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1.
Int J Stroke ; 19(2): 158-168, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37824730

RESUMEN

BACKGROUND: Mobility is a key priority for stroke survivors. Worldwide consensus of standardized outcome instruments for measuring mobility recovery after stroke is an essential milestone to optimize the quality of stroke rehabilitation and recovery studies and to enable data synthesis across trials. METHODS: Using a standardized methodology, which involved convening of 13 worldwide experts in the field of mobility rehabilitation, consensus was established through an a priori defined survey-based approach followed by group discussions. The group agreed on balance- and mobility-related definitions and recommended a core set of outcome measure instruments for lower extremity motor function, balance and mobility, biomechanical metrics, and technologies for measuring quality of movement. RESULTS: Selected measures included the Fugl-Meyer Motor Assessment lower extremity subscale for motor function, the Trunk Impairment Scale for sitting balance, and the Mini Balance Evaluation System Test (Mini-BESTest) and Berg Balance Scale (BBS) for standing balance. The group recommended the Functional Ambulation Category (FAC, 0-5) for walking independence, the 10-meter Walk Test (10 mWT) for walking speed, the 6-Minute Walk Test (6 MWT) for walking endurance, and the Dynamic Gait Index (DGI) for complex walking. An FAC score of less than three should be used to determine the need for an additional standing test (FAC < 3, add BBS to Mini-BESTest) or the feasibility to assess walking (FAC < 3, 10 mWT, 6 MWT, and DGI are "not testable"). In addition, recommendations are given for prioritized kinetic and kinematic metrics to be investigated that measure recovery of movement quality of standing balance and walking, as well as for assessment protocols and preferred equipment to be used. CONCLUSIONS: The present recommendations of measures, metrics, technology, and protocols build on previous consensus meetings of the International Stroke Recovery and Rehabilitation Alliance to guide the research community to improve the validity and comparability between stroke recovery and rehabilitation studies as a prerequisite for building high-quality, standardized "big data" sets. Ultimately, these recommendations could lead to high-quality, participant-specific data sets to aid the progress toward precision medicine in stroke rehabilitation.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Humanos , Consenso , Rehabilitación de Accidente Cerebrovascular/métodos , Caminata , Evaluación de Resultado en la Atención de Salud
2.
Neurorehabil Neural Repair ; 38(1): 41-51, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37837351

RESUMEN

BACKGROUND: Mobility is a key priority for stroke survivors. Worldwide consensus of standardized outcome instruments for measuring mobility recovery after stroke is an essential milestone to optimize the quality of stroke rehabilitation and recovery studies and to enable data synthesis across trials. METHODS: Using a standardized methodology, which involved convening of 13 worldwide experts in the field of mobility rehabilitation, consensus was established through an a priori defined survey-based approach followed by group discussions. The group agreed on balance- and mobility-related definitions and recommended a core set of outcome measure instruments for lower extremity motor function, balance and mobility, biomechanical metrics, and technologies for measuring quality of movement. RESULTS: Selected measures included the Fugl-Meyer Motor Assessment lower extremity subscale for motor function, the Trunk Impairment Scale for sitting balance, and the Mini Balance Evaluation System Test (Mini-BESTest) and Berg Balance Scale (BBS) for standing balance. The group recommended the Functional Ambulation Category (FAC, 0-5) for walking independence, the 10-meter Walk Test (10 mWT) for walking speed, the 6-Minute Walk Test (6 MWT) for walking endurance, and the Dynamic Gait Index (DGI) for complex walking. An FAC score of less than three should be used to determine the need for an additional standing test (FAC < 3, add BBS to Mini-BESTest) or the feasibility to assess walking (FAC < 3, 10 mWT, 6 MWT, and DGI are "not testable"). In addition, recommendations are given for prioritized kinetic and kinematic metrics to be investigated that measure recovery of movement quality of standing balance and walking, as well as for assessment protocols and preferred equipment to be used. CONCLUSIONS: The present recommendations of measures, metrics, technology, and protocols build on previous consensus meetings of the International Stroke Recovery and Rehabilitation Alliance to guide the research community to improve the validity and comparability between stroke recovery and rehabilitation studies as a prerequisite for building high-quality, standardized "big data" sets. Ultimately, these recommendations could lead to high-quality, participant-specific data sets to aid the progress toward precision medicine in stroke rehabilitation.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Humanos , Consenso , Rehabilitación de Accidente Cerebrovascular/métodos , Caminata , Velocidad al Caminar , Equilibrio Postural
3.
J Stroke Cerebrovasc Dis ; 32(7): 106890, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37099928

