Somatosensory and Motor Research最新文献

Background and purpose: Alzheimer disease (AD) is the most common form of dementia and the sixth leading cause of death in the United States. Falls are associated with AD and can lead to injury. The Balance Evaluation Systems Test (BESTest) is a balance measure used in other neurological conditions to predict fall risk. The purpose of this study is to examine the relationship between MiniBestest, BESTest, and BESTest subsection scores and fall incidence among individuals with a diagnosis of mild AD.

Methods: The study was a single centre, prospective, observational cohort study. Participants completed baseline questionnaires including a demographic form, a fall history questionnaire and the Barthel Index of Activities of Daily Living (ADLs). Balance and gait were assessed using the MiniBESTest and BESTest. After completing baseline assessment, participants were given monthly fall calendars to track falls for the next 12 months.

Results: MiniBESTest total raw score for fallers was 13.4 out of 28 (SD = 3.6) and for non-fallers was 18.4 of out 28 (SD = 3.7). MiniBESTest total percentage score for fallers was 47.8% (SD = 12.8%) and for non-fallers was 65.5% (SD = 13.1%). BESTest total percentage scores for fallers was 58.2% (SD = 3.9%) and for non-fallers was 73.9% (SD = 7.9%). Subsections II-IV of the BESTest correlated with faller status.

Discussion and conclusions: Among individuals with mild AD, fall status was associated with certain balance deficits on the BESTest including moving body outside base of support (subsection II), changing centre of mass (subsection III), and reacting to external perturbations (subsection IV). Future studies could explore differences between AD and other neurological conditions and how physical therapy could improve these areas to reduce fall risk.

Aim of the study: The purpose of this study was to investigate the effects of receptor density in the glabrous skin of the hand on the perception of the roughness of a textured surface.Materials and methods: This was done by having observers make magnitude estimates of the perceived roughness of raised-dot surfaces at the fingertip, with its high receptor density, and the thenar eminence, with its much lower receptor density.Results: Judgments of perceived roughness averaged over the inter-dot spacings (0.8-5.9 mm) employed in the study did not differ significantly between the two sites, which suggested that roughness perception is not exclusively dependent upon a neural code involving variation in the activity levels of the nerve fibers of spatially distributed receptors, as is the case in spatial discrimination tasks such as spatial-gap detection, grove-orientation discrimination and letter recognition. This hypothesis was further supported by the finding that the elimination of temporal cues by preventing movement of the skin over the raised-dot surface drastically impaired judgments of perceived roughness at the thenar but had little effect on judgments of perceived roughness at the fingertip.Conclusion: These findings suggested that the neural code for perceived roughness at the fingertip is mediated primarily by spatial variation in the activity levels of spatially distributed receptors whereas the neural code for perceived roughness at the thenar is mediated primarily by temporal variation in the activity levels of individual receptors.

Purpose: Satellite glial cells (SGC) surrounding neurons in sensory ganglia can buffer extracellular potassium, regulating the excitability of injured neurons and possibly influencing a shift from acute to neuropathic pain. SGC apoptosis may be a key component in this process. This work evaluated induction or enhancement of apoptosis in cultured trigeminal SGC following changes in intracellular potassium [K]ic.

Materials and methods: We developed SGC primary cultures from rat trigeminal ganglia (TG). Purity of our cultures was confirmed using immunofluorescence and western blot analysis for the presence of the specific marker of SGC, glutamine synthetase (GS). SGC [K]ic was depleted using hypo-osmotic shock and 4 mM bumetanide plus 10 mM ouabain. [K]ic was measured using the K⁺ fluorescent indicator potassium benzofuran isophthalate (PBFI-AM).

Results: SGC tested positive for GS and hypo-osmotic shock induced a significant decrease in [K]ic at every evaluated time. Cells were then incubated for 5 h with either 2 mM staurosporine (STS) or 20 ng/ml of TNF-α and evaluated for early apoptosis and late apoptosis/necrosis by flow cytometry using annexin V and propidium iodide. A significant increase in early apoptosis, from 16 to 38%, was detected in SGC with depleted [K]ic after incubation with STS. In contrast, TNF-α did not increase early apoptosis in normal or [K]ic depleted SGC.

Conclusion: Hypo-osmotic shock induced a decrease in intracellular potassium in cultured trigeminal SGC and this enhanced apoptosis induced by STS that is associated with the mitochondrial pathway. These results suggest that K⁺ dysregulation may underlie apoptosis in trigeminal SGC.

Aim: To determine the effect of arm-raising pattern on upper limb proprioceptive accuracy for movements made to overhead targets.

Materials and methods: Sixteen healthy young adults were tested in standing with arms at the sides, made dominant arm-raising movements to an unseen overhead stop, randomly placed at one of five different overhead targets. Movements were made either as a uni-joint shoulder flexion movement in an arc, or as an unconstrained arm raising that was a series of multi-joint movements involving the shoulder, elbow, and wrist.

