Posts Tagged neurological recovery

[WEB SITE] Neural works

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STROKE IS THE leading cause of disability in adults, and can affect many parts of the brain, causing multiple deficits including the ones in cognitive, behavioural, visual, speech, sensation, movement, muscle tone and sphincter functions. There are two types of recovery after stroke—spontaneous neurological recovery, which happens in the first three to six months owing to resolution of local injury and can be modified by newer interventions, and functional recovery, for which the time period is unlimited and that involves intensive training that triggers newer electrical circuits in the brain.

Similarly, there are two different approaches of neurological rehabilitation—compensation and remediation. In the compensatory approach, for example, if someone has difficulty in walking because of lack of movements in the leg, then we give him a stick to walk. In remediation, on the other hand, we try to minimise the impairment or improve power in the leg muscles and reduce the chances of using a stick. This ability of the brain to restore the function by minimising the impairment depends upon the formation of new or alternative circuits in the brain. This inherent but not widely known ability of the brain to change in response to a triggered stimulus is called neuroplasticity.

Neuroplasticity is the capacity of neurons and neural networks in the brain to change their connections and behaviour in response to new information, sensory stimulation, development, damage or dysfunction. In fact, for many years, it was believed that certain functions were hard-wired in specific, localised regions of the brain and that any incidents of brain change or recovery were mere exceptions to the rule—’brain cannot change’. However, since the 1970s and 1980s, neuroplasticity has gained wide acceptance in the scientific community as a complex, multifaceted, fundamental property of the brain. Remodelling of neural circuits through plasticity can occur spontaneously or can be triggered by intensive training (experience-dependent plasticity) and biological treatments (pharmacological agents and transcranial magnetic stimulation).

Dr Abhishek Srivastava

Dr Abhishek Srivastava

There are four different types of neuroplasticity: map expansion, homologous area adaptation, compensatory masquerade and cross-modal reassignment.

Map expansion entails flexibility of local brain regions that are dedicated to performing one type of function or storing a particular form of information. The arrangement of these local regions in the cerebral cortex is referred to as a ‘map’. When one function is carried out frequently enough through repeated behaviour or stimulus, the region of the cortical map dedicated to this function grows and shrinks as an individual exercises this function. This phenomenon usually takes place during the learning and practising of a skill such as playing a musical instrument or in task-specific trainings in stroke patients to improve specific functions like arm or leg movements, speech, language, cognitive or swallow function. This is the most commonly used approach in neurorehab.

Homologous area adaptation occurs during the early critical period of development. If a particular brain module becomes damaged in early life, its normal operations have the ability to shift to brain areas that do not include the affected module. The function is often shifted to a module in the matching or homologous area of the opposite brain hemisphere. This concept can help improve speech and language function after stroke with involvement of the dominant lobe.

Compensatory masquerade can simply be described as the brain figuring out an alternative strategy for carrying out a task when the initial strategy cannot be followed due to impairment. One example is when a person attempts to navigate from one location to another. Most people have an intuitive sense of direction and distance that they employ for navigation. However, a person who suffers some form of brain injury or stroke and impaired spatial sense will resort to another strategy for spatial navigation, such as memorising landmarks. The only change that occurs in the brain is a reorganisation of preexisting neuronal networks. This is a simple and novel way by which stroke survivors who were not able to do a complex everyday task can be trained to do it themselves.

Cross-modal reassignment entails the introduction of new inputs into a brain area deprived of its main inputs. A classic example of this is the ability of an adult who has been blind since birth to have touch or somatosensory input redirected to the visual cortex in the occipital lobe of the brain—specifically, in an area known as V1. Sighted people, however, do not display any V1 activity when presented with similar touch-oriented experiments. This occurs because neurons communicate with one another in the same abstract language of electrochemical impulses regardless of sensory modality. This strategy is useful to improve visual or auditory functions after stroke.

Most of the recent rehabilitation approaches to improve sensory-motor recovery, including rehab robotics, virtual reality, mirror training, constraint induced therapy, task-specific training and intensive locomotor training, work on the principles of neuroplasticity. These help in improving most of the functions after stroke including cognitive, visual, behavioural, speech, language, swallow, movements, tone or sphincter functions. I have seen many stroke patients, thought to be in a vegetative state for life, now living independently, thanks to neurological rehabilitation.

Srivastava is a neurorehab specialist and director, centre for rehabilitation, Kokilaben Dhirubhai Ambani Hospital, Mumbai.