RESUMEN

BACKGROUND: Very early rehabilitation after stroke appears to worsen outcome, particularly in intracerebral haemorrhage (ICH). Plausible mechanisms include increased mean blood pressure (BP) and BP variability. AIMS: To test associations between early mobilisation, subacute BP and survival, in observational data of ICH patients during routine clinical care. METHODS: We collected demographic, clinical and imaging data from 1372 consecutive spontaneous ICH patients admitted between 2 June 2013 and 28 September 2018. Time to first mobilisation (defined as walking, standing, or sitting out-of-bed) was extracted from electronic records. We evaluated associations between early mobilisation (within 24 h of onset) and both subacute BP and death by 30 days using multifactorial linear and logistic regression analyses respectively. RESULTS: Mobilisation at 24 h was not associated with increased odds of death by 30 days when adjusting for key prognostic factors (OR 0.4, 95% CI 0.2 to 1.1, p = 0.07). Mobilisation at 24 h was independently associated with both lower mean systolic BP (-4.5 mmHg, 95% CI -7.5 to -1.5 mmHg, p = 0.003) and lower diastolic BP variability (-1.3 mmHg, 95% CI -2.4 to -0.2 mg, p = 0.02) during the first 72 h after admission. CONCLUSIONS: Adjusted analysis in this observational dataset did not find an association between early mobilisation and death by 30 days. We found early mobilisation at 24 h to be independently associated with lower mean systolic BP and lower diastolic BP variability over 72 h. Further work is needed to establish mechanisms for the possible detrimental effect of early mobilisation in ICH.


Asunto(s)
Hipotensión , Accidente Cerebrovascular , Humanos , Presión Sanguínea , Ambulación Precoz , Estudios Retrospectivos , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/complicaciones , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/terapia , Accidente Cerebrovascular/complicaciones
4.
AMRC Open Res ; 3: 19, 2022 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-35726231

RESUMEN

Introduction: Dysphagia often occurs during Parkinson's disease (PD) and can have severe consequences. Recently, neuromodulatory techniques have been used to treat neurogenic dysphagia. Here we aimed to compare the neurophysiological and swallowing effects of three different types of neurostimulation, 5 Hertz (Hz) repetitive transcranial magnetic stimulation (rTMS), 1 Hz rTMS and pharyngeal electrical stimulation (PES) in patients with PD. Method: 12 PD patients with dysphagia were randomised to receive either 5 Hz rTMS, 1 Hz rTMS, or PES. In a cross-over design, patients were assigned to one intervention and received both real and sham stimulation. Patients received a baseline videofluoroscopic (VFS) assessment of their swallowing, enabling penetration aspiration scores (PAS) to be calculated for: thin fluids, paste, solids and cup drinking. Swallowing timing measurements were also performed on thin fluid swallows only. They then had baseline recordings of motor evoked potentials (MEPs) from both pharyngeal and (as a control) abductor pollicis brevis (APB) cortical areas using single-pulse TMS. Subsequently, the intervention was administered and post interventional TMS recordings were taken at 0 and 30 minutes followed by a repeat VFS within 60 minutes of intervention. Results: All interventions were well tolerated. Due to lower than expected recruitment, statistical analysis of the data was not undertaken. However, with respect to PAS swallowing timings and MEP amplitudes, there was small but visible difference in the outcomes between active and sham. Conclusion: PES, 5 Hz rTMS and 1 Hz rTMS are tolerable interventions in PD related dysphagia. Due to small patient numbers no definitive conclusions could be drawn from the data with respect to individual interventions improving swallowing function and comparative effectiveness between interventions. Larger future studies are needed to further explore the efficacy of these neuromodulatory treatments in Parkinson's Disease associated dysphagia.

