Revisión sistemática sobre la aplicación de la realidad virtual en enfermedades neurológicas con afectación motora

Aims: the aim of this review is to examine systematically the evidence of the application of virtual reality as a therapy in persons with neurological diseases with motor disorders. Methodology: we carried out a search in the literature of two electronic databases, PubMed and Scopus, identifying published papers between January 2000 and April 2011. Results: following the search strategy discussed above were obtained 29 papers which examined the quality, type of study, the methodology used, the effects obtained and the involvement of occupational therapy with the following results: most studies of patient with stroke are no randomized controlled studies, the type of virtual reality primary used is semi-inmersive and the results after application of virtual reality are positive. Conclusions: virtual reality is an effective tool for the evaluation and treatment of motor disorders in people with neurological disorders. There is a great involvement of occupational therapy in implementing this technology. However further randomized controlled studies are needed in order to implement into practice.Traballo fin de grao (UDC.FCS). Terapia ocupacional. Curso 2010/201

Desarrollo de un protocolo de realidad virtual con el objetivo de la reeducación funcional del movimiento de alcance en pacientes con Parkinson

Programa Oficial de Doutoramento en Neurociencias. 5028V01[Resumen] Los estudios y terapias basados en la creación de un entorno de realidad virtual son cada vez de uso más frecuente en diversas áreas de neuro-rehabilitación, y ello es debido a que la realidad virtual permite el diseño de actividades y movimientos funcionales específicos para su entrenamiento. En el presente trabajo se diseñó un sistema de evaluación y entrenamiento del movimiento de alcance en un entorno de realidad virtual de bajo coste, para la intervención en distintas poblaciones. Como estudio central de la tesis se evaluó su utilidad en el entrenamiento de esta actividad funcional en enfermos de Parkinson. Se planteó el estudio piloto atendiendo a la hipótesis de que la observación de una acción podría inducir mejoras en la realización de la misma acción por parte de los pacientes, y así plantearse como una posible estrategia terapéutica que facilite un re-aprendizaje motor, con la consiguiente mejora en la función motora de la enfermedad. Para lograr estos objetivos se realizaron una serie de estudios en los que se evaluaban variables cinemáticas y neurofisiológicas, mediante el uso de acelerometría, electromiografía y estimulación magnética transcraneal. Los resultados de la terapia basada en la observación durante la ejecución en realidad virtual mostraron cambios modestos en la ejecución motora de los pacientes. Estos hallazgos indican que el uso de la realidad virtual combinada con la observación de un movimiento durante su ejecución podría mejorar el movimiento de alcance en la enfermedad de Parkinson, pero sería necesaria la realización de más estudios en los que se optimice el protocolo de entrenamiento.[Resumo] Os estudos e terapias baseadas na creación dun ambiente de realidade virtual son cada vez de uso máis frecuente en varias áreas de neuro-rehabilitación, isto débese a que a realidade virtual permite o deseño de actividades específicas e movementos funcionais específicos para o seu adestramento. Neste traballo deseñouse un sistema de avaliación e adestramento do movemento de alcance nun entorno de realidade virtual de baixo custe para a intervención en diferentes pobacións. Como estudo central da tese, avaliouse a súa utilidade no adestramento desta actividade funcional en enfermos de Parkinson. Desenrolouse un estudo piloto considerando a hipótese de que a observación dunha acción podería inducir melloras na execución da mesma acción por parte dos pacientes, e así poder plantearse como unha potencial estratexia terapéutica para facilitar a re-aprendizaxe motora, mellorando a función motora da enfermidade. Para acadar estes obxectivos realizáronse unha serie de estudos nos que se avaliaban variables cinemáticas e neurofisiolóxicas, mediante o emprego da acelerometría, eletromiografía e estimulación magnética transcraniana. Os resultados da terapia baseada na observación durante a execución en realidade virtual mostraron cambios modestos na execución motora dos pacientes. Estes resultados indican que o uso de realidade virtual combinado coa observación dun movemento durante a súa execución pode mellorar o movemento de alcance na enfermidade de Parkinson, pero sería necesaria a realización de máis estudos nos que se optimice o protocolo de adestramento.[Abstract] Studies and therapies based on the creation of a virtual reality environment are increasingly used in various areas of neuro-rehabilitation. Perhaps, the reason for this is virtual reality allows the design of specific functional activities and movements for their traning. In the present work, we designed a low-cost virtual reality system for the evaluation and traning of arm reaching movements in different clinical populations. As a central study of the thesis, we evaluated the effect of training the reaching movement in Parkinson’s disease patients. A pilot study was conceived on the hypothesis that the observation of an action would facilitate the performance of the same action in the patients, which would suggest a possible therapeutic strategy that facilitates motor re-learning and improves motor function in the disease. To achieve these objectives, a series of studies were carried out, in which kinematic and neurophysiological variables were evaluated with accelerometry, electromyography or transcranial magnetic stimulation. The results of the therapy based on movement observation during the execution in virtual reality showed mild changes in patient’s motor execution. These findings indicate that the use of virtual reality combined with the observation of a movement during its execution might improve reaching movements in Parkinson’s disease, but further research should optimize the intervention protocol

