1. Arkesteyn A, Cornelissen V, Steyaert J, Claes J, Michielsen M, Van Damme T. The concurrent validity and test-retest reliability of a submaximal exercise test in adolescents with autism. Disabil Rehabil;2024 (Apr 21):1-11.

PURPOSE: There is a need for valid and reliable clinical assessment tools to assess cardiorespiratory fitness (CRF) levels in adolescents with autism. Therefore, this study aimed to examine the concurrent validity and test-retest reliability of the Astrand-Rhyming Test (ART) in this population. MATERIALS AND METHODS: 45 adolescents with autism aged 12-18 years (n = 32 males, 14.47 ± 1.79 years) performed the ART twice (test-retest reliability) and completed a maximal cardiopulmonary exercise test (CPET) (concurrent validity). Reliability parameters included Pearson correlations, intraclass correlation coefficients (ICCs), standard error of measurements (SEM), minimal detectable changes (MDC), coefficients of variation, paired sample t-tests, linear regressions and Bland-Altman plots. The concurrent validity was evaluated with Pearson correlations, ICCs, paired sample t-tests, linear regressions and Bland-Altman plots. RESULTS: Strong test-retest reliability (r = 0.84-0.85, ICC = 0.84-0.85) was found for the ART, but the wide limits of agreement intervals suggest the presence of substantial variability. The large SEM (4.73-5.08 mL/kg/min) and MDC (13.20-14.07 mL/kg/min) values suggest lower absolute reliability. Moderate to strong levels of association (r = 0.74-0.75) and agreement (ICC = 0.59-0.66) were found between estimated (ART1) and measured (CPET) VO(2) max levels, but significant systematic differences (5.71-8.82 mL/kg/min) were observed. CONCLUSION: The ART is an accessible and promising method to monitor submaximal CRF levels over time but is less appropriate to estimate maximal CRF levels in this population. Adolescents with autism are at increased risk of exhibiting low cardiorespiratory fitness (CRF) levels and as a result, placing them at risk for poor physical and mental health outcomes.In clinical practice, the CRF levels of this population should be screened and monitored routinely to identify those at risk and most likely to benefit from a targeted intervention.A submaximal exercise test appears to be feasible in adolescents with autism.The Astrand-Rhyming Test shows good reliability to monitor submaximal CRF levels over time, but is less appropriate to estimate maximal CRF levels in adolescents with autism.The use of the age correction factor of the Astrand-Rhyming Test nomogram is not required to adequately estimate CRF levels in adolescents with autism. eng

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2. Chiappini E, Massaccesi C, Korb S, Steyrl D, Willeit M, Silani G. Neural hyperresponsivity during the anticipation of tangible social and non-social rewards in autism spectrum disorder: a concurrent neuroimaging and facial electromyography study. Biol Psychiatry Cogn Neurosci Neuroimaging;2024 (Apr 18)

BACKGROUND: Atypical anticipation of social reward has been indicated to lie at the core of the social challenges faced by individuals with autism spectrum disorder (ASD). However, past research has yielded inconsistent results, often overlooking crucial characteristics of stimuli. Here, we investigated ASD reward processing using social and non-social tangible stimuli, carefully matched on several key dimensions. METHODS: We examined the anticipation and consumption of social (interpersonal touch) and non-social (flavored milk) rewards in 25 high-functioning ASD and 25 neurotypical adult individuals. Besides subjective ratings of wanting and liking, we measured physical energetic expenditure to get the rewards, brain activity with neuroimaging, and facial reactions through electromyography, on a trial-by-trial basis. RESULTS: ASD participants did not exhibit reduced motivation for social or non-social rewards; their subjective ratings, motivated efforts, and facial reactions were comparable to those of neurotypical participants. However, anticipation of higher-value rewards increased neural activation in lateral parietal cortices, sensorimotor regions and the orbitofrontal cortex. Moreover, ASD participants exhibited hyperconnectivity between frontal medial regions and occipital regions and the thalamus. CONCLUSIONS: Individuals with ASD experiencing rewards with tangible characteristics, whether social or non-social, displayed typical subjective and objective motivational and hedonic responses. Notably, the observed hyperactivations in sensory and attentional nodes during anticipation suggest atypical sensory over-processing of forthcoming rewards rather than decreased reward value. While these atypicalities may not manifest in observable behavior here, they could impact real-life social interactions that require nuanced predictions, potentially leading to the misperception of ASD reduced interest in rewarding social stimuli.

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3. Gurbuz E, Riby DM, South M, Hanley M. Associations between autistic traits, depression, social anxiety and social rejection in autistic and non-autistic adults. Sci Rep;2024 (Apr 20);14(1):9065.

