Clinical impact of non-lying time on hospital-associated functional decline in older patients undergoing transcatheter aortic valve implantation.

The purposes of the present study were: (1) to investigate the relationship between hospital-associated functional decline (HAFD) and non-lying time and (2) to clarify the optimal cut-off value for non-lying time associated with HAFD in older patients undergoing transcatheter aortic valve implantation (TAVI). From January 2021 to December 2022, patients admitted to a university hospital who underwent trans-femoral TAVI were consecutively recruited. We measured short physical performance battery (SPPB) pre and post-TAVI, and non-lying time from post-operative days 3-5. HAFD was defined as at least 1 point decrease in SPPB during pre and post-TAVI. Among 75 patients (47 female, mean age of 84.5 years) enrolled, 14 patients were classified as having HAFD. Non-lying time was significantly shorter in the HAFD group than in the non-HAFD group (371 min vs. 539 min, P < 0.001). Receiver-operating characteristic analysis determined an optimal cut-off value of 477 min for differentiating the patients more likely to experience HAFD (sensitivity, 75%; specificity, 92%; area under the curve, 0.798). The non-lying time could be one of the associated factors of HAFD in older patients with TAVI. Non-lying time of about 480 min (8 h) during hospitalization may be an initial target for preventing HAFD.

Determinants of Gait Parameters in Patients With Severe Hip Osteoarthritis.

OBJECTIVE: To investigate the characteristics and symptoms of patients with hip osteoarthritis that are associated with spatiotemporal gait parameters, including their variability and asymmetry. DESIGN: A retrospective, cross-sectional study. SETTING: University hospital. PARTICIPANTS: The study analyzed the gait analysis data of 155 patients (N=155) with hip osteoarthritis who were admitted to a university hospital for total hip replacement and were able to walk on a treadmill without a handrail. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The dependent variables were gait parameters during treadmill walking. These included gait speed, stride length, cadence, coefficient of variation of stride length and stride time, swing time symmetry index, and step symmetry index. Single and multiple regression analyses were conducted using independent variables of the characteristics and symptoms of the patients, including age, sex, height, pain, leg-length discrepancy, and muscle strength of the affected and normal sides measured with a hand-held dynamometer (iliopsoas, gluteus medius, and quadriceps). RESULTS: In the analysis, gait speed and stride were the dependent variables, whereas age, height, and muscle strength on the affected side were the significant independent variables (P<.05). Additionally, pain demonstrated a marginal association with gait speed (P=.053). Only the leg-length discrepancy correlated with cadence. When the coefficient of variation of the stride length was the dependent variable, age and muscle strength on the affected side were significant. For the swing time symmetry index, only the muscle strength on the affected side was significant. Furthermore, the step symmetry index only correlated with leg-length discrepancy. The muscle strength on the affected side was the only significant independent variable for the coefficient of variation of the stride time. CONCLUSIONS: The results revealed that each of the frequent clinical symptoms of hip osteoarthritis, such as pain, muscle weakness, and leg-length discrepancy, can explain different aspects of gait performance.

Effect of the Effortful Swallow on Pharyngeal Cavity Volume: Kinematic Analysis in Three Dimensions Using 320-Row Area Detector Computed Tomography.

This study evaluated the effects of the effortful swallow (ES) on pharyngeal cavity volume using three-dimensional kinematic analyses. Nine healthy volunteers (30.7 ± 7.8 years old) underwent a CT scan while swallowing 10 ml of honey thick liquid using no maneuvers (control) and during an ES. Upper and lower volumes (bordered by valleculae) of the pharyngeal air column and the bolus were measured at every frame and were compared between ES and control swallows. Duration of pharyngeal obliteration and the timing of swallowing events were also measured. Maximum volume and volume at the onset of hyoid anterosuperior movement using ES were significantly smaller than those in control swallows (p = 0.012, p = 0.015) in the upper pharynx but not significantly different in lower pharynx. Minimum pharyngeal volume was sustained for a longer time when ES was used compared to control swallows in both upper and lower pharynx (upper p = 0.016, lower p = 0.027). Onset of velopharyngeal closure was earlier when comparing ES and control swallows (p = 0.04). Termination of all events was significantly delayed when the ES was used (p < 0.05). Changes in the upper pharyngeal volume and in the onset of velopharyngeal closure suggest earlier pharyngeal constriction when using the ES. Longer pharyngeal obliteration and prolonged termination of velopharyngeal closure and epiglottis inversion suggest the prolonged pharyngeal constriction during the ES. These findings suggest the ES can be useful for improving the efficiency of swallowing.

