily activities are scarce. This study aimed to compare cognitive strategies and gait characteristics of young and older healthy adults as they engaged in a complex task while navigating in a real shopping mall and a high-fidelity virtual replica of the mall. METHODS: Seventeen older adults (mean (SD) age = 71.2 (5.6) years, 64% males) and 17 young adults (26.7 (3.7) years, 35% males) participated. In two separate sessions they performed the Multiple Errands Test (MET) in a real-world mall or the Virtual MET (VMET) in the virtual environment. The real-world environment was a small shopping area and the virtual environment was created within the CAREN™ (Computer Assisted Rehabilitation Environment) Integrated Reality System. The performance of the task was assessed using motor and physiological measures (gait parameters and heart rate), MET or VMET time and score, and navigation efficiency (cognitive performance and strategy). Between (age groups) and within (environment) differences were analyzed with ANOVA repeated measures. RESULTS: There were no significant age effects for any of the gait parameters but there were significant environment effects such that both age groups walked faster (F(1,32) = 154.96, p < 0.0001) with higher step lengths (F(1,32) = 86.36, p < 0.0001), had lower spatial and temporal gait variability (F(1,32) = 95.71-36.06, p < 0.0001) and lower heart rate (F(1,32) = 13.40, p < 0.01) in the real-world. There were significant age effects for MET/VMET scores (F(1,32) = 19.77, p < 0.0001) and total time (F(1,32) = 11.74, p < 0.05) indicating better performance of the younger group, and a significant environment effect for navigation efficiency (F(1,32) = 7.6, p < 0.01) that was more efficient in the virtual environment. CONCLUSIONS: This comprehensive, ecological approach in the measurement of performance during tasks reminiscent of complex life situations showed the strengths of using virtual environments in assessing cognitive aspects and limitations of assessing motor aspects of performance. Difficulties by older adults were apparent mainly in the cognitive aspects indicating a need to evaluate them during complex task performance.

Patterns of whole-body muscle activations following vertical perturbations during standing and walking.

BACKGROUND: Falls commonly occur due to losses of balance associated with vertical body movements (e.g. reacting to uneven ground, street curbs). Research, however, has focused on horizontal perturbations, such as forward and backward translations of the standing surface. This study describes and compares muscle activation patterns following vertical and horizontal perturbations during standing and walking, and investigates the role of vision during standing postural responses. METHODS: Fourteen healthy participants (ten males; 27±4 years-old) responded to downward, upward, forward, and backward perturbations while standing and walking in a virtual reality (VR) facility containing a moveable platform with an embedded treadmill; participants were also exposed to visual perturbations in which only the virtual scenery moved. We collected bilateral surface electromyography (EMG) signals from 8 muscles (tibialis anterior, rectus femoris, rectus abdominis, external oblique, gastrocnemius, biceps femoris, paraspinals, deltoids). Parameters included onset latency, duration of activation, and activation magnitude. Standing perturbations comprised dynamic-camera (congruent), static-camera (incongruent) and eyes-closed sensory conditions. ANOVAs were used to compare the effects of perturbation direction and sensory condition across muscles. RESULTS: Vertical perturbations induced longer onset latencies and shorter durations of activation with lower activation magnitudes in comparison to horizontal perturbations (p<0.0001). Downward perturbations while standing generated earlier activation of anterior muscles to facilitate flexion (for example, p=0.0005 and p=0.0021 when comparing the early activators, rectus femoris and tibialis anterior, to a late activator, the paraspinals), whereas upward perturbations generated earlier activation of posterior muscles to facilitate extension (for example, p<0.0001 and p=0.0004, when comparing the early activators, biceps femoris and gastrocnemius, to a late activator, the rectus abdominis). Static-camera conditions induced longer onset latencies (p=0.0085 and p<0.0001 compared to eyes-closed and dynamic-camera conditions, respectively), whereas eyes-closed conditions induced longer durations of activation (p=0.0001 and p=0.0008 compared to static-camera and dynamic-camera, respectively) and larger activation magnitudes. During walking, downward perturbations promptly activated contralateral trunk and deltoid muscles (e.g., p=0.0036 for contralateral deltoid versus a late activator, the ipsilateral tibialis anterior), and upward perturbations triggered early activation of trunk flexors (e.g., p=0.0308 for contralateral rectus abdominis versus a late activator, the ipsilateral gastrocnemius). Visual perturbations elicited muscle activation in 67.7% of trials. CONCLUSION: Our results demonstrate that vertical (vs. horizontal) perturbations generate unique balance-correcting muscle activations, which were consistent with counteracting vertical body extension induced by downward perturbations and vertical body flexion induced by upward perturbations. Availability of visual input appears to affect response efficiency, and incongruent visual input can adversely affect response triggering. Our findings have clinical implications for the design of robotic exoskeletons (to ensure user safety in dynamic balance environments) and for perturbation-based balance and gait rehabilitation.