5.
Eur Stroke J ; 7(1): 6-14, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35300252

RESUMEN

Purpose: To describe the association between factors routinely available in hyperacute care of spontaneous intracerebral haemorrhage (ICH) patients and functional outcome. Methods: We searched Medline, Embase and CINAHL in February 2020 for original studies reporting associations between markers available within six hours of arrival in hospital and modified Rankin Scale (mRS) at least 6 weeks post-ICH. A random-effects meta-analysis was performed where three or more studies were included. Findings: Thirty studies were included describing 40 markers. Ten markers underwent meta-analysis and age (OR = 1.06; 95%CI = 1.05 to 1.06; p < 0.001), pre-morbid dependence (mRS, OR = 1.73; 95%CI = 1.52 to 1.96; p < 0.001), level of consciousness (Glasgow Coma Scale, OR = 0.82; 95%CI = 0.76 to 0.88; p < 0.001), stroke severity (National Institutes of Health Stroke Scale, OR=1.19; 95%CI = 1.13 to 1.25; p < 0.001), haematoma volume (OR = 1.12; 95%CI=1.07 to 1.16; p < 0.001), intraventricular haemorrhage (OR = 2.05; 95%CI = 1.68 to 2.51; p < 0.001) and deep (vs. lobar) location (OR = 2.64; 95%CI = 1.65 to 4.24; p < 0.001) were predictive of outcome but systolic blood pressure, CT hypodensities and infratentorial location were not. Of the remaining markers, sex, medical history (diabetes, hypertension, prior stroke), prior statin, prior antiplatelet, admission blood results (glucose, cholesterol, estimated glomerular filtration rate) and other imaging features (midline shift, spot sign, sedimentation level, irregular haematoma shape, ultraearly haematoma growth, Graeb score and onset to CT time) were associated with outcome. Conclusion: Multiple demographic, pre-morbid, clinical, imaging and laboratory factors should all be considered when prognosticating in hyperacute ICH. Incorporating these in to accurate and precise models will help to ensure appropriate levels of care for individual patients.

6.
Disabil Rehabil ; 44(20): 6026-6033, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-34372752

RESUMEN

PURPOSE: The study explored the acceptability of high repetition arm training as part of a randomised controlled trial, early after stroke, when fatigue levels and emotional strain are often high. MATERIALS AND METHODS: 36 sub-acute stroke survivors (61 years+/-15) attended for assessment sessions at 3, 6, and 12 weeks after stroke. Individuals were randomised to receive 6 high repetition arm training sessions between 3 and 6 weeks (intervention) or the control group. Semi-structured interviews were conducted at trial completion. Interview transcripts were analysed through framework analysis conducted independently by 2 researchers. RESULTS: Stroke survivors participated despite high levels of fatigue because they hoped for personal benefit or to potentially benefit future patients. Benefits reported from participation included physical improvements, psychological benefit, improved understanding of their condition as well as a feeling of hope and distraction. The arm training at three weeks after stroke, aiming for 420 movement repetitions was not considered to be too intensive or too early, and most individuals felt lucky to have been, or would have preferred to be in the early training group. CONCLUSION: High repetition arm training early after stroke was acceptable to participants. Study participation was generally viewed as a positive experience, suggesting that early intervention may not only be physically beneficial but also psychologically.Implications for rehabilitationStroke survivors report that high repetition arm training early after stroke is acceptable.Participation in rehabilitation research early after stroke provides stroke survivors with hope and meaning despite the high prevalence of fatigue.Complex information needs to be repeated and provided in a number of formats early after stroke.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular , Brazo , Fatiga/etiología , Humanos , Accidente Cerebrovascular/psicología , Sobrevivientes/psicología
7.
Neurorehabil Neural Repair ; 35(9): 812-822, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34219510

