The role of cognitive reserve in traumatic brain injury: a systematic review of observational studies.

OBJECTIVE: Evaluate the role of cognitive reserve (CR) on cognitive and physical sequelae in traumatic brain injury (TBI). METHODS: A comprehensive search strategy was conducted in four databases in English and Spanish in the last 12 years (2011-2023). Inclusion criteria: original cross-sectional and longitudinal studies whose main or secondary objective was to evaluate the effect of CR in adult patients with TBI. PRISMA guidelines were used to report the search and selection method and STROBE checklist was used to evaluate the quality of studies. RESULTS: Eighteen observational studies were included in this review. Multiple sources of variability were observed: number of patients, time of evolution, severity of the TBI, type of CR proxy, cognitive assessment instrument, etc. However, the most commonly used indicators of CR were premorbid IQ and educational attainment. A positive and consistent association between CR and performance on cognitive tests after injury was found. CONCLUSIONS: CR has a consistent positive effect on cognition and on some other aspects of recovery in traumatic brain injury. In future studies, it will be necessary to promote the use of CR indices based on various indicators and explore the effects of CR on other aspects related to the recovery of brain trauma.

Crosstalk between Exercise-Derived Endocannabinoidome and Kynurenines: Potential Target Therapies for Obesity and Depression Symptoms.

The kynurenine pathway (KP) and the endocannabinoid system (ECS) are known to be deregulated in depression and obesity; however, it has been recognized that acute physical exercise has an important modulating role inducing changes in the mobilization of their respective metabolites-endocannabinoids (eCBs) and kynurenines (KYNs)-which overlap at some points, acting as important antidepressant, anti-nociceptive, anti-inflammatory, and antioxidant biomarkers. Therefore, the aim of this review is to analyze and discuss some recently performed studies to investigate the potential interactions between both systems, particularly those related to exercise-derived endocannabinoidome and kynurenine mechanisms, and to elucidate how prescription of physical exercise could represent a new approach for the clinical management of these two conditions.

Education Level Modulates the Presence of Poststroke Depression and Anxiety, But It Depends on Age.

ABSTRACT: Depression and anxiety are common complications after stroke and little is known about the modulatory roles of education and age. Our study aimed to evaluate the modulatory effects of education level on anxiety and depression after stroke and their effect on each age group. Adults with first stroke took part in this cross-sectional observational clinical study. We used the following instruments: Hospital Anxiety and Depression Scale (HADS), Montreal Cognitive Scale, Pittsburgh Sleep Quality Index, Barthel index, and Functional Independence Measure. There were 89 patients. The mean (SD) age was 58.01 (13) years, mean (SD) years of education was 9.91 (5.22), 55.1% presented depression symptoms and 47.2% anxiety symptoms, 56.2% were young adults and 43.8% were older adults. We identified a negative association between education and anxiety score ( r = -0. 269, p = 0.011) and depression score ( r = -0.252, p = 0.017). In the linear regression analysis, we found that education is negatively associated with HADS, but this influence was more consistent in young adults. In conclusion, a higher education level reduces the risk of depression and anxiety, but their effect is less consistent in older adults.

Continuous versus discrete robotic feedback for brain-computer interfaces aimed for neurorehabilitation.

Introduction: Brain-Computer Interfaces (BCI) can allow control of external devices using motor imagery (MI) decoded from electroencephalography (EEG). Although BCI have a wide range of applications including neurorehabilitation, the low spatial resolution of EEG, coupled to the variability of cortical activations during MI, make control of BCI based on EEG a challenging task. Methods: An assessment of BCI control with different feedback timing strategies was performed. Two different feedback timing strategies were compared, comprised by passive hand movement provided by a robotic hand orthosis. One of the timing strategies, the continuous, involved the partial movement of the robot immediately after the recognition of each time segment in which hand MI was performed. The other feedback, the discrete, was comprised by the entire movement of the robot after the processing of the complete MI period. Eighteen healthy participants performed two sessions of BCI training and testing, one with each feedback. Results: Significantly higher BCI performance (65.4 ± 17.9% with the continuous and 62.1 ± 18.6% with the discrete feedback) and pronounced bilateral alpha and ipsilateral beta cortical activations were observed with the continuous feedback. Discussion: It was hypothesized that these effects, although heterogenous across participants, were caused by the enhancement of attentional and closed-loop somatosensory processes. This is important, since a continuous feedback timing could increase the number of BCI users that can control a MI-based system or enhance cortical activations associated with neuroplasticity, important for neurorehabilitation applications.

