Posts Tagged neuromodulation

[ARTICLE] Technological Approaches for Neurorehabilitation: From Robotic Devices to Brain Stimulation and Beyond – Full Text

Neurological diseases causing motor/cognitive impairments are among the most common causes of adult-onset disability. More than one billion of people are affected worldwide, and this number is expected to increase in upcoming years, because of the rapidly aging population. The frequent lack of complete recovery makes it desirable to develop novel neurorehabilitative treatments, suited to the patients, and better targeting the specific disability. To date, rehabilitation therapy can be aided by the technological support of robotic-based therapy, non-invasive brain stimulation, and neural interfaces. In this perspective, we will review the above methods by referring to the most recent advances in each field. Then, we propose and discuss current and future approaches based on the combination of the above. As pointed out in the recent literature, by combining traditional rehabilitation techniques with neuromodulation, biofeedback recordings and/or novel robotic and wearable assistive devices, several studies have proven it is possible to sensibly improve the amount of recovery with respect to traditional treatments. We will then discuss the possible applied research directions to maximize the outcome of a neurorehabilitation therapy, which should include the personalization of the therapy based on patient and clinician needs and preferences.

Introduction

According to the World Health Organization (WHO), neurological disorders and injuries account for the 6.3% of the global burden of disease (GBD) (12). With more than 6% of DALY (disability-adjusted life years) in the world, neurological disorders represent one of the most widespread clinical condition. Among neurological disorders, more than half of the burden in DALYs is constituted by cerebral-vascular disease (55%), such as stroke. Stroke, together with spinal cord injury (SCI), accounts for 52% of the adult-onset disability and, over a billion people (i.e., about a 15% of the population worldwide) suffer from some form of disability (3). These numbers are likely to increase in the coming years due to the aging of the population (4), since disorders affecting people aged 60 years and older contribute to 23% of the total GBD (5).

Standard physical rehabilitation favors the functional recovery after stroke, as compared to no treatment (6). However, the functional recovery is not always satisfactory as only 20% of patients fully resume their social life and job activities (7). Hence, the need of more effective and patient-tailored rehabilitative approaches to maximize the functional outcome of neurological injuries as well as patients’ quality of life (8). Modern technological methodologies represent one of the most recent advances in neurorehabilitation, and an increasing body of evidence supports their role in the recovery from brain and/or medullary insults. This manuscript provides a perspective on how technologies and methodologies could be combined in order to maximize the outcome of neurorehabilitation.

Current Systems and Therapeutic Approaches for Neurorehabilitation

The great progress made in interdisciplinary fields, such as neural engineering (910), has allowed to investigate many neural mechanisms, by detecting and processing the neural signals at high spatio-temporal resolution, and by interfacing the nervous system with external devices, thus restoring neurological functions lost due to disease/injury. The progress continues in parallel to technological advancements. The last two decades there has seen a large proliferation of technological approaches for human rehabilitation, such as robots, wearable systems, brain stimulation, and virtual environments. In the next sections, we will focus on: robotic therapy, non-invasive brain stimulation (NIBS), and neural interfaces.

Robotic Devices

Robots for neurorehabilitation are designed to support the administration of physical exercises to the upper or lower extremities, with the purpose of promoting neuro-motor recovery. This technology has a relatively long history, dating back to the early 1990s (11). Robot devices for rehabilitation differ widely in terms of mechanical design, number of degrees of freedom, and control architectures. As regards the mechanical design, robots may have either a single point of interaction (i.e., end effector) with the user body (endpoint robots or manipulanda) or multiple points of interaction (exoskeletons and wearable robots) (12).