Role of a Novel Human Leukocyte Antigen-DQA1*01:02;DRB1*15:01 Mixed Isotype Heterodimer in the Pathogenesis of "Humanized" Multiple Sclerosis-like Disease.

Gene-wide association and candidate gene studies indicate that the greatest effect on multiple sclerosis (MS) risk is driven by the HLA-DRB1*15:01 allele within the HLA-DR15 haplotype (HLA-DRB1*15:01-DQA1*01:02-DQB1*0602-DRB5*01:01). Nevertheless, linkage disequilibrium makes it difficult to define, without functional studies, whether the functionally relevant effect derives from DRB1*15:01 only, from its neighboring DQA1*01:02-DQB1*06:02 or DRB5*01:01 genes of HLA-DR15 haplotype, or from their combinations or epistatic interactions. Here, we analyzed the impact of the different HLA-DR15 haplotype alleles on disease susceptibility in a new "humanized" model of MS induced in HLA-transgenic (Tg) mice by human oligodendrocyte-specific protein (OSP)/claudin-11 (hOSP), one of the bona fide potential primary target antigens in MS. We show that the hOSP-associated MS-like disease is dominated by the DRB1*15:01 allele not only as the DRA1*01:01;DRB1*15:01 isotypic heterodimer but also, unexpectedly, as a functional DQA1*01:02;DRB1*15:01 mixed isotype heterodimer. The contribution of HLA-DQA1/DRB1 mixed isotype heterodimer to OSP pathogenesis was revealed in (DRB1*1501xDQB1*0602)F1 double-Tg mice immunized with hOSP(142-161) peptide, where the encephalitogenic potential of prevalent DRB1*1501/hOSP(142-161)-reactive Th1/Th17 cells is hindered due to a single amino acid difference in the OSP(142-161) region between humans and mice; this impedes binding of DRB1*1501 to the mouse OSP(142-161) epitope in the mouse CNS while exposing functional binding of mouse OSP(142-161) to DQA1*01:02;DRB1*15:01 mixed isotype heterodimer. This study, which shows for the first time a functional HLA-DQA1/DRB1 mixed isotype heterodimer and its potential association with disease susceptibility, provides a rationale for a potential effect on MS risk from DQA1*01:02 through functional DQA1*01:02;DRB1*15:01 antigen presentation. Furthermore, it highlights a potential contribution to MS risk also from interisotypic combination between products of neighboring HLA-DR15 haplotype alleles, in this case the DQA1/DRB1 combination.

Self-selected gait speed--over ground versus self-paced treadmill walking, a solution for a paradox.

