Motor imagery and gait control in Parkinson's disease: techniques and new perspectives in neurorehabilitation.

INTRODUCTION: Motor imagery (MI), defined as the ability to mentally represent an action without actual movement, has been used to improve motor function in athletes and, more recently, in neurological disorders such as Parkinson's disease (PD). Several studies have investigated the neural correlates of motor imagery, which change also depending on the action imagined. AREAS COVERED: This review focuses on locomotion, which is a crucial activity in everyday life and is often impaired by neurological conditions. After a general discussion on the neural correlates of motor imagery and locomotion, we review the evidence highlighting the abnormalities in gait control and gait imagery in PD patients. Next, new perspectives and techniques for PD patients' rehabilitation are discussed, namely Brain Computer Interfaces (BCIs), neurofeedback, and virtual reality (VR). EXPERT OPINION: Despite the few studies, the literature review supports the potential beneficial effects of motor imagery interventions in PD focused on locomotion. The development of new technologies could empower the administration of training based on motor imagery locomotor tasks, and their application could lead to new rehabilitation protocols aimed at improving walking ability in patients with PD.

Effects of a posture shirt with back active correction keeper on static and dynamic balance in Parkinson's disease.

BACKGROUND: Patients with Parkinson's disease (PD) suffer from postural disorders. This study aims at investigating the short- and medium-term effects of a shirt with appropriate tie-rods that allows to correct the posture of the trunk. METHODS: This is a longitudinal clinical study in which a pressure platform was used to assess the static and dynamic baropodometry and the static stabilometry of 20 patients with PD (70.95 ± 8.39 years old; 13 males, time from the onset of symptoms: 6.95 ± 4.04 years, Unified Parkinson's Disease Rating Scale score: UPDRS = 7.25 ± 6.26) without and with a shirt, specifically designed for improving posture, at baseline and after one month of wearing. RESULTS: The results showed a significant improvement in symmetry of loads (p = 0.015) and an enlargement of the foot contact surface (p = 0.038). A significant correlation was found between the change in forefoot load and time spent daily in wearing the shirt (R = 0.575, p = 0.008), with an optimal value identified at 8 h per day. CONCLUSION: The use of a postural shirt in patients with PD symmetrized the postural load and enlarged the foot contact surface improving their balance.

Music-based techniques and related devices in neurorehabilitation: a scoping review.

Introduction:The music as a powerful, and versatile stimulus for the brain, is at the date sometimes used in neurorehabilitation and proposed as a promising complementary strategy provided in combination with other therapy in individuals with neurological disorders. Different techniques and devices have been developed in the field of the music-based neurorehabilitation.Areas covered:This scoping review analyzes the current scientific literature concerning the different techniques and devices used in the music-supported neurorehabilitation, also focusing on the devices used in music-based therapies in patients with neurological disorders: 46 studies met the inclusion criteria and were included.Expert opinion:Included studies, highlight the potentiality and the versatility of the music-based therapy in the rehabilitation of neurological disorders. The variety of existing techniques allow to applied the music-based therapy in different situations and conditions. Moreover, the wide range of used devices that ranging from the simple musical instruments to the more advanced technologies, allows to develop customized exercises based on the needs of the patient. This review may be considered as a starting point to better design future RCTs that would investigate the effectiveness of music therapy on neurological disorders.

Differentiation among bio- and augmented- feedback in technologically assisted rehabilitation.

Introduction: In rehabilitation practice, the term 'feedback' is often improperly used, with augmented feedback and biofeedback frequently confused, especially when referring to the human-machine interaction during technologically assisted training. The absence of a clear differentiation between these categories represents an unmet need for rehabilitation, emphasized by the advent of new technologies making extensive use of video feedback, exergame, and virtual reality.Area covered: In this review we tried to present scientific knowledge about feedback, biofeedback, augmented feedback and neurofeedback, and related differences in rehabilitation settings, for a more proper use of this terminology. Despite the continuous expansion of the field, few researches clarify the differences among these terms. This scoping review was conducted through the searching of current literature up to May 2020, using following databases: PUBMED, EMBASE and Web of Science. After literature search a classification system, distinguishing feedback, augmented feedback, and biofeedback, was applied.Expert opinion: There is a need for clear definitions of feedback, biofeedback, augmented feedback, and neurofeedback in rehabilitation, especially in the technologically assisted one based on human-machine interaction. In fact, the fast development of new technologies requires to be based on solid concepts and on a common terminology shared among bioengineers and clinicians.

