Hand Motor Impairment Research Articles

MouseClicker: Exploring Tactile Feedback and Physical Agency for People with Hand Motor Impairments

Assistive technology (AT) design is critical in enabling functionality for people with disabilities, blending essential elements of both practical utility and user experience. Traditionally, AT has successfully addressed core functional needs, such as enabling cursor movement and clicking actions with devices like computer mice. However, a comprehensive approach to AT design also necessitates a thorough consideration of sensory feedback, including tactile sensations, ergonomics, and auditory cues like button click sounds. These aspects are not merely supplementary but are integral to the device’s functionality, enhancing user interaction and long-term comfort, especially for individuals with motor impairments. In this work, we present MouseClicker, a mechatronic AT to surrogate physical agency over a computer mouse and to foster the haptic sensory experience of clicking on it tailored specifically for an individual with Spinal Muscular Atrophy (SMA) who faces challenges in using a standard mouse due to severe hand motor impairments. Our design aims at replicating the holistic experience of clicking a mouse, from its functional mechanical actions to its nuanced tactile and auditory feedback. This work details the MouseClicker’s design and reports on an exploratory user study aimed at identifying optimal vibrotactile feedback parameters – such as location, and intensity – that represent mouse button clicks. MouseClicker presents a step forward in AT design by integrating the functionality, sensory feedback, and the overall experience of taking control over non-AT devices.

A Low Cost of an Exoskeleton Finger for Stroke Patient

Hand motor impairment poses a significant obstacle for stroke survivors, profoundly affecting their capacity to perform crucial daily tasks. This impairment frequently includes an inability to flex fingers effectively. This research is dedicated to the development of a low-cost exoskeleton finger tailored for stroke patient rehabilitation. The proposed exoskeleton finger boasts characteristics of being lightweight, affordable, and straightforward to manufacture. Moreover, it prioritizes portability and user-friendliness. The design integrates PLA material, springs, servo motors, and Arduino Uno technology. The study introduces two distinct exoskeleton finger designs, with one of them incorporating a glove component. Both exoskeleton finger variations comprise three degrees of freedom (DOF), three links, and two joints. The findings show that the exoskeleton finger's ability to effectively maneuver a paralyzed finger into different positions as commanded, facilitating the rehabilitation process. Furthermore, both designs exhibit reliability in aiding the opening and closing exercises of impaired fingers.

An Exosuit System With Bidirectional Hand Support for Bilateral Assistance Based on Dynamic Gesture Recognition.

Hand motor impairment has seriously affected the daily life of the elderly. We developed an electromyography (EMG) exosuit system with bidirectional hand support for bilateral coordination assistance based on a dynamic gesture recognition model using graph convolutional network (GCN) and long short-term memory network (LSTM). The system included a hardware subsystem and a software subsystem. The hardware subsystem included an exosuit jacket, a backpack module, an EMG recognition module, and a bidirectional support glove. The software subsystem based on the dynamic gesture recognition model was designed to identify dynamic and static gestures by extracting the spatio-temporal features of the patient's EMG signals and to control glove movement. The offline training experiment built the gesture recognition models for each subject and evaluated the feasibility of the recognition model; the online control experiments verified the effectiveness of the exosuit system. The experimental results showed that the proposed model achieve a gesture recognition rate of 96.42% ± 3.26 %, which is higher than the other three traditional recognition models. All subjects successfully completed two daily tasks within a short time and the success rate of bilateral coordination assistance are 88.75% and 86.88%. The exosuit system can effectively help patients by bidirectional hand support strategy for bilateral coordination assistance in daily tasks, and the proposed method can be applied to various limb assistance scenarios.

A mirror therapy system using virtual reality and an actuated exoskeleton for the recovery of hand motor impairments: a study of acceptability, usability, and embodiment

Hand motor impairments are one of the main causes of disabilities worldwide. Rehabilitation procedures like mirror therapy are given crucial importance. In the traditional setup, the patient moves the healthy hand in front of a mirror; the view of the mirrored motion tricks the brain into thinking that the impaired hand is moving as well, stimulating the recovery of the lost hand functionalities. We propose an innovative mirror therapy system that leverages and couples cutting-edge technologies. Virtual reality recreates an immersive and effective mirroring effect; a soft hand exoskeleton accompanies the virtual visual perception by physically inducing the mirrored motion to the real hand. Three working modes of our system have been tested with 21 healthy users. The system is ranked as acceptable by the system usability scale; it does not provoke adverse events or sickness in the users, according to the simulator sickness questionnaire; the three execution modes are also compared w.r.t. the sense of embodiment, evaluated through another customized questionnaire. The achieved results show the potential of our system as a clinical tool and reveal its social and economic impact.