Thin Liquid Bolus Volume Alters Pharyngeal Swallowing: Kinematic Analysis Using 3D Dynamic CT.

The previous studies reported that different volumes of thick liquid had an impact on spatiotemporal characteristics and pharyngeal response of swallowing. However, the bolus flow and swallowing motion pattern were different between thick and thin liquids. The effects of thin bolus volume on pharyngeal swallowing, especially true vocal cord (TVC) closure is still unclear. This study assessed the temporal characteristics when swallowing different volumes of thin liquid to determine the mechanical adaptation using 320-row area detector computed tomography (320-ADCT) and investigated a change of swallowing physiology including laryngeal closure, particularly TVC closure. Fourteen healthy women (28-45 years) underwent 320-ADCT while swallowing of 3, 10, and 20 ml of thin liquid barium in 45° semi-reclining position. Kinematic analysis was performed for each swallow including temporal characteristic, structural movements while swallowing, and maximal cross-sectional area of the upper esophageal sphincter (UES) opening. Bolus head reached to pharynx and esophagus earlier in larger volume significantly, indicating faster bolus transport as volume increased. There were significant effects on swallowing mechanism revealing earlier TVC closure and UES opening with increasing volume. Maximum cross-sectional area of the UES opening was increased to accommodate a larger bolus. Differences in mechanical adaptation through bolus transit and motion of swallowing structures were detected across increasing volumes. These volume-dependent adaptations potentially reduce the risk of aspiration. Understanding the swallowing physiological changes as volume increased is helpful for diagnosis and treatment of dysphagia patients as well as outcomes of swallowing rehabilitation in clinical practice.

Stroke Patients with Nearly Independent Transfer Ability are at High Risk of Falling.

OBJECTIVES: To examine the relationship between patients' transfer ability and fall risk in stroke patients during hospitalization. MATERIALS AND METHODS: We retrospectively enrolled 237 stroke patients who were transferred to a convalescent rehabilitation ward from acute wards in the same hospital. Using incident reports, we investigated their fall rates and activity status at the falls according to their transfer abilities, which were assessed with Functional Independence Measure (FIM) transfer scores. The bi-weekly time trend of fall rates in all patients and in three subgroups based on FIM transfer scores of 1-3, 4-5, and 6-7, and activity status at the falls, were investigated. In addition, changes of patients' transfer ability on admission, at the first fall, and at discharge were investigated among falling patients. RESULTS: The fall rate was the greatest in patients with a FIM transfer score of 4 (14.3 times/1000 person-days). The majority of falls for patients with a FIM transfer score of 1 occurred at the activity status of "on the bed" and "sitting", while three quarters of patients with a FIM score of 7 had falls during "standing" and "walking". No longitudinal trend in fall rates was found overall; however, the fall rate trends differed depending on the FIM transfer score. The majority of the patients who fell required full assistance for transfers upon admission but required no assistance at discharge. CONCLUSIONS: Fall risk differed among patients with various transfer abilities; the greatest risk was in those who needed minimal assistance for transfers.

Development of a clinical tool for rating the body function categories of the ICF generic-30/rehabilitation set in Japanese rehabilitation practice and examination of its interrater reliability.

