Establishing a Clinical Brain-Computer Interface Program for Children With Severe Neurological Disabilities.

BACKGROUND: Children with severe motor impairment but intact cognition are deprived of fundamental human rights. Quadriplegic cerebral palsy is the most common scenario where rehabilitation options remain limited. Brain-computer interfaces (BCI) represent a potential solution, but pediatric populations have been neglected. Direct engagement of children and families could provide meaningful opportunities while informing program development. We describe a patient-centered, clinical, non-invasive pediatric BCI program. METHODS: Eligible children were identified within a population-based, tertiary care children's hospital. Criteria included 1) age six to 18 years, 2) severe physical disability (non-ambulatory, minimal hand use), 3) severely limited speech, and 4) evidence of grade 1 cognitive capacity. After initial screening for BCI competency, participants attended regular sessions, attempting commercially available and customized systems to play computer games, control devices, and attempt communication. RESULTS: We report the first 10 participants (median 11 years, range 6-16, 60% male). Over 334 hours of participation, there were no serious adverse events. BCI training was well tolerated, with favorable feedback from children and parents. All but one participant demonstrated the ability to perform BCI tasks. The majority performed well, using motor imagery based tasks for games and entertainment. Difficulties were most significant using P300, visual evoked potential based paradigms where maintenance of attention was challenging. Children and families expressed interest in continuing and informing program development. CONCLUSIONS: Patient-centered clinical BCI programs are feasible for children with severe disabilities. Carefully selected participants can often learn quickly to perform meaningful tasks on readily available systems. Patient and family motivation and engagement appear high.

Unlocking Independence: Exploring Movement with Brain-Computer Interface for Children with Severe Physical Disabilities.

Children with severe physical disabilities are often unable to independently explore their environments, further contributing to complex developmental delays. Brain-computer interfaces (BCIs) could be a novel access method to power mobility for children who struggle to use existing alternate access technologies, allowing them to reap the developmental, social, and psychological benefits of independent mobility. In this pilot study we demonstrated that children with quadriplegic cerebral palsy can use a simple BCI system to explore movement with a power mobility device. Four children were able to use the BCI to drive forward at least 7m, although more practice is needed to achieve more efficient driving skills through sustained BCI activations.

Multi-joint gait clustering for children and youth with diplegic cerebral palsy.

BACKGROUND: Clinical management of children and youth with cerebral palsy (CP) is increasingly supported by computerized gait analysis. Methods have been developed to reduce the complexity of interpreting biomechanical data and quantify meaningful movement patterns. However, few methods are inclusive of multiple joints and planes of motion, and consider the entire duration of gait phases; potentially limiting insight into this heterogeneous pathology. The objective of this study was to assess the implementation of k-means clustering to determine clusters of participants with CP based on multi-joint gait kinematics. METHODS: Barefoot walking kinematics were analyzed for a historical cohort (2007-2015) of 37 male and female children and youth with spastic diplegic CP [male n = 21; female n = 16; median age = 12 (range 5-25) years; Gross Motor Function Classification System Level I n = 17 and Level II n = 20]. Mean stance phase hip (sagittal, coronal, transverse), knee (sagittal), and ankle (sagittal) kinematics were time (101 data points), mean and range normalized. Normalized kinematics data vectors (505 data points) for all participants were then combined in a single data matrix M (37x505 data points). K-means clustering was conducted 10 times for all data in M (2-5 seeds, 50 repetitions). Cluster quality was assessed using the mean Silhouette value ([Formula: see text]) and cluster repeatability. The mean kinematic patterns of each cluster were explored with respect to a dataset of normally developing (ND) children using Statistical Parametric Mapping (SPM, alpha 0.05). Differences in potentially confounding variables (age, height, weight, walking speed) between clusters (C) were assessed individually in SPSS (IBM, USA) using Kruskal-Wallis H tests (alpha 0.05). RESULTS: Four clusters (n1 = 5, n2 = 12, n3 = 12, n4 = 8) provided the largest possible data separation based on high cluster repeatability (96.8% across 10 repetitions) and comparatively greater cluster quality [[Formula: see text] (SD), 0.275 (0.152)]. Participant data with low cluster quality values displayed a tendency toward lower cluster allocation repeatability. Distinct kinematic differences between clusters and ND data were observable. Specifically, C1 displayed a unique continuous hip abduction and external rotation pattern. In contrast, participants in C2 moved from hip adduction (loading response) to abduction (mid to terminal stance) and featured a unique ankle plantarflexor pattern during pre-swing. C3 was characterized by gait deviations in the sagittal plane of the hip, knee and ankle only. C4 displayed evidence for the most substantial hip and knee extension, and ankle plantarflexion deficit from midstance to pre-swing. DISCUSSION: K-means clustering enabled the determination of up to four kinematic clusters of individuals with spastic diplegic CP using multi-joint angles without a priori data reduction. A cluster boundary effect was demonstrated by the Silhouette value, where data with values approaching zero were more likely to change cluster allocation. Exploratory analyses using SPM revealed significant differences across joints and between clusters indicating the formation of clinically meaningful clusters. Further work is needed to determine the effects of including further topographical classifications of CP, additional biomechanical data, and the sensitivity to clinical interventions to assess the potential for informing clinical decision-making.