Endpoint robots for the upper extremity, include Inmotion2 (IMT, USA) (13), KINARM End-Point (BKIN, Canada), and Braccio di Ferro (14) (Figure 1A1, left). Only some of these devices have been tested in randomized clinical trials (15), confirming an improvement of upper limb motor function after stroke (16). However, convincing evidence in favor of significant changes in activities of daily living (ADL) indicators is lacking (17), possibly because performance in ADL is highly affected by hand functionality. A good example of lower limb endpoint robot is represented by gait trainer GT1 (Reha-Stim, Germany). Its efficacy was tested by Picelli et al. (18), who demonstrated an improvement in multiple clinical measures in subjects with Parkinson’s disease following robotic-assisted rehabilitation when compared to physical rehabilitation alone (18). Endpoint robots are also available for postural rehabilitation. For instance, Hunova (Movendo Technology, Italy, launched in 2017) is equipped with a seat and a platform that induce multidirectional movements to improve postural stability (Figure 1A1, right).

 

Figure 1. Neurorehabilitation therapies. (A1) Endpoint robots: on the left the “Braccio di Ferro” manipulandum, on the right the postural robot Hunova. Braccio di ferro (14) is a planar manipulandum with 2-DOF, developed at the University of Genoa (Italy). It is equipped with direct-drive brushless motors and is specially designed to minimize endpoint inertia. It uses the H3DAPI programming environment, which allows to share exercise protocol with other devices. Written informed consent was obtained from the subject depicted in the panel. Movendo Technology’s Hunova is a robotic device that permits full-body rehabilitation. It has two 2-DOF actuated and sensorized platforms located under the seat and on the floor level that allow it to rehabilitate several body districts, including lower limb (thanks to the floor-level platform), the core, and the back, using the platform located underneath the seat. Different patient categories (orthopedic, neurological, and geriatric) can be treated, and interact with the machine through a GUI based on serious games. (A2) Wearable device: the recent exoskeleton Twin. Twin is a fully modular device developed at IIT and co-funded by INAIL (the Italian National Institute for Insurance against Accidents at Work). The device can be easily assembled/disassembled by the patient/therapist. It provides total assistance to patients in the 5–95th percentile range with a weight up to 110 kg. Its modularity is implemented by eight quick release connectors, each located at both mechanical ends of each motor, that allow mechanical and electrical connection with the rest of the structure. It can implement three different walking patterns that can be fully customized according to the patient’s needs viaa GUI on mobile device, thus enabling personalization of the therapy. Steps can be triggered via an IMU-based machine state controller. (B1) Repetitive transcranial magnetic stimulation (rTMS) representation. rTMS refers to the application of magnetic pulses in a repetitive mode. Conventional rTMS applied at low frequency (0.2–1 Hz) results in plastic inhibition of cortical excitability, whereas when it is applied at high frequency (≥5Hz), it leads to excitation (19). rTMS can also be applied in a “patterned mode.” Theta burst stimulation involves applying bursts of high frequency magnetic stimulation (three pulses at 50 Hz) repeated at intervals of 200 ms (20). Intermittent TBS increases cortical excitability for a period of 20–30 min, whereas continuous TBS leads to a suppression of cortical activity for approximately the same amount of time (20). (B2) Transcranial current stimulation (tCS) representation. tCS uses ultra-low intensity current, to manipulate the membrane potential of neurons and modulate spontaneous firing rates, but is insufficient on its own to discharge resting neurons or axons (21). tCS is an umbrella term for a number of brain modulating paradigms, such as transcranial direct current stimulation (22), transcranial alternating current stimulation (23), and transcranial random noise stimulation (24). (C) A typical BCI system. Five stages are represented: brain-signal acquisition, preprocessing, feature extraction/selection, classification, and application interface. In the first stage, brain-signal acquisition, suitable signals are acquired using an appropriate modality. Since the acquired signals are normally weak and contain noise (physiological and instrumental) and artifacts, preprocessing is needed, which is the second stage. In the third stage, some useful data or so-called “features” are extracted. These features, in the fourth stage, are classified using a suitable classifier. Finally, in the fifth stage, the classified signals are transmitted to a computer or other external devices for generating the desired control commands to the devices. In neurofeedback applications, the application interface is a real-time display of brain activity, which enables self-regulation of brain functions (25).