BACKGROUND: The study of gait at self-selected speed is important. Traditional gait laboratories being relatively limited in space provide insufficient path length, while treadmill (TM) walking compromises natural gait by imposing speed variables. Self-paced (SP) walking can be realized on TM using feedback-controlled belt speed. We compared over ground walking vs. SP TM in two self-selected gait speed experiments: without visual flow, and while subjects were immersed in a virtual reality (VR) environment inducing natural visual flow. METHODS: Young healthy subjects walked 96 meters at self-selected comfortable speed, first over ground and then on the SP TM without (n=15), and with VR visual flow (n=11). Gait speed was compared across conditions for four 10 m long segments (7.5 - 17.5, 30.5 - 40.5, 55.5 - 65.5 and 78.5-88.5 m). RESULTS: During over ground walking mean (± SD) gait speed was equal for both experimental groups (1.50 ± 0.13 m/s). Without visual flow, gait speed over SP TM was smaller in the first and second epochs as compared to over ground (first: 1.15 ±0.18 vs. second: 1.53 ± 0.13 m/s; p<0.05), and was comparable in the third and fourth (1.45 ± 0.19 vs. 1.49 ± 0.15 m/s; p>0.3). With visual flow, gait speed became comparable to that of over ground performance already in the first epoch (1.43 ± 0.22 m/s; p>0.17). Curve fitting analyses estimated that steady state velocity in SP TM walking is reached after shorter distanced passed with visual flow (24.6 ± 14.7 m) versus without (36.5 ± 18.7 m, not statistically significant; p=0.097). Steady state velocity was estimated to be higher in the presence of visual flow (1.61 ± 0.17 m/s) versus its absence (1.42 ± 1.19 m/s; p<0.05). CONCLUSIONS: The SP TM walking is a reliable method for recording typical self-selected gait speed, provided that sufficient distance is first passed for reaching steady state. Seemingly, in the presence of VR visual flow, steady state of gait speed is reached faster. We propose that the gait research community joins forces to standardize the use of SP TMs, e.g., by unifying protocols or gathering normative data.

Higher Regional Gray Matter Volume and White Matter Integrity in Individuals With Central Neuropathic Pain After Spinal Cord Injury.

Spinal cord injury (SCI) is a debilitating neurological condition that often leads to central neuropathic pain (CNP). As the fundamental mechanism of CNP is not fully established, its management is one of the most challenging problems among people with SCI. To shed more light on CNP mechanisms, the aim of this cross-sectional study was to compare the brain structure between individuals with SCI and CNP and those without CNP by examining the gray matter (GM) volume and the white matter (WM) integrity. Fifty-two individuals with SCI-28 with CNP and 24 without CNP-underwent a magnetic resonance imaging (MRI) session, including a T1-weighted scan for voxel-based morphometry, and a diffusion-weighted imaging (DWI) scan for WM integrity analysis, as measured by fractional anisotropy (FA) and mean diffusivity (MD). We found significantly higher GM volume in individuals with CNP compared with pain-free individuals in the right superior (p < 0.0014) and middle temporal gyri (p < 0.0001). Moreover, individuals with CNP exhibited higher WM integrity in the splenium of the corpus callosum (p < 0.0001) and in the posterior cingulum (p < 0.0001), compared with pain-free individuals. The results suggest that the existence of CNP following SCI is associated with GM and WM structural abnormalities in regions involved in pain intensification and spread, and which may reflect maladaptive neural plasticity in CNP.

Lack of gut microbiome recovery with spinal cord injury rehabilitation.

Spinal cord injury (SCI) is a devastating event that significantly changes daily function and quality of life and is linked to bowel and bladder dysfunction and frequent antibiotic treatment. We aimed to study the composition of the gut microbiome in individuals with SCI during the initial sub-acute rehabilitation process and during the chronic phase of the injury. This study included 100 fecal samples from 63 participants (Median age 40 years, 94% males): 13 cases with SCI in the sub-acute phase with 50 longitudinal samples, 18 cases with chronic SCI, and 32 age and gender-matched controls. We show, using complementary methods, that the time from the injury was a dominant factor linked with gut microbiome composition. Surprisingly, we demonstrated a lack of gut microbial recovery during rehabilitation during the sub-acute phase, with further deviation from the non-SCI control group in the chronic ambulatory SCI group. To generalize the results, we were able to show significant similarity of the signal when comparing to a previous cohort with SCI, to subjects from the American Gut Project who reported low physical activity, and to subjects from another population-based cohort who reported less normal stool consistency. Restoration of the microbiome composition may be another desirable measure for SCI recovery in the future, but further research is needed to test whether such restoration is associated with improved neurological outcomes and quality of life.

Upward perturbations trigger a stumbling effect.