Effects of early or late-evening fatiguing physical activity on sleep quality in non-professional sportsmen

[Abstract] Background: This study aims to understand whether night sleep-quality is distorted by fatiguing physical activity (PA) when conducted early or late in the evening. Methods: Nine males (18-38yrs) performed sessions of fatiguing-PA over 3 consecutive days (Mon-Wed), for 2 weeks. One week the PA was performed at 17h, and in the other week at 21h. A Control-week included no PA (PAABSENT). The fatiguing-PA sessions comprised several sets of the 20m Shuttle-Run-Test (20mSRT). Sleep was assessed by actigraphic recordings acquired over three nights each week. It included the nights following the PA-sessions and the same days in the week of PAABSENT. Sleep-quality perception was evaluated by mean of the National Sleep Foundation-Sleep Diary. The heart-rate (HR) and body-temperature (BT) at bed-time and waking-up were also registered. Results: Neither the 20mSTR-estimated VO2max nor the number of maximal 20mSRT sets were different in the PA17h and PA21h sessions. Compared to the PAABSENT, the PA17h and PA21h sessions increased the HR at bedtime, which recovered to baseline level after the night of sleep. BT was also reduced when waking-up compared to bed-time, but this was also observed in PAABSENT. Sleep parameters measured by means of actigraphy were not modified by fatiguing activity when compared to PAABSENT. Nevertheless, the subjective perception of sleep-quality was negatively altered by fatiguing PA. Conclusions: Fatiguing PA performed early or late at the evening has no impact on objective sleep-quality but, subjectively, a deterioration of sleep-quality is perceived by the subjects

Validity of the finger tapping test in Parkinson’s disease, elderly and young healthy subjects: is there a role for central fatigue?

[Abstract] Objective: The main goal of this work is to evaluate the validity of the finger tapping test (FT) to detect alterations in rhythm formation. Methods: We use FT to study the alterations in motor rhythm in three different groups: Parkinson’s patients, elderly healthy controls, and young healthy control subjects (HY). The test was performed in COMFORT and FAST tapping modes and repeated on two different days. Results: For the variables analyzed (frequency and variability) both modes were repeatable in all groups. Also, intra-class correlation coefficients showed excellent levels of consistency between days. The test clearly differentiated the groups in both FAST and COMFORT modes. However, when fatigue was analyzed, a decrease in the tapping frequency was observed in HY during the FAST mode only. The amplitude of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) was early-potentiated but not delayed-depressed, both for COMFORT and FAST modes. This suggests that fatigue was not of cortico-spinal origin. Other forms of central fatigue are discussed. Conclusions: FT at FAST mode is not a valid test to detect differences in rhythm formation across the groups studied; fatigue is a confounding variable in some groups if the test is performed as fast as possible. Significance: COMFORT mode is recommended in protocols including the FT for evaluating rhythm formation

Spatiotemporal gait patterns during overt and covert evaluation in patients with Parkinson’s disease and healthy subjects: is there a hawthorne effect?