Continue —> Frontiers | Technological Approaches for Neurorehabilitation: From Robotic Devices to Brain Stimulation and Beyond | Neurology

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[BOOK] Emerging Therapies in Neurorehabilitation II – Βιβλία Google

Εξώφυλλο
José L. PonsRafael RayaJosé González
Springer30 Οκτ 2015 – 318 σελίδες

This book reports on the latest technological and clinical advances in the field of neurorehabilitation. It is, however, much more than a conventional survey of the state-of-the-art in neurorehabilitation technologies and therapies. It was written on the basis of a week of lively discussions between PhD students and leading research experts during the Summer School on Neurorehabilitation (SSNR2014), held September 15-19 in Baiona, Spain. Its unconventional format makes it a perfect guide for all PhD students, researchers and professionals interested in gaining a multidisciplinary perspective on current and future neurorehabilitation scenarios. The book addresses various aspects of neurorehabilitation research and practice, including a selection of common impairments affecting CNS function, such as stroke and spinal cord injury, as well as cutting-edge rehabilitation and diagnostics technologies, including robotics, neuroprosthetics, brain-machine interfaces and neuromodulation.

via Emerging Therapies in Neurorehabilitation II – Βιβλία Google

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[Abstract] Cranial nerve non-invasive neuromodulation improves gait and balance in stroke survivors: A pilot randomised controlled trial

First page of article

Cranial nerve non-invasive neuromodulation (CN-NINM) is delivered using a Portable Neuromodulation Stimulation (PoNS™) device that stimulates two cranial nerve nuclei (trigeminal and facial nerve nuclei) using electrodes embedded in a mouthpiece that rests on the tongue. Danilov and colleagues reported that prolonged and repetitive (20 minutes or more) tongue stimulation coupled with specific training of balance and gait can initiate long-lasting neuronal reorganization that can be measured in participants’ behaviour [1].

via Cranial nerve non-invasive neuromodulation improves gait and balance in stroke survivors: A pilot randomised controlled trial – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation

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[ARTICLE] Impact of Transcranial Magnetic Stimulation on Functional Movement Disorders: Cortical Modulation or a Behavioral Effect? – Full Text

Introduction: Recent studies suggest that repeated transcranial magnetic stimulation (TMS) improves functional movement disorders (FMDs), but the underlying mechanisms are unclear. The objective was to determine whether the beneficial action of TMS in patients with FMDs is due to cortical neuromodulation or rather to a cognitive-behavioral effect.

Method: Consecutive patients with FMDs underwent repeated low-frequency (0.25 Hz) magnetic stimulation over the cortex contralateral to the symptoms or over the spinal roots [root magnetic stimulation (RMS)] homolateral to the symptoms. The patients were randomized into two groups: group 1 received RMS on day 1 and TMS on day 2, while group 2 received the same treatments in reverse order. We blindly assessed the severity of movement disorders before and after each stimulation session.

Results: We studied 33 patients with FMDs (dystonia, tremor, myoclonus, Parkinsonism, or stereotypies). The median symptom duration was 2.9 years. The magnetic stimulation sessions led to a significant improvement (>50%) in 22 patients (66%). We found no difference between TMS and RMS.

Conclusion: We suggest that the therapeutic benefit of TMS in patients with FMDs is due more to a cognitive-behavioral effect than to cortical neuromodulation.

Introduction

Individuals with functional movement disorders (FMDs) account for 3–20% of all patients seen in movement-disorder clinics (13). There is no consensus treatment for FMDs (46). These movement disorders are not due to irreversible brain damage but their outcome is nonetheless poor: symptoms are persistent or worse after 1.5–7 years of follow-up in between 44 and 90% of patients (6, 7). FMDs generate major healthcare costs, as well as indirect costs due to unemployment and disability (8).