Results: Overall proprioceptive accuracy for discrimination between the five unseen overhead targets was not different after arm-raising with either a uni-joint or mult-joint pattern (F_{1, 15} = 0.50, p = 0.49, partial η² = 0.03). Better performers with one pattern also tended to perform well with the other (r = 0.70, p = 0.003). Trend analysis across the 4 pairwise scores for discriminations between the target positions (171.8°-173.6°, 173.6°-175.4°, 175.4°-177.2°, and 177.2°-179.0°) showed worsening discrimination towards the more distant targets (F_{1, 15} = 8.44, p = 0.01, partial η² = 0.36). However, this linear trend of falling discrimination accuracy was not different between the two movement patterns (p = 0.27).

Conclusion: Proprioceptive accuracy did not differ between simple uni-joint and more complex multi-joint arm-raising movement patterns, and the further the extent of the overhead target movement, the worse proprioceptive discrimination sensitivity for both movement patterns. Upper limb proprioceptive accuracy was therefore movement extent dependent, but movement pattern independent.

Purpose/aim of the study: Generation of smooth movement relies on the central nervous system (CNS) having information from the visual, vestibular and somatosensory systems to effectively execute motor behaviour. Recently, cutaneous afferent inputs have been linked to lower leg motorneuron pools, resulting in a growing interest of adding texture to the plantar foot sole interface as a novel method to facilitate cutaneous feedback. The aim of this study was to characterize the changes in magnitude and temporal organization of muscle activity, and to investigate motor output changes from enhanced tactile feedback during perturbed gait termination.Materials and methods: Thirty young adults experienced an unpredictable platform perturbation when completing planned gait termination. The study manipulated two experimental variables: 1) direction of platform tilt (anterior, posterior, medial, lateral), and 2) foot sensory facilitation (non-facilitated, facilitated). Upper and lower leg EMG onset, cessation time and integrated EMG (iEMG) were measured in addition to common gait parameters (walking velocity, step length, step width).Results: Gait termination over a textured surface resulted in significantly earlier upper leg EMG onset times and modified iEMG of rectus femoris, vastus medialis and biceps femoris muscles.Conclusions: Results of this study suggest that the addition of cutaneous feedback under the plantar-surface of the foot increases the ability to generate an earlier muscle response, consequently improving response ability to an unexpected perturbation. Secondly, enhanced tactile feedback appears to inform the CNS of the magnitude of the threat to the balance control system, providing additional insight into how the CNS uses enhanced tactile feedback during a gait termination task.

Purpose: Previous research has found hemispheric asymmetries in the utilization of proprioceptive information. It is undetermined, however, if there is any change in asymmetry in proprioceptive function when external stimulation, such as vibration, is presented. The present study was to investigate the immediate effects of vibration stimulation (VS) on bilateral ankle proprioception.

Materials and methods: Forty-six recreational male basketball players were included. Proprioception was assessed by using the active movement extent discrimination apparatus (AMEDA) in standing, and vibration was provided by using a vibrating form roller on the peroneal or gastrocnemius muscles.

Results: When participants were divided into high score and low score groups, according to the median of the baseline proprioceptive performance, VS (irrespective of whether vibrating the peroneal or gastrocnemius muscles) significantly improved left non-dominant ankle proprioception in the low proprioceptive performer group (p = 0.019), while significantly deteriorated right dominant ankle proprioception in the high proprioceptive performer group (p = 0.011).

Conclusions: The results found that external stimuli reversely affect proprioception in better and worse performing groups. This suggests that there are differences in the processing of external stimulus signals on different bilateral hemispheres and in different groups (high score vs low score groups), which may be related to hemispheric asymmetry and stochastic resonance. Therefore, it is necessary to explore more specific interventions in the future.

Purpose: The present study aimed to investigate the relationship between the ultrasonography parameters of transversus abdominis and neck pain manifestations in women with chronic neck pain.

Materials and methods: Thirty women (mean age: 38.44 ± 9.56 years, BMI: 25.57 ± 3.32 kg/m²) with chronic neck pain were included in the study. The pain severity, disability scores, and bilateral pain pressure threshold of upper trapezius were assessed. The thickness of transversus abdominis in-rest and abdominal draw-in conditions were evaluated by two-dimensional ultrasonography. Pearson's correlation coefficients and linear regression statistics were determined.