Autistic people frequently experience negative judgements from non-autistic people, often fuelled by misconceptions that autistic people lack empathy. Understanding responses to negative social judgement among autistic people is crucial because of the potential negative impact on wellbeing and future interactions. We investigated the role of autistic traits, social anxiety, and depression on behavioural indices of social rejection in 20 autistic (AUT; 11 males) and 40 non-autistic (N-AUT; 21 males) university students. Participants completed the Social Judgement Task (SJT) where they predicted whether they were liked by another person, then received feedback on whether those evaluations were correct. Participants also completed an Age Judgement Task (AJT) where they estimated the age of the pictured person. The AUT group had lower positive expectation scores, meaning less tendency to predict being liked. Across the whole sample, higher social anxiety predicted greater tendency to anticipate rejection from others, not autistic traits. These findings suggest early experiences of rejection might lead to a negative self-bias in autistic people and emphasise the importance of using a transdiagnostic approach by showing that social anxiety rather than autistic traits is associated with expectation of social rejection.

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4. Klitzman R, Bezborodko E, Chung WK, Appelbaum PS. Views of Genetic Testing for Autism Among Autism Self-Advocates: A Qualitative Study. AJOB Empir Bioeth;2024 (Apr 21):1-18.

BACKGROUND: Autism self-advocates’ views regarding genetic tests for autism are important, but critical questions about their perspectives arise. METHODS: We interviewed 11 autism self-advocates, recruited through autism self-advocacy websites, for 1 h each. RESULTS: Interviewees viewed genetic testing and its potential pros and cons through the lens of their own indiviudal perceived challenges, needs and struggles, especially concerning stigma and discrimination, lack of accommodations and misunderstandings from society about autism, their particular needs for services, and being blamed by others and by themselves for autistic traits. Their views of genetic testing tended not to be binary, but rather depended on how the genetic test results would be used. Interviewees perceived pros of genetic testing both in general and with regard to themselves (e.g., by providing « scientific proof » of autism as a diagnosis and possibly increasing availability of services). But they also perceived disadvantages and limitations of testing (e.g., possible eugenic applications). Participants distinguished between what they felt would be best for themselves and for the autistic community as a whole. When asked if they would undergo testing for themselves, if offered, interviewees added several considerations (e.g., undergoing testing because they support science in general). Interviewees were divided whether a genetic diagnosis would or should reduce self-blame, and several were wary of testing unless treatment, prevention or societal attitudes changed. Weighing these competing pros and cons could be difficult. CONCLUSIONS: This study, the first to use in-depth qualitative interviews to assess views of autism self-advocates regarding genetic testing, highlights key complexities. Respondents felt that such testing is neither wholly good or bad in itself, but rather may be acceptable depending on how it is used, and should be employed in beneficial, not harmful ways. These findings have important implications for practice, education of multiple stakeholders, research, and policy.

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5. Lakhani DA, Agarwal AK, Middlebrooks EH. Ultra-high-field 7-Tesla magnetic resonance imaging in fragile X tremor/ataxia syndrome (FXTAS). Neuroradiol J;2024 (Apr 21):19714009241247464.

Fragile X tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder characterized by premutation expansion of fragile X mental retardation 1 (FMR1) gene. It is a common single-gene cause of tremor, ataxia, and cognitive decline in adults. FXTAS affects the central, peripheral and autonomic nervous systems, leading to a range of neurological symptoms from dementia to dysautonomia. A characteristic imaging feature of FXTAS is symmetric T2 hyperintensity in the deep white matter of the cerebellar hemispheres and middle cerebral peduncle. However, recent studies have reported additional findings on diffusion weighted images (DWI), such as a symmetric high-intensity band-like signal at the cerebral corticomedullary junction. These findings, along with the characteristic cerebellar signal alterations, overlap with imaging findings seen in adult-onset neuronal intranuclear inclusion disease (NIID). Importantly, recent pathology studies have shown that both FXTAS and NIID can manifest intranuclear inclusion bodies, posing a diagnostic challenge and potential for misdiagnosis. We describe a 58-year-old man with FXTAS who received an erroneous diagnosis based on imaging and histopathology results. We emphasize the potential pitfalls in distinguishing NIID from FXTAS and stress the importance of genetic analysis in all cases with suspected NIID and FXTAS for confirmation. Additionally, we present the 7T MRI brain findings of FXTAS.

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6. Lingwood C. Is cholesterol both the lock and key to abnormal transmembrane signals in Autism Spectrum Disorder?. Lipids Health Dis;2024 (Apr 20);23(1):114.

Disturbances in cholesterol homeostasis have been associated with ASD. Lipid rafts are central in many transmembrane signaling pathways (including mTOR) and changes in raft cholesterol content affect their order function. Cholesterol levels are controlled by several mechanisms, including endoplasmic reticulum associated degradation (ERAD) of the rate limiting HMGCoA reductase. A new approach to increase cholesterol via temporary ERAD blockade using a benign bacterial toxin-derived competitor for the ERAD translocon is suggested.A new lock and key model for cholesterol/lipid raft dependent signaling is proposed in which the rafts provide both the afferent and efferent ‘tumblers’ across the membrane to allow ‘lock and key’ receptor transmembrane signals.

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