BACKGROUND: The International Classification of Functioning, Disability, and Health (ICF) Generic-30 (Rehabilitation) Set is a tool used to assess the functioning of a clinical population in rehabilitation. The ICF Generic-30 consists of nine ICF categories from the component "body functions" and 21 from the component "activities and participation". This study aimed to develop a rating reference guide for the nine body function categories of the ICF Generic-30 Set using a predefined, structured process and to examine the interrater reliability of the ratings using the rating reference guide. METHODS: The development of the first version of the rating reference guide involved the following steps: (1) a trial of rating patients by several raters; (2) cognitive interviews with each rater to analyze the thought process involved in each rating; (3) the drafting of the rating reference guide by a multidisciplinary panel; and (4) a review by ICF specialists to confirm consistency with the ICF. Subsequently, we conducted a first field test to gain insight into the use of the guide in practice. The reference guide was modified based on the raters' feedback in the field test, and an inter-rater reliability test was conducted thereafter. Interrater agreement was evaluated using weighted kappa statistics with linear weights. RESULTS: The first version of the rating reference guide was successfully developed and tested. The weighted kappa coefficient in the field testing ranged from 0.25 to 0.92. The interrater reliability testing of the rating reference guide modified based on the field test results yielded an improved weighted kappa coefficient ranging from 0.53 to 0.78. Relative improvements in the weighted kappa coefficients were observed in seven out of the nine categories. Consequently, seven out of nine categories were found to have a weighted kappa coefficient of 0.61 or higher. CONCLUSIONS: In this study, we developed and modified a rating reference guide for the body function categories of the ICF Generic-30 Set. The interrater reliability test using the final version of the rating reference guide showed moderate to substantial interrater agreement, which encouraged the use of the ICF in rehabilitation practice.

Outcomes of Dysphagia Following Stroke: Factors Influencing Oral Intake at 6 Months After Onset.

PURPOSE: This study aimed to describe recovery of dysphagia after stroke. We determined the proportion of stroke survivors with dysphagia on admission, discharge, and 6 months after stroke. Additionally, the factors affecting oral feeding 6 months after stroke were explored. METHODS: A total of 427 acute stroke patients were recruited prospectively. Presence of dysphagia was evaluated on admission, weekly until recovery was achieved, and at discharge. We compared stroke survivors with dysphagia who had complete recovery, who had dysphagia but achieved oral feeding, and who required tube feeding. Patient-reported eating ability was evaluated at 6 months. Patients who achieved oral feeding by 6 months were compared to those who had persistent tube feeding need. RESULTS: Fifty-five percent of stroke survivors had dysphagia on initial evaluation (3.1 ± 1.4 days after admission) and 37% at discharge (21.1 ± 12.4 days). At 6 months, 5% of patients required tube feeding. Among those who had dysphagia at initial evaluation, 32% had resolution of dysphagia within two weeks, 44% had dysphagia but started oral feeding before discharge, and 23% required alternative means of alimentation (nasogastric tube feeding, percutaneous endoscopic gastrostomy, parental nutrition) throughout hospitalization. At 6 months, 90% of stroke survivors who achieved oral feeding by discharge continued with oral feeding. Patients who achieved oral feeding after discharge had less cognitive impairments on admission and a higher speech therapist intervention rate after discharge. CONCLUSIONS: More than half of stroke survivors had dysphagia but the vast majority were able to return to oral feeding by 6 months. Cognitive function and dysphagia rehabilitation interventions were associated with return to oral feeding after hospital discharge.

Supporting the clinical use of the ICF in Japan - development of the Japanese version of the simple, intuitive descriptions for the ICF Generic-30 set, its operationalization through a rating reference guide, and interrater reliability study.