Alternative medicine therapies in neurological disorders: Prevalence, reasons and associated factors. A systematic review.

OBJECTIVE: This systematic review aimed to identify the prevalence of CAM use in patients with neurological disorders, and also to know most frequent types of CAM used. METHODS: Five databases: PubMed, Science Direct, EBSCO, Latindex and Scielo (in English and Spanish) were searched from January 2010 to May 2021. Only original cross-sectional, retrospective and cohort studies were included, whose primary objective was to describe the frequency of CAM use in neurological disorders and/or the related factors to its use in adults. Based on the data, a descriptive analysis was performed, covering the characteristics of studies, measuring methods, prevalence, types and related factors. To control the risk of bias, a quality assessment of each study was performed using STROBE checklist. RESULTS: For the final analysis, 40 studies were included. Most common pathologies observed in the studies were multiple sclerosis, headache, stroke, Parkinson and epilepsy. The STROBE score of studies ranged from 13 to 22 points, with an average of 18.2. Prevalence of CAM use was highly variable from one study to another (16% in stroke patients, to 100% in amyotrophic lateral sclerosis or spinal cord injury patients). Biological therapies (dietary supplements and herbal medicine) were the most commonly CAM types used. The associated factors identified were female sex, an age between 40 and 50 years, and higher socioeconomic level. Not all studies investigated about the results of CAMs but these ranged from 35% to more than 80% of reporting positive effects. CONCLUSIONS: The prevalence of CAM use in neurological diseases is highly variable (16%-100%); the most used type of CAM was biological therapies and the associated factors were female sex, age between 40 and 50 years old and high socioeconomic level.

Intoxicación por metanol por consumo de bebidas alcohólicas adulteradas. Efectos en el sistema nervioso. Reporte de un caso / Methanol Poisoning by Consumption of Adulterated Alcoholic Beverages. Effects on the Nervous System. A Case Report

Resumen La intoxicación por metanol puede ocurrir de forma inadvertida por la ingesta de bebidas alcohólicas adulteradas. Se trata una entidad poco frecuente, sin embargo, se ha reportado un aumento en la incidencia durante la pandemia de COVID-19. La intoxicación con metanol representa una urgencia médica, ya que puede provocar daño severo en el sistema nervioso central y periférico, además de acidosis metabólica, daño renal agudo e incluso la muerte. En este artículo se presenta el caso de un paciente que cursó con intoxicación por metanol de manera inadvertida al consumir bebidas alcohólicas presumiblemente adulteradas. En el encéfalo se demostró necrosis hemorrágica de ambos núcleos putamen, además de cursar con neuritis óptica bilateral y polineuropatía periférica. Fue manejado con pulsos de esteroides intravenosos, con lo cual, mejoró significativamente su función visual, sensitiva y motora. En el presente caso no existieron complicaciones fatales y presentó una buena respuesta al tratamiento, sin embargo, el caso pone de relieve la necesidad de una mejor regulación en la producción y comercialización de bebidas alcohólicas en nuestro país, y, por otro lado, permite hacer a un llamado a los consumidores a tomar más precauciones en el consumo de bebidas alcohólicas de dudosa calidad o procedencia.

Abstract Methanol poisoning can occur unnoticed, by the ingestion of adulterated alcoholic beverages. In general, it is a rare entity, however, an increase in incidence has been reported during the SARS-CoV-2 pandemic. Methanol poisoning represents a medical emergency as it can cause severe damage to the central and peripheral nervous systems, as well as metabolic acidosis, acute kidney injury, and even death. This article presents the case of a patient who inadvertently developed methanol intoxication after consuming presumably adulterated alcoholic beverages. In the brain, hemorrhagic necrosis of both putamen nuclei was demonstrated, in addition to presenting with bilateral optic neuritis and peripheral polyneuropathy. He was managed with intravenous steroid pulses, which significantly improved his visual, sensory, and motor function. In the present case there were no fatal complications and presented a good response to treatment, however, the case highlights the need for better regulation in the production and marketing of alcoholic beverages in our country, and on the other hand, to invite consumers to take more precautions in the consumption of alcoholic beverages of dubious quality or origin.