RESUMEN

Background. Upper-limb impairment in patients with chronic stroke appears to be partly attributable to an upregulated reticulospinal tract (RST). Here, we assessed whether the impact of corticospinal (CST) and RST connectivity on motor impairment and skill-acquisition differs in sub-acute stroke, using transcranial magnetic stimulation (TMS)-based proxy measures. Methods. Thirty-eight stroke survivors were randomized to either reach training 3-6 weeks post-stroke (plus usual care) or usual care only. At 3, 6 and 12 weeks post-stroke, we measured ipsilesional and contralesional cortical connectivity (surrogates for CST and RST connectivity, respectively) to weak pre-activated triceps and deltoid muscles with single pulse TMS, accuracy of planar reaching movements, muscle strength (Motricity Index) and synergies (Fugl-Meyer upper-limb score). Results. Strength and presence of synergies were associated with ipsilesional (CST) connectivity to the paretic upper-limb at 3 and 12 weeks. Training led to planar reaching skill beyond that expected from spontaneous recovery and occurred for both weak and strong ipsilesional tract integrity. Reaching ability, presence of synergies, skill-acquisition and strength were not affected by either the presence or absence of contralesional (RST) connectivity. Conclusion. The degree of ipsilesional CST connectivity is the main determinant of proximal dexterity, upper-limb strength and synergy expression in sub-acute stroke. In contrast, there is no evidence for enhanced contralesional RST connectivity contributing to any of these components of impairment. In the sub-acute post-stroke period, the balance of activity between CST and RST may matter more for the paretic phenotype than RST upregulation per se.


Asunto(s)
Aprendizaje/fisiología , Corteza Motora/fisiopatología , Desempeño Psicomotor/fisiología , Tractos Piramidales/fisiopatología , Accidente Cerebrovascular/fisiopatología , Extremidad Superior/fisiopatología , Adulto , Femenino , Humanos , Masculino , Recuperación de la Función/fisiología , Estimulación Magnética Transcraneal
8.
Gait Posture ; 81: 261-267, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32846357

RESUMEN

BACKGROUND: The high prevalence of falls due to trips and slips following stroke may signify difficulty adjusting foot-placement in response to the environment. However, little is known about under what circumstances foot-placement adjustment becomes difficult for stroke survivors (SS), making the design of targeted rehabilitation interventions to improve independent community mobility difficult. RESEARCH QUESTION: To investigate the effect of planned and reactive target-stepping on foot-placement accuracy in stroke survivors and young and older healthy adults? METHODS: Young (N = 11, 30 ± 6 years) and older (N = 10, 64 ± 8 years) healthy adults and SS (N = 11, 67 ± 9 years) walked, at preferred pace, on a force instrumented treadmill. Each participant walked to illuminated targets, visible two steps in advance (planned) or appearing at contralateral midstance (reactive). Foot-placement error (magnitude and bias) and number of missed targets were compared. RESULTS: All participants missed more reactive than planned targets (p = 0.05), and SS missed more targets than young (p < 0.001) and older (p = 0.001) adults. But no interaction showing SS missed more reactive targets than other groups was found. For all groups: reactive adaptations to steps in the antero-posterior plane resulted in lower error than planned adaptations (p = 0.027). Lengthening steps where undershot more than shortening (p < 0.001) by all groups. Reactive medio-lateral adaptations over all induced larger error (p = 0.029) than planned and changed the direction of bias (p = 0.018). SIGNIFICANCE: SS experience difficulty making all adjustments, they showed increased error in all conditions but less pronounced difference between planned and reactive stepping. SS may use a reactive control strategy for all adjustments, in contrast to healthy young adults who may plan foot-placement in advance. The likelihood of stroke survivors misplacing a step is large, with 9.8% targets missed; possibly leading to falls. Further investigation is needed to understand foot-placement control strategies used by SS and the role of planning in gait adaptability.