The Evolution of Hand Proprioceptive and Motor Impairments in the Sub-Acute Phase After Stroke.

Hand proprioception is essential for fine movements and therefore many activities of daily living. Although frequently impaired after stroke, it is unclear how hand proprioception evolves in the sub-acute phase and whether it follows a similar pattern of changes as motor impairments. This work investigates whether there is a corresponding pattern of changes over time in hand proprioception and motor function as comprehensively quantified by a combination of robotic, clinical, and neurophysiological assessments. Finger proprioception (position sense) and motor function (force, velocity, range of motion) were evaluated using robotic assessments at baseline (<3 months after stroke) and up to 4 weeks later (discharge). Clinical assessments (among others, Box & Block Test [BBT]) as well as Somatosensory/Motor Evoked Potentials (SSEP/MEP) were additionally performed. Complete datasets from 45 participants post-stroke were obtained. For 42% of all study participants proprioception and motor function had a dissociated pattern of changes (only 1 function considerably improved). This dissociation was either due to the absence of a measurable impairment in 1 modality at baseline, or due to a severe lesion of central somatosensory or motor tracts (absent SSEP/MEP). Better baseline BBT correlated with proprioceptive gains, while proprioceptive impairment at baseline did not correlate with change in BBT. Proprioception and motor function frequently followed a dissociated pattern of changes in sub-acute stroke. This highlights the importance of monitoring both functions, which could help to further personalize therapies.

A bidirectional fabric-based soft robotic glove for hand function assistance in patients with chronic stroke

BackgroundChronic stroke patients usually experience reduced hand functions, impeding their ability to perform activities of daily living (ADLs) independently. Additionally, improvements in hand functions by physical therapy beyond six months after the initial onset of stroke are much slower than in the earlier months. As such, chronic stroke patients could benefit from an assistive device to enhance their hand functions, allowing them to perform ADLs independently daily. In recent years, soft robotics has provided a novel approach to assistive devices for motor impaired individuals, offering more compliant and lightweight alternatives to traditional robotic devices. The scope of this study is to demonstrate the viability of a fabric-based soft robotic (SR) glove with bidirectional actuators in assisting chronic stroke study participants with hand impairments in performing ADLs.MethodsForce and torque measurement tests were conducted to characterize the SR Glove, and hand functional tasks were given to eight chronic stroke patients to assess the efficacy of the SR Glove as an assistive device. The tasks involved object manipulation tasks that simulate ADLs, and the series of tasks was done by the participants once without assistance for baseline data, and once while using the SR Glove. A usability questionnaire was also given to each participant after the tasks were done to gain insight into how the SR Glove impacts their confidence and reliance on support while performing ADLs.ResultsThe SR Glove improved the participants’ manipulation of objects in ADL tasks. The difference in mean scores between the unassisted and assisted conditions was significant across all participants. Additionally, the usability questionnaire showed the participants felt more confident and less reliant on support while using the SR Glove to perform ADLs than without the SR Glove.ConclusionsThe results from this study demonstrated that the SR Glove is a viable option to assist hand function in chronic stroke patients who suffer from hand motor impairments.

Design and experimental study of a flexible finger rehabilitation robot driven by shape memory alloy

The importance of hand function is evident in daily human life. However, different degrees of hand motor impairments after damage caused by stroke and other nervous system diseases bring great trouble to patients’ daily life. For this reason, a flexible finger rehabilitation robot driven by shape memory alloy wire was proposed in this paper and was equipped with a range extender of shape memory alloy wire wiring. The structural design was optimized by exploring the movement mechanism of the finger joint to achieve the requirement of imitating the normal motion function of the human finger. Based on the driving model of the finger rehabilitation robot, the prototype was made and tested, in which the total weight of the prototype is 393 g. When the drive voltage is 20 V, the maximum joint angle that the finger rehabilitation robot can achieve is about 85% of that of healthy people, in addition, it can help patients grasp most of the daily objects successfully, and can meet the basic requirements of finger rehabilitation.