Alternative and complementary medicine in neurological disorders and neurological disability patients: Prevalence, factors, opinions and reasons.

OBJECTIVES: This cross-sectional study is aimed to investigate the prevalence of the use of complementary and alternative medicine (CAM), types of CAMs used, as well as reasons and factors found in patients with neurological diseases or neurological disability. METHODS: An anonymous, self-administered survey was designed to collect information about demographics, personal medical history, CAM usage habits, and different opinions about CAM vs. conventional medicine (CM). The survey was applied by non-medical personnel in a rehabilitation hospital to patients older than 18 years, with a confirmed diagnosis of neurological disorder or neurological disability. RESULTS: 453 patients were included, 59.7 % were female. Mean age: 49 years (SD: 18.2). 200 patients (44.2 %) had a history of chronic diseases. Depression was found in 139 patients (30.7 %). Neurological disorders were: peripheral neuropathy: 97 (21.4 %), headache or migraine: 78 (17.2 %), neurodegenerative diseases: 69 (15.2 %) and stroke: 58 (12.8 %). 60.2 % (n = 273) had some degree of disability. Prevalence of CAM use was 36 % (n = 163). Most common CAMs were: Biological therapies: 133 (71.1 %), energy-based therapies: 63 (33.7 %) and body manipulation therapies: 51 (27.3 %). Reasons to use CAM were: "to complement the pharmacological treatment" (45 = 27.6 %), and "treatment failure with CM" (43 = 26.4 %). Finally, older age (p = 0.0280) and having a chronic disease (p = 0.0229) or depression (p < 0.001) were the factors associated with the current use of CAM. CONCLUSION: One third of patients with neurological pathologies use CAM, the most popular type of CAM is biologic therapies. As in other pathologies, CAM use was associated with older age, history of depression, and chronic diseases. Therefore, it is suggested that physicians routinely ask patients about the use of CAM, if they need more information about CAM, and even verify the possibility of drug interactions or adverse effects.

Comparative Efficacy of Botulinum Toxin in Salivary Glands vs. Oromotor Therapy in the Management of Sialorrhea in Cerebral Palsy Impact on Sleep Quality.

Aims: The aim of this study was to compare the effects of intraglandular abobotuliniumtoxinA application and oromotor therapy in the management of sialorrhea in patients with cerebral palsy and its effect on sleep quality. Methods: A comparative study (n = 134), mean age 7.1 years (± 3.9 years) was performed in pediatric patients, between the efficacy of abobotuliniumtoxinA in salivary glands and oromotor therapy (JT), with a control group receiving exclusive oromotor therapy (EOMT). Demographic variables, as well as Gross Motor Function Classification System (GMFCS), Drooling Severity and Frequency Scale (DSFS), Sleep Disturbance Scale for Children (SDSC) and Eating and Drinking Ability Classification System (EDACS) were analyzed in 134 patients considering two measurements 6 months apart. Statistical analysis was developed between both groups. Results: The greatest improvement in safety and efficacy of swallowing were those in the JT group with initial levels of EDACS IV and V. Both therapies result in favorable changes of all subscales means of SDSC, with joint therapy showing the greater benefit (p = 0.003) over EOMT (p = 0.06), especially for Sleep Breathing Disorders and Disorders of initiating and maintaining sleep (p < 0.01 vs. p = 0.07). No major adverse effects were found, only those expected from the application of the toxin, such as pain, mild, and transient local inflammation. Interpretation: A correlation between frequency and intensity of sialorrhea, with the frequency of sleep disorders and dysphagia was found. Conventional EOMT proved to be useful, improving the safety and efficacy of swallowing, sialorrhea and sleep disorder, however it can be enhanced with the application of abobotuliniumtoxinA.

Role of the Dopaminergic System in the Striatum and Its Association With Functional Recovery or Rehabilitation After Brain Injury.