Asunto(s)
Pie/fisiopatología , Marcha/fisiología , Accidente Cerebrovascular/fisiopatología , Caminata/fisiología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/mortalidad , Sobrevivientes
9.
Gait Posture ; 76: 224-230, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31874454

RESUMEN

BACKGROUND: The high prevalence of falls due to trips and slips following stroke may signify difficulty controlling balance and adjusting foot-placement in response to the environment. We know very little about how controlling foot-placement is affected by balance requirements and the effects of stroke. Therefore, in this study the research question is how foot-placement control is affected by balance support from crutches and reducing or enlarging the base of support. By understanding how foot-placement control and balance deficits following stroke interact, rehabilitation efforts can be more effectively targeted towards the cause of poor mobility. METHODS: Young (N=13, 30±6 years) and older (N=10, 64±8 years) healthy adults and stroke survivors (N=11, 67±9 years) walked to targets on an instrumented treadmill with or without crutch support for balance. Targets were randomized to either reduce or increase the base of support in the antero-posterior (AP) or medio-lateral (ML) direction. Mean and absolute foot-placement error were measured using motion analysis. These outcomes were compared using repeated measures ANCOVA with walking speed as a covariate. RESULTS: Overall, stroke survivors missed more targets (9.1±2.3%, p=0.001) than young (1.0±2.5%) and older (0.2±2.1%) healthy adults (p=0.001). However, there were no significant differences between groups in foot-placement error. Crutch support reduced both AP and ML foot-placement error (p=<0.001, AP 5.2±0.5cm unsupported, 4.1±0.4cm supported, ML 2.3±0.2cm unsupported, 1.9±0.2cm supported) for all participants. Interaction effects indicate crutch support reduced foot-placement error more when narrowing (unsupported 2.8±0.2cm, supported 1.8±0.2cm) than widening (unsupported 2.6±0.4cm, supported 2.4±0.4cm) steps (p<0.001), SIGNIFICANCE: Stroke survivors have greater difficulty accurately adjusting steps in response to the environment. Crutch support reduces foot-placement error for all steps, but particularly when narrowing foot-placement. These results provide support for the implication of walking aids, which support balance to improve ability to adjust footplacement in response to the environment.


Asunto(s)
Accidentes por Caídas/prevención & control , Muletas , Pie/fisiopatología , Marcha/fisiología , Rehabilitación de Accidente Cerebrovascular/métodos , Accidente Cerebrovascular/fisiopatología , Caminata/fisiología , Adolescente , Adulto , Anciano , Fenómenos Biomecánicos , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Adulto Joven
10.
Brain Sci ; 9(12)2019 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-31847166

RESUMEN

We established spatial neglect prevalence, disease profile and amount of therapy that inpatient stroke survivors received, and outcomes at discharge using Sentinel Stroke National Audit Programme (SSNAP) data. We used data from 88,664 National Health Service (NHS) admissions in England, Wales and Northern Ireland (July 2013-July 2015), for stroke survivors still in hospital after 3 days with a completed baseline neglect National Institute for Health Stroke Scale (NIHSS) score. Thirty percent had neglect (NIHSS item 11 ≥ 1) and they were slightly older (78 years) than those without neglect (75 years). Neglect was observed more commonly in women (33 vs. 27%) and in individuals with a premorbid dependency (37 vs. 28%). Survivors of mild stroke were far less likely to present with neglect than those with severe stroke (4% vs. 84%). Those with neglect had a greatly increased length of stay (27 vs. 10 days). They received a comparable amount of average daily occupational and physiotherapy during their longer inpatient stay but on discharge a greater percentage of individuals with neglect were dependent on the modified Rankin scale (76 vs. 57%). Spatial neglect is common and associated with worse clinical outcomes. These results add to our understanding of neglect to inform clinical guidelines, service provision and priorities for future research.