 

via Neural works | health

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[Abstract] Gamification in Physical Therapy: More Than Using Games

Abstract

The implementation of computer games in physical therapy is motivated by characteristics such as attractiveness, motivation, and engagement, but these do not guarantee the intended therapeutic effect of the interventions. Yet, these characteristics are important variables in physical therapy interventions because they involve reward-related dopaminergic systems in the brain that are known to facilitate learning through long-term potentiation of neural connections. In this perspective we propose a way to apply game design approaches to therapy development by “designing” therapy sessions in such a way as to trigger physical and cognitive behavioral patterns required for treatment and neurological recovery. We also advocate that improving game knowledge among therapists and improving communication between therapists and game designers may lead to a novel avenue in designing applied games with specific therapeutic input, thereby making gamification in therapy a realistic and promising future that may optimize clinical practice.

Source: Gamification in Physical Therapy: More Than Using Games : Pediatric Physical Therapy

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[ARTICLE] Long-Term Training with a Brain-Machine Interface-Based Gait Protocol Induces Partial Neurological Recovery in Paraplegic Patients – Full Text HTML

Abstract

Brain-machine interfaces (BMIs) provide a new assistive strategy aimed at restoring mobility in severely paralyzed patients. Yet, no study in animals or in human subjects has indicated that long-term BMI training could induce any type of clinical recovery. Eight chronic (3–13 years) spinal cord injury (SCI) paraplegics were subjected to long-term training (12 months) with a multi-stage BMI-based gait neurorehabilitation paradigm aimed at restoring locomotion. This paradigm combined intense immersive virtual reality training, enriched visual-tactile feedback, and walking with two EEG-controlled robotic actuators, including a custom-designed lower limb exoskeleton capable of delivering tactile feedback to subjects. Following 12 months of training with this paradigm, all eight patients experienced neurological improvements in somatic sensation (pain localization, fine/crude touch, and proprioceptive sensing) in multiple dermatomes. Patients also regained voluntary motor control in key muscles below the SCI level, as measured by EMGs, resulting in marked improvement in their walking index. As a result, 50% of these patients were upgraded to an incomplete paraplegia classification. Neurological recovery was paralleled by the reemergence of lower limb motor imagery at cortical level. We hypothesize that this unprecedented neurological recovery results from both cortical and spinal cord plasticity triggered by long-term BMI usage.

Introduction

Spinal Cord Injury (SCI) rehabilitation remains a major clinical challenge, especially in cases involving chronic complete injury. Clinical studies using body weight support systems1,2, robotic assistance1,2,3,4, and functional electrostimulation of the leg5,6 have proposed potential solutions for assisting SCI patients in walking7,8. Yet, none of these approaches have generated any consistent clinical improvement in neurological functions, namely somatosensory (tactile, proprioceptive, pain, and temperature) perception and voluntary motor control, below the level of the spinal cord lesion.

Since the first experimental demonstrations in rats9, monkeys10,11, and the subsequent clinical reports in humans12,13,14, brain-machine interfaces (BMIs) have emerged as potential options to restore mobility in patients who are severely paralyzed as a result of spinal cord injuries (SCIs) or neurodegenerative disorders15. However, to our knowledge, no study has suggested that long-term training associating BMI-based paradigms and physical training could trigger neurological recovery, particularly in patients clinically diagnosed as having a complete SCI. Yet, in 60–80% of these “complete” SCI patients, neurophysiological assessments16,17 and post-mortem anatomical18 studies have indicated the existence of a number of viable axons crossing the level of the SCI. This led some authors to refer to these patients as having a “discomplete” SCI17 and predict that these remaining axons could mediate some degree of neurological recovery.

For the past few years, our multidisciplinary team has been engaged in a project to implement a multi-stage neurorehabilitation protocol – the Walk Again Neurorehabilitation (WA-NR) – in chronic SCI patients. This protocol included the intensive employment of immersive virtual-reality environments, combining training on non-invasive brain-control of virtual avatar bodies with rich visual and tactile feedback, and the use of closed-loop BMI platforms in conjunction with lower limb robotic actuators, such as a commercially available robotic walker (Lokomat, Hocoma AG, Volketswil, Switzerland), and a brain-controlled robotic exoskeleton, custom-designed specifically for the execution of this project.

Originally, our central goal was to explore how much such a long-term BMI-based protocol could help SCI patients regain their ability to walk autonomously using our brain-controlled exoskeleton. Among other innovations, this device provides tactile feedback to subjects through the combination of multiple force-sensors, applied to key locations of the exoskeleton, such as the plantar surface of the feet, and a multi-channel haptic display, applied to the patient’s forearm skin surface.

Unexpectedly, at the end of the first 12 months of training with the WA-NR protocol, a comprehensive neurological examination revealed that all of our eight patients had experienced a significant clinical improvement in their ability to perceive somatic sensations and exert voluntary motor control in dermatomes located below the original SCI. EEG analysis revealed clear signs of cortical functional plasticity, at the level of the primary somatosensory and motor cortical areas, during the same period. These findings suggest, for the first time, that long-term exposure to BMI-based protocols enriched with tactile feedback and combined with robotic gait training may induce cortical and subcortical plasticity capable of triggering partial neurological recovery even in patients originally diagnosed with a chronic complete spinal cord injury.