Disabilities are estimated to occur in approximately 2% of survivors of traumatic brain injury (TBI) worldwide, and disability may persist even decades after brain injury. Facilitation or modulation of functional recovery is an important goal of rehabilitation in all patients who survive severe TBI. However, this recovery tends to vary among patients because it is affected by the biological and physical characteristics of the patients; the types, doses, and application regimens of the drugs used; and clinical indications. In clinical practice, diverse dopaminergic drugs with various dosing and application procedures are used for TBI. Previous studies have shown that dopamine (DA) neurotransmission is disrupted following moderate to severe TBI and have reported beneficial effects of drugs that affect the dopaminergic system. However, the mechanisms of action of dopaminergic drugs have not been completely clarified, partly because dopaminergic receptor activation can lead to restoration of the pathway of the corticobasal ganglia after injury in brain structures with high densities of these receptors. This review aims to provide an overview of the functionality of the dopaminergic system in the striatum and its roles in functional recovery or rehabilitation after TBI.

Brain-Computer Interface Coupled to a Robotic Hand Orthosis for Stroke Patients' Neurorehabilitation: A Crossover Feasibility Study.

Brain-Computer Interfaces (BCI) coupled to robotic assistive devices have shown promise for the rehabilitation of stroke patients. However, little has been reported that compares the clinical and physiological effects of a BCI intervention for upper limb stroke rehabilitation with those of conventional therapy. This study assesses the feasibility of an intervention with a BCI based on electroencephalography (EEG) coupled to a robotic hand orthosis for upper limb stroke rehabilitation and compares its outcomes to conventional therapy. Seven subacute and three chronic stroke patients (M = 59.9 ± 12.8) with severe upper limb impairment were recruited in a crossover feasibility study to receive 1 month of BCI therapy and 1 month of conventional therapy in random order. The outcome measures were comprised of: Fugl-Meyer Assessment of the Upper Extremity (FMA-UE), Action Research Arm Test (ARAT), motor evoked potentials elicited by transcranial magnetic stimulation (TMS), hand dynamometry, and EEG. Additionally, BCI performance and user experience were measured. All measurements were acquired before and after each intervention. FMA-UE and ARAT after BCI (23.1 ± 16; 8.4 ± 10) and after conventional therapy (21.9 ± 15; 8.7 ± 11) were significantly higher (p < 0.017) compared to baseline (17.5 ± 15; 4.3 ± 6) but were similar between therapies (p > 0.017). Via TMS, corticospinal tract integrity could be assessed in the affected hemisphere of three patients at baseline, in five after BCI, and four after conventional therapy. While no significant difference (p > 0.05) was found in patients' affected hand strength, it was higher after the BCI therapy. EEG cortical activations were significantly higher over motor and non-motor regions after both therapies (p < 0.017). System performance increased across BCI sessions, from 54 (50, 70%) to 72% (56, 83%). Patients reported moderate mental workloads and excellent usability with the BCI. Outcome measurements implied that a BCI intervention using a robotic hand orthosis as feedback has the potential to elicit neuroplasticity-related mechanisms, similar to those observed during conventional therapy, even in a group of severely impaired stroke patients. Therefore, the proposed BCI system could be a suitable therapy option and will be further assessed in clinical trials.

Prognosis of stroke upper limb recovery with physiological variables using regression tree ensembles.

Objective.This study assesses upper limb recovery prognosis after stroke with solely physiological information, which can provide an objective estimation of recovery.Approach.Clinical recovery was forecasted using EEG-derived Event-Related Desynchronization/Synchronization and coherence, in addition to Transcranial Magnetic Stimulation elicited motor-evoked potentials and upper limb grip and pinch strength. A Regression Tree Ensemble predicted clinical recovery of a stroke database (n= 10) measured after a two-month intervention with the Fugl-Meyer Assessment for the Upper Extremity (FMA-UE) and the Action Research Arm Test (ARAT).Main results.There were no significant differences between predicted and actual outcomes with FMA-UE (p= 0.29) and ARAT (p= 0.5). Median prediction error for FMA-UE and ARAT were of 0.3 (IQR = 6.2) and 3.4 (IQR = 9.4) points, respectively. Predictions with the most pronounced errors were due to an underestimation of high upper limb recovery. The best features for FMA-UE prediction included mostly beta activity over the sensorimotor cortex. Best ARAT prediction features were cortical beta activity, corticospinal tract integrity of the unaffected hemisphere, and upper limb strength.Significance.Results highlighted the importance of measuring cortical activity related to motor control processes, the unaffected hemisphere's integrity, and upper limb strength for prognosis. It was also implied that stroke upper limb recovery prediction is feasible using solely physiological variables with a Regression Tree Ensemble, which can also be used to analyze physiological relationships with recovery.