BACKGROUND: Vertical perturbations are one major cause of falling. Incidentally, while conducting a comprehensive study comparing effects of vertical versus horizontal perturbations, we commonly observed a stumbling-like response induced by upward perturbations. The present study describes and characterizes this stumbling effect. METHODS: Fourteen individuals (10 male; 27 ± 4 yr) walked self-paced on a treadmill embedded in a moveable platform and synchronized to a virtual reality system. Participants experienced 36 perturbations (12 types). Here, we report only on upward perturbations. We determined stumbling based on visual inspection of recorded videos, and calculated stride time and anteroposterior, whole-body center of mass (COM) distance relative to the heel, i.e., COM-to-heel distance, extrapolated COM (xCOM) and margin of stability (MOS) before and after perturbation. RESULTS: From 68 upward perturbations across 14 participants, 75% provoked stumbling. During the first gait cycle post-perturbation, stride time decreased in the perturbed foot and the unperturbed foot (perturbed = 1.004 s vs. baseline = 1.119 s and unperturbed = 1.017 s vs. baseline = 1.125 s, p < 0.001). In the perturbed foot, the difference was larger in stumbling-provoking perturbations (stumbling: 0.15 s vs. non-stumbling: 0.020 s, p = 0.004). In addition, the COM-to-heel distance decreased during the first and second gait cycles after perturbation in both feet (first cycle: 0.58 m, second cycle: 0.665 m vs. baseline: 0.72 m, p-values<0.001). During the first gait cycle, COM-to-heel distance was larger in the perturbed foot compared to the unperturbed foot (perturbed foot: 0.61 m vs. unperturbed foot: 0.55 m, p < 0.001). MOS decreased during the first gait cycle, whereas the xCOM increased during the second through fourth gait cycles post-perturbation (maximal xCOM at baseline: 0.5 m, second cycle: 0.63 m, third cycle: 0.66 m, fourth cycle: 0.64 m, p < 0.001). CONCLUSIONS: Our results show that upward perturbations can induce a stumbling effect, which - with further testing - has the potential to be translated into balance training to reduce fall risk, and for method standardization in research and clinical practice.

The month of birth and the incidence of multiple sclerosis in the Israeli population.

BACKGROUND: Recent studies on date of birth of multiple sclerosis (MS) patients showed a spring peak and an autumn nadir. We examined the effect of date of birth in a large group of MS patients and non-MS patients, compared to the general population in Israel. METHODS: A retrospective analysis was performed in a large cohort of MS patients and patients with other neurological disorders. The date of birth, gender, and country of birth were identified for each patient. The results were compared to a national database. RESULTS: There were 2,264 MS patients and 1,758 patients with other diagnoses. No significant peak or nadir in the date of birth was identified in either group, both in patients born in Israel or in immigrants. No difference was found compared to the national birth rate. When we controlled for the country of birth, there was no difference. CONCLUSION: An increased frequency of MS patients born in the months of April and May was considered as a proof of maternal influence. The results of our study show that this finding is not consistent worldwide. The month of birth was not found to be a significant factor in Israeli MS patients.

Gait Speed Modulations Are Proportional to Grades of Virtual Visual Slopes-A Virtual Reality Study.

Gait is a complex mechanism relying on integration of several sensory inputs such as vestibular, proprioceptive, and visual cues to maintain stability while walking. Often humans adapt their gait to changes in surface inclinations, and this is typically achieved by modulating walking speed according to the inclination in order to counteract the gravitational forces, either uphill (exertion effect) or downhill (braking effect). The contribution of vision to these speed modulations is not fully understood. Here we assessed gait speed effects by parametrically manipulating the discrepancy between virtual visual inclination and the actual surface inclination (aka visual incongruence). Fifteen healthy participants walked in a large-scale virtual reality (VR) system on a self-paced treadmill synchronized with projected visual scenes. During walking they were randomly exposed to varying degrees of physical-visual incongruence inclinations (e.g., treadmill leveled & visual scene uphill) in a wide range of inclinations (-15° to +15°). We observed an approximately linear relation between the relative change in gait speed and the anticipated gravitational forces associated with the virtual inclinations. Mean relative gait speed increase of ~7%, ~11%, and ~17% were measured for virtual inclinations of +5°, +10°, and +15°, respectively (anticipated decelerating forces were proportional to sin[5°], sin[10°], sin[15°]). The same pattern was seen for downhill virtual inclinations with relative gait speed modulations of ~-10%, ~-16%, and ~-24% for inclinations of -5°, -10°, and -15°, respectively (in anticipation of accelerating forces). Furthermore, we observed that the magnitude of speed modulation following virtual inclination at ±10° was associated with subjective visual verticality misperception. In conclusion, visual cues modulate gait speed when surface inclinations change proportional to the anticipated effect of the gravitational force associated the inclinations. Our results emphasize the contribution of vision to locomotion in a dynamic environment and may enhance personalized rehabilitation strategies for gait speed modulations in neurological patients with gait impairments.