To engage or not engage: Early incentive motivation prevents symptoms of chronic post-stroke depression – A longitudinal study

BackgroundAlthough post-stroke depression (PSD) is known to disrupt motor rehabilitation after stroke, PSD is often undertreated and its relationship with motor impairment remains poorly understood. MethodsIn a longitudinal study design we investigated, which factors at the early post-acute stage may increase the risk for PSD symptoms. We were especially interested in whether interindividual differences in the motivational drive to engage in physically demanding tasks indicate PSD development in patients suffering from motor impairments. Accordingly, we used a monetary incentive grip force task where participants were asked to hold their grip force for high and low rewards at stake to maximize their monetary outcome. Individual grip force was normalized according to the maximal force prior to the experiment. Experimental data, depression, and motor impairment were assessed from 20 stroke patients (12 male; 7.7 ± 6.78 days post-stroke) with mild-to-moderate hand motor impairment and 24 age-matched healthy participants (12 male). ResultsBoth groups showed incentive motivation as indicated by stronger grip force for high versus low reward trials and the overall monetary outcome in the task. In stroke patients, severely impaired patients showed stronger incentive motivation, whereas early PSD symptoms were associated with reduced incentive motivation in the task. Larger lesions in corticostriatal tracts correlated with reduced incentive motivation. Importantly, chronic motivational deficits were preceded by initially reduced incentive motivation and larger corticostriatal lesions in the early stage post-stroke. ConclusionsMore severe motor impairment motivates reward-dependent motor engagement, whereas PSD and corticostriatal lesions potentially disturb incentive motivational behavior, thereby increasing the risk of chronic motivational PSD symptoms. Acute interventions should address motivational aspects of behavior to improve motor rehabilitation post-stroke.

A preliminary study of radioulnar wrist compression in improving patient-reported outcomes of carpal tunnel syndrome

Previous studies have shown radioulnar wrist compression augments carpal arch space. This study investigated the effects of radioulnar wrist compression on patient-reported outcomes associated with carpal tunnel syndrome. Subjects underwent thrice-daily (15 min each time 45 min daily) wrist compression over 4 weeks with an additional four weeks of follow-up without treatment. Primary outcomes included Boston Carpal Tunnel Questionnaire symptom and functional severity scales (SSS and FSS) and symptoms of numbness/tingling based on Visual Analog Scales. Our results showed that radioulnar wrist compression improved SSS by 0.55 points after 2 weeks (p < 0.001) and 0.51 points at 4 weeks (p < 0.006) compared to the baseline scale. At the four-week follow-up, SSS remined improved at 0.47 points (p < 0.05). Symptoms of numbness/tingling improved at two and 4 weeks, as well as the follow-up (p < 0.05). Hand motor impairment such as weakness had a lower frequency across carpal tunnel syndrome sufferers and does not significantly improve (p > 0.05). Radioulnar wrist compression might be an effective alternative treatment in improving sensory related symptoms in patients with mild to moderate carpal tunnel syndrome.

Characterizing Pediatric Hand Grasps During Activities of Daily Living to Inform Robotic Rehabilitation and Assistive Technologies.

Hand function plays a critical role in how we interact with our physical environment. Hand motor impairments in children can compromise many facets of their daily life including physical independence and social interactions. For adults, there has been an emergence of mechatronic rehabilitation systems to improve hand mobility, strength, and dexterity; assistive technologies such as exoskeletons to drive impaired digits; and highly dexterous upper limb prostheses. Although similar devices are on the clinical horizon for children, childhood play, motor development, and daily activities mean they use their hands in fundamentally different ways than adults. It is imperative that devices for this population facilitate their unique needs; yet it is not completely known which hand movements may be of the highest priority during daily tasks or rehabilitation to best foster functional independence. Here, we evaluated and categorized the hand activity of two children in their home environments. Small wearable video cameras were attached to the children as they performed daily tasks and the video footage was analyzed to obtain the frequency and duration of their hand grasp movements. It was found that 7 common grasps accounted for 90% or greater of the children's hand activity in duration and frequency. This suggests, that like adults, a repertoire of common hand grasps may be prioritized by rehabilitative or assistive devices to ensure effective outcomes in performing daily activities.

EEG-EMG hybrid real-time classification of hand grasp and release movements intention in chronic stroke patients.