Cognitive Impairment Induced by Lead Exposure during Lifespan: Mechanisms of Lead Neurotoxicity.

Lead (Pb) is considered a strong environmental toxin with human health repercussions. Due to its widespread use and the number of people potentially exposed to different sources of this heavy metal, Pb intoxication is recognized as a public health problem in many countries. Exposure to Pb can occur through ingestion, inhalation, dermal, and transplacental routes. The magnitude of its effects depends on several toxicity conditions: lead speciation, doses, time, and age of exposure, among others. It has been demonstrated that Pb exposure induces stronger effects during early life. The central nervous system is especially vulnerable to Pb toxicity; Pb exposure is linked to cognitive impairment, executive function alterations, abnormal social behavior, and fine motor control perturbations. This review aims to provide a general view of the cognitive consequences associated with Pb exposure during early life as well as during adulthood. Additionally, it describes the neurotoxic mechanisms associated with cognitive impairment induced by Pb, which include neurochemical, molecular, and morphological changes that jointly could have a synergic effect on the cognitive performance.

Cambios fisiológicos durante el embarazo normal / Physiological Changes During a Normal Pregnancy

Resumen: El organismo de la mujer experimenta una serie de cambios fisiológicos, a todos niveles, que tienen la finalidad de adaptarse y dar respuesta a la gran demanda que representan las 40 semanas de gestación que durará la formación un nuevo ser humano en su interior. Dichos cambios ocurren de manera gradual, pero continua, a lo largo de todo el embarazo y van desde cambios cardiovasculares, digestivos, pulmonares, hematológicos y endocrinos, los cuales al final también terminan por revertirse de manera paulatina durante el puerperio. Los cambios fisiológicos se relacionan con el desarrollo de distintos síntomas, signos y alteraciones en la mujer embarazada, así como cambios en los parámetros de los estudios paraclínicos, lo cual hace que resulte especialmente relevante que el médico general o de primer contacto esté familiarizado con estos cambios y el momento en el que ocurren en el embarazo, para que pueda realizar una oportuna identificación de las alteraciones que pueden representar estados patológicos que resulten una amenaza para el bienestar materno y fetal. Por todo lo anterior, el objetivo de la presente revisión temática fue recopilar y describir los principales cambios fisiológicos que ocurren en la mujer durante el embarazo normal, así como los cambios que se presentan en los estudios paraclínicos más comunes.

Abstract: The woman's body undergoes a series of physiological changes at all levels that hace the purpose of adapting and responding to the the 40 weeks of gestation. These changes occur gradually, but in a continuously, throughout the pregnancy and range from cardiovascular, digestive, pulmonary, hematological and endocrine changes, which at the end also end up gradually reversing during the puerperium. The physiological changes are related to the development of different symptoms, signs and alterations in the pregnant woman, as well as changes in the parameters of the paraclinical studies, which makes it especially relevant for the general practitioner or first contact doctor to recognize these changes and the moment in which they occur in pregnancy so that they can make a timely identification of the alterations that can represent pathological states that are a threat to maternal and fetal well-being. For all of the above, the objective of this thematic review was to collect and describe the main physiological changes that occur in women during a normal pregnancy, as well as the changes that occur in the most common paraclinical studies.

Automatic selection and feature extraction of motor-evoked potentials by transcranial magnetic stimulation in stroke patients.

