Fabian J. David

Hyperresponsive sensory patterns in young children with autism, developmental delay, and typical development.

The nature of hyperresponsiveness to sensory stimuli in children with autism, using a new observational measure, the SPA, was examined. Three groups of young participants were assessed (autism, developmental delay, typical). Across all groups, MA was a predictor of hyperresponsiveness, such that aversion to multisensory toys decreased as MA increased. The two clinical groups displayed higher levels of sensory aversion than the typical group. The groups did not differ in the proportion of children habituating to an auditory stimulus; however, nonresponders were more prevalent in the autism group. These findings elucidate developmental influences on sensory features and the specificity of hyperresponsiveness to clinical groups. Implications for understanding pathogenesis, differentiating constructs of hypersensitivity, and planning treatment are discussed.

A two-year randomized controlled trial of progressive resistance exercise for Parkinson's disease

The effects of progressive resistance exercise (PRE) on the motor signs of Parkinsons disease have not been studied in controlled trials. The objective of the current trial was to compare 6‐, 12‐, 18‐, and 24‐month outcomes of patients with Parkinsons disease who received PRE with a stretching, balance, and strengthening exercise program. The authors conducted a randomized controlled trial between September 2007 and July 2011. Pairs of patients matched by sex and off‐medication scores on the Unified Parkinsons Disease Rating Scale, motor subscale (UPDRS‐III), were randomly assigned to the interventions with a 1:1 allocation ratio. The PRE group performed a weight‐lifting program. The modified fitness counts (mFC) group performed a stretching, balance, and strengthening exercise program. Patients exercised 2 days per week for 24 months at a gym. A personal trainer directed both weekly sessions for the first 6 months and 1 weekly session after 6 months. The primary outcome was the off‐medication UPDRS‐III score. Patients were followed for 24 months at 6‐month intervals. Of 51 patients, 20 in the PRE group and 18 in the mFC group completed the trial. At 24 months, the mean off‐medication UPDRS‐III score decreased more with PRE than with mFC (mean difference, −7.3 points; 95% confidence interval, −11.3 to −3.6; P<0.001). The PRE group had 10 adverse events, and the mFC group had 7 adverse events. PRE demonstrated a statistically and clinically significant reduction in UPDRS‐III scores compared with mFC and is recommended as a useful adjunct therapy to improve Parkinsonian motor signs.

Hyporesponsiveness to Social and Nonsocial Sensory Stimuli in Children with Autism, Children with Developmental Delays, and Typically Developing Children

This cross-sectional study seeks to (a) describe developmental correlates of sensory hyporesponsiveness to social and nonsocial stimuli, (b) determine whether hyporesponsiveness is generalized across contexts in children with autism relative to controls, and (c) test the associations between hyporesponsiveness and social communication outcomes. Three groups of children ages 11-105 months (N = 178; autism = 63, developmental delay = 47, typical development = 68) are given developmental and sensory measures including a behavioral orienting task (the Sensory Processing Assessment). Lab measures are significantly correlated with parental reports of sensory hyporesponsiveness. Censored regression models show that hyporesponsiveness decreased across groups with increasing mental age (MA). Group differences are significant but depend upon two-way interactions with MA and context (social and nonsocial). At a very young MA (e.g., 6 months), the autism group demonstrates more hyporesponsiveness to social and nonsocial stimuli (with larger effects for social) than developmental delay and typically developing groups, but at an older MA (e.g., 60 months) there are no significant differences. Hyporesponsiveness to social and nonsocial stimuli predicts lower levels of joint attention and language in children with autism. Generalized processes in attention disengagement and behavioral orienting may have relevance for identifying early risk factors of autism and for facilitating learning across contexts to support the development of joint attention and language.

Developmental trajectories and correlates of sensory processing in young boys with fragile X syndrome.

Background and Purpose: No longitudinal study on sensory processing in children with fragile X syndrome (FXS) exists. This study examined developmental trajectories and correlates of sensory processing from infancy through preschool years in 13 boys with FXS. Method: Participants were assessed using observational and parent-report measures 2–6 times between 9 and 54 months of age. Results: Over time, an increasing proportion of boys displayed sensory processing that differed significantly from test norms. Observational measures were more sensitive than parent-reports early in infancy. Age and developmental quotient significantly predicted levels of hyporesponsiveness; there was a trend for hyperresponsiveness to increase with age. Baseline physiological and biological measures were not predictive. Conclusions: Sensory processing problems are observable early and grow increasingly problematic from infancy through the preschool ages. Early identification and intervention may attenuate long-term difficulties for children with FXS.

Exercise improves cognition in Parkinson's disease: The PRET-PD randomized, clinical trial.

This article reports on the findings of the effect of two structured exercise interventions on secondary cognitive outcomes that were gathered as part of the Progressive Resistance Exercise Training in Parkinsons disease (PD) randomized, controlled trial.

A Pilot Study: Coordination of Precision Grip in Children and Adolescents with High Functioning Autism

Purpose: This pilot study compared temporal coordination during a precision grip task between 13 children and adolescents with autism spectrum disorders (ASD) who were high functioning and 13 peers with typical development. Methods: Temporal coordination between grip and load forces was measured using latency between onset of grip and load forces, grip force at onset of load force, peak grip force (PGF), and time to PGF. Results: Compared with peers with typical development, participants with ASD demonstrated prolonged latency between grip and load forces, elevated grip force at onset of load force, and increased movement variability. PGF and time to PGF were not significantly different between the 2 groups. Conclusions: These findings indicate temporal dyscoordination in participants with ASD. The findings also enhance our understanding of motor coordination deficits in persons with ASD and have theoretical as well as clinical implications.