[Abstract] Parkinson's disease (PD) and aging lead to gait impairments. Some of the disturbances of gait are focused on step length, cadence, and temporal variability of gait cycle. Under experimental conditions gait can be overtly evaluated, but patients with PD are prone to expectancy efiects; thus it seems relevant to determine if such evaluation truly reflects the spontaneous gait pattern in such patients, and also in healthy subjects. Thirty subjects (15 subjects with PD and 15 healthy control subjects) were asked to walk using their natural, preferred gait pattern. In half ot the trials subjects were made aware that they were being evaluated (overt evaluation), while in the rest of the trials the evaluation was performed covertly (covert evaluation). During covert evaluation the gait pattern was modified in all groups. Gait speed was significantly increased (P = .022); step cadence and average step length were also significantly modified, the average step length increased (P - .002) and the cadence was reduced (P < .001). Stride cycle time variability was unchanged significantly (P = .084). These changes were not significantly different compared between elderly and young healthy controls either. Due to the small sample size, a note of caution is in order; however, the significant results suggest that covert evaluation of gait might be considered to complement experimental evaluations of gait.Galicia. Conslellería de Educación; 2007/000140-0Ministerio de Educación, Cultura y Deporte; FPU-MECD AP2010-2774Ministerio de Educación, Cultura y Deporte; FPU-MECD AP2010-277

Central fatigue induced by short-lasting finger tapping and isometric tasks: a study of silent periods evoked at spinal and supraspinal levels

[Abstract] The neural substrates of fatigue induced by muscular activity have been addressed in depth in relation to isometric tasks. For these activities, when fatigue develops, it has been noted that the duration of the silent periods (SPs) increases in response to both transcranial magnetic stimulation (TMS) of primary motor cortex or electric cervicomedullary stimulation (CMS). However, fatigue is known to be task-dependent and the mechanisms giving rise to a decrease in motor performance during brief, fast repetitive tasks have been less studied. We hypothesized that fatigue induced by repetitive fast finger tapping may have physiological mechanisms different from those accounting for fatigue during an isometric contraction, even in cases of matched effort durations. In these tasks, we examined the contribution of spinal and supraspinal motor circuits to the production of fatigue. The tapping rate and maximal voluntary contractions (MVC), and TMS- and CMS-evoked SPs were obtained at the time of fatigue, and while subjects maintained maximal muscle activation after fast finger-tapping (or isometric activity) of different durations (10 or 30 s). Results showed different mechanisms of fatigue triggered by isometric contraction and repetitive movements, even of short duration. Short-lasting repetitive movements induce fatigue within intracortical inhibitory circuits. They increased TMS-SPs, but not CMS-SPs. On the other hand, isometric contraction had a clear impact on spinal circuits. The consideration of these differences might help to optimize the study of fatigue in physiological conditions and neurological disorders.Galicia. Consellería de Educación; 2007/000140-

Effects of movement imitation training in Parkinson's disease: a virtual reality pilot study

[Abstract] Background. Hypometria is a clinical motor sign in Parkinson's disease. Its origin likely emerges from basal ganglia dysfunction, leading to an impaired control of inhibitory intracortical motor circuits. Some neurorehabilitation approaches include movement imitation training; besides the effects of motor practice, there might be a benefit due to observation and imitation of un-altered movement patterns. In this sense, virtual reality facilitates the process by customizing motor-patterns to be observed and imitated. Objective. To evaluate the effect of a motor-imitation therapy focused on hypometria in Parkinson's disease using virtual reality. Methods. We carried out a randomized controlled pilot-study. Sixteen patients were randomly assigned in experimental and control groups. Groups underwent 4-weeks of training based on finger-tapping with the dominant hand, in which imitation was the differential factor (only the experimental group imitated). We evaluated self-paced movement features and cortico-spinal excitability (recruitment curves and silent periods in both hemispheres) before, immediately after, and two weeks after the training period. Results. Movement amplitude increased significantly after the therapy in the experimental group for the trained and un-trained hands. Motor thresholds and silent periods evaluated with transcranial magnetic stimulation were differently modified by training in the two groups; although the changes in the input–output recruitment were similar. Conclusions. This pilot study suggests that movement imitation therapy enhances the effect of motor practice in patients with Parkinson's disease; imitation-training might be helpful for reducing hypometria in these patients. These results must be clarified in future larger trials.Galicia. Conselleria de Educación 2007/000140-0Ministerio de Educación, Cultura y Deporte; AP2010-2774Ministerio de Educación, Cultura y Deporte; FPU-AP2010-277