Recent studies suggest a beneficial effect of repeated supraliminal low-frequency transcranial magnetic stimulation (TMS) (i.e., TMS ≤ 1 Hz) on functional motor symptoms (914) [Ref. (15) for a review]. Among these studies, only one included a blinded assessment (11), and only one included a control group (sham treatment) (9). Focusing on FMDs more specifically, two studies showed a beneficial effect of supraliminal low-frequency TMS, with a mean improvement rate of 67% (11) and 97% (13). It is unclear whether the therapeutic benefit is due to cortical neuromodulation, i.e., to changes in cortical excitability and in connectivity between brain areas (15, 16). The alternative hypothesis is a cognitive-behavioral effect, a therapeutic effect that is linked to suggestion and/or motor relearning.

To address this issue, we blindly compared the therapeutic effect of repeated TMS and repeated root magnetic stimulation (RMS) in patients with FMDs. RMS was chosen as the control treatment to mimic TMS-induced movement without directly stimulating the cortex.

Continue —>  Frontiers | Impact of Transcranial Magnetic Stimulation on Functional Movement Disorders: Cortical Modulation or a Behavioral Effect? | Neurology

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[ARTICLE] Transcranial direct current stimulation and stroke recovery: opportunities and challenges – Full Text PDF

ABSTRACT

Objectives: Transcranial direct current stimulation (tDCS) is one type of neuromodulation, which is an emerging technology that holds promise for the future studies on therapeutic and diagnosis applications in treatment of neurological and psychiatric diseases. However, there is a serious question among developing countries with limited financial and human resources, about the potential returns of an investment in this field and regarding the best time to transfer this technology from controlled experimental settings to health systems in the public and private sectors. This article reviews the tDCS as tools of neuromodulation for stroke and discusses the opportunities and challenges available for clinicians and researchers interested in advancing neuromodulation therapy. The aim of this review is to highlight the usefulness of tDCS and to generate an interest that will lead to appropriate studies that assess the true clinical value of tDCS for brain diseases in developing countries.

Methods: Literature review was done on PubMed from 2016 on neuromodulation in under-developed countries (UDCs) by non-invasive brain stimulation methods, using the key words “stroke”, “rehabilitation”, and “tDCS”.

Results: We first identified articles and websites, of which were further selected for extensive analysis mainly based on clinical relevance, study quality and reliability, and date of publication.

Conclusion: Despite the promising results obtained with tDCS in basic and clinical neuroscience, further progress has been impeded by a lack of clarity to use in mostly UDCs.

INTRODUCTION
During stroke, an interruption to all or part of the brain’s
blood supply, with the subsequent deprivation of oxygen
and glucose to the affected area, causes the rapid loss
of brain function through the destruction of neuronal
function and the initiation of an ischemic cascade that
seriously damages or kills neurons1. Strokes are
classified as an ischemic (caused by embolism,
thrombosis or systemic hypoperfusion) approximately
80% and hemorrhagic (intracerebral, subarachnoid,
subdural or epidural in type) strokes(1, 2). The main
symptoms associated with stroke are weakness in
facial, speech and a loss in visual field and paralysis in
the arm or leg. These symptoms may last only a few
hours and disappear completely within 24 hours, as
with TIAs, but even under these circumstances,
immediate medical assistance should be sought, as
this will help minimise damage to the brain and help
prevent progression to larger, more serious episodes of
stroke(2). Stroke can result in lasting neurological
damage or may even cause death unless it is
diagnosed and treated promptly. When the stroke is
severe, the patient often faces a prolonged stay in
hospital and, following their discharge and depending
on the severity of the consequences, constant care.
This care is either provided by a family member or, in
the most severe cases, by a nursing home. Stroke
disease not only affects health-related quality of life
(HRQOL) of patients but it can also increase their
hospital length of stay (HLoS)(3, 4). HLoS will even be
more increased if patients are suffering with stroke
combined with diabetes mellitus and hypertension(5). […]

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[Abstract] The treatment of fatigue by non-invasive brain stimulation

