Parametric Covariability in the Standard Model of the Saccadic Main Sequence.

SIGNIFICANCE: Saccades present a direct relationship between the size of the movement (SACSIZE) and its peak velocity (SACPEAK), the main sequence, which is traditionally quantified using the model SACPEAK = Vmax × (1 - e). This study shows that Vmax and SAT are not veridical indicators of saccadic dynamics. PURPOSE: Alterations in saccadic dynamics are used as a diagnostic tool. Are the 95% reference ranges (RRs) of Vmax and SAT correctly quantifying the variability in saccadic dynamics of a population? METHODS: Visually driven horizontal and vertical saccades were acquired from 116 normal subjects using the Neuro Kinetics Inc. Concussion Protocol with a 100-Hz I-Portal NOTC Vestibular System, and the main sequence models were computed. RESULTS: The 95% RRs of Vmax, the asymptotic peak velocity, and SAT, the speed of the exponential rise toward Vmax, were quite large. The finding of a strong correlation between Vmax and SAT suggests that their variability might be, in part, a computational interaction. In fact, the interplay between the two parameters greatly reduced the actual peak velocity variability for saccades less than 15°. This correlation was not strong enough to support the adoption of a one-parameter model, where Vmax is estimated from SAT using the regression parameters. We also evaluated the effects of interpolating the position data to a simulated acquisition rate of 1 kHz. Interpolation had no effect on the population average of Vmax and brought a decrease of the average SAT by roughly 8%. CONCLUSIONS: The 95% RRs of Vmax and SAT, treated as independent entities, are not a veridical representation of the variability in saccadic dynamics inside a population, especially for small saccades. We introduce a novel three-step method to determine if a data set is inside or outside a reference population that takes into account the correlation between Vmax and SAT.

Vestibular and Oculomotor Function in Children with Cerebral Palsy: A Scoping Review.

Cerebral palsy (CP) is a nonprogressive permanent brain injury that causes an impairment of movement and posture. This scoping review aimed to answer the following questions: (1) "What is the status of oculomotor function in children with CP?" (2) "What is the status of vestibular function (i.e., gaze stability, perception of vertical, vestibular-related balance abilities) in children with CP?" Using Arksey's and O'Malley's five-stage framework, we searched six online databases for relevant articles. The inclusion criteria were: (1) participants of the studies included individuals with CP; (2) a primary outcome in the studies was measurement of oculomotor, vestibular, and/or balance; (3) studies were published within the past 20 years; and (4) the participants in the studies were between 0 and 21 years of age. Twenty-one articles were found that described impairments in oculomotor function ( n = 9), vestibular function ( n = 1), and oculomotor and vestibular integration ( n = 11) in children with CP. The evidence suggests that children with CP may have altered saccadic and smooth pursuit eye movements, abnormal saccular function, poor eye-hand coordination, and abnormal use of vestibular information for balance. Future studies should explore peripheral and central vestibular function using reliable and valid methods for this population. This scoping review demonstrated a paucity of rigorous and objective research to describe the status of oculomotor and vestibular function in children with CP. However, preliminary studies suggest that more research is warranted.

The effect of intense physical therapy for children with cerebral palsy.

PURPOSE: To determine the effect of an intense physical therapy intervention on gross motor function, community walking and participation in children with cerebral palsy (CP). METHODS: A single group design was used with two pre-test and two post-test measures. Subjects were 17 ambulatory children with CP who participated in an intense intervention (i.e., four hours per day, five days per week, three weeks), a modified version of the TheraSuit protocol. Gross motor function measure (GMFM-66), Step watch activity monitor (SAM), Canadian occupational performance measure (COPM) and pediatric outcomes data collection instrument (PODCI) were tested twice at baseline, immediately following the intervention, and three months later. RESULTS: Immediately following the intervention, GMFM-66, COPM and PODCI scores improved significantly (p < 0.001). At three months, improvements remained for GMFM-66 and COPM (p < 0.01). Walking amount or intensity (SAM) did not improve. CONCLUSIONS: Participants improved gross motor skills and participation but not community ambulation following this intense physical therapy intervention.

Parent and therapist perceptions of an intense model of physical therapy.

PURPOSE: The purpose of this study was to determine parent and therapist perceptions regarding the effect of an intense model of physical therapy for children with cerebral palsy. METHODS: Informants included 5 parents, 5 therapists, and 5 children with cerebral palsy who previously participated in an intense program (ie, strengthening and functional activities 4 hours/day, 5 days/week for 3 weeks). Parents and therapists were interviewed, and children were observed. Data were collected and analyzed using qualitative methodology. RESULTS: Five common themes emerged, based on perceptions: (1) improvement in motor function, (2) improvement in confidence and independence, (3) stress during the program but a time of no therapy between sessions, (4) increased participation in the community, and (5) fatigue during the program but perceived rapid attainment of goals. CONCLUSIONS: The constructs identified should be considered by clinicians in program development and by researchers for further study.