A high-performance speech neuroprosthesis.

Speech brain-computer interfaces (BCIs) have the potential to restore rapid communication to people with paralysis by decoding neural activity evoked by attempted speech into text1,2 or sound3,4. Early demonstrations, although promising, have not yet achieved accuracies sufficiently high for communication of unconstrained sentences from a large vocabulary1-7. Here we demonstrate a speech-to-text BCI that records spiking activity from intracortical microelectrode arrays. Enabled by these high-resolution recordings, our study participant-who can no longer speak intelligibly owing to amyotrophic lateral sclerosis-achieved a 9.1% word error rate on a 50-word vocabulary (2.7 times fewer errors than the previous state-of-the-art speech BCI2) and a 23.8% word error rate on a 125,000-word vocabulary (the first successful demonstration, to our knowledge, of large-vocabulary decoding). Our participant's attempted speech was decoded  at 62 words per minute, which is 3.4 times as fast as the previous record8 and begins to approach the speed of natural conversation (160 words per minute9). Finally, we highlight two aspects of the neural code for speech that are encouraging for speech BCIs: spatially intermixed tuning to speech articulators that makes accurate decoding possible from only a small region of cortex, and a detailed articulatory representation of phonemes that persists years after paralysis. These results show a feasible path forward for restoring rapid communication to people with paralysis who can no longer speak.

Usability, occupational performance and satisfaction evaluation of a smart environment controlled by infrared oculography by people with severe motor disabilities.

A smart environment is an assistive technology space that can enable people with motor disabilities to control their equipment (TV, radio, fan, etc.) through a human-machine interface activated by different inputs. However, assistive technology resources are not always considered useful, reaching quite high abandonment rate. This study aims to evaluate the effectiveness of a smart environment controlled through infrared oculography by people with severe motor disabilities. The study sample was composed of six individuals with motor disabilities. Initially, sociodemographic data forms, the Functional Independence Measure (FIMTM), and the Canadian Occupational Performance Measure (COPM) were applied. The participants used the system in their domestic environment for a week. Afterwards, they were reevaluated with regards to occupational performance (COPM), satisfaction with the use of the assistive technology resource (QUEST 2.0), psychosocial impact (PIADS) and usability of the system (SUS), as well as through semi-structured interviews for suggestions or complaints. The most common demand from the participants of this research was 'control of the TV'. Two participants did not use the system. All participants who used the system (four) presented positive results in all assessment protocols, evidencing greater independence in the control of the smart environment equipment. In addition, they evaluated the system as useful and with good usability. Non-acceptance of disability and lack of social support may have influenced the results.

Effects of pulmonary rehabilitation program on amyotrophic lateral sclerosis: A meta-analysis of randomized controlled trials.

BACKGROUND: Patients with amyotrophic lateral sclerosis (ALS) develop respiratory failure and progressive muscle weakness. The effects of pulmonary rehabilitation on the lung function of patients with ALS are unclear. OBJECTIVE: Through this meta-analysis of randomized controlled trials (RCTs), we evaluated the effects of pulmonary rehabilitation, such as type of treatment, on patients with ALS and compared the effectiveness of this treatment. METHODS: PubMed, EMBASE, Web of Science, and Cochrane databases were searched until December 2020. The methodological quality of each study was assessed using the updated Cochrane Risk of Bias tool (RoB 2.0). Data were analyzed using Review Manager version 5.4 (Cochrane Collaboration, Oxford, England), and the meta-analysis was performed in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. RESULTS: Of 2168 articles, 10 trials were reviewed; among these trials, two focused on respiratory training and eight on physical exercise, three of which involved a combination of aerobic and resistance training. Our meta-analysis demonstrated no difference in the ALSFRS-R score and % FVC among patients with ALS. CONCLUSIONS: Respiratory training or physical exercise did not significantly affect the ALSFRS-R score and % FVC of patients with ALS. At 12 months after intervention, the ALSFRS-R score in the physical exercise group was higher than that in the usual care group. Further clinical trials are warranted to develop approaches for improving the lung function of patients with ALS.

Inspiratory muscle training in neuromuscular patients: Assessing the benefits of a novel protocol.