Balancing the excitability of M1 circuitry during movement observation without overt replication

[Abstract] Although observation of a movement increases the excitability of the motor system of the observer, it does not induce a motor replica. What is the mechanism for replica suppression? We performed a series of experiments, involving a total of 66 healthy humans, to explore the excitability of different M1 circuits and the spinal cord during observation of simple movements. Several strategies were used. In the first and second experimental blocks, we used several delay times from movement onset to evaluate the time-course modulation of the cortico-spinal excitability (CSE), and its potential dependency on the duration of the movement observed; in order to do this single pulse transcranial magnetic stimulation (TMS) over M1 was used. In subsequent experiments, at selected delay times from movement-onset, we probed the excitability of the cortico-spinal circuits using three different approaches: (i) electric cervicomedullary stimulation (CMS), to test spinal excitability, (ii) paired-pulse TMS over M1, to evaluate the cortical inhibitory-excitatory balance (short intracortical inhibition (SICI) and intracortical facilitation (ICF)], and (iii) continuous theta-burst stimulation (cTBS), to modulate the excitability of M1 cortical circuits. We observed a stereotyped response in the modulation of CSE. At 500 ms after movement-onset the ICF was increased; although the most clear-cut effect was a decrease of CSE. The compensatory mechanism was not explained by changes in SICI, but by M1-intracortical circuits targeted by cTBS. Meanwhile, the spinal cord maintained the elevated level of excitability induced when expecting to observe movements, potentially useful to facilitate any required response to the movement observed

The effects of expectancy on corticospinal excitability: passively preparing to observe a movement

[Abstract] The corticospinal tract excitability is modulated when preparing movements. Earlier to movement execution, the excitability of the spinal cord increases waiting for supraspinal commands to release the movement. Movement execution and movement observation share processes within the motor system, although movement observation research has focused on processes later to movement onset. We used single and paired pulse transcranial magnetic stimulation on M1 (n = 12), and electrical cervicomedullary stimulation (n = 7), to understand the modulation of the corticospinal system during the “preparation” to observe a third person's movement. Subjects passively observed a hand that would remain still or make an index finger extension. The observer's corticospinal excitability rose when “expecting to see a movement” vs. when “expecting to see a still hand.” The modulation took origin at a spinal level and not at the corticocortical networks explored. We conclude that expectancy of seeing movements increases the excitability of the spinal cord.Galicia. Consellería de Educación; 2007/000140-

Bilateral tDCS on Primary Motor Cortex: Effects on Fast Arm Reaching Tasks.

The effects produced by transcranial direct current stimulation (tDCS) applied to the motor system have been widely studied in the past, chiefly focused on primary motor cortex (M1) excitability. However, the effects on functional tasks are less well documented.This study aims to evaluate the effect of tDCS-M1 on goal-oriented actions (i.e., arm-reaching movements; ARM), in a reaction-time protocol.13 healthy subjects executed dominant ARM as fast as possible to one of two targets in front of them while surface EMG was recorded. Participants performed three different sessions. In each session they first executed ARM (Pre), then received tDCS, and finally executed Post, similar to Pre. Subjects received three different types of tDCS, one per session: In one session the anode was on right-M1 (AR), and the cathode on the left-M1 (CL), thus termed AR-CL; AL-CR reversed the montage; and Sham session was applied likewise. Real stimulation was 1mA-10min while subjects at rest. Three different variables and their coefficients of variation (CV) were analyzed: Premotor times (PMT), reaction-times (RT) and movement-times (MT).triceps-PMT were significantly increased at Post-Sham, suggesting fatigue. Results obtained with real tDCS were not different depending on the montage used, in both cases PMT were significantly reduced in all recorded muscles. RT and MT did not change for real or sham stimulation. RT-CV and PMT-CV were reduced after all stimulation protocols.tDCS reduces premotor time and fatigability during the execution of fast motor tasks. Possible underlying mechanisms are discussed