Transcranial magnetic stimulation (TMS) allows the assessment of stroke patients' cortical excitability and corticospinal tract integrity, which provide information regarding motor function recovery. However, the extraction of features from motor-evoked potentials (MEP) elicited by TMS, such as amplitude and latency, is performed manually, increasing variability due to observer-dependent subjectivity. Therefore, an automatic methodology could improve MEP analysis, especially in stroke, which increases the difficulty of manual MEP measurements due to brain lesions. A methodology based on time-frequency features of stroke patients' MEPs that allows to automatically select and extract MEP amplitude and latency is proposed. The method was validated using manual measurements, performed by three experts, computed from patients' affected and unaffected hemispheres. Results showed a coincidence of 58.3 to 80% between automatic and manual MEP selection. There were no significant differences between the amplitudes and latencies computed by two of the experts with those obtained with the automatic method, for most comparisons. The median relative error of amplitudes and latencies computed by the automatic method was 5% and 23%, respectively. Therefore, the proposed method has the potential to reduce processing time and improve the computation of MEP features, by eliminating observer-dependent variability due to the subjectivity of manual measurements.

Serum Kynurenines Correlate With Depressive Symptoms and Disability in Poststroke Patients: A Cross-sectional Study.

BACKGROUND: Poststroke depression (PSD) is related to adverse functional and cognitive prognosis in stroke patients. The participation of kynurenine pathway metabolites in depression has been previously proposed; however, there are few studies on its role in PSD and disability in stroke. OBJECTIVE: To investigate if there is a correlation between serum kynurenines levels with poststroke anxiety and depression symptoms and disability scales. METHODS: A cross-sectional case-control study was conducted in patients with first stroke, of >1 month and <1 year of evolution, with no history of previous psychiatric or neurological disorders; the Hospital Anxiety and Depression Scale (HADS), Montreal Cognitive Assessment (MoCA), functional evaluations (Barthel index, Functional Independence Measure [FIM]) were applied and serum kynurenines (Kyns) were determined. RESULTS: Sixty patients were included; significant depressive symptoms were found in 63% of the cases; a significant and positive correlation was obtained between levels of 3-hydroxykynurenine (3-HK) with HADS-T (r = 0.30, P = .025) and HADS-D (r = 0.28, P = .039). Depressed patients showed significantly higher levels of 3HK (P = .048) and KYNA (P = .0271) than nondepressed patients; the 3HK levels were inversely correlated with functional scales: Barthel index (r = -0.31, P = .02), FIM (r = -0.40, P = .01); in addition, serum 3HK levels were significantly higher in patients with poor sleep quality (P = .0190). CONCLUSIONS: Serum Kyns show correlation with the presence and severity of depressive symptoms and with the disability and sleep quality. Kyns may be a potential marker of depression risk and disability in stroke in future.

Coexistence of Fragile-X Syndrome, 8p23.1 Deletion, and Balanced Translocation t(7;10)(p10;q24) in a Single Family.

Aims: Fragile-X syndrome (FXS) is the most common inherited form of intellectual disability; it is caused by an abnormal CGG-repeat expansion at the FMR1 gene. However, a few cases of girls with mutations in the FMR1 gene have been reported in the literature. In this study, we describe the clinical and genetic assessment of a family who exhibits the unusual coexistence of FXS, an 8p23.1 deletion, and balanced translocation t(7;10)(p10;q24) in multiple members, including a symptomatic girl with FXS. Materials and Methods: All of the family members underwent comprehensive clinical and neurological examinations. All members of the family were also molecularly diagnosed using a combination of fluorescent-polymerase chain reaction (PCR), Triplet Repeat Primed-PCR, capillary electrophoresis, and karyotyping. Results: We identified a male proband and a female patient that presented with the craniofacial characteristics of FXS, neuropsychomotor developmental delay, speech delay, intellectual deficit, and a positive molecular diagnosis of FXS. Interestingly, the female patient presented with a severe phenotype also associated with the presence of 8p23.1 deletion, while the proband patient presented a balanced translocation t(7;10)(p10;q24). Moreover, we detected multiple carriers of the FXS premutation in the family. Conclusions: To our knowledge, we describe for the first time the simultaneous occurrence of FXS and an 8p23.1 deletion and their possible synergistic effects on the phenotype of a female patient. Moreover, we describe the coexistence of FXS, an 8p23.1 deletion, and a balanced translocation t(7;10)(p10;q24) in the same family.

Brain-computer interface performance analysis of monozygotic twins with discordant hand dominance: A case study.