BACKGROUND: Neuromuscular diseases are characterized by the compromise of respiratory muscles, thoracic ventilation, muscle strength and coughing capacity. Patients have low quality of life and increased morbidity and mortality mostly due to respiratory impairment. OBJECTIVE: To assess the benefits of adding inspiratory muscle training to neuromuscular patients' treatment and their compliance to the approach. METHODS: We conducted a single-center prospective study with neuromuscular patients with decreased maximal inspiratory pressure. We developed an inspiratory muscle training protocol with three-month duration and once-daily training. The protocol had a progressive intensity that was individually tailored based on patients' baseline characteristics and tolerance. We used Powerbreathe Medic Classic devices to perform the training. RESULTS: There were 21 patients who met the inclusion criteria and were enrolled in the study. Muscular dystrophy (n= 12, 57.3%) and amyotrophic lateral sclerosis (n= 4, 19%) were the most common diseases. After three months of training, patients increased their maximal inspiratory muscle pressure (p= 0.002) and peak cough flow (p= 0.011). Compliance to the protocol was 99 ± 5.5%. CONCLUSIONS: This protocol showed significant improvements on pulmonary muscles function and might be considered as an adjunct treatment to neuromuscular treatment. However, these positive results require larger further studies to validate the clinical benefits long-term.

Interaction symmetry: Assessing augmented speaker and oral speaker performances across four tasks.

This investigation examined the impact of speech-generating devices (SGDs) on the interaction dynamics (i.e., symmetry) of augmented speakers and their conversation partners while performing several interaction tasks. This study involved 20 dyads: 10 in which one individual had ALS and primarily used an SGD for communication while the other participant primarily used speech (AS group); and 10 in a control group comprised of individuals who used speech as a primary means of communication (OS group). Interactions between participants in the AS group were compared across four tasks (i.e., map, retell, sequencing, and personal narrative). These results were also compared to performances of participants in the OS group performing the same tasks. Task completion times, talk times, contribution types (i.e., main/repair), and contribution functions (i.e., presentation/acceptance) were used to index symmetry performance patterns across tasks for the 20 dyads. Within- and between-group comparisons were significant in differentiating the two groups in terms of the ways in which they were able to adapt to different interaction task dynamics. Findings suggest symmetry is a useful metric for identifying the constraining influence of carrying out in-person interactions with an SGD.

The current state of electrocorticography-based brain-computer interfaces.

Brain-computer interfaces (BCIs) provide a way for the brain to interface directly with a computer. Many different brain signals can be used to control a device, varying in ease of recording, reliability, stability, temporal and spatial resolution, and noise. Electrocorticography (ECoG) electrodes provide a highly reliable signal from the human brain surface, and these signals have been used to decode movements, vision, and speech. ECoG-based BCIs are being developed to provide increased options for treatment and assistive devices for patients who have functional limitations. Decoding ECoG signals in real time provides direct feedback to the patient and can be used to control a cursor on a computer or an exoskeleton. In this review, the authors describe the current state of ECoG-based BCIs that are approaching clinical viability for restoring lost communication and motor function in patients with amyotrophic lateral sclerosis or tetraplegia. These studies provide a proof of principle and the possibility that ECoG-based BCI technology may also be useful in the future for assisting in the cortical rehabilitation of patients who have suffered a stroke.

Auditory Electrooculogram-based Communication System for ALS Patients in Transition from Locked-in to Complete Locked-in State.

Patients in the transition from locked-in (i.e., a state of almost complete paralysis with voluntary eye movement control, eye blinks or twitches of face muscles, and preserved consciousness) to complete locked-in state (i.e., total paralysis including paralysis of eye-muscles and loss of gaze-fixation, combined with preserved consciousness) are left without any means of communication. An auditory communication system based on electrooculogram (EOG) was developed to enable such patients to communicate. Four amyotrophic lateral sclerosis patients in transition from locked-in state to completely locked-in state, with ALSFRS-R score of 0, unable to use eye trackers for communication, learned to use an auditory EOG-based communication system. The patients, with eye-movement amplitude between the range of ±200µV and ±40µV, were able to form complete sentences and communicate independently and freely, selecting letters from an auditory speller system. A follow-up of one year with one patient shows the feasibility of the proposed system in long-term use and the correlation between speller performance and eye-movement decay. The results of the auditory speller system have the potential to provide a means of communication to patient populations without gaze fixation ability and with low eye-movement amplitude range.