Results: We found a moderate correlation between the thickness of transversus abdominis in abdominal draw-in and the pain pressure threshold of right (r = 0.636, p < 0.001), and left upper trapezius (r = 0.403, p = 0.03). Moreover, there was a moderate correlation between the pain pressure threshold of the right upper trapezius and the thickness of transversus abdominis in-rest (r = 0.498, p = 0.006). No significant correlation was found between pain intensity, disability scores, and ultrasonography parameters of transversus abdominis. There was also a significant total effect of transversus abdominis' thickness on abdominal draw-in manoeuvre on predicting pain pressure threshold of right upper trapezius (B = 0.636, SE = 0.765, p < 0.001) and pain pressure threshold of left upper trapezius (B = 0.403, SE = 0.840, p = 0.03).

Conclusions: Our results revealed that upper trapezius muscle tenderness may associated with decreased muscle thickness of transversus abdominis. Addressing new exercise methodologies including transversus abdominis training in the management of chronic neck pain may be helpful to improve neck pain symptoms.

Background: Balance issues and poor gross motor function affect the daily needs of children with cerebral palsy.

Purpose: The study objective was to examine the effects of virtual reality gaming and physiotherapy on balance, gross motor performance and daily functioning among children with bilateral spastic cerebral palsy.

Method: Thirty-eight children with bilateral spastic cerebral palsy aged 6-12 years with GMFCS- level II-III, Manual Ability Classification System level I-III participated in this randomized controlled trial. The experimental group performed virtual reality games and physiotherapy, while the control group underwent physiotherapy alone. The exercise intensity was 60 minutes session a day, 4-days a week for 6-weeks. Paediatric Balance Scale (PBS), Kids-Mini-Balance Evaluation System Test (Kids-Mini-BESTest), Gross Motor Function Measure-88 (GMFM-88), and Wee-Functional Independence Measure (WeeFIM) were the outcome measures collected at baseline, 6-week post-training and 2-months follow-up.

Results: The time by group interaction of repeated measures ANOVA revealed no statistical significance for all the outcome measures except Kids-Mini-BESTest (p < 0.05). The PBS and, Kids-Mini-BESTest improved by a mean (standard deviation) score of 5.1(1.7) and 8.7(2.8) points, respectively in the experimental group as compared to control group [3.4(1.6) and 5.8(2.5) points]. These gains remained at follow-up (p < 0.001).

Conclusion: Combined virtual reality gaming and physiotherapy is not superior over physiotherapy alone in improving the gross motor performance and daily functioning among children with bilateral spastic cerebral palsy. Virtual gaming, along with physiotherapy, appears to be beneficial in their balance capacity, warranting further trials to investigate the same in children with GMFCS level-III.

Purpose: Progressive loss of dopaminergic neurons in basal ganglia is blamed as the main source of gait disturbance in Parkinson's disease (PD). It is known that the normal step pattern does not disappear in PD, but there is a problem in activating the correct step response. The aim of this study was to investigate the effect of Rhythmic Auditory Stimulation (RAS), which is an external stimulus, on gait in individuals with PD.

Materials and methods: Twenty-six individuals, 13 in the PD group and 13 in the control group, participated in the study. All individuals were asked to walk under four different RAS conditions configured with beat frequency and melodic variations. Time-distance parameters and gait performance of the individuals were evaluated.

Results: RAS significantly increased the gait speed of the individuals with PD compared to the control group. RAS set to 10% increase in the cadence of the patient with melody (10 M+) was found to be more effective than the RAS set to normal cadence of the patient without melody (0 M-) (p < 0.05). While all RAS implementations increased the stride length of the individuals with PD (p < 0.05), there was no change in the control group. RAS did not affect the return time in both groups.

Conclusions: Our study has shown that RAS implementation improves gait in individuals with PD both in terms of time-distance parameters and performance, especially when set to 10% more than the patient's gait cadence. It was concluded that cadence-compatible melodic RAS can be safely included in PD rehabilitation programs.

Objective: The objective of this study is to examine time perception impairment in multiple sclerosis (MS) patients.

Method: The study was performed with 60 MS patients and 60 age-matched healthy people. Estimation and Production Tests were carried out with a standard personal laptop computer and participants were aware to count the seconds by the 'start' command and to stop by the 'stop' command. The outcome measure was the ratio between the estimated duration and the target (7 s, 32 s, or 58 s) one for the Estimation Test and the Produced duration and the target (7 s, 32 s, or 58 s) one for the Production Test; and each time duration was repeated three times both for Production and Estimation Tests.

Results: We found a significant difference in the Estimation Test (7 s, 32 s, 58 s), and the Production Test (7 s, 32 s, 58 s) between the MS group and healthy control group (p < .05). It was observed that patients with MS had a higher deviation from the target time compared to the control group. It was found that this difference was statistically significant (p < .05). There was a high and negative correlation between the Estimation and Production Tests in MS patients.

Conclusion: In conclusion, our data suggests that time estimation and production are disturbed in MS patients, and cognitive rehabilitation is required for most of them.