BACKGROUND: The World Health Organization developed the International Classification of Functioning, Disability, and Health (ICF) in 2001 and has been in the process of implementing it in clinics since then. Current international efforts to implement ICF in rehabilitation clinics include the implementation of ICF Core Sets and the development of simple, intuitive descriptions for the ICF Generic-30 Set (also called Rehabilitation Set). The present study was designed to operationalize these ICF tools for clinical practice in Japan. This work included 1) the development of the Japanese version of the simple, intuitive descriptions for the ICF Generic-30 Set, 2) the development of a rating reference guide for Activity and Participation categories, and 3) the examination of the interrater reliability of rating Activity and Participation categories. METHODS: The Japanese version of the simple, intuitive descriptions for the ICF Generic-30 Set was developed following the process employed to develop the Chinese and Italian versions. For further operationalization of this ICF Set in practice, a rating reference guide was developed. The development of the rating reference guide involved the following steps: 1) a trial of rating patients by several raters, 2) cognitive interviewing of the raters to analyse the thinking process involved in rating, 3) drafting of the rating reference guide, and 4) review by ICF specialists to confirm consistency with the original ICF concepts. After the rating reference guide was developed, interrater reliability of the rating with the reference guide was determined. Interrater reliability was examined using weighted kappa statistics with linear weight. RESULTS: Through the pre-defined process, the Japanese version of the simple, intuitive descriptions for 30 categories of the ICF Generic-30 Set and the rating reference guides for 21 Activity and Participation categories were successfully developed. The weighted kappa statistics ranged from 0.61 to 0.85, showing substantial to excellent agreement of the ratings between raters. CONCLUSIONS: The present study demonstrates that ICF categories can be translated into clinical practice. Collaboration between clinicians and researchers would further enhance the implementation of the ICF in Japan.

Robot-assisted Gait Training Using Welwalk in Hemiparetic Stroke Patients: An Effectiveness Study with Matched Control.

OBJECTIVE: Although studies on the efficacy of the rehabilitation robot are increasing, there are few reports using the robot for gait training in the actual clinical setting. This study aimed to investigate the effectiveness of gait training using Welwalk in hemiparetic stroke patients in a real clinical setting. MATERIALS AND METHODS: This prospective study included 36 hemiparetic stroke patients who underwent gait training using Welwalk. We examined the walking ability improvement efficiency using Functional Independence Measure (FIM)-walk as the primary outcome, which was compared with that of 36 patients (matched control group) who underwent conventional rehabilitation. Other outcomes were the actual gait training period using Welwalk, raw FIM-walk score, lower extremity motor functions score in Stroke Impairment Assessment Set at discharge, and duration from stroke onset until discharge. RESULTS: The improvement efficiency of the FIM-walk was significantly higher in the Welwalk group than in the matched control group (control 0.48 ± 0.31, Welwalk 0.80 ± 0.38, p-value < 0.001). The mean gait training period using Welwalk was 5 weeks. No significant differences were found in other outcomes between the Welwalk group and the matched control group. CONCLUSION: This study demonstrated the effectiveness of gait training using Welwalk on the improvement efficiency of the FIM-walk in hemiparetic stroke patients in an actual clinical setting.

The impact of ankle-foot orthoses on toe clearance strategy in hemiparetic gait: a cross-sectional study.

BACKGROUND: Ankle-foot orthoses (AFOs) are frequently used to improve gait stability, toe clearance, and gait efficiency in individuals with hemiparesis. During the swing phase, AFOs enhance lower limb advancement by facilitating the improvement of toe clearance and the reduction of compensatory movements. Clinical monitoring via kinematic analysis would further clarify the changes in biomechanical factors that lead to the beneficial effects of AFOs. The purpose of this study was to investigate the actual impact of AFOs on toe clearance, and determine the best strategy to achieve toe clearance (including compensatory movements) during the swing phase. METHODS: This study included 24 patients with hemiparesis due to stroke. The gait performance of these patients with and without AFOs was compared using three-dimensional treadmill gait analysis. A kinematic analysis of the paretic limb was performed to quantify the contribution of the extent of lower limb shortening and compensatory movements (such as hip elevation and circumduction) to toe clearance. The impact of each movement related to toe clearance was assessed by analyzing the change in the vertical direction. RESULTS: Using AFOs significantly increased toe clearance (p = 0.038). The quantified limb shortening and pelvic obliquity significantly differed between gaits performed with versus without AFOs. Among the movement indices related to toe clearance, limb shortening was increased by the use of AFOs (p < 0.0001), while hip elevation due to pelvic obliquity (representing compensatory strategies) was diminished by the use of AFOs (p = 0.003). The toe clearance strategy was not significantly affected by the stage of the hemiparetic condition (acute versus chronic) or the type of AFO (thermoplastic AFOs versus adjustable posterior strut AFOs). CONCLUSIONS: Simplified three-dimensional gait analysis was successfully used to quantify and visualize the impact of AFOs on the toe clearance strategy of hemiparetic patients. AFO use increased the extent of toe clearance and limb shortening during the swing phase, while reducing compensatory movements. This approach to visualization of the gait strategy possibly contributes to clinical decision-making in the real clinical settings. TRIAL REGISTRATION: UMIN000028946 . Registered 31 August 2017 (retrospectively registered).