Rehabilitation of the hand motor function is essential for stroke patients to resume activities of daily living. Recent studies have shown that wearable robot systems, like a multi degree-of-freedom soft glove, have the potential to improve hand motor impairment. The rehabilitation system, which is intuitively controlled according to the user's intention, is expected to induce active participation of the user and further promote brain plasticity. However, due to the patient-specific nature of stroke patients, extracting the intention from stroke patients is still challenging. In this study, we implemented a classifier that combines EEG and EMG to detect chronic stroke patients' four types of intention: rest, grasp, hold, and release. Three chronic stroke patients participated in the experiment and performed rest, grasp, hold, and release actions. The rest vs. grasp binary classifier and release vs. hold binary classifier showed 76.9% and 86.6% classification accuracy in real-time, respectively. In addition, patient-specific accuracy comparisons showed that the hybrid approach was robust to upper limb impairment level compared to other approaches. We believe that these results could pave the way for the development of BCI-based robotic hand rehabilitation therapy.

P 61 Robotic assessments of upper limb sensorimotor impairments in neurological disorders

Background: Upper limb sensorimotor impairments are common in neurological disorders. In order to personalize and evaluate interventions aiming to improve upper limb function, it is essential to accurately assess the presence and extent of these impairments. Clinical assessments rely on experience-based observations, subjective evaluation, and ordinal scales, thus challenging a sensitive capture of intervention-induced changes in clinical trials. Novel robotic technologies promise sensitive and objective endpoints describing upper limb kinematic and kinetics during behavioural tasks. Over the last decades, we successfully developed, validated, and clinically applied such technologies in neurological disorders. The aim is to report on the feasibility, clinimetric properties, and clinical applicability of two complementary robotic assessments quantifying upper limb sensorimotor impairments. Methods: First, we relied on a haptic end-effector to record upper limb movement patterns and hand grip forces during a goal-directed pick-and-place task (Kanzler et al. 2020). Second, we custom-designed a robotic device and behavioural tasks providing precise stimuli to the index finger metacarpophalangeal joint, thereby allowing to study finger proprioception as well as motor and sensorimotor impairments (Zbytniewska et al. 2021). The recorded sensor data is analyzed with signal processing pipelines to generate objective digital health metrics describing movement quality (e.g., efficiency), grip force control (e.g., smoothness), and the response to well-controlled displacements (e.g., position matching error). Results: Feasibility of the assessments was established in persons with stroke, multiple sclerosis, or ataxia and matched able-bodied controls, revealing that the approaches are rapidly and easily applicable in a wide range of patients. For each platform, a core set of statistically optimal metrics was selected based on their test-retest reliability, measurement error, and discriminative power. Concurrent validity indicated low-moderate correlations with clinical scales, highlighting that the metrics provide novel, complementary information. By applying the metrics, we were able to reveal the presence of sensorimotor impairments and subtle longitudinal changes in persons that did not show abnormalities in clinical assessments. Conclusions: Robotic assessments are valuable tools to accurately and sensitively assess upper limb sensory, motor, and sensorimotor impairments in neurological disorders, thus opening novel avenues for evaluating clinical trials. References Kanzler CM, et al. A data-driven framework for selecting and validating digital health metrics: use-case in neurological sensorimotor impairments. npj Digit. Med. 2020;3(1):80. Zbytniewska M, et al. Reliable and valid robot-assisted assessments of hand proprioceptive, motor and sensorimotor impairments after stroke. J. Neuroeng. Rehabil. 2021;18(1):115.

Engineered glove to evaluate hand disability in rheumatoid arthritis: A pilot-study.

The Hand Test System (HTS) is an engineered-sensorized glove that has been originally developed in the neuroscientific field for the evaluation of hand fingers' speed movement. This pilot-study aimed to evaluate the reproducibility of HTS analysis in rheumatoid arthritis (RA), correlating glove-derived parameters with clinical disease activity indexes, self-reported disability-related questionnaires and hand strength. Fifty-five RA patients and fifty age and sex matched healthy controls (HCs) performed HTS analysis. The glove recognized the touch speed between the finger tips during standard sequences of movements, providing three quantitative parameters: touch duration (TD), inter-tapping interval (ITI) and movement rate (MR). These variables were correlated with Health Assessment Questionnaire (HAQ), Health Assessment Questionnaire-Disease Index (HAQ-DI), Hand Disability Index (HDI), Hand Grip Strength (HGS), DAS28-CRP, CDAI and SDAI. Intraclass correlation coefficient was 0.93 (CI: 0.92, 0.95). RA patients showed significantly slower TD, ITI and MR than HCs, for all classes of disease activity (P<0.001). All HTS parameters correlated significantly with HAQ, HAQ-DI, HDI, HGS, DAS28-CRP, SDAI, CDAI (between P<0.05 and P<0.001). Of note, also RA patients in clinical remission showed a significantly higher TD compared with HCs (P<0.001). HTS seems a new safe and fast tool to evaluate rheumatoid hand's functionality, measuring the speed of finger movements. Furthermore, the HTS parameters significantly correlate with quality of life, disease activity, hand strength and perceived hand disability, evaluating also potential hand motor impairment in RA clinical remission.