Brain-computer interfaces for amyotrophic lateral sclerosis.

A brain-computer interface (BCI) is a device that detects signals from the brain and transforms them into useful commands. Researchers have developed BCIs that utilize different kinds of brain signals. These different BCI systems have differing characteristics, such as the amount of training required and the degree to which they are or are not invasive. Much of the research on BCIs to date has involved healthy individuals and evaluation of classification algorithms. Some BCIs have been shown to have potential benefit for users with minimal muscular function as a result of amyotrophic lateral sclerosis. However, there are still several challenges that need to be successfully addressed before BCIs can be clinically useful.

Quality of life and functional independence in amyotrophic lateral sclerosis: A systematic review.

Amyotrophic Lateral Sclerosis (ALS) leads to functional capacity decline, generating great impact in quality of life. Quality of life is directly related to physical integrity and functional independence. This systematic review aimed to analyze treatment protocols and their outcomes from clinical trials with focus on ALS rehabilitation that evaluated the effects on quality of life and functional independence from their intervention process. A literature search was conducted through MEDLINE-PubMed, Science Direct, Web of Science and Scopus databases. A total of 3630 articles were identified. Eleven studies met the inclusion criteria. They focused on different aspects of quality of life or functional independence, which are: respiratory care, mental health, communication skills and exercises. Use of bipap and inspiratory muscle training, anxiety and depression, communication devices implementation and exercises safety and tolerability were considered as key points. However, the drastic evolution of the disease is a limiting factor to the perception of quality of life improvement by patients. Further studies should be done to validate the benefits on patients' quality of life.

Optimized artificial neural network based performance analysis of wheelchair movement for ALS patients.

Individuals with neurodegenerative attacks loose the entire motor neuron movements. These conditions affect the individual actions like walking, speaking impairment and totally make the person in to locked in state (LIS). To overcome the miserable condition the person need rehabilitation devices through a Brain Computer Interfaces (BCI) to satisfy their needs. BMI using Electroencephalogram (EEG) receives the mental thoughts from brain and converts into control signals to activate the exterior communication appliances in the absence of biological channels. To design the BCI, we conduct our study with three normal male subjects, three normal female subjects and three ALS affected individuals from the age of 20-60 with three electrode systems for four tasks. One Dimensional Local Binary Patterns (LBP) technique was applied to reduce the digitally sampled features collected from nine subjects was treated with Grey wolf optimization Neural Network (GWONN) to classify the mentally composed words. Using these techniques, we compared the three types of subjects to identify the performances. The study proves that subjects from normal male categories performance was maximum compared with the other subjects. To assess the individual performance of the subject, we conducted the recognition accuracy test in offline mode. From the accuracy test also, we obtained the best performance from the normal male subjects compared with female and ALS subjects with an accuracy of 98.33 %, 95.00 % and 88.33 %. Finally our study concludes that patients with ALS attack need more training than that of the other subjects.

Posteroanterior cervical transcutaneous spinal stimulation targets ventral and dorsal nerve roots.

OBJECTIVE: We aim to non-invasively facilitate activation of spared neural circuits after cervical spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS). We developed and tested a novel configuration for cervical transcutaneous spinal stimulation (cTSS). METHODS: cTSS was delivered via electrodes placed over the midline at ~T2-T4 levels posteriorly and ~C4-C5 levels anteriorly. Electromyographic responses were measured in arm and hand muscles across a range of stimulus intensities. Double-pulse experiments were performed to assess homosynaptic post-activation depression (PAD). Safety was closely monitored. RESULTS: More than 170 cTSS sessions were conducted without major safety or tolerability issues. A cathode-posterior, 2 ms biphasic waveform provided optimal stimulation characteristics. Bilateral upper extremity muscle responses were easily obtained in subjects with SCI and ALS. Resting motor threshold at the abductor pollicis brevis muscle ranged from 5.5 to 51.0 mA. As stimulus intensity increased, response latencies to all muscles decreased. PAD was incomplete at lower stimulus intensities, and decreased at higher stimulus intensities. CONCLUSIONS: Posteroanterior cTSS has the capability to target motor neurons both trans-synaptically via large-diameter afferents and non-synaptically via efferent motor axons. SIGNIFICANCE: Posteroanterior cTSS is well tolerated and easily activates upper extremity muscles in individuals with SCI and ALS.