Peak Jump Power Reflects the Degree of Ambulatory Ability in Patients with Mitochondrial and Other Rare Diseases.

Metabolic diseases that lead to neuromuscular, bone, and joint involvement can reduce ambulation and quality of life. Using jumping mechanography, we developed a novel assessment, peak jump power (PJP), and related this to ambulatory ability in patients either having a known or suspected underlying rare disease. From adults and children, we recruited 88 healthy controls and 115 patients (61 with mitochondrial disease and 54 with another diagnosis). Patients were categorized as having no complaints of weakness or ambulation (ambulatory competent; AC), weakness but able to ambulate without aids (ambulatory weakness; AW), or not able to ambulate without aids such as a walker, cane, or wheelchair (ambulatory assistance; AA). Subjects were asked to perform five successive jumps from a squat position. Instantaneous power (W; watts) was calculated and the highest result was divided by the body mass (kg) to calculate PJP (W/kg). Between healthy controls and AC patients, there was no difference in mean PJP (20.5 ± 7.0 W/kg vs. 19.0 ± 7.4 W/kg, p = 0.601; mean ± SD). Progressively lower results were found in patients with AW with a mean PJP of 11.7 ± 5.1 W/kg (p < 0.001 versus AC) and further those with AA with a mean PJP of 5.8 ± 3.2 W/kg (p < 0.001 versus AW). A subgroup analysis of subjects showed that those who did not use ambulatory aids all had a PJP above 10 W/kg. Using this threshold, the receiver operating characteristic curve (ROC) analysis showed PJP to be highly sensitive evaluation of ambulatory ability (sensitivity 95.8%, specificity 52.1%).

Side alternating vibration training in patients with mitochondrial disease: a pilot study.

BACKGROUND: Side alternating vibration training (SAVT) is a mechanical oscillation using a vibrating platform that simulates exercise. We hypothesized that patients with mitochondrial myopathies, who experience muscle weakness, may see an improvement in muscle power with SAVT. METHODS: Patients with mitochondrial disease started either a treatment (SAVT) or control phase (standing without vibration) for 12 weeks, then 12 weeks of washout, and then a 12-week cross-over. The main outcome measure was peak jump power (PJP). We compared this to a natural history cohort from clinic. RESULTS: Seven out of 13 patients completed at least 80% of their SAVT sessions and were analyzed. The ΔPJP after the control phase was -2.7 ± 1.7 W/kg (mean ± SEM), SAVT was +2.8 ± 0.6 W/kg (p < 0.05) and from the natural history cohort was -2.4 ± 0.8 W/kg/year. CONCLUSIONS: SAVT is well tolerated and may improve muscle power in mitochondrial disease patients.

Side-alternating vibration training improves muscle performance in a patient with late-onset pompe disease.

Side-alternating vibration training (SAVT) was used for 15 weeks in a patient with Late-onset Pompe disease who had never used enzyme replacement or chaperone therapy. Prior to the use of SAVT, the patient had experienced declining muscle performance and her 6-minute walk distance decreased from 210 to 155 metres in 6 months. After SAVT, her 6-minute walk distance increased 70% from 166 to 282 metres, muscle jumping power increased by 64% from 83 to 166 watts, isometric knee extensor strength increased 17% from 38 to 44 Nm, and she achieved a more normal pattern of ankle, knee, and joint kinematics and kinetics. Her functional ability measured through the Rotterdam 9-item score was unchanged at 19/36. There were no elevations in serum creatine kinase or lactate. This is the first report, to our knowledge, of a performance improvement in a patient with Pompe disease using SAVT.

Navigational strategies during fast walking: a comparison between trained athletes and non-athletes.

Many common activities such as walking in a shopping mall, moving in a busy subway station, or even avoiding opponents during sports, all require different levels of navigational skills. Obstacle circumvention is beginning to be understood across age groups, but studying trained athletes with greater levels of motor ability will further our understanding of skillful adaptive locomotor behavior. The objective of this work was to compare navigational skills during fast walking between elite athletes (e.g. soccer, field hockey, basketball) and aged-matched non-athletes under different levels of environmental complexity in relation to obstacle configuration and visibility. The movements of eight women athletes and eight women non-athletes were measured as they walked as fast as possible through different obstacle courses in both normal and low lighting conditions. Results showed that athletes, despite similar unobstructed maximal speeds to non-athletes, had faster walking times during the navigation of all obstructed environments. It appears that athletes can process visuo-spatial information faster since both groups can make appropriate navigational decisions, but athletes can navigate through complex, novel, environments at greater speeds. Athletes' walking times were also more affected by the low lighting conditions suggesting that they normally scan the obstructed course farther ahead. This study also uses new objective measures to assess functional locomotor capacity in order to discriminate individuals according to their level of navigational ability. The evaluation paradigm and outcome measures developed may be applicable to the evaluation of skill level in athletic training and selection, as well as in gait rehabilitation following impairment.