Motor Imagery-Based Brain-Computer Interface Combined with Multimodal Feedback to Promote Upper Limb Motor Function after Stroke: A Preliminary Study.

Background Recently, the brain-computer interface (BCI) has seen rapid development, which may promote the recovery of motor function in chronic stroke patients. Methods Twelve stroke patients with severe upper limb and hand motor impairment were enrolled and randomly assigned into two groups: motor imagery (MI)-based BCI training with multimodal feedback (BCI group, n = 7) and classical motor imagery training (control group, n = 5). Motor function and electrophysiology were evaluated before and after the intervention. The Fugl-Meyer assessment-upper extremity (FMA-UE) is the primary outcome measure. Secondary outcome measures include an increase in wrist active extension or surface electromyography (the amplitude and cocontraction of extensor carpi radialis during movement), the action research arm test (ARAT), the motor status scale (MSS), and Barthel index (BI). Time-frequency analysis and power spectral analysis were used to reflect the electroencephalogram (EEG) change before and after the intervention. Results Compared with the baseline, the FMA-UE score increased significantly in the BCI group (p = 0.006). MSS scores improved significantly in both groups, while ARAT did not improve significantly. In addition, before the intervention, all patients could not actively extend their wrists or just had muscle contractions. After the intervention, four patients regained the ability to extend their paretic wrists (two in each group). The amplitude and area under the curve of extensor carpi radialis improved to some extent, but there was no statistical significance between the groups. Conclusion MI-based BCI combined with sensory and visual feedback might improve severe upper limb and hand impairment in chronic stroke patients, showing the potential for application in rehabilitation medicine.

Ipsilesional Mu Rhythm Desynchronization Correlates With Improvements in Affected Hand Grip Strength and Functional Connectivity in Sensorimotor Cortices Following BCI-FES Intervention for Upper Extremity in Stroke Survivors.

Stroke is a leading cause of acquired long-term upper extremity motor disability. Current standard of care trajectories fail to deliver sufficient motor rehabilitation to stroke survivors. Recent research suggests that use of brain-computer interface (BCI) devices improves motor function in stroke survivors, regardless of stroke severity and chronicity, and may induce and/or facilitate neuroplastic changes associated with motor rehabilitation. The present sub analyses of ongoing crossover-controlled trial NCT02098265 examine first whether, during movements of the affected hand compared to rest, ipsilesional Mu rhythm desynchronization of cerebral cortical sensorimotor areas [Brodmann’s areas (BA) 1-7] is localized and tracks with changes in grip force strength. Secondly, we test the hypothesis that BCI intervention results in changes in frequency-specific directional flow of information transmission (direct path functional connectivity) in BA 1-7 by measuring changes in isolated effective coherence (iCoh) between cerebral cortical sensorimotor areas thought to relate to electrophysiological signatures of motor actions and motor learning. A sample of 16 stroke survivors with right hemisphere lesions (left hand motor impairment), received a maximum of 18–30 h of BCI intervention. Electroencephalograms were recorded during intervention sessions while outcome measures of motor function and capacity were assessed at baseline and completion of intervention. Greater desynchronization of Mu rhythm, during movements of the impaired hand compared to rest, were primarily localized to ipsilesional sensorimotor cortices (BA 1-7). In addition, increased Mu desynchronization in the ipsilesional primary motor cortex, Post vs. Pre BCI intervention, correlated significantly with improvements in hand function as assessed by grip force measurements. Moreover, the results show a significant change in the direction of causal information flow, as measured by iCoh, toward the ipsilesional motor (BA 4) and ipsilesional premotor cortices (BA 6) during BCI intervention. Significant iCoh increases from ipsilesional BA 4 to ipsilesional BA 6 were observed in both Mu [8–12 Hz] and Beta [18–26 Hz] frequency ranges. In summary, the present results are indicative of improvements in motor capacity and behavior, and they are consistent with the view that BCI-FES intervention improves functional motor capacity of the ipsilesional hemisphere and the impaired hand.