Remotely supervised transcranial direct current stimulation: A feasibility study for amyotrophic lateral sclerosis.

BACKGROUND: Transcranial direct current stimulation (tDCS) has been investigated as a therapeutic neuromodulation tool in several neurological disorders. However, evidence supporting its efficacy in disorders such as amyotrophic lateral sclerosis (ALS) is limited possibly due to limited patient accessibility for research, particularly for individuals with advanced disease progression. Telerehabilitation using home-based protocols allows for remote supervision of tDCS over longer durations, thereby increasing participation, compliance and adherence. In this study, we explored the safety, feasibility and preliminary effects of a remotely supervised tDCS (RS-tDCS) protocol in ALS. MATERIAL AND METHODS: In this pre-post case series study, two individuals with ALS completed 24 remotely supervised anodal tDCS sessions (20 minutes, 2 mA). Outcomes included adherence, compliance, disease progression, walking speed, risk of fall, endurance, fatigue and depression. RESULTS: Both participants successfully completed the study without any major adverse effects. Minor side effects included mild sensations of itching and throbbing under the electrodes during stimulation. Clinical outcomes showed minimal to no change for any of the measures. CONCLUSIONS: Preliminary findings suggest that the RS-tDCS protocol is safe and feasible in individuals with ALS. Our protocol serves as a model for future long-term studies to evaluate the clinical and neurophysiological effects of tDCS using a telerehabilitation protocol in ALS.

Eye-controlled, power wheelchair performs well for ALS patients.

BACKGROUND: Our pilot study tested the feasibility and performance of an eye-controlled power wheelchair for amyotrophic lateral sclerosis (ALS) patients. METHODS: In this prospective pilot study, participants drove the wheelchair three times around an indoor course. We assessed the time to complete the course; starting and stopping on command; turning 90, 135, and 180 degrees; time to backup; and obstacle negotiation. Following their use of the wheelchair, subjects were given a questionnaire to assess user experience. RESULTS: Twelve patients participated, and all were able to complete three trials without difficulty. Eight participants completed all of the individual tasks (eg, turning, stopping, etc.) without any errors. Overall performance ratings were high across all participants (4.6/5-excellent). CONCLUSIONS: Our eye-controlled power wheelchair prototype is feasible and has a very favorable user experience. This system has the potential to improve the mobility and independence of ALS patients, and other groups with motor impairments.

Intentions of Canadian health professionals towards recommending exercise for people living with ALS.

BACKGROUND: To provide a nationwide overview of the attitudes, social pressure, perceived ability and intentions of health professionals toward exercise prescription for people living with ALS (pALS). METHODS: An online survey of physician and non-physician health professionals (HPs) working in academic ALS clinics across Canada. RESULTS: The response rate was 48% (84/176) with 30% of respondents identifying as physicians, 63% as other HPs and the remainder as administrative or research personnel. Respondents were sharply divided in their intentions to provide exercise counsel: 24% unlikely and 45% likely. Respondents with low intentions were HPs that considered this activity outside their scope of practice. Measures of intention and attitude were more positive for flexibility compared to strength and aerobic exercise. Perceptions of social pressure and ability to provide exercise counsel were significantly correlated with intention across the three exercise modes in all respondents. Qualitative themes identified as barriers to exercise prescription were lack of confidence or competence (31% physicians, 32% HP), patient tolerance (30% HP), lack of evidence (22% physicians) and lack of infrastructure (22% physicians). CONCLUSIONS: While "lack of evidence" for the benefit of exercise was a deterrent for physicians, the larger issue for all respondents was building competence and confidence in exercise prescription for pALS.