Sensorized Assessment of Dynamic Locomotor Imagery in People with Stroke and Healthy Subjects.

Dynamic motor imagery (dMI) is a motor imagery task associated with movements partially mimicking those mentally represented. As well as conventional motor imagery, dMI has been typically assessed by mental chronometry tasks. In this paper, an instrumented approach was proposed for quantifying the correspondence between upper and lower limb oscillatory movements performed on the spot during the dMI of walking vs. during actual walking. Magneto-inertial measurement units were used to measure limb swinging in three different groups: young adults, older adults and stroke patients. Participants were tested in four experimental conditions: (i) simple limb swinging; (ii) limb swinging while imagining to walk (dMI-task); (iii) mental chronometry task, without any movement (pure MI); (iv) actual level walking at comfortable speed. Limb swinging was characterized in terms of the angular velocity, frequency of oscillations and sinusoidal waveform. The dMI was effective at reproducing upper limb oscillations more similar to those occurring during walking for all the three groups, but some exceptions occurred for lower limbs. This finding could be related to the sensory feedback, stretch reflexes and ground reaction forces occurring for lower limbs and not for upper limbs during walking. In conclusion, the instrumented approach through wearable motion devices adds significant information to the current dMI approach, further supporting their applications in neurorehabilitation for monitoring imagery training protocols in patients with stroke.

A stimulus for eating. The use of neuromuscular transcutaneous electrical stimulation in patients affected by severe dysphagia after subacute stroke: A pilot randomized controlled trial.

BACKGROUND: Oropharyngeal dysphagia is a common problem in subacute stroke patients leading to aspiration pneumonia and malnutrition. Non-invasive neuromuscular electrical stimulation (NMES) coupled with traditional therapy could be best treatment option for patients with post-stroke dysphagia, however results are still inconclusive and more studies are requested. OBJECTIVE: The aim of the study was to investigate the effect of laryngopharyngeal neuromuscular electrical stimulation on dysphagia caused by stroke. METHODS: Thirty-three patients affected by subacute stroke and dysphagia participated in this study. The subjects were divided into NMES plus traditional dysphagia training (n = 17) and traditional dysphagia training alone in a time matched condition (n = 16). Both groups were treated 5 days/week for 8 weeks. All patients were evaluated before and after the treatment. The study was designed as a single blind randomized controlled trial. Primary outcomes were considered the status of swallowing function according to the Functional Oral Intake Scale (FOIS), the instrumental Fiberoptic Endoscopic Examination of Swallowing examination, the Penetration Aspiration Scale and the Pooling score and the presence of oropharyngeal secretion. Secondary outcomes were the type of diet taken by mouth; the need for postural compensations and the duration of the dysphagia training. RESULTS: A functional improvement was observed in both groups but treatment group showed a significant improvement for primary outcome with the exception of the pooling Score (p = 0.015, p = 0.203; p = 0.003; p = 0.048 respectively) and for secondary outcome p <0.005. The results confirm that laryngopharyngeal neuromuscular electrical stimulation in post-stroke patients with dysphonia improve outcome of the training. CONCLUSIONS: Laryngopharyngeal neuromuscular electrical stimulation may be considered as an additional and effective treatment option for dysphagia after stroke.

Rehabilitative devices for a top-down approach.

INTRODUCTION: In recent years, neurorehabilitation has moved from a 'bottom-up' to a 'top down' approach. This change has also involved the technological devices developed for motor and cognitive rehabilitation. It implies that during a task or during therapeutic exercises, new 'top-down' approaches are being used to stimulate the brain in a more direct way to elicit plasticity-mediated motor re-learning. This is opposed to 'Bottom up' approaches, which act at the physical level and attempt to bring about changes at the level of the central neural system. AREAS COVERED: In the present unsystematic review, we present the most promising innovative technological devices that can effectively support rehabilitation based on a top-down approach, according to the most recent neuroscientific and neurocognitive findings. In particular, we explore if and how the use of new technological devices comprising serious exergames, virtual reality, robots, brain computer interfaces, rhythmic music and biofeedback devices might provide a top-down based approach. EXPERT COMMENTARY: Motor and cognitive systems are strongly harnessed in humans and thus cannot be separated in neurorehabilitation. Recently developed technologies in motor-cognitive rehabilitation might have a greater positive effect than conventional therapies.