After-effects of pedaling exercise on spinal excitability and spinal reciprocal inhibition in patients with chronic stroke.

PURPOSE OF THE STUDY: To evaluate the after-effects of pedaling on spinal excitability and spinal reciprocal inhibition in patients with post-stroke spastic hemiparesis. MATERIALS AND METHODS: Twenty stroke patients with severe hemiparesis participated in this study and were instructed to perform 7 min of active pedaling and 7 min of passive pedaling with a recumbent ergometer at a comfortable speed. H reflexes and M waves of paretic soleus muscles were recorded at rest before, immediately after and 30 min after active and passive pedaling. The Hmax/Mmax ratio and H recruitment curve were measured. Reciprocal inhibition was assessed using the soleus H reflex conditioning test paradigm. RESULTS: The Hmax/Mmax ratio was significantly decreased after active and passive pedaling exercise. The decreased Hmax/Mmax ratio after active pedaling lasted at least for 30 min. The H recruitment curve and reciprocal inhibition did not change significantly after active or passive pedaling exercise. CONCLUSIONS: Pedaling exercise decreased spinal excitability in patients with severe hemiparesis. Pedaling may be effective in rehabilitation following stroke.

Reliability and validity of a force-instrumented treadmill for evaluating balance: A preliminary study of feasibility in healthy young adults.

BACKGROUND: With the development of computer technology, computerized dynamic posturography provides objective assessments of balance and posture control under static and dynamic conditions. Although a force-instrumented treadmill-based balance assessment is feasible for balance evaluations, currently no data exists. OBJECTIVE: This study was undertaken to assess the reliability and validity of balance evaluations using a force-instrumented treadmill. METHODS: Ten healthy adults participated in evaluations using both the treadmill and the EquiTest. Four balance evaluations were conducted: Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, Weight Bearing Squat, and Motor Control Test. RESULTS: All balance evaluations using the force-instrumented treadmill method shared good reliability (intraclass correlation coefficient ≥0.6). The Modified Clinical Test of Sensory Interaction on Balance, Unilateral Stance, and Weight Bearing Squat evaluations had a correlation of r < 0.5 with EquiTest, whereas the Motor Control Test balance evaluation had moderate correlations (r > 0.5) with the EquiTest. CONCLUSION: The results demonstrated that all balance evaluations using the force-instrumented treadmill were reliable, and that the Motor Control Test evaluation was moderately correlated with the EquiTest. Therefore, the use of a force-instrumented treadmill in balance evaluations might provide a certain level of value to clinical practice.

Functional recovery from chronic writer's cramp by brain-computer interface rehabilitation: a case report.

BACKGROUND: Dystonia is often currently treated with botulinum toxin injections to spastic muscles, or deep brain stimulation to the basal ganglia. In addition to these pharmacological or neurosurgical measures, a new noninvasive treatment concept, functional modulation using a brain-computer interface, was tested for feasibility. We recorded electroencephalograms (EEGs) over the bilateral sensorimotor cortex from a patient suffering from chronic writer's cramp. The patient was asked to suppress an exaggerated beta frequency component in the EEG during hand extension. RESULTS: The patient completed biweekly one-hour training for 5 months without any adverse effects. Significant decrease of the beta frequency component during handwriting was confirmed, and was associated with clear functional improvement. CONCLUSION: The current pilot study suggests that a brain-computer Interface can give explicit feedback of ongoing cortical excitability to patients with dystonia and allow them to suppress exaggerated neural activity, resulting in functional recovery.