Multi-point surface FES hand rehabilitation system for stroke patients based on eye movement control

Recently, the number of stroke patients has increased greatly. Most of them suffer from hand motor impairment, which creates the need for effective rehabilitation systems. Functional electrical stimulation (FES) is a neurorehabilitation method based on brain plasticity, which is widely accepted because it is non-invasive and convenient. However, it is still a challenge to achieve fine finger control by using surface FES. Here, we use multi-point surface FES to achieve individual finger motion. Besides, simple FES does not engage the subjects' attention, and an optimal stimulation position is difficult to identify. Hence, we try to integrate FES with sensory control by presenting a multi-point FES system based on eye movement control. By programming the electrodes display interface and establishing communication with the FES device and the eye tracker, subjects can change stimulation points via their eye movements. Experiments were performed to test the validity and safety of the proposed system. Feedback data was obtained using a 3D motion capture device. The results indicate that achieving individual finger motion is possible and stimulation points can be changed via eye movements. The system is practical and can be used in hand motor training for stroke patients to shorten the rehabilitation period.

Reliable and valid robot-assisted assessments of hand proprioceptive, motor and sensorimotor impairments after stroke

BackgroundNeurological injuries such as stroke often differentially impair hand motor and somatosensory function, as well as the interplay between the two, which leads to limitations in performing activities of daily living. However, it is challenging to identify which specific aspects of sensorimotor function are impaired based on conventional clinical assessments that are often insensitive and subjective. In this work we propose and validate a set of robot-assisted assessments aiming at disentangling hand proprioceptive from motor impairments, and capturing their interrelation (sensorimotor impairments).MethodsA battery of five complementary assessment tasks was implemented on a one degree-of-freedom end-effector robotic platform acting on the index finger metacarpophalangeal joint. Specifically, proprioceptive impairments were assessed using a position matching paradigm. Fast target reaching, range of motion and maximum fingertip force tasks characterized motor function deficits. Finally, sensorimotor impairments were assessed using a dexterous trajectory following task. Clinical feasibility (duration), reliability (intra-class correlation coefficient ICC, smallest real difference SRD) and validity (Kruskal-Wallis test, Spearman correlations rho with Fugl-Meyer Upper Limb Motor Assessment, kinesthetic Up-Down Test, Box & Block Test) of robotic tasks were evaluated with 36 sub-acute stroke subjects and 31 age-matched neurologically intact controls.ResultsEighty-three percent of stroke survivors with varied impairment severity (mild to severe) could complete all robotic tasks (duration: <15 min per tested hand). Further, the study demonstrated good to excellent reliability of the robotic tasks in the stroke population (ICC>0.7, SRD<30%), as well as discriminant validity, as indicated by significant differences (p-value<0.001) between stroke and control subjects. Concurrent validity was shown through moderate to strong correlations (rho=0.4-0.8) between robotic outcome measures and clinical scales. Finally, robotic tasks targeting different deficits (motor, sensory) were not strongly correlated with each other (rho le0.32, p-value>0.1), thereby presenting complementary information about a patient’s impairment profile.ConclusionsThe proposed robot-assisted assessments provide a clinically feasible, reliable, and valid approach to distinctly characterize impairments in hand proprioceptive and motor function, along with the interaction between the two. This opens new avenues to help unravel the contributions of unique aspects of sensorimotor function in post-stroke recovery, as well as to contribute to future developments towards personalized, assessment-driven therapies.

Non-verbal Intelligence in Unilateral Perinatal Stroke Patients With and Without Epilepsies.