Ventilatory response to hypercapnia in C(5-8) chronic tetraplegia: the effect of posture.

OBJECTIVE: To study the effect of posture on the hypercapnic ventilatory responses (HCVR). DESIGN: Nonrandomized controlled study. SETTING: Rehabilitation hospital and a pulmonary institute. PARTICIPANTS: Patients with neurologically stable C(5-8) tetraplegia (n=12) and healthy control subjects (n=7). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Supine and seated forced vital capacity (FVC) and HCVR, and supine and erect blood pressure. RESULTS: FVC in the sitting position was reduced in patients with tetraplegia (52+/-13% predicted); supine FVC was 21% higher (P=.0005). In the sitting position, HCVR was lower in patients than in controls (0.8+/-0.4 vs 2.46+/-0.3 L/min/mmHg, P<.001). Supine HCVR was not significantly different between the groups. When HCVR was normalized to FVC, there was still a significant difference between patients and controls in the sitting position. Patients with tetraplegia were orthostatic (mean supine blood pressure 91+/-13 mmHg vs mean erect blood pressure 61+/-13 mmHg, respectively, P<.0001). The magnitude of the orthostatism correlated with that of the postural change in HCVR (r=.93, P<.0001). CONCLUSIONS: Respiratory muscle weakness may contribute to the attenuated HCVR in tetraplegia. However, the observation that supine HCVR is still low even when normalized to FVC suggests a central posture-dependent effect on the HCVR, which may be linked to the postural effect on arterial blood pressure.

Gait analysis in multiple sclerosis: characterization of temporal-spatial parameters using GAITRite functional ambulation system.

BACKGROUND: Gait impairment is a significant problem in multiple sclerosis (MS), leading to decreased activity and limitations in function. However, specific characterization of abnormal gait in MS patients has only been described in small groups of patients, mainly using observational tools. OBJECTIVE: The aim of the current study was to characterize the spatio-temporal gait parameters in MS patients and ascribe them to clinical variables, in order to enable target-oriented management. METHODS: Eighty-one MS patients with relatively short disease duration (5.3; S.E.=0.3) able of independent walking and 25 age-matched healthy subjects were evaluated using the GAITRite Functional Ambulation System. Subjects also underwent a thorough neurological examination to assess their disability using the Expanded Disability Status Scale (EDSS). Gait parameters were compared between patients and able-bodied controls to characterize the gait impairments in MS. Within the group of patients the correlation of gait parameters with clinical neurological variables was investigated. RESULTS: MS patients demonstrated significant impairments in all spatio-temporal gait parameters compared to able-bodied healthy subjects. MS patients had a mean Functional Ambulation Profile (FAP) score of 83.0 and a mean velocity of 85.5m/s while the controls had a FAP score of 95.0 (p<0.001) and a velocity of 138.6m/s (p<0.001). Cadence was 94.4 steps/min in MS patients and 115.2 in controls (p<0.001). Step length was 45.3 cm in MS patients and 72.1 cm in controls (p<0.001). FAP score negatively correlated with disease duration (p<0.001) and EDSS (p<0.001). The most significant correlations of the FAP were found with the pyramidal (p<0.002), and the cerebellar (p<0.05) functional scores. Specifically, gait velocity, single support time and swing time negatively correlated with the pyramidal functional score, while double support time positively correlated with the pyramidal score. The base support width positively correlated with cerebellar functional score. CONCLUSIONS: Gait parameters were impaired in MS, even in patients with relatively short disease duration. The impaired gait patterns correlated with the associated neurological disability. Specific and accurate assessment of gait can be a useful tool to monitor MS evolution and can be used to advise target-oriented rehabilitative management of MS patients.

