Disorders, Disabilities, and Differences: Reconciling the Medical Model with a Neurodiversity Perspective.

CASE SECTION: Zoe is a 25-month-old girl who presented to developmental-behavioral pediatrics with her parents for follow-up after receiving a diagnosis of autism spectrum disorder with global developmental delay and language impairment 3 months ago. Zoe was born by spontaneous vaginal delivery at term after an uncomplicated pregnancy, labor, and delivery. She had a routine newborn course and was discharged home with her parents 2 days after her birth.At 7 months, Zoe was not able to sit independently, had poor weight gain, and had hypertonia on physical examination. Her parents described her to tense her arms and have hand tremors when she held her bottle during feedings and reported that she had resisted their attempts to introduce pureed or other age-appropriate table foods into her diet. The Bayley Scales of Infant and Toddler Development Screening Test was administered and found a cognitive composite score of 70, language composite score of 65, and motor composite score of 67. Chromosomal microarray analysis, testing for fragile X syndrome, laboratory studies for metabolic disorders, magnetic resonance imaging of the brain, and an audiologic examination were normal. Zoe was referred to and received early intervention services including physical therapy, feeding therapy, and infant stimulation services. By 16 months, Zoe was walking independently and was gaining weight well but continued to have sensory aversions to some foods.At 22 months, Zoe was evaluated by a multidisciplinary team because of ongoing developmental concerns and concerning results on standardized screening for autism spectrum disorder completed at her 18-month preventive care visit. Her parents also reported concern about the possibility of autism spectrum disorder (ASD) because they both were diagnosed with ASD as young children. Both parents completed college and were employed full-time. Zoe's mother seemed to be somewhat anxious during the visit and provided fleeting eye contact throughout the evaluation. Zoe's father was assertive, but polite, and was the primary historian regarding parental concerns during the evaluation.Zoe was noted to have occasional hand flapping and squealing vocalizations while she roamed the examination area grabbing various objects and casting them to the floor while watching the trajectory of their movements. She did not use a single-finger point to indicate her wants or needs and did not initiate or follow joint attention. She met criteria for ASD. In discussing the diagnosis with Zoe's parents, they shared that they were not surprised by the diagnosis. They expressed feeling that Zoe was social and playful, although delayed in her language. Hence, they were more concerned about her disinterest in eating. They were not keen on behavioral intervention because they did not want Zoe to be "trained to be neurotypical." Although the mother did not receive applied behavior analysis (ABA), the father had received ABA for 3 years beginning at age 5 years. He believed that ABA negatively changed his personality, and he did not want the same for Zoe.How would you assist Zoe's parents in identification of priorities for her developmental care while ensuring respect for their perspective of neurodiversity?

Simulation of exercise-dependent difference in metabolism with a mathematical model for analyses of measurements using near-infrared spectroscopy.

Near-infrared spectroscopy (NIRS) is a useful technique for noninvasive measurement of muscle oxygenation. However, analyses of the dynamic changes in muscle metabolism based only on experimental observations of NIRS are difficult. Therefore, we constructed a mathematical model of muscle metabolism, comprising of the ATP synthesizing systems and O2 diffusion system, to identify the mechanisms responsible for those observations. A customized NIRS instrument was used to measure the changes in muscle oxygenation of the forearm flexor muscles during intermittent and continuous isometric flexion exercises when healthy male subjects participated in exercises tests. The exercise-dependent difference in changes could be distinguished and the simulated results agreed well with that measured experimentally. Although the contraction intensity for both exercises was identical, the magnitude of energy needed to perform the respective exercises was different. This difference was reflected by the changes in the ATP synthesizing systems, in which the energy needed during the latter-half of continuous exercise was mostly supplied by anaerobic system, whereas that during intermittent exercise was supplied by the aerobic and anaerobic systems that operated synergistically. From the results, we conclude that the model could be a useful tool for the elucidation of the relationship between experimental observations of NIRS and muscle metabolism.

Imaging of Regional Differences of Muscle Oxygenation during Exercise Using Spatially Resolved NIRS.

The development of imaging systems using near-infrared spectroscopy (NIRS) has enabled noninvasive measurement of regional changes in muscle oxygenation. A spatially resolved NIRS (SR-NIRS) imaging instrument was utilized for real-time measurement of spatial-temporal changes in muscle oxygenation during exercises. Changes in muscle oxygenation and localized O2consumption in the quadriceps muscle were measured during sustained isometric knee extension without and with leg-press to the ground exercises. In the former exercise, the level of tissue oxygen saturation (TOS) of the rectus femoris (RF) muscle was found to be lower than that of vastus lateralis (VL) and vastus medialis (VM) muscles. The highest localized O2consumption rate, VO2, reflecting the localization in distribution of muscle metabolism, was detected in the RF muscle at the initial stage of exercise. As exercise progressed, VO2of the RF muscle decreased whereas that of the VL and VM muscles increased. In contrast, TOS decreased to about the same level for the VL, RF and VM muscles in the latter exercise. Also, VO2of all three muscles decreased as exercise progressed. Initial results demonstrated that the SR-NIRS instrument enables measurement of regional differences in muscle oxygenation in the quadriceps muscle during different exercises.