Vestibular training promotes adaptation of multisensory integration in postural control.

BACKGROUND: Postural stability depends on the integration of the multisensory system to produce motor outputs. When visual and somatosensory input is reliable, this reduces reliance on the vestibular system. Despite this, vestibular loss can still cause severe postural dysfunction. Training one or more of the three sensory systems through vestibular habituation and adaptation can alter sensory weighting and change postural behavior. AIM: The purpose of this study was to assess sensory reweighting of postural control processing after combined vestibular activation with voluntary weight shift training in healthy adults. METHODS: Thirty-three healthy individuals (18-35 y.o.) were randomly assigned to one of three groups: No training (control), visual feedback weight shift training (WST) coupled with an active horizontal headshake (HS) activity to elicit a vestibular perturbation, or the same WST without HS (NoHS). Training was performed 2x/day, every other day (M, W, F), totaling six sessions. Pre- and post- assessments on the Sensory Organization Test (SOT) were performed. Separate between- and within- repeated measures ANOVAs were used to analyze the six SOT equilibrium scores, composite scores, sensory ratios and center of pressure (COP) variables by comparing baseline to post-training. Alpha level was set at p < .05. RESULTS: There was a significant group x session x condition change (p = .012) in the COP multiscale entropy (MSE) velocity sway in the HS group during SOT conditions 5 and 6. Similarly, COP medio-lateral standard deviation sway (ML Std) showed group x session x visual condition (p = .028), due to HS in condition 6 relative to other two groups. CONCLUSION: Postural training can alter sensory organization after a visual feedback-vestibular activation training protocol, suggesting a possible sensory reweighting through vestibular adaptation and/or habituation. SIGNIFICANCE: Translating these findings into a vestibular-impaired population can stimulate the design of a rehabilitation balance protocol.

Vestibular and Oculomotor Assessments May Increase Accuracy of Subacute Concussion Assessment.

In this study, we collected and analyzed preliminary data for the internal consistency of a new condensed model to assess vestibular and oculomotor impairments following a concussion. We also examined this model's ability to discriminate concussed athletes from healthy controls. Each participant was tested in a concussion assessment protocol that consisted of the Neurocom's Sensory Organization Test (SOT), Balance Error Scoring System exam, and a series of 8 vestibular and oculomotor assessments. Of these 10 assessments, only the SOT, near point convergence, and the signs and symptoms (S/S) scores collected following optokinetic stimulation, the horizontal eye saccades test, and the gaze stabilization test were significantly correlated with health status, and were used in further analyses. Multivariate logistic regression for binary outcomes was employed and these beta weights were used to calculate the area under the receiver operating characteristic curve ( area under the curve). The best model supported by our findings suggest that an exam consisting of the 4 SOT sensory ratios, near point convergence, and the optokinetic stimulation signs and symptoms score are sensitive in discriminating concussed athletes from healthy controls (accuracy=98.6%, AUC=0.983). However, an even more parsimonious model consisting of only the optokinetic stimulation and gaze stabilization test S/S scores and near point convergence was found to be a sensitive model for discriminating concussed athletes from healthy controls (accuracy=94.4%, AUC=0.951) without the need for expensive equipment. Although more investigation is needed, these findings will be helpful to health professionals potentially providing them with a sensitive and specific battery of simple vestibular and oculomotor assessments for concussion management.

Exercise training improves walking function in an African group of stroke survivors: a randomized controlled trial.

OBJECTIVE: To evaluate the effects of treadmill walking and overground walking exercise training on recovery of walking function in an African group of stroke survivors. DESIGN: Prospective, randomized controlled study. SETTING: Outpatient stroke rehabilitation unit in a tertiary hospital. SUBJECTS: Sixty patients with chronic stroke (≥3 months). INTERVENTION: All subjects received individual outpatient conventional physiotherapy rehabilitation for 12 weeks. In addition, subjects in Group A (n = 20) received treadmill walking exercise training (TWET) while those in Group B (n = 20) received overground walking exercise training (OWET). Those in Group C (control) (n = 20) received conventional physiotherapy rehabilitation only. MAIN MEASURES: Outcome measures were (i) 10-metre walk time (10MWT) test and (ii) six-minute walk distance (6MWD) test. These were evaluated at entry into the study and at the end of every four weeks. Paired t-tests were used to evaluate the significance of the difference between pre-training and post-training scores on the two measures (P < 0.05). RESULTS: Subjects in the TWET group recorded 22.6 ± 1.5% decrease in 10MWT and 31.0 ± 4.3% increase in 6MWD; those in the OWET group made 26.8 ± 1.3% and 45.2 ± 4.6% improvement in 10MWT and 6MWD respectively. Subjects in the control group made 2.2 ± 0.7% and 2.9 ± 0.8% improvement in the two functions. These changes were significant for the TWET and OWET groups (P < 0.05). CONCLUSION: This study indicated that treadmill and overground walking exercise training programmes, combined with conventional rehabilitation, improved walking function in an African group of adult stroke survivors. Therefore, professionals who conduct stroke rehabilitation programmes should utilize exercise training to optimize patient outcomes.

Effects of two exercise training techniques on walking function in adult patients with stroke.

BACKGROUND: Patients with stroke usually demonstrate activity limitations manifested by reduced ability to perform daily functions. OBJECTIVE: The purpose of this study was to examine the effects of treadmill walking and overground walking exercise training on walking function in adult patients with stroke. METHODS: Participants were forty (40) patients with stroke comprising 22 males and 18 females. Inclusion criteria included absence of any co-morbidity that could affect rehabilitation. They were randomly assigned to 2 exercise training groups (20 in each group). All study subjects received conventional physiotherapy rehabilitation for 12 weeks. During the same period, subjects in Group A had treadmill walking exercise training (TWET) while those in Group B had overground walking exercise training (OWET) in addition to the conventional physiotherapy. Outcomes were measured as (i) Ten-metre walk time and (ii) Six-minute walk distance. They were evaluated at entry into the study and at the end of every 4 weeks. Results at weeks 0, 4, 8 and 12 were used for analysis. For each of the 2 groups, paired t-tests were used to evaluate the significance of the differences between the pre-intervention (week 0) mean scores on both tests and the mean scores at weeks 4, 8 and 12. RESULTS: With 12 weeks of exercise training, both TWET and OWET produced significant improvement in walking function (P < 0.05). However, OWET resulted in significantly greater reduction (26.8%) in mean walking time over 10 metres than TWET (22.6%); and significantly greater increase (45.2%) in mean walking distance over 6 minutes than TWET (31.0%). CONCLUSION: Exercise training, especially overground walking, could be integrated into the traditional rehabilitation care given to adult patients with stroke.