Brain-computer interfaces (BCI) decode user's intentions to control external devices. However, performance variations across individuals have limited their use to laboratory environments. Handedness could contribute to these variations, especially when motor imagery (MI) tasks are used for BCI control. To further understand how handedness affects BCI control, performance differences between two monozygotic twins were analysed during offline movement and MI tasks, and while twins controlled a BCI using right-hand MI. Quantitative electroencephalography (qEEG), brain structures' volumes, and neuropsychological tests were assessed to evaluate physiological, anatomical and psychological relationships with BCI performance. Results showed that both twins had good motor imagery and attention abilities, similar volumes on most subcortical brain structures, more pronounced event-related desynchronization elicited by the twin performing non-dominant MI, and that this twin also obtained significant higher performances with the BCI. Linear regression analysis implied a strong association between twins' BCI performance, and more pronounced cortical activations in the contralateral hemisphere relative to hand MI. Therefore, it is possible that BCI performance was related with the ability of each twin to elicit cortical activations during hand MI, and less associated with subcortical brain structures' volumes and neuropsychological tests.

Longitudinal Analysis of Stroke Patients' Brain Rhythms during an Intervention with a Brain-Computer Interface.

Stroke is a leading cause of motor disability worldwide. Upper limb rehabilitation is particularly challenging since approximately 35% of patients recover significant hand function after 6 months of the stroke's onset. Therefore, new therapies, especially those based on brain-computer interfaces (BCI) and robotic assistive devices, are currently under research. Electroencephalography (EEG) acquired brain rhythms in alpha and beta bands, during motor tasks, such as motor imagery/intention (MI), could provide insight of motor-related neural plasticity occurring during a BCI intervention. Hence, a longitudinal analysis of subacute stroke patients' brain rhythms during a BCI coupled to robotic device intervention was performed in this study. Data of 9 stroke patients were acquired across 12 sessions of the BCI intervention. Alpha and beta event-related desynchronization/synchronization (ERD/ERS) trends across sessions and their association with time since stroke onset and clinical upper extremity recovery were analyzed, using correlation and linear stepwise regression, respectively. More EEG channels presented significant ERD/ERS trends across sessions related with time since stroke onset, in beta, compared to alpha. Linear models implied a moderate relationship between alpha rhythms in frontal, temporal, and parietal areas with upper limb motor recovery and suggested a strong association between beta activity in frontal, central, and parietal regions with upper limb motor recovery. Higher association of beta with both time since stroke onset and upper limb motor recovery could be explained by beta relation with closed-loop communication between the sensorimotor cortex and the paralyzed upper limb, and alpha being probably more associated with motor learning mechanisms. The association between upper limb motor recovery and beta activations reinforces the hypothesis that broader regions of the cortex activate during movement tasks as a compensatory mechanism in stroke patients with severe motor impairment. Therefore, EEG across BCI interventions could provide valuable information for prognosis and BCI cortical activity targets.

Motor Imagery-Based Brain-Computer Interface Coupled to a Robotic Hand Orthosis Aimed for Neurorehabilitation of Stroke Patients.

Motor imagery-based brain-computer interfaces (BCI) have shown potential for the rehabilitation of stroke patients; however, low performance has restricted their application in clinical environments. Therefore, this work presents the implementation of a BCI system, coupled to a robotic hand orthosis and driven by hand motor imagery of healthy subjects and the paralysed hand of stroke patients. A novel processing stage was designed using a bank of temporal filters, the common spatial pattern algorithm for feature extraction and particle swarm optimisation for feature selection. Offline tests were performed for testing the proposed processing stage, and results were compared with those computed with common spatial patterns. Afterwards, online tests with healthy subjects were performed in which the orthosis was activated by the system. Stroke patients' average performance was 74.1 ± 11%. For 4 out of 6 patients, the proposed method showed a statistically significant higher performance than the common spatial pattern method. Healthy subjects' average offline and online performances were of 76.2 ± 7.6% and 70 ± 6.7, respectively. For 3 out of 8 healthy subjects, the proposed method showed a statistically significant higher performance than the common spatial pattern method. System's performance showed that it has a potential to be used for hand rehabilitation of stroke patients.