Advanced virtual reality-based rehabilitation of balance and gait in clinical practice.

BACKGROUND: Extensive research shows that virtual reality (VR) enhances motor learning and has advantages in balance and gait rehabilitation of neurological patients. There is still uncertainty, however, as for the practicality and efficacy of VR in long-term clinical routine. The objective of this study was to report on 3 years of clinical practice conducting VR-based rehabilitation of balance and gait in a large medical center. METHODS: This retrospective study systematically analyzed clinical records of patients who received VR-based rehabilitation in a large rehabilitation center during 3 years. We evaluated the effect of VR-based rehabilitation treatments on balance and gait, cognitive dual-task load, patient's balance confidence (ABC-scale) and perception of suitability. Patients were either neurological patients, allocated to five groups: Parkinson's disease (PD), poststroke (PS), multiple sclerosis, traumatic brain injury, and 'other conditions', or non-neurological patients. RESULTS: Records of 167 patients were analyzed. The availability of multiple VR systems and environments contributed to highly personalized interventions that tailored specific deficits with therapeutic goals. VR-based rehabilitation significantly improved balance and gait (measured by 10-Meter Walk Test, Timed-Up-and-Go, Berg Balance Scale, and Mini BESTest). Patients with PD and PS decreased dual-task cost while walking. Patients increased balance confidence and deemed VR suitable for rehabilitation. CONCLUSIONS: Our results suggest that VR-based rehabilitation is practicable and effective in clinical routine. Functional measures of balance and gait show significant improvements following VR-based interventions. Clinical approaches should exploit VR advantages for promoting motor learning and motivation. This study serves to aid transition to long-term clinical implementation of VR.

Seeing Gravity: Gait Adaptations to Visual and Physical Inclines - A Virtual Reality Study.

Using advanced virtual reality technology, we demonstrate that exposure to virtual inclinations visually simulating inclined walking induces gait modulations in a manner consistent with expected gravitational forces (i.e., acting upon a free body), suggesting vision-based perception of gravity. The force of gravity critically impacts the regulation of our movements. However, how humans perceive and incorporate gravity into locomotion is not well understood. In this study, we introduce a novel paradigm for exposing humans to incongruent sensory information under conditions constrained by distinct gravitational effects, facilitating analysis of the consistency of human locomotion with expected gravitational forces. Young healthy adults walked under conditions of actual physical inclinations as well as virtual inclinations. We identify and describe 'braking' and 'exertion' effects - locomotor adaptations accommodating gravito-inertial forces associated with physical inclines. We show that purely visual cues (from virtual inclinations) induce consistent locomotor adaptations to counter expected gravity-based changes, consistent with indirect prediction mechanisms. Specifically, downhill visual cues activate the braking effect in anticipation of a gravitational boost, whereas uphill visual cues promote an exertion effect in anticipation of gravitational deceleration. Although participants initially rely upon vision to accommodate environmental changes, a sensory reweighting mechanism gradually reprioritizes body-based cues over visual ones. A high-level neural model outlines a putative pathway subserving the observed effects. Our findings may be pivotal in designing virtual reality-based paradigms for understanding perception and action in complex environments with potential translational benefits.

Advantages of virtual reality in the rehabilitation of balance and gait: Systematic review.

BACKGROUND: Virtual reality (VR) has emerged as a therapeutic tool facilitating motor learning for balance and gait rehabilitation. The evidence, however, has not yet resulted in standardized guidelines. The aim of this study was to systematically review the application of VR-based rehabilitation of balance and gait in 6 neurologic cohorts, describing methodologic quality, intervention programs, and reported efficacy. METHODS: This study follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. VR-based treatments of Parkinson disease, multiple sclerosis, acute and chronic poststroke, traumatic brain injury, and cerebral palsy were researched in PubMed and Scopus, including earliest available records. Therapeutic validity (CONTENT scale) and risk of bias in randomized controlled trials (RCT) (Cochrane Collaboration tool) and non-RCT (Newcastle-Ottawa scale) were assessed. RESULTS: Ninety-seven articles were included, 68 published in 2013 or later. VR improved balance and gait in all cohorts, especially when combined with conventional rehabilitation. Most studies presented poor methodologic quality, lacked a clear rationale for intervention programs, and did not utilize motor learning principles meticulously. RCTs with more robust methodologic designs were widely recommended. CONCLUSION: Our results suggest that VR-based rehabilitation is developing rapidly, has the potential to improve balance and gait in neurologic patients, and brings additional benefits when combined with conventional rehabilitation. This systematic review provides detailed information for developing theory-driven protocols that may assist overcoming the observed lack of argued choices for intervention programs and motor learning implementation and serves as a reference for the design and planning of personalized VR-based treatments. REGISTRATION: PROSPERO CRD42016042051.