Botulinum Toxin Type A and Physiotherapy in Spasticity of the Lower Limbs Due to Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease (unknown pathogenesis) of the central nervous system that causes death within 1-5 years. Clinically, flabby paralysis, areflexia, muscular atrophy, and muscle fasciculations, signs of II motor neuron damage, appear. Sometimes, clinical manifestations of damage of the I motor neuron come out in lower limbs; spastic paralysis, iperflexia, and clonus emerge, and they impair deambulation and management of activities of daily living, such as personal hygiene or dressing. Thus, the first therapeutic approach in these patients involves antispasmodic drugs orally followed by botulinum toxin type A injection (BTX-A). In this study, we study the efficacy of BTX-A and physiotherapy in lower limb spasticity due to ALS and no response to treatment with oral antispastic drugs. We evaluated 15 patients (10 male and five female), with a mean age of 48.06 ± 5.2 with spasticity of adductor magnus (AM), at baseline (T0, before BTX-A treatment) and in the following three follow-up visits (T1 30 days, T2 60 days, and T3 90 days after infiltration). We evaluated myometric measure of muscle tone, the Modified Ashworth Scale of AM, Barthel Index, Adductor Tone Rating Scale, and Hygiene Score. The study was conducted between November 2018 and April 2019. We treated AM with incobotulinum toxin type A (Xeomin®, Merz). Spasticity (myometric measurement, Adductor Tone Rating Scale, and Modified Ashworth Scale) and clinical (Barthel Index and Hygiene Score) improvements were obtained for 90 days after injection (p < 0.05). Our study shows the possibility of using BTX-A in the treatment of spasticity in patients with ALS and no response to oral antispastic drugs, with no side effects. The limitation of the study is the small number of patients and the limited time of observation; therefore, it is important to increase both the number of patients and the observation time in future studies.

Electrooculograms for Human-Computer Interaction: A Review.

Eye movements generate electric signals, which a user can employ to control his/her environment and communicate with others. This paper presents a review of previous studies on such electric signals, that is, electrooculograms (EOGs), from the perspective of human-computer interaction (HCI). EOGs represent one of the easiest means to estimate eye movements by using a low-cost device, and have been often considered and utilized for HCI applications, such as to facilitate typing on a virtual keyboard, moving a mouse, or controlling a wheelchair. The objective of this study is to summarize the experimental procedures of previous studies and provide a guide for researchers interested in this field. In this work the basic characteristics of EOGs, associated measurements, and signal processing and pattern recognition algorithms are briefly reviewed, and various applications reported in the existing literature are listed. It is expected that EOGs will be a useful source of communication in virtual reality environments, and can act as a valuable communication tools for people with amyotrophic lateral sclerosis.

Titration of Mechanical Insufflation-Exsufflation Optimal Pressure Combinations in Neuromuscular Diseases by Flow/Pressure Waveform Analysis / Titulación de las combinaciones de presión óptima de insuflación-exuflación mecánica en las enfermedades neuromusculares mediante análisis de la onda de fujo/presión

Introduction: The aim of this study was to assess several air-pressure settings for MI-E to determine their effect on peak cough flow (PCF), and to compare the best pressures with those are more common used in the literature (±40cmH2O) in patients with neuromuscular disorders (NMD). Methods: Adults with NMD in whom MI-E was indicated were recruited. Assisted PCF was measured by an external pneumotachograph. The protocol included 9 PCF measures per patient: 1 baseline (non-assisted), 4 with increasing inspiratory pressures without negative pressure (10, 20, 30 and 40cmH2O or maximum tolerated), and then 4 adding expiratory pressures (-10, -20, -30 and -40cm H2O or maximum tolerated) with maximum inspiratory pressure previously achieved. Results: Twenty one patients were included, 61% with amyotrophic lateral sclerosis (ALS). Mean PCFs with recommended pressures (± 40 cmH2O) were lower than the scored in the individualized steps of the titration protocol (197.7 ± 67l/min vs 214.2 ± 60 l/min, p < 0.05). Regarding subgroups, mean PCFmax values in ALS patients with bulbar symptoms were significantly higher than those achieved with recommended pressures (163.6 ± 80 vs 189 ± 66l/min, p < 0.05). Conclusion: The PCFmax obtained with the protocol did not always match the recommended settings. It may be advisable to perform MI-E titration assessed by non-invasive PCF monitoring in patients with NMD, especially in ALS with bulbar involvement to improve the therapy detecting airway collapse induced by high pressures