11.
Clin Neurophysiol ; 130(5): 781-788, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30925310

RESUMEN

OBJECTIVE: Ipsilateral connectivity from the non-stroke hemisphere to paretic arm muscles appears to play little role in functional recovery, which instead depends on contralateral connectivity from the stroke hemisphere. Yet the incidence of ipsilateral projections in stroke survivors is often reported to be higher than normal. We tested this directly using a sensitive measure of connectivity to proximal arm muscles. METHOD: TMS of the stroke and non-stroke motor cortex evoked responses in pre-activated triceps and deltoid muscles of 17 stroke survivors attending reaching training. Connectivity was defined as a clear MEP or a short-latency silent period in ongoing EMG in ≥ 50% of stimulations. We measured reaching accuracy at baseline, improvement after training and upper limb Fugl-Meyer (F-M) score. RESULTS: Incidence of ipsilateral connections to triceps (47%) and deltoid (58%) was high, but unrelated to baseline reaching accuracy and F-M scores. Instead, these were related to contralateral connectivity from the stroke hemisphere. Absolute but not proportional improvement after training was greater in patients with ipsilateral responses. CONCLUSIONS: Despite enhanced ipsilateral connectivity, arm function and learning was related most strongly to contralateral pathway integrity from the stroke hemisphere. SIGNIFICANCE: Further work is needed to decipher the role of ipsilateral connections.


Asunto(s)
Brazo/fisiopatología , Potenciales Evocados Motores/fisiología , Lateralidad Funcional/fisiología , Corteza Motora/fisiopatología , Músculo Esquelético/fisiopatología , Paresia/fisiopatología , Accidente Cerebrovascular/fisiopatología , Anciano , Anciano de 80 o más Años , Electromiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiopatología , Paresia/etiología , Recuperación de la Función/fisiología , Accidente Cerebrovascular/complicaciones
12.
J Biomech ; 79: 218-222, 2018 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-30135014

RESUMEN

BACKGROUND: Target-stepping paradigms are increasingly used to assess and train gait adaptability. Accurate gait-event detection (GED) is key to locating targets relative to the ongoing step cycle as well as measuring foot-placement error. In the current literature GED is either based on kinematics or centre of pressure (CoP), and both have been previously validated with young healthy individuals. However, CoP based GED has not been validated for stroke survivors who demonstrate altered CoP pattern. METHODS: Young healthy adults and individuals affected by stroke stepped to targets on a treadmill, while gait events were measured using three detection methods; verticies of CoP cyclograms, and two kinematic criteria, (1) vertical velocity and position and of the heel marker, (2) anterior velocity and position of the heel and toe marker, were used. The percentage of unmatched gait events was used to determine the success of the GED method. The difference between CoP and kinematic GED methods were tested with two one sample (two-tailed) t-tests against a reference value of zero. Differences between group and paretic and non-paretic leg were tested with a repeated measures ANOVA. RESULTS: The kinematic method based on vertical velocity only detected about 80% of foot contact events on the paretic side in stroke survivors while the method on anterior velocity was more successful in both young healthy adults as stroke survivors (3% young healthy and 7% stroke survivors unmatched). Both kinematic methods detected gait events significantly earlier than CoP GED (p < 0.001) except for foot contact in stroke survivors based on the vertical velocity. CONCLUSIONS: CoP GED may be more appropriate for gait analyses of SS than kinematic methods; even when walking and varying steps.


Asunto(s)
Análisis de la Marcha/métodos , Paresia/fisiopatología , Presión , Adulto , Fenómenos Biomecánicos , Estudios de Casos y Controles , Prueba de Esfuerzo , Femenino , Marcha , Talón/fisiopatología , Humanos , Masculino , Persona de Mediana Edad
13.
Neurorehabil Neural Repair ; 31(6): 499-508, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28506150

RESUMEN

BACKGROUND: Recovery from stroke is often said to have "plateaued" after 6 to 12 months. Yet training can still improve performance even in the chronic phase. Here we investigate the biomechanics of accuracy improvements during a reaching task and test whether they are affected by the speed at which movements are practiced. METHOD: We trained 36 chronic stroke survivors (57.5 years, SD ± 11.5; 10 females) over 4 consecutive days to improve endpoint accuracy in an arm-reaching task (420 repetitions/day). Half of the group trained using fast movements and the other half slow movements. The trunk was constrained allowing only shoulder and elbow movement for task performance. RESULTS: Before training, movements were variable, tended to undershoot the target, and terminated in contralateral workspace (flexion bias). Both groups improved movement accuracy by reducing trial-to-trial variability; however, change in endpoint bias (systematic error) was not significant. Improvements were greatest at the trained movement speed and generalized to other speeds in the fast training group. Small but significant improvements were observed in clinical measures in the fast training group. CONCLUSIONS: The reduction in trial-to-trial variability without an alteration to endpoint bias suggests that improvements are achieved by better control over motor commands within the existing repertoire. Thus, 4 days' training allows stroke survivors to improve movements that they can already make. Whether new movement patterns can be acquired in the chronic phase will need to be tested in longer term studies. We recommend that training needs to be performed at slow and fast movement speeds to enhance generalization.