Antiepileptic drug use and the occurrence of pressure ulcers among bedridden institutionalized elderly patients: a retrospective chart review.

BACKGROUND: Phenytoin (PH) is indicated primarily for the control of grand mal and psychomotor seizures. However, topical PH has been used for the treatment of various types of ulcers, including pressure ulcers. OBJECTIVE: The aim of this study was to investigate the possibility of a relationship between the use of oral PH and the prevalence of pressure ulcers among bedridden institutionalized elderly patients. METHODS: This retrospective chart review was conducted in a state-run urban geriatric medical center in Israel and involved long-term bedridden institutionalized patients who were receiving chronic antiepileptic medication during the 7-year period between January 1996 and December 2003. The prevalence of pressure ulcers in patients who received treatment with PH alone or in combination with other antiepileptic drugs was compared with that in patients who received antiepileptic agents other than PH. RESULTS: The study analyzed data from the medical charts of 153 patients, 72 of whom received PH alone or in combination with other antiepileptic drugs, and 81 of whom received antiepileptic agents other than PH. Patients' mean (SD) age was 78.5 (7.2) years; 106 (69.3%) were women. All patients were totally dependent with respect to activities of daily living (mean Katz score, 2.0 [2.0]) and had severe cognitive decline (mean Mini-Mental State Examination score, 3.5 [3.3]). Pressure ulcers occurred in 9.7% of PH recipients and 27.2% of non-PH recipients (P = 0.006; chi2 = 7.55). In PH recipients, 85.7% of pressure ulcers were of mild to moderate severity (stage I or II), compared with 59.1% of ulcers in non-PH recipients; the difference between groups was not statistically significant. Four (18.2%) non-PH recipients and no PH recipients had stage IV pressure ulcers. In the PH group, 71.4% of patients had a pressure ulcer in only 1 anatomic location, compared with 22.7% of the non-PH group (P = 0.023; chi2 = 5.13); 28.6% of PH recipients and 63.6% of non-PH recipients had pressure ulcers in 2 or 3 anatomic locations; and 3 (13.6%) non-PH recipients and no PH recipients had pressure ulcers in > or = 4 areas. CONCLUSIONS: In the long-term bedridden institutionalized patients studied, those who received PH had lower rates of pressure ulcers, as well as less severe ulcers. PH may be a useful anticonvulsive agent in frail elderly patients, who are at risk for the development of pressure ulcers.

Five-year experience with the 'Sheba' model of comprehensive orthogeriatric care for elderly hip fracture patients.

BACKGROUND AND PURPOSE: The Sheba model of orthogerioatric medicine is a unique model of in-hospital care for elderly hip fractured patients, based upon the concept that a hip fracture represents a geriatric, rather than an orthopedic disease. The nature and feasibility of such a comprehensive orthogeriatric unit, taking care of all surgical, medical and rehabilitation needs, in a single geriatric-based setting (rather than orthopedic-based), were questioned. The aim of the study is to describe the results of its operation during a five-year period. METHOD: A retrospective charts analysis of consecutive older patients with hip fractures, admitted from the emergency unit directly to the orthogeriatric unit of a department of geriatric medicine. RESULTS: A total number of 592 patients were admitted. Mean age of patients was 83.2 years, mostly women. A total of 538 (91%) were treated surgically. Delay to surgery was 3.6 +/- 2.9 days. A total of 65.6% were suitable for rehabilitation, and had a mean Functional Independence Measure (FIM) gain of 22.3 +/- 7.9. Mean total hospital length of stay was 29.9 days and 68.7% of patients returned to their previous living residence. Rates of major complications (4.1%) and in-hospital mortality (3.2%, equivalent to 30 days mortality) were low. CONCLUSIONS: Treatment within this unit was associated with low rates of major morbidity and mortality, short stay and acceptable functional outcomes. The data provide clinical evidence supporting the implementation of this model of comprehensive orthogeriatric care, being a practical, applicable and feasible service for elderly hip fractured patients, and covering the various needs of these patients. The present model of organization could also help in skillful use of economic resources, facilitating effective treatment strategies.