Two-year exercise program improves physical function in Parkinson's disease: the PRET-PD randomized clinical trial.

Background. The progressive resistance exercise (PRE) in Parkinson’s disease trial (PRET-PD) showed that PRE improved the motor signs of PD compared to a modified Fitness Counts (mFC) program. It is unclear how long-term exercise affects physical function in these individuals. Objective. To examine the effects of long-term PRE and mFC on physical function outcome measures in individuals with PD. Methods. A preplanned secondary analysis was conducted using data from the 38 patients with idiopathic PD who completed the PRET-PD trial. Participants were randomized into PRE or mFC groups and exercised 2 days/week up to 24 months. Blinded assessors obtained functional outcomes on and off medication at baseline, 6 and 24 months with the Modified Physical Performance Test, 5 times sit to stand test, Functional Reach Test, Timed Up and Go, Berg Balance Scale, 6 minute walk test (6MWT), and 50-ft walking speed (walk speed). Results. The groups did not differ on any physical function measure at 6 or 24 months (Ps > .1). Across time, all physical function measures improved from baseline to 24 months when tested on medication (Ps < .0001), except for 6MWT (P = .068). Off medication results were similar except that the 6MWT was now significant. Conclusions. Twenty-four months of supervised and structured exercise (either PRE or mFC) is effective at improving functional performance outcomes in individuals with moderate PD. Clinicians should strive to include structured and supervised exercise in the long-term plan of care for individuals with PD.

Progressive Resistance Exercise and Parkinson's Disease: A Review of Potential Mechanisms

This paper reviews the therapeutically beneficial effects of progressive resistance exercise (PRE) on Parkinsons disease (PD). First, this paper discusses the rationale for PRE in PD. Within the first section, the review discusses the central mechanisms that underlie bradykinesia and muscle weakness, highlights findings related to the central changes that accompany PRE in healthy individuals, and extends these findings to individuals with PD. It then illustrates the hypothesized positive effects of PRE on nigro-striatal-thalamo-cortical activation and connectivity. Second, it reviews recent findings of the use of PRE in individuals with PD. Finally, knowledge gaps of using PRE on individuals with PD are discussed along with suggestions for future research.

Two-Year Exercise Program Improves Physical Function in Parkinson’s Disease

Background. The progressive resistance exercise (PRE) in Parkinson’s disease trial (PRET-PD) showed that PRE improved the motor signs of PD compared to a modified Fitness Counts (mFC) program. It is unclear how long-term exercise affects physical function in these individuals. Objective. To examine the effects of long-term PRE and mFC on physical function outcome measures in individuals with PD. Methods. A preplanned secondary analysis was conducted using data from the 38 patients with idiopathic PD who completed the PRET-PD trial. Participants were randomized into PRE or mFC groups and exercised 2 days/week up to 24 months. Blinded assessors obtained functional outcomes on and off medication at baseline, 6 and 24 months with the Modified Physical Performance Test, 5 times sit to stand test, Functional Reach Test, Timed Up and Go, Berg Balance Scale, 6 minute walk test (6MWT), and 50-ft walking speed (walk speed). Results. The groups did not differ on any physical function measure at 6 or 24 months (Ps > .1). Across time, all physical function measures improved from baseline to 24 months when tested on medication (Ps < .0001), except for 6MWT (P = .068). Off medication results were similar except that the 6MWT was now significant. Conclusions. Twenty-four months of supervised and structured exercise (either PRE or mFC) is effective at improving functional performance outcomes in individuals with moderate PD. Clinicians should strive to include structured and supervised exercise in the long-term plan of care for individuals with PD.

Coordination of precision grip in 2-6 years-old children with autism spectrum disorders compared to children developing typically and children with developmental disabilities

Impaired motor coordination is prevalent in children with Autism Spectrum Disorders (ASD) and affects adaptive skills. Little is known about the development of motor patterns in young children with ASD between 2 and 6 years of age. The purpose of the current study was threefold: (1) to describe developmental correlates of motor coordination in children with ASD, (2) to identify the extent to which motor coordination deficits are unique to ASD by using a control group of children with other developmental disabilities (DD), and (3) to determine the association between motor coordination variables and functional fine motor skills. Twenty-four children with ASD were compared to 30 children with typical development (TD) and 11 children with DD. A precision grip task was used to quantify and analyze motor coordination. The motor coordination variables were two temporal variables (grip to load force onset latency and time to peak grip force) and two force variables (grip force at onset of load force and peak grip force). Functional motor skills were assessed using the Fine Motor Age Equivalents of the Vineland Adaptive Behavior Scale and the Mullen Scales of Early Learning. Mixed regression models were used for all analyses. Children with ASD presented with significant motor coordination deficits only on the two temporal variables, and these variables differentiated children with ASD from the children with TD, but not from children with DD. Fine motor functional skills had no statistically significant associations with any of the motor coordination variables. These findings suggest that subtle problems in the timing of motor actions, possibly related to maturational delays in anticipatory feed-forward mechanisms, may underlie some motor deficits reported in children with ASD, but that these issues are not unique to this population. Further research is needed to investigate how children with ASD or DD compensate for motor control deficits to establish functional skills.