Effects on balance skills and patient compliance of biofeedback training with inertial measurement units and exergaming in subacute stroke: a pilot randomized controlled trial.

Stroke patients have reduced balance and postural control that limits their activities of daily living and participation in social life. Recently, many exergaming systems based on video-biofeedback have been developed for balance training in neurological conditions, however their efficacy remains to be proven. The aim of this study was to investigate the effects on balance skills and patient compliance of biofeedback training based on inertial measurement units and exergaming in subacute stroke. The enrolled subjects were randomized into two groups: subjects allocated to the experimental group performed 10 sessions of biofeedback balance training using inertial sensors, whereas subjects allocated to the control group performed 10 sessions of conventional balance training. All subjects were assessed at T0 (pre-treatment), T1 (posttreatment) and T2 (1-month follow-up). The Berg Balance Scale, Rivermead Mobility Index and modified Barthel Index were used to assess balance, mobility and global disability, respectively. To assess the severity of the stroke and its effects on the patient we used the National Institutes of Health Stroke Scale and the Canadian Neurological Scale. Finally, a static force platform evaluating stabilometric parameters was used to assess balance skills. Fifteen subjects with subacute stroke (4F; age 57.80 ± 13.7) completed the experimental protocol. The analysis showed a significant improvement in balance skills and in the overall clinical outcomes in the experimental group compared with the control group; the experimental group also showed better compliance with the training. The biofeedback system of the device used in this study probably enhances neuroplasticity mechanisms of postural and balance skills in subacute stroke patients.

Caloric Vestibular Stimulation Reduces Pain and Somatoparaphrenia in a Severe Chronic Central Post-Stroke Pain Patient: A Case Study.

Central post-stroke pain is a neuropathic syndrome characterized by intolerable contralesional pain and, in rare cases, somatic delusions. To date, there is limited evidence for the effective treatments of this disease. Here we used caloric vestibular stimulation to reduce pain and somatoparaphrenia in a 57-year-old woman suffering from central post-stroke pain. Resting-state functional magnetic resonance imaging was used to assess the neurological effects of this treatment. Following vestibular stimulation we observed impressive improvements in motor skills, pain, and somatic delusions. In the functional connectivity study before the vestibular stimulation, we observed differences in the patient's left thalamus functional connectivity, with respect to the thalamus connectivity of a control group (N = 20), in the bilateral cingulate cortex and left insula. After the caloric stimulation, the left thalamus functional connectivity with these regions, which are known to be involved in the cortical response to pain, disappeared as in the control group. The beneficial use of vestibular stimulation in the reduction of pain and somatic delusion in a CPSP patient is now documented by behavioral and imaging data. This evidence can be applied to theoretical models of pain and body delusions.

The dynamic motor imagery of locomotion is task-dependent in patients with stroke.

PURPOSE: Recently, Motor Imagery (MI) has been associated with the execution of movements miming in part the mentally represented action (dynamic MI, dMI). Preliminary studies have reported as dMI may improve trainings in sport, with imagery timing close to the physical execution one. This study was aimed to investigate time and spatial parameters of dMI with actual locomotion in people with stroke. METHODS: Twelve patients (stroke group, SG) were compared with twelve healthy elderly (elderly group, EG) and twenty young adults (young group, YG). Subjects performed mental representations of different walking (forward, FW; lateral, LW, backward, BW), accompanied or not by movements imitating walking (dMI and static MI, sMI). Then, they performed actual locomotion (AL). Outcome measures were related to the time and the number of steps spent for completing the tasks for all the given locomotor conditions. RESULTS: Significant differences were found in patients with respect to healthy subjects, with time in sMI significantly shorter than in dMI (p < 0.004) and AL (p < 0.002), but not between dMI and AL in FW (p = 0.806). In patients, times obtained in sMI and dMI was significantly shorter with respect to those of AL in LW and BW. Patients performed imagery tasks with similar times in all locomotion. Healthy groups did not reveal differences among tasks in BW, while significant differences were found in LW. Analogous results were found in terms of number of performed steps. CONCLUSIONS: In patients with stroke, a spatiotemporal functional equivalence with AL was found only for dMI, and not for sMI, in forward walking. This could be due to familiarity with this task. These results might have implications for the rehabilitative techniques based on MI.

Brain-computer interface boosts motor imagery practice during stroke recovery.