Risk factors for failure of heparin thromboprophylaxis in patients with acute traumatic spinal cord injury.

UNLABELLED: Venous thromboembolism (VTE) is a well-recognized complication of Acute Traumatic Spinal Cord Injury (ATSCI). Despite prophylaxis by heparins, VTE occurs in a substantial number of ATSCI patients without an obvious explanation. In this matched case-control study we examined whether thrombophilia and other risk factors are associated with failure of thromboprophylaxis. Cases and controls receiving heparin thromboprophylaxis were selected from consecutively admitted ATSCI patients. Patients who developed a new, objectively confirmed, symptomatic VTE despite prophylaxis at hospital were matched by gender, age, level and mechanism of ATSCI with 2-3 controls without VTE. Patients were interviewed about VTE risk factors and tested for factor V Leiden (FVL), prothrombin G20210A (PT), methylenetetrahydrofolate reductase C677T homozygosity (MTHFR), lupus anticoagulant, homocysteine (Hcy) and plasma factor VIII (FVIII) levels. Twenty-two patients with new VTE episodes and 64 controls were ascertained. The total number of gene alterations for MTHFR, FVL and PT or elevated levels of Hcy or FVIII was significantly more common in patients compared to controls (82% vs. 48%, p=0.006). Multiple logistic regression proved the PT mutation, a positive family history of thrombosis and elevated levels of either FVIII or Hcy to be predictors of thrombosis. CONCLUSION: A positive family history of VTE, carriership of the prothrombin mutation and elevated FVIII or Hcy levels were significantly associated with failure to prevent VTE by heparin therapy following ATSCI. Testing for thrombophilia in patients with ATSCI and possibly a more intense thromboprophylactic regimen seem desirable but need to be verified by a prospective study.

Bulbocavernosus reflex testing: a preliminary study on the prognostic factors for potency and response to sildenafil citrate after bilateral nerve-sparing radical prostatectomy.

OBJECTIVE: Erectile dysfunction (ED) following radical prostatectomy is of major concern for both patients and caring physicians. We evaluated the bulbocavernosus reflex latency (BCRL) and amplitude (BCRA) following bilateral nerve-sparing radical retropubic prostatectomy (NS-RRP) to predict the response to sildenafil citrate (SC). METHODS: Patients were recruited in our ED clinic following NS-RRP. Exclusion criteria included preoperative significant ED, neurological disease, and nitrates treatment. Patients were defined as non-responders only after four consecutive unsuccessful trials of 100 mg SC. RESULTS: Twenty patients at least 3 months after surgery were included in this study. Five patients (25%) regained spontaneous erections, although insufficient for vaginal penetration. All of them had normal BCRL and normal BCRA as well as good response to 100 mg SC. Three patients (15%) lacked spontaneous erections and had prolonged BCRL with normal BCRA. This subgroup eventually regained erections using SC. Twelve patients (60%) lacked spontaneous erections and had prolonged BCRL and low BCRA. They failed SC trials and achieved erections using intra-cavernosal injections (ICI) of 10 microg PGE(1). CONCLUSIONS: Neurophysiologic evaluation consisting of BCRL and BCRA was found to be useful in the prediction of the response to SC following bilateral NS-RRP. Patients who do not regain an erection, and have abnormal BCRL and BCRA 6 months after surgery, will probably be SC non-responders and may benefit from ICI. A subset of patients with preserved BCRA and prolonged latencies has been shown to have a better chance to respond to SC.