Functional outcomes of protocol-based rehabilitation for patients with coronavirus disease 2019 in an acute care setting.

Objectives: To examine the functional outcomes of patients with coronavirus disease 2019 (COVID-19) who underwent a new protocol-based rehabilitation program. Methods: In this retrospective cohort study, we enrolled patients who were hospitalised in a university hospital in Japan because of COVID-19 from 1st September, 2020-5th July, 2021. The primary outcome was the Functional Independence Measure (FIM) subtotal score for motor items at discharge. The secondary outcomes included the FIM cognitive subtotal score, length of hospital stay, rehabilitation period, total rehabilitation time, final rehabilitation protocol level, and discharge destination. Results: Of the 78 enrolled patients (49 men; mean age [standard deviation], 70.3 [13.9] years), 24 died (30.8%) during hospitalisation. Disease severity was classified as mild, moderate I, moderate II, and severe in 1, 6, 41, and 30 patients, respectively. The FIM motor subtotal score differed significantly among groups for all participants (p=0.027). Post hoc analysis revealed that the FIM motor subtotal score in the severe group was significantly lower than that in the moderate II group (p=0.030). Conclusions: Disease severity significantly affected patients' functional outcome for COVID-19 at discharge. Our protocol-based program provides a benchmark for COVID-19 rehabilitation in an acute care setting.

Highlighting Unseen Activity Through 48-Hour Continuous Measurement in Subacute Stroke Rehabilitation: Preliminary Cohort Study.

BACKGROUND: Motor impairments not only lead to a significant reduction in patient activity levels but also trigger a further deterioration in motor function due to deconditioning, which is an issue that is particularly pronounced during hospitalization. This deconditioning can be countered by sustaining appropriate activity levels. Activities that occur outside of scheduled programs, often overlooked, are critical in this context. Wearable technology, such as smart clothing, provides a means to monitor these activities. OBJECTIVE: This study aimed to observe activity levels in patients who had strokes during the subacute phase, focusing on both scheduled training sessions and other nontraining times in an inpatient rehabilitation environment. A smart clothing system is used to simultaneously measure heart rate and acceleration, offering insights into both the amount and intensity of the physical activity. METHODS: In this preliminary cohort study, 11 individuals undergoing subacute stroke rehabilitation were enrolled. The 48-hour continuous measurement system, deployed at admission and reassessed 4 weeks later, monitored accelerometry data for physical activity (quantified with a moving SD of acceleration [MSDA]) and heart rate for intensity (quantified with percent heart rate reserve). The measurements were performed using a wearable activity monitoring system, the hitoe (NTT Corporation and Toray Industries, Inc) system comprising a measuring garment (wear or strap) with integrated electrodes, a data transmitter, and a smartphone. The Functional Independence Measure was used to assess the patients' daily activity levels. This study explored factors such as differences in activity during training and nontraining periods, correlations with activities of daily living (ADLs) and age, and changes observed after 4 weeks. RESULTS: A significant increase was found in the daily total MSDA after the 4-week program, with the average percent heart rate reserve remaining consistent. Physical activity during training positively correlated with ADL levels both at admission (ρ=0.86, P<.001) and 4 weeks post admission (ρ=0.96, P<.001), whereas the correlation between age and MSDA was not significant during training periods at admission (ρ=-0.41, P=.21) or 4 weeks post admission (ρ=-0.25, P=.45). Conversely, nontraining activity showed a negative correlation with age, with significant negative correlations with age at admission (ρ=-0.82, P=.002) and 4 weeks post admission (ρ=-0.73, P=.01). CONCLUSIONS: Inpatient rehabilitation activity levels were positively correlated with ADL levels. Further analysis revealed a strong positive correlation between scheduled training activities and ADL levels, whereas nontraining activities showed no such correlation. Instead, a negative correlation between nontraining activities and age was observed. These observations suggest the importance of providing activity opportunities for older patients, while it may also suggest the need for adjusting the activity amount to accommodate the potentially limited fitness levels of this demographic. Future studies with larger patient groups are warranted to validate and further elucidate these findings.