Summary

The use of non-invasive brain neurostimulation (NIBS) techniques to treat neurological or psychiatric diseases is currently under development. Fatigue is a commonly observed symptom in the field of potentially treatable pathologies by NIBS, yet very little data has been published regarding its treatment. We conducted a review of the literature until the end of February 2017 to analyze all the studies that reported a clinical assessment of the effects of NIBS techniques on fatigue. We have limited our analysis to repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS). We found only 15 studies on this subject, including 8 tDCS studies and 7 rTMS studies. Of the tDCS studies, 6 concerned patients with multiple sclerosis while 6 rTMS studies concerned fibromyalgia or chronic fatigue syndrome. The remaining 3 studies included patients with post-polio syndrome, Parkinson’s disease and amyotrophic lateral sclerosis. Three cortical regions were targeted: the primary sensorimotor cortex, the dorsolateral prefrontal cortex and the posterior parietal cortex. In all cases, tDCS protocols were performed according to a bipolar montage with the anode over the cortical target. On the other hand, rTMS protocols consisted of either high-frequency phasic stimulation or low-frequency tonic stimulation. The results available to date are still too few, partial and heterogeneous as to the methods applied, the clinical profile of the patients and the variables studied (different fatigue scores) in order to draw any conclusion. However, the effects obtained, especially in multiple sclerosis and fibromyalgia, are really carriers of therapeutic hope.

Source: The treatment of fatigue by non-invasive brain stimulation

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[Abstract] Targeting interhemispheric inhibition with neuromodulation to enhance stroke rehabilitation

Highlights

  • This review focuses on interhemispheric inhibition and its role in the healthy and stroke lesioned brain.
  • Measurement method and movement phase should be considered when comparing studies associating interhemispheric inhibition with functional recovery.
  • Neuromodulation of interhemispheric inhibition to augment stroke recovery requires the targeting of specific neural circuitry. We discuss the effectiveness of current and novel neurostimulation techniques at targeting interhemispheric inhibition and enhancing stroke rehabilitation.

Abstract

Background/Objectives

Interhemispheric inhibition in the brain plays a dynamic role in the production of voluntary unimanual actions. In stroke, the interhemispheric imbalance model predicts the presence of asymmetry in interhemispheric inhibition, with excessive inhibition from the contralesional hemisphere limiting maximal recovery. Stimulation methods to reduce this asymmetry in the brain may be promising as a stroke therapy, however determining how to best measure and modulate interhemispheric inhibition and who is likely to benefit, remain important questions.

Methods

This review addresses current understanding of interhemispheric inhibition in the healthy and stroke lesioned brain. We present a review of studies that have measured interhemispheric inhibition using different paradigms in the clinic, as well as results from recent animal studies investigating stimulation methods to target abnormal inhibition after stroke.

Main findings/Discussion

The degree to which asymmetric interhemispheric inhibition impacts on stroke recovery is controversial, and we consider sources of variation between studies which may contribute to this debate. We suggest that interhemispheric inhibition is not static following stroke in terms of the movement phase in which it is aberrantly engaged. Instead it may be dynamically increased onto perilesional areas during early movement, thus impairing motor initiation. Hence, its effect on stroke recovery may differ between studies depending on the technique and movement phase of eliciting the measurement. Finally, we propose how modulating excitability in the brain through more specific targeting of neural elements underlying interhemispheric inhibition via stimulation type, location and intensity may raise the ceiling of recovery following stroke and enhance functional return.

Source: Targeting interhemispheric inhibition with neuromodulation to enhance stroke rehabilitation – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation

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[Abstract] Targeting interhemispheric inhibition with neuromodulation to enhance stroke rehabilitation. – Brain Stimulation

Highlights

  • This review focuses on interhemispheric inhibition and its role in the healthy and stroke lesioned brain.
  • Measurement method and movement phase should be considered when comparing studies associating interhemispheric inhibition with functional recovery.
  • Neuromodulation of interhemispheric inhibition to augment stroke recovery requires the targeting of specific neural circuitry. We discuss the effectiveness of current and novel neurostimulation techniques at targeting interhemispheric inhibition and enhancing stroke rehabilitation.