Introducción: El objetivo del estudio fue evaluar varios ajustes de presión para insuflación-exuflación mecánica (IEM) para determinar su efecto sobre el flujo pico de tos (FPT), y comparar las mejores presiones con aquellas que son habitualmente utilizadas en la literatura (± 40 cmH2O) en pacientes con enfermedades neuromusculares (ENM). Métodos: Se reclutaron adultos con ENM en los que se indicó IEM. Se midió el FPT asistido mediante un neumotacógrafo externo, y se registraron las curvas de presión y flujo/tiempo. El protocolo incluía 9 medidas de FPT por paciente: una basal (no asistida), 4 con presiones inspiratorias crecientes sin presión negativa (10, 20, 30 y 40 cmH2O o máximo tolerado), y luego 4 presiones espiratorias (-10, -20, -30, -40 cmH2O o máxima tolerada) con la presión inspiratoria máxima conseguida. Resultados: Se incluyeron 21 pacientes, 61% con esclerosis lateral amiotrófica (ELA). Las altas presiones (>±35 cmH2O) lograron el mejor FPT solo en el 50% de los sujetos. Los FPT medios con presiones recomendadas de ± 40 cmH2O (197,7 ± 67 l/min) fueron más bajos que los conseguidos con presiones de titulación individualizadas con el protocolo (214,2 ± 60 l/min, p < 0,05). Con respecto a los subgrupos, los valores medios de FPT máximos en los pacientes con ELA con síntomas bulbares fueron significativamente mayores que los logrados con las presiones recomendadas (163,6±80 frente a 189 ± 66 l/min p < 0,05). Conclusión: El FPT máximo obtenido con el protocolo no siempre coincide con las presiones más altas. Puede ser aconsejable realizar una valoración de IEM evaluada mediante monitorización no invasiva de FPT en pacientes con ENM, especialmente en ELA con afectación bulbar, para mejorar la terapia que detecta el colapso de la vía aérea inducida por altas presiones

Variation in assistive technology use in Motor Neuron Disease according to clinical phenotypes and ALS Functional Rating Scale - Revised Score: A prospective observational study.

BACKGROUND: Assistive devices enhance independence and quality of life for people living with motor neuron disease (MND), but prescription can be challenging. OBJECTIVE: Improved prescription of assistive devices, through improved understanding of the relationship between clinical phenotypes, Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised (ALSFRS-R) functional domain sub-scores and assistive technology required by people living with MND. METHODS: Prospective, observational consecutive-sample study of 269 patients with MND diagnosis. MAIN OUTCOME MEASURES: MND phenotype, ALSFRS-R scores and assistive technology devices in use. RESULTS: A statistically significant difference in total concurrent assistive technology item use was found between phenotypes (p = 0.001), with those with ALS Bulbar onset using the least. There was also a statistically significant difference in assistive technology usage in five of seven assistive technology categories across the clinical phenotypes, namely orthoses (p < 0.000), mobility devices (p < 0.000), transfer devices (p < 0.000), communication devices (p < 0.000), and activities of daily living devices (p = 0.016). Correlations between ALSFRS-R sub-score items and assistive technology count confirmed the utility of this outcome measure for equipment prescription. CONCLUSIONS: Clinicians need to consider MND phenotype and/or ALSFRS-R domain sub-score in clinical decision-making regarding assistive technology, as this will determine the pattern of disease and its progression, and hence assistive technology required.

Provisional best practices guidelines for the evaluation of bulbar dysfunction in amyotrophic lateral sclerosis.

INTRODUCTION: Universally established comprehensive clinical bulbar scales objectively assessing disease progression in amyotrophic lateral sclerosis (ALS) are currently lacking. The goal of this working group project is to design a best practice set of provisional bulbar ALS guidelines, available for immediate implementation within all ALS clinics. METHODS: ALS specialists across multiple related disciplines participated in a series of clinical bulbar symposia, intending to identify and summarize the currently accepted best practices for the assessment and management of bulbar dysfunction in ALS Results: Summary group recommendations for individual speech, Augmentative and Alternative Communication (AAC), and swallowing sections were achieved, focusing on the optimal proposed level of care within each domain. DISCUSSION: We have identified specific clinical recommendations for each of the 3 domains of bulbar functioning, available for incorporation within all ALS clinics. Future directions will be to establish a formal set of bulbar guidelines through a methodological and evidence-based approach. Muscle Nerve 59:531-531, 2019.