Developmental Trajectories and Correlates of Sensory Processing in Young Boys with Fragile X Syndrome

ArticleinPhysical & Occupational Therapy in Pediatrics 28(1):79-98 · February 2008with43 Reads
DOI: 10.1300/J006v28n01_06 · Source: PubMed
Abstract
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. Participants were assessed using observational and parent-report measures 2-6 times between 9 and 54 months of age. 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. 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.
    • "These data indicated that the fear/anxiety-related circuit would be more vulnerability against neonatal whisker trimming than the reward relation in the amygdala. Tactile defensiveness, defined as extreme sensitivity or aversive responsiveness to touch that would be benign to most people (e.g., light touch or clothing texture) is a common feature of neurodevelopmental disorders such as ASD and fragile X syndrome [49][50][51] . The tactile perception system is the earliest to develop among sensory systems. "
    [Show abstract] [Hide abstract] ABSTRACT: Abnormalities in tactile perception, such as sensory defensiveness, are common features in autism spectrum disorder (ASD). While not a diagnostic criterion for ASD, deficits in tactile perception contribute to the observed lack of social communication skills. However, the influence of tactile perception deficits on the development of social behaviors remains uncertain, as do the effects on neuronal circuits related to the emotional regulation of social interactions. In neonatal rodents, whiskers are the most important tactile apparatus, so bilateral whisker trimming is used as a model of early tactile deprivation. To address the influence of tactile deprivation on adult behavior, we performed bilateral whisker trimming in mice for 10 days after birth (BWT10 mice) and examined social behaviors, tactile discrimination, and c-Fos expression, a marker of neural activation, in adults after full whisker regrowth. Adult BWT10 mice exhibited significantly shorter crossable distances in the gap-crossing test than age-matched controls, indicating persistent deficits in whisker-dependent tactile perception. In contrast to controls, BWT10 mice exhibited no preference for the social compartment containing a conspecific in the three-chamber test. Furthermore, the development of amygdala circuitry was severely affected in BWT10 mice. Based on the c-Fos expression pattern, hyperactivity was found in BWT10 amygdala circuits for processing fear/anxiety-related responses to height stress but not in circuits for processing reward stimuli during whisker-dependent cued learning. These results demonstrate that neonatal whisker trimming and concomitant whisker-dependent tactile discrimination impairment severely disturbs the development of amygdala-dependent emotional regulation.
    Full-text · Article · Jun 2016
    • "The symptoms can be evaluated by clinical assessment or parent report (Baranek et al., 2008; Ben-Sasson et al., 2007; Tavassoli et al., 2015) and have recently been included as a criterion for ASD diagnosis in the Diagnostic and Statistical Manual of Mental Disorders, 5 th edition (DSM-5). Sensory abnormalities in ASD and FXS are not only among the most replicable features of these disorders (Ben-Sasson et al., 2008; Donkers et al., 2015; Klintwall et al., 2011; Liss et al., 2006), they are also present early in childhood (Baranek et al., 2008; Elison et al., 2013; Elsabbagh et al., 2013; Germani et al., 2014; Zwaigenbaum et al., 2005) and are strong predictors of some later-emerging symptoms, such as anxiety (Green et al., 2012; Sullivan et al., 2014). Importantly, sensory deficits may be accompanied by neurophysiological abnormalities of sensory processing which can be quantified objectively and non-invasively using electroencephalography (EEG) (Brandwein et al., 2015; Castrén et al., 2003; Lepisto et al., 2005; Machado et al., 2013; Orekhova et al., 2007; Orekhova et al., 2008; Stroganova et al., 2007; Van der Molen et al., 2012a, b; van Diessen et al., 2014; Wang et al., 2013 ) or electromyography (EMG) and/or behavioral measures of prepulse inhibition and habituation of the startle reflex (Perry et al., 2007a). "
    [Show abstract] [Hide abstract] ABSTRACT: Brains are constantly flooded with sensory information that needs to be filtered at the pre-attentional level and integrated into endogenous activity in order to allow for detection of salient information and an appropriate behavioral response. People with Autism Spectrum Disorder (ASD) or Fragile X Syndrome (FXS) are often over- or under-reactive to stimulation, leading to a wide range of behavioral symptoms. This altered sensitivity may be caused by disrupted sensory processing, signal integration and/or gating, and is often being neglected. Here, we review translational experimental approaches that are used to investigate sensory processing in humans with ASD and FXS, and in relevant rodent models. This includes electroencephalographic measurement of event related potentials, neural oscillations and mismatch negativity, as well as habituation and pre-pulse inhibition of startle. We outline robust evidence of disrupted sensory processing in individuals with ASD and FXS, and in respective animal models, focusing on the auditory sensory domain. Animal models provide an excellent opportunity to examine common mechanisms of sensory pathophysiology in order to develop therapeutics.
    Full-text · Article · May 2016
    • "Maladaptive sensory responses and impaired sensory integration are characteristic of FXS patients and model animals [6]–[9]. Studies of the Fmr1 KO mouse indicate that the null mutation has different effects on development in visual and somatosensory systems. "
    [Show abstract] [Hide abstract] ABSTRACT: Fragile X syndrome is a developmental disorder that affects sensory systems. A null mutation of the Fragile X Mental Retardation protein 1 (Fmr1) gene in mice has varied effects on developmental plasticity in different sensory systems, including normal barrel cortical plasticity, altered ocular dominance plasticity and grossly impaired auditory frequency map plasticity. The mutation also has different effects on long-term synaptic plasticity in somatosensory and visual cortical neurons, providing insights on how it may differentially affect the sensory systems. Here we present evidence that long-term potentiation (LTP) is impaired in the developing auditory cortex of the Fmr1 knockout (KO) mice. This impairment of synaptic plasticity is consistent with impaired frequency map plasticity in the Fmr1 KO mouse. Together, these results suggest a potential role of LTP in sensory map plasticity during early sensory development.
    Full-text · Article · Aug 2014
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