Asunto(s)
Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Fenómenos Biomecánicos , Enfermedad Crónica/rehabilitación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Actividad Motora , Recuperación de la Función , Sobrevivientes , Resultado del Tratamiento , Extremidad Superior
14.
J Neurophysiol ; 111(1): 128-34, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24133220

RESUMEN

How does the motor system choose the speed for any given movement? Many current models assume a process that finds the optimal balance between the costs of moving fast and the rewards of achieving the goal. Here, we show that such models also need to take into account a prior representation of preferred movement speed, which can be changed by prolonged practice. In a time-constrained reaching task, human participants made 25-cm reaching movements within 300, 500, 700, or 900 ms. They were then trained for 3 days to execute the movement at either the slowest (900-ms) or fastest (300-ms) speed. When retested on the 4th day, movements executed under all four time constraints were biased toward the speed of the trained movement. In addition, trial-to-trial variation in speed of the trained movement was significantly reduced. These findings are indicative of a use-dependent mechanism that biases the selection of speed. Reduced speed variability was also associated with reduced errors in movement amplitude for the fast training group, which generalized nearly fully to a new movement direction. In contrast, changes in perpendicular error were specific to the trained direction. In sum, our results suggest the existence of a relatively stable but modifiable prior of preferred movement speed that influences the choice of movement speed under a range of task constraints.


Asunto(s)
Destreza Motora , Adulto , Femenino , Humanos , Masculino , Práctica Psicológica , Análisis y Desempeño de Tareas , Factores de Tiempo
15.
Neurorehabil Neural Repair ; 26(8): 976-87, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22412171

RESUMEN

BACKGROUND: Noninvasive cortical stimulation could represent an add-on treatment to enhance motor recovery after stroke. However, its clinical value, including anticipated size and duration of the treatment effects, remains largely unknown. OBJECTIVE: The authors designed a small semi-randomized clinical trial to explore whether long-lasting clinically important gains can be achieved by adding theta burst stimulation (TBS), a form of repetitive transcranial magnetic stimulation (TMS), to a rehabilitation program for the hand. METHODS: A total of 41 chronic stroke patients received excitatory TBS to the ipsilesional hemisphere or inhibitory TBS to the contralesional hemisphere in 2 centers; each active group was compared with a group receiving sham TBS. TBS was followed by physical therapy for 10 working days. Patients and therapists were blinded to the type of TBS. Primary outcome measures (9-hole Peg Test [9HPT], Jebsen Taylor Test [JTT], and grip and pinch-grip dynamometry) were assessed 4, 30, and 90 days post treatment. The clinically important difference was defined as 10% of the maximum score. RESULTS: There were no differences between the active treatment and sham groups in any of the outcome measures. All patients achieved small sustainable improvements--9HPT, 5% of maximum (confidence interval [CI] = 3%-7%); JTT, 5.7% (CI = 3%-8%); and grip strength, 6% (CI = 2%-10%)--all below the defined clinically important level. CONCLUSIONS: Cortical stimulation did not augment the gains from a late rehabilitation program. The effect size anticipated by the authors was overestimated. These results can improve the design of future work on therapeutic uses of TMS.


Asunto(s)
Fuerza de la Mano/fisiología , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Estimulación Magnética Transcraneal , Extremidad Superior/fisiopatología , Adulto , Anciano , Análisis de Varianza , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Dinamómetro de Fuerza Muscular , Dimensión del Dolor , Factores de Tiempo , Resultado del Tratamiento
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