OBJECTIVE: Motor imagery (MI) is assumed to enhance poststroke motor recovery, yet its benefits are debatable. Brain-computer interfaces (BCIs) can provide instantaneous and quantitative measure of cerebral functions modulated by MI. The efficacy of BCI-monitored MI practice as add-on intervention to usual rehabilitation care was evaluated in a randomized controlled pilot study in subacute stroke patients. METHODS: Twenty-eight hospitalized subacute stroke patients with severe motor deficits were randomized into 2 intervention groups: 1-month BCI-supported MI training (BCI group, n = 14) and 1-month MI training without BCI support (control group; n = 14). Functional and neurophysiological assessments were performed before and after the interventions, including evaluation of the upper limbs by Fugl-Meyer Assessment (FMA; primary outcome measure) and analysis of oscillatory activity and connectivity at rest, based on high-density electroencephalographic (EEG) recordings. RESULTS: Better functional outcome was observed in the BCI group, including a significantly higher probability of achieving a clinically relevant increase in the FMA score (p < 0.03). Post-BCI training changes in EEG sensorimotor power spectra (ie, stronger desynchronization in the alpha and beta bands) occurred with greater involvement of the ipsilesional hemisphere in response to MI of the paralyzed trained hand. Also, FMA improvements (effectiveness of FMA) correlated with the changes (ie, post-training increase) at rest in ipsilesional intrahemispheric connectivity in the same bands (p < 0.05). INTERPRETATION: The introduction of BCI technology in assisting MI practice demonstrates the rehabilitative potential of MI, contributing to significantly better motor functional outcomes in subacute stroke patients with severe motor impairments.

Different performances in static and dynamic imagery and real locomotion. An exploratory trial.

Motor imagery (MI) is a mental representation of an action without its physical execution. Recently, the simultaneous movement of the body has been added to the mental simulation. This refers to dynamic motor imagery (dMI). This study was aimed at analyzing the temporal features for static and dMI in different locomotor conditions (natural walking, NW, light running, LR, lateral walking, LW, backward walking, BW), and whether these performances were more related to all the given conditions or present only in walking. We have been also evaluated the steps performed in the dMI in comparison with the ones performed by real locomotion. 20 healthy participants (29.3 ± 5.1 years old) were asked to move towards a visualized target located at 10 mt. In dMI, no significant temporal differences respect the actual locomotion were found for all the given tasks (NW: p = 0.058, LR: p = 0.636, BW: p = 0.096; LW: p = 0,487). Significant temporal differences between static imagery and actual movements were found for LR (p < 0.001) and LW (p < 0.001), due to an underestimation of time needed to achieve the target in imagined locomotion. Significant differences in terms of number of steps among tasks were found for LW (p < 0.001) and BW (p = 0.036), whereas neither in NW (p = 0.124) nor LR (p = 0.391) between dMI and real locomotion. Our results confirmed that motor imagery is a task-dependent process, with walking being temporally closer than other locomotor conditions. Moreover, the time records of dMI are nearer to the ones of actual locomotion respect than the ones of static motor imagery.

After vs. priming effects of anodal transcranial direct current stimulation on upper extremity motor recovery in patients with subacute stroke.

PURPOSE: Transcranial direct current stimulation (tDCS) of the motor cortex seems to be effective in improving motor performance in patients with chronic stroke, while some recent findings have reported conflicting results for the subacute phase. We aimed to verify whether upper extremity motor rehabilitation could be enhanced by treatment with tDCS administered before a rehabilitative session. METHODS: Hand dexterity and force in 16 individuals with subacute stroke were assessed before (T0) and after anodal stimulation (T1) and after a successive session of motor rehabilitation (T2) in a double-blind, randomized, sham-controlled, crossover trial. To confirm the value of the device as a specific effector, behavioral tests were also administered. RESULTS: Anodal and sham stimulation plus rehabilitation significantly improved manual dexterity (repeated-measure Anova: A-tDCS: p = 0.005; S-tDCS: p = 0.042). Post hoc analysis revealed a significant stimulation effect only for A-tDCS (p = 0.013 between T0 and T1) and not for S-tDCS, whereas the rehabilitation effect (between T1 and T2) was not significant in either group. Hand force and behavioral features were unchanged. CONCLUSIONS: Anodal brain stimulation improves hand dexterity but does not increase the effectiveness of the rehabilitation directly. These results suggest the presence of aftereffects, not priming effects, of A-tDCS superimposed onto motor learning phenomena.