Somatosensory temporal discrimination threshold changes during motor learning.

PURPOSE: Mechanisms underlying the somatosensory temporal discrimination threshold and its relationship with motor control have been reported; however, little is known regarding the change in temporal processing of tactile information during motor learning. We investigated the somatosensory temporal discrimination threshold changes during motor learning in a feedback-control task. MATERIALS AND METHODS: We included 15 healthy individuals. The somatosensory temporal discrimination threshold was measured on the index finger. A 10-session coin rotation task was performed, with 2 min' training per session. The coin rotation scores were determined through tests (continuous coin rotation at 180° at maximum speed for 10 s). The coin rotation test score and the somatosensory temporal discrimination threshold were determined at baseline and after 5 and 10 sets of training, as follows: pre-test; training5set (1 set × 5); post-test5block; training5set (1 set × 5); and post-test10block. The coin rotation score and the somatosensory temporal discrimination threshold were compared between the tests. The latter was also compared between the right (the within-subject control) and left fingers. RESULTS: The coin rotation score showed significant differences among all tests. In the somatosensory temporal discrimination threshold, there was a significant difference between the pre-test and post-test5block values, pre-test and post-test10block values of the left side and between the right and left sides in the post-test5block and the post-test10block values. CONCLUSIONS: The somatosensory temporal discrimination threshold decreased along with task-performance progress following motor learning during a feedback-control task.

Comparing movement-related cortical potential between real and simulated movement tasks from an ecological validity perspective.

Introduction: Concerns regarding the ecological validity of movement-related cortical potential (MRCP) experimental tasks that are related to motor learning have recently been growing. Therefore, we compared MRCP during real movement task (RMT) and simulated movement task (SMT) from an ecological validity perspective. Methods: The participants performed both RMT and SMT, and MRCP were measured using electroencephalogram (EEG). EEG was based on the 10-20 method, with electrodes placed in the motor cortex (C3 and C4) and supplementary motor cortex (FCz [between Fz and Cz] and Cz) areas. This experiment examined the MRCP using Bereitschaftspotential (BP) and negative slope (NS') onset times, and BP, NS', and motor potential (MP) amplitudes during the task. Results: The results revealed that the SMT exhibited later BP and NS' onset times and smaller BP, NS', and MP amplitudes than the RMT. Furthermore, in RMT, the onset time of MRCP was delayed, and the amplitude of MRCP was smaller in the second half of the 200 times task than in the first half, whereas in SMT, there was no change in onset time and amplitude. The SMT showed a different MRCP than the RMT, suggesting that the ecological validity of the task should be fully considered when investigating the cortical activity associated with motor skill learning using MRCP. Conclusion: Ecological validity of the study should be fully considered when investigating the cortical activity associated with motor skill learning using MRCP. Moreover, it is important to understand the differences between the two methods when applied clinically.

Association of patient quality of life with the degree of agreement in the perceptions of patient disability within the stroke patient-rehabilitation therapist dyad: a cross-sectional study in postdischarge rehabilitation setting.

OBJECTIVES: The purpose of study was to explore the association between patient physical and psychological quality of life (QOL) with the degree of agreement in perceptions of patient disability within the stroke patient-rehabilitation therapist dyad. DESIGN: Cross-sectional dyadic study with a tablet-based structured questionnaire. SETTING: Rehabilitation, nursing and long-term care facilities that provide rehabilitation services in the Kanagawa prefecture, Japan. PARTICIPANTS: The 81 dyads of a male patient with stroke living at home and the rehabilitation therapist in charge of the eligible patient were recruited from March 2019 to February 2020. METHOD: Patient physical and psychological QOL was measured using the WHOQOL BREF. Perceptions of patient disability were measured using the 12-item WHO Disability Assessment Schedule V.2.0 (DAS). DAS scores of patients and therapists were classified into two (high and low) and three (high, medium, low) categories, respectively, and six patterns of agreement about patient function were created and used in the analysis. Generalised estimating equations were used to examine multivariable associations between WHOQOL scores in patients and the degree of agreement within dyads adjusting for other covariates and clustering effects. RESULTS: Among 81 enrolled dyads, 48 (59.3%) were classified into one of four disagreement groups (low medium, low high, high medium, high low). When the patient appraised himself as having mild disability, the degree of patient-therapist disagreement was negatively associated with patient's physical and psychological QOL. When the patient appraised himself as having severe disability, his physical and/or psychological QOL was poorer, regardless of the degree of agreement. CONCLUSIONS: Disagreement in the perception of disability within patient-rehabilitation therapist dyad could be associated with patient's poor QOL, especially when the patient perceives himself as having mild disability. Reaching an agreement about patient disability is needed in the delivery of rehabilitation care for patients with stroke living at home to improve their QOL.