Methods

Eight paraplegic patients, suffering from chronic (>1 year) spinal cord injury (SCI, seven complete and one incomplete, see Fig. 1A, Supplementary Methods Inclusion/exclusion Criteria), were followed by a multidisciplinary rehabilitation team, comprised of clinical staff, engineers, neuroscientists, and roboticists, during the 12 months of 2014. Our clinical protocol, which we named the Walk Again Neurorehabilitation (WA-NR), was approved by both a local ethics committee (Associação de Assistência à Criança Deficiente, Sao Paulo, Sao Paulo, Brazil #364.027) and the Brazilian federal government ethics committee (CONEP, CAAE: 13165913.1.0000.0085). All research activities were carried out in accordance with the guidelines and regulations of the Associação de Assistência à Criança Deficiente and CONEP. Each participant signed written informed consent before enrolling in the study. The central goal of this study was to investigate the clinical impact of the WA-NR, which consisted of the integration between traditional physical rehabilitation and the use of multiple brain-machine interface paradigms (BMI). This protocol included six components: (1) an immersive virtual reality environment in which a seated patient employed his/her brain activity, recorded via a 16-channel EEG, to control the movements of a human body avatar, while receiving visuo-tactile feedback; (2) identical interaction with the same virtual environment and BMI protocol while patients were upright, supported by a stand-in-table device; (3) training on a robotic body weight support (BWS) gait system on a treadmill (Lokomat, Hocoma AG, Switzerland); (4) training with a BWS gait system fixed on an overground track (ZeroG, Aretech LLC., Ashburn, VA); (5) training with a brain-controlled robotic BWS gait system on a treadmill; and (6) gait training with a brain-controlled, sensorized 12 degrees of freedom robotic exoskeleton (seeSupplementary Material).

(A) Cumulated number of hours and sessions for all patients over 12 months. We report cumulated hours for the following activities: classic physiotherapy activities (e.g. strengthening/stretching), gait-BMI-based neurorehabilitation, one-to-one consultations with a psychologist, periodic measurements for research purposes and routine medical monitoring (vital signs, etc.). (B) Neurorehabilitation training paradigm and corresponding cumulated number of hours for all patients: 1) Brain controlled 3D avatar with tactile feedback when patient is seated on a wheelchair or 2) in an orthostatic position on a stand-in-table, 3) Gait training using a robotic body weight support (BWS) system on a treadmill (LokomatPro, Hocoma), 4) Gait training using an overground BWS system (ZeroG, Aretech). 5–6) Brain controlled robotic gait training integrated with the sensory support of the tactile feedback at gait devices (BWS system on a treadmill or the exoskeleton). (C) Material used for the clinical sensory assessment of dermatomes in the trunk and lower limbs: to evaluate pain sensitivity, examiner used a pin-prick in random positions of the body segments. Nylon monofilaments applying forces ranging between 300 to 0.2 grams on the skin, were used to evaluate patients’ sensitivity for crude to fine touch. Dry cotton and alcohol swabs were used to assess respectively warm and cold sensation. Vibration test was done using a diapason on patients’ legs bone surface. Deep pressure was assessed with an adapted plicometer in every dermatome.

Continue —> Long-Term Training with a Brain-Machine Interface-Based Gait Protocol Induces Partial Neurological Recovery in Paraplegic Patients : Scientific Reports

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[ARTICLE] The lingering effects of a busted myth—false time limits in stroke rehabilitation

ABSTRACT

It was once falsely believed that neurological and functional recovery after stroke occurred only in the first six months after lesion. The perception of this “6 month myth” continues to negatively impact the attitudes of patients towards their rehabilitation and on the clinicians and therapists making optimal training plans.

Here we briefly outline some evidence that debunked the “6-month myth”, where the concept of this temporal limit may have originated, and the lingering misunderstanding that individuals with stroke reach a plateau of recovery after six months even with rehabilitation training. We present evidence that significant functional improvement can occur years after stroke when rehabilitation training is applied.

We frame the concepts of active and passive neurological recovery and that active neurological recovery continues far beyond any temporal limit. Because the effects of this busted “6 month myth” persist, we aim to remind active physicians, therapists, exercise professionals and people with stroke to continuously seek opportunities for active rehabilitation training.

Meanwhile, trained and certified exercise professionals can play critical roles in facilitating rehabilitative training for community-dwelling stroke survivors.

via The lingering effects of a busted myth—false time limits in stroke rehabilitation – Applied Physiology, Nutrition, and Metabolism.

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