Background: The risk factors for impaired cognitive development after unilateral perinatal stroke are poorly understood. Non-verbal intelligence seems to be at particular risk, since language can shift to the right hemisphere and may thereby reduce the capacity of the right hemisphere for its originary functions. Pharmaco-refractory epilepsies, a frequent complication of perinatal strokes, often lead to impaired intelligence. Yet, the role of well-controlled epilepsies is less well-understood. Here, we investigated whether well-controlled epilepsies, motor impairment, lesion size, lesion side, and lateralization of language functions influence non-verbal functions.Methods: We recruited 8 patients with well-controlled epilepsies (9–26 years), 15 patients without epilepsies (8–23 years), and 23 healthy controls (8–27 years). All underwent the Test of Non-verbal Intelligence, a motor-independent test, which excludes biased results due to motor impairment. Language lateralization was determined with functional MRI, lesion size with MRI-based volumetry, and hand motor impairment with the Jebson-Taylor Hand Function-Test.Results: Patients with epilepsies showed significantly impaired non-verbal intelligence [Md = 89.5, interquartile range (IQR) = 13.5] compared with controls (Md = 103, IQR = 17). In contrast, patients without epilepsies (Md = 97, IQR = 15.0) performed within the range of typically developing children. A multiple regression analysis revealed only epilepsy as a significant risk factor for impaired non-verbal functions.Conclusion: In patients with unilateral perinatal strokes without epilepsies, the neuroplastic potential of one healthy hemisphere is able to support the development of normal non-verbal cognitive abilities, regardless of lesion size, lesion side, or language lateralization. In contrast, epilepsy substantially reduces this neuroplastic potential; even seizure-free patients exhibit below-average non-verbal cognitive functions.

Recovery of Apraxia of Speech and Aphasia in Patients With Hand Motor Impairment After Stroke.

Objective: Aphasia and apraxia of speech (AOS) after stroke frequently co-occur with a hand motor impairment but few studies have investigated stroke recovery across motor and speech-language domains. In this study, we set out to test the shared recovery hypothesis. We aimed to (1) describe the prevalence of AOS and aphasia in subacute stroke patients with a hand motor impairment and (2) to compare recovery across speech-language and hand motor domains. In addition, we also explored factors predicting recovery from AOS.Methods: Seventy participants with mild to severe paresis in the upper extremity were assessed; 50% of these (n = 35) had left hemisphere (LH) lesions. Aphasia, AOS and hand motor assessments and magnetic resonance imaging were conducted at 4 weeks (A1) and at 6 months (A2) after stroke onset. Recovery was characterized in 15 participants showing initial aphasia that also had complete follow-up data at 6 months.Results: All participants with AOS and/or aphasia had LH lesions. In LH lesioned, the prevalence of aphasia was 71% and of AOS 57%. All participants with AOS had aphasia; 80% of the participants with aphasia also had AOS. Recovery in aphasia (n = 15) and AOS (n = 12) followed a parallel pattern to that observed in hand motor impairment and recovery correlated positively across speech-language and motor domains. The majority of participants with severe initial aphasia and AOS showed a limited but similar amount of recovery across domains. Lesion volume did not correlate with results from behavioral assessments, nor with recovery. The initial aphasia score was the strongest predictor of AOS recovery.Conclusion: Our findings confirm the common occurrence of AOS and aphasia in left hemisphere stroke patients with a hand motor impairment. Recovery was similar across speech-language and motor domains, even in patients with severe impairment, supporting the shared recovery hypothesis and that similar brain recovery mechanisms are involved in speech-language and motor recovery post stroke. These observations contribute to the knowledge of AOS and its relation to motor and language functions and add information that may serve as a basis for future studies of post stroke recovery. Studies including neuroimaging and/or biological assays are required to gain further knowledge on shared brain recovery mechanisms.

Manipulating Single-Trial Motor Performance in Chronic Stroke Patients by Closed-Loop Brain State Interaction

Motor impaired patients performing repetitive motor tasks often reveal large single-trial performance variations. Based on a data-driven framework, we extracted robust oscillatory brain states from pre-trial intervals, which are predictive for the upcoming motor performance on the level of single trials. Based on the brain state estimate, i.e. whether the brain state predicts a good or bad upcoming performance, we implemented a novel gating strategy for the start of trials by selecting specifically suitable or unsuitable trial starting time points. In a pilot study with four chronic stroke patients with hand motor impairments, we conducted a total of 41 sessions. After few initial calibration sessions, patients completed approximately 15 hours of effective hand motor training during eight online sessions using the gating strategy. Patients' reaction times were significantly reduced for suitable trials compared to unsuitable trials and shorter overall trial durations under suitable states were found in two patients. Overall, this successful proof-of-concept pilot study motivates to transfer this closed-loop training framework to a clinical study and to other application fields, such as cognitive rehabilitation, sport sciences or systems neuroscience.