The Effect of Cane Use on Attentional Demands During Walking.

We investigated the effects of cane use, lateral walking stability, and cane use practice on attentional demands during walking. Attentional demands were assessed using dual-task methodology with a reaction time (RT) task. Sixteen healthy young subjects performed the RT task during walking, before and after cane use practice under four conditions: with/without cane use while wearing normal/unstable shoes. Among normal shoe conditions, cane use resulted in longer RTs. In contrast, RTs were similar regardless of cane use in the unstable shoe conditions. Among conditions without cane use, unstable shoes resulted in longer RTs. In contrast, RTs were similar regardless of shoe type in the cane use conditions. This study suggests that using a cane during walking requires additional attention; however, the resulting attentional demands depend on walking stability.

Time Course of Corticospinal Excitability and Intracortical Inhibition Just before Muscle Relaxation.

Using transcranial magnetic stimulation (TMS), we investigated how short-interval intracortical inhibition (SICI) was involved with transient motor cortex (M1) excitability changes observed just before the transition from muscle contraction to muscle relaxation. Ten healthy participants performed a simultaneous relaxation task of the ipsilateral finger and foot, relaxing from 10% of their maximal voluntary contraction (MVC) force after the go signal. In the simple reaction time (RT) paradigm, single or paired TMS pulses were randomly delivered after the go signal, and motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous (FDI) muscle. We analyzed the time course prior to the estimated relaxation reaction time (RRT), defined here as the onset of voluntary relaxation. SICI decreased in the 80-100 ms before RRT, and MEPs were significantly greater in amplitude in the 60-80 ms period before RRT than in the other intervals in single-pulse trials. TMS pulses did not effectively increase RRT. These results show that cortical excitability in the early stage, before muscle relaxation, plays an important role in muscle relaxation control. SICI circuits may vary between decreased and increased activation to continuously maintain muscle relaxation during or after a relaxation response. With regard to M1 excitability dynamics, we suggest that SICI also dynamically changes throughout the muscle relaxation process.

Effectiveness and Cost-Effectiveness of Occupation-Based Occupational Therapy Using the Aid for Decision Making in Occupation Choice (ADOC) for Older Residents: Pilot Cluster Randomized Controlled Trial.

BACKGROUND: Care-home residents are mostly inactive, have little interaction with staff, and are dependent on staff to engage in daily occupations. We recently developed an iPad application called the Aid for Decision-making in Occupation Choice (ADOC) to promote shared decision-making in activities and occupation-based goal setting by choosing from illustrations describing daily activities. This study aimed to evaluate if interventions based on occupation-based goal setting using the ADOC could focus on meaningful activities to improve quality of life and independent activities of daily living, with greater cost-effectiveness than an impairment-based approach as well as to evaluate the feasibility of conducting a large cluster, randomized controlled trial. METHOD: In this single (assessor)-blind pilot cluster randomized controlled trial, the intervention group (ADOC group) received occupational therapy based on occupation-based goal setting using the ADOC, and the interventions were focused on meaningful occupations. The control group underwent an impairment-based approach focused on restoring capacities, without goal setting tools. In both groups, the 20-minute individualized intervention sessions were conducted twice a week for 4 months. MAIN OUTCOME MEASURES: Short Form-36 (SF-36) score, SF-6D utility score, quality adjusted life years (QALY), Barthel Index, and total care cost. RESULTS: We randomized and analyzed 12 facilities (44 participants, 18.5% drop-out rate), with 6 facilities each allocated to the ADOC (n = 23) and control (n = 21) groups. After the 4-month intervention, the ADOC group had a significantly greater change in the BI score, with improved scores (P = 0.027, 95% CI 0.41 to 6.87, intracluster correlation coefficient = 0.14). No other outcome was significantly different. The incremental cost-effectiveness ratio, calculated using the change in BI score, was $63.1. CONCLUSION: The results suggest that occupational therapy using the ADOC for older residents might be effective and cost-effective. We also found that conducting an RCT in the occupational therapy setting is feasible. TRIAL REGISTRATION: UMIN Clinical Trials Registry UMIN000012994.

Changes in Cerebral Hemodynamics during Complex Motor Learning by Character Entry into Touch-Screen Terminals.