Abstract

Background/Objectives

Interhemispheric inhibition in the brain plays a dynamic role in the production of voluntary unimanual actions. In stroke, the interhemispheric imbalance model predicts the presence of asymmetry in interhemispheric inhibition, with excessive inhibition from the contralesional hemisphere limiting maximal recovery. Stimulation methods to reduce this asymmetry in the brain may be promising as a stroke therapy, however determining how to best measure and modulate interhemispheric inhibition and who is likely to benefit, remain important questions.

Methods

This review addresses current understanding of interhemispheric inhibition in the healthy and stroke lesioned brain. We present a review of studies that have measured interhemispheric inhibition using different paradigms in the clinic, as well as results from recent animal studies investigating stimulation methods to target abnormal inhibition after stroke.

Main findings/Discussion

The degree to which asymmetric interhemispheric inhibition impacts on stroke recovery is controversial, and we consider sources of variation between studies which may contribute to this debate. We suggest that interhemispheric inhibition is not static following stroke in terms of the movement phase in which it is aberrantly engaged. Instead it may be dynamically increased onto perilesional areas during early movement, thus impairing motor initiation. Hence, its effect on stroke recovery may differ between studies depending on the technique and movement phase of eliciting the measurement. Finally, we propose how modulating excitability in the brain through more specific targeting of neural elements underlying interhemispheric inhibition via stimulation type, location and intensity may raise the ceiling of recovery following stroke and enhance functional return.

Source: Targeting interhemispheric inhibition with neuromodulation to enhance stroke rehabilitation – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation

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[Abstract] Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS) – Clinical Neurophysiology

Highlights

  • A group of European experts reviewed current evidence for therapeutic efficacy of tDCS.
  • Level B evidence (probable efficacy) was found for fibromyalgia, depression and craving.
  • The therapeutic relevance of tDCS needs to be further explored in these and other indications.

Abstract

A group of European experts was commissioned by the European Chapter of the International Federation of Clinical Neurophysiology to gather knowledge about the state of the art of the therapeutic use of transcranial direct current stimulation (tDCS) from studies published up until September 2016, regarding pain, Parkinson’s disease, other movement disorders, motor stroke, poststroke aphasia, multiple sclerosis, epilepsy, consciousness disorders, Alzheimer’s disease, tinnitus, depression, schizophrenia, and craving/addiction.

The evidence-based analysis included only studies based on repeated tDCS sessions with sham tDCS control procedure; 25 patients or more having received active treatment was required for Class I, while a lower number of 10–24 patients was accepted for Class II studies. Current evidence does not allow making any recommendation of Level A (definite efficacy) for any indication. Level B recommendation (probable efficacy) is proposed for: (i) anodal tDCS of the left primary motor cortex (M1) (with right orbitofrontal cathode) in fibromyalgia; (ii) anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) (with right orbitofrontal cathode) in major depressive episode without drug resistance; (iii) anodal tDCS of the right DLPFC (with left DLPFC cathode) in addiction/craving. Level C recommendation (possible efficacy) is proposed for anodal tDCS of the left M1 (or contralateral to pain side, with right orbitofrontal cathode) in chronic lower limb neuropathic pain secondary to spinal cord lesion. Conversely, Level B recommendation (probable inefficacy) is conferred on the absence of clinical effects of: (i) anodal tDCS of the left temporal cortex (with right orbitofrontal cathode) in tinnitus; (ii) anodal tDCS of the left DLPFC (with right orbitofrontal cathode) in drug-resistant major depressive episode.

It remains to be clarified whether the probable or possible therapeutic effects of tDCS are clinically meaningful and how to optimally perform tDCS in a therapeutic setting. In addition, the easy management and low cost of tDCS devices allow at home use by the patient, but this might raise ethical and legal concerns with regard to potential misuse or overuse. We must be careful to avoid inappropriate applications of this technique by ensuring rigorous training of the professionals and education of the patients.

Source: Evidence-based guidelines on the therapeutic use of transcranial direct current stimulation (tDCS) – Clinical Neurophysiology

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