Development of a Conversion Table Linking Functional Independence Measure Scores to International Classification of Functioning, Disability, and Health Qualifiers: Insights from a Survey of Healthcare Professionals.

In clinical practice, patient assessments rely on established scales. Integrating data from these scales into the International Classification of Functioning, Disability, and Health (ICF) framework has been suggested; however, a standardized approach is lacking. Herein, we tested a new approach to develop a conversion table translating clinical scale scores into ICF qualifiers based on a clinician survey. The survey queried rehabilitation professionals about which functional independence measure (FIM) item scores (1-7) corresponded to the ICF qualifiers (0-4). A total of 458 rehabilitation professionals participated. The survey findings indicated a general consensus on the equivalence of FIM scores with ICF qualifiers. The median value for each item remained consistent across all item groups. Specifically, FIM 1 had a median value of 4; FIM 2 and 3 both had median values of 3; FIM 4 and 5 both had median values of 2; FIM 6 had a median value of 1; and FIM 7 had a median value of 0. Despite limitations due to the irreconcilable differences between the frameworks of existing scales and the ICF, these results underline the ICF's potential to serve as a central hub for integrating clinical data from various scales.

Therapeutic potential of appropriately evaluated safe-induced pluripotent stem cells for spinal cord injury.

Various types of induced pluripotent stem (iPS) cells have been established by different methods, and each type exhibits different biological properties. Before iPS cell-based clinical applications can be initiated, detailed evaluations of the cells, including their differentiation potentials and tumorigenic activities in different contexts, should be investigated to establish their safety and effectiveness for cell transplantation therapies. Here we show the directed neural differentiation of murine iPS cells and examine their therapeutic potential in a mouse spinal cord injury (SCI) model. "Safe" iPS-derived neurospheres, which had been pre-evaluated as nontumorigenic by their transplantation into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mouse brain, produced electrophysiologically functional neurons, astrocytes, and oligodendrocytes in vitro. Furthermore, when the safe iPS-derived neurospheres were transplanted into the spinal cord 9 d after contusive injury, they differentiated into all three neural lineages without forming teratomas or other tumors. They also participated in remyelination and induced the axonal regrowth of host 5HT(+) serotonergic fibers, promoting locomotor function recovery. However, the transplantation of iPS-derived neurospheres pre-evaluated as "unsafe" showed robust teratoma formation and sudden locomotor functional loss after functional recovery in the SCI model. These findings suggest that pre-evaluated safe iPS clone-derived neural stem/progenitor cells may be a promising cell source for transplantation therapy for SCI.

Use of artificial intelligence large language models as a clinical tool in rehabilitation medicine: a comparative test case.

OBJECTIVE: To explore the potential use of artificial intelligence language models in formulating rehabilitation prescriptions and International Classification of Functioning, Disability and Health (ICF) codes.  Design: Comparative study based on a single case report compared to standard answers from a textbook. SUBJECTS: A stroke case from textbook.  Methods: Chat Generative Pre-Trained Transformer-4 (ChatGPT-4)was used to generate comprehensive medical and rehabilitation prescription information and ICF codes pertaining to the stroke case. This information was compared with standard answers from textbook, and 2 licensed Physical Medicine and Rehabilitation (PMR) clinicians reviewed the artificial intelligence recommendations for further discussion. RESULTS: ChatGPT-4 effectively formulated rehabilitation prescriptions and ICF codes for a typical stroke case, together with a rationale to support its recommendations. This information was generated in seconds. Compared with standard answers, the large language model generated broader and more general prescriptions in terms of medical problems and management plans, rehabilitation problems and management plans, as well as rehabilitation goals. It also demonstrated the ability to propose specified approaches for each rehabilitation therapy. The language model made an error regarding the ICF category for the stroke case, but no mistakes were identified in the ICF codes assigned.  Conclusion: This test case suggests that artificial intelligence language models have potential use in facilitating clinical practice and education in the field of rehabilitation medicine.