INTRODUCTION: Studies of cerebral hemodynamics during motor learning have mostly focused on neurorehabilitation interventions and their effectiveness. However, only a few imaging studies of motor learning and the underlying complex cognitive processes have been performed. METHODS: We measured cerebral hemodynamics using near-infrared spectroscopy (NIRS) in relation to acquisition patterns of motor skills in healthy subjects using character entry into a touch-screen terminal. Twenty healthy, right-handed subjects who had no previous experience with character entry using a touch-screen terminal participated in this study. They were asked to enter the characters of a randomly formed Japanese syllabary into the touch-screen terminal. All subjects performed the task with their right thumb for 15 s alternating with 25 s of rest for 30 repetitions. Performance was calculated by subtracting the number of incorrect answers from the number of correct answers, and gains in motor skills were evaluated according to the changes in performance across cycles. Behavioral and oxygenated hemoglobin concentration changes across task cycles were analyzed using Spearman's rank correlations. RESULTS: Performance correlated positively with task cycle, thus confirming motor learning. Hemodynamic activation over the left sensorimotor cortex (SMC) showed a positive correlation with task cycle, whereas activations over the right prefrontal cortex (PFC) and supplementary motor area (SMA) showed negative correlations. CONCLUSIONS: We suggest that increases in finger momentum with motor learning are reflected in the activity of the left SMC. We further speculate that the right PFC and SMA were activated during the early phases of motor learning, and that this activity was attenuated with learning progress.

Excitability of the primary motor cortex increases more strongly with slow- than with normal-speed presentation of actions.

INTRODUCTION: The aim of the present study was to investigate how the speed of observed action affects the excitability of the primary motor cortex (M1), as assessed by the size of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS). METHODS: Eighteen healthy subjects watched a video clip of a person catching a ball, played at three different speeds (normal-, half-, and quarter-speed). MEPs were induced by TMS when the model's hand had opened to the widest extent just before catching the ball ("open") and when the model had just caught the ball ("catch"). These two events were locked to specific frames of the video clip ("phases"), rather than occurring at specific absolute times, so that they could easily be compared across different speeds. MEPs were recorded from the thenar (TH) and abductor digiti minimi (ADM) muscles of the right hand. RESULTS: The MEP amplitudes were higher when the subjects watched the video clip at low speed than when they watched the clip at normal speed. A repeated-measures ANOVA, with the factor VIDEO-SPEED, showed significant main effects. Bonferroni's post hoc test showed that the following MEP amplitude differences were significant: TH, normal vs. quarter; ADM, normal vs. half; and ADM, normal vs. quarter. Paired t-tests showed that the significant MEP amplitude differences between TMS phases under each speed condition were TH, "catch" higher than "open" at quarter speed; ADM, "catch" higher than "open" at half speed. CONCLUSIONS: These results indicate that the excitability of M1 was higher when the observed action was played at low speed. Our findings suggest that the action observation system became more active when the subjects observed the video clip at low speed, because the subjects could then recognize the elements of action and intention in others.

Reliability and validity of individualized satisfaction score in aid for decision-making in occupation choice.

PURPOSE: The iPad application aid for decision-making in occupation choice (ADOC) was developed to measure the client's satisfaction with individualized occupational performance of meaningful and purposeful activities. The present study examined the reliability and validity of individualized satisfaction measurement using the ADOC. METHOD: The Japanese version of the ADOC was used by 36 occupational therapists on 92 of their clients (44 males, 48 females, mean age 66.4 ± 17.8 years). Convergent and discriminant validity were examined using Pearson's correlation between ADOC satisfaction score and the Life Satisfaction Index K (LSIK) factors: Factor 1 (satisfaction with life), Factor 2 (optimistic and positive disposition) and Factor 3 (evaluation of own aging). Test-retest reliability was assessed using the intraclass correlation coefficient (ICC). RESULTS: Ninety-two clients completed the validation study. Satisfaction with ADOC significantly correlated with LSIK Factor 1 (r = 0.297, p < 0.01), but not with Factors 2 or 3 (r = -0.045 and -0.089, respectively). Of the 92 clients, 78 participated in the test-retest reliability study. Good to moderate correlation was revealed (ICC = 0.712, p < 0.001). CONCLUSIONS: The Japanese version of the ADOC is a valid and reliable instrument for measuring client satisfaction with individualized occupational performance.

Utilization of the iPad application: Aid for Decision-making in Occupation Choice.

The purpose of the study was to develop and evaluate an iPad (Apple) application, Aid for Decision-making in Occupation Choice (ADOC), so as to promote shared decision-making in an occupation-based goal setting. This application involves the client choosing from 94 illustrations describing daily activities related to the category of "activities and participation". One hundred occupational therapy clients evaluated the ADOC for goal setting; the clients and 37 occupational therapists underwent a survey to determine their perceptions of decision-making in the goal setting. More than 90% of the clients felt that they could give their opinions using the ADOC regarding goal setting. The majority of the occupational therapists (>90%) felt that ADOC would be useful in their clinical practice for setting client goals. The results indicated that ADOC is a useful and acceptable tool for both clients and occupational therapists in shared decision-making in occupation-based goal setting.