Some recent evidence has suggested abnormalities of the dorsal stream and possibly the mirror neuron system in autism, which may be responsible for impairments of joint attention, imitation, and secondarily for language delays. The current study investigates functional connectivity along the dorsal stream in autism, examining interregional blood oxygenation level dependent (BOLD) signal cross-correlation during visuomotor coordination. Eight high-functioning autistic men and 8 handedness and age-matched controls were included. Visually prompted button presses were performed with the preferred hand. For each subject, functional connectivity was computed in terms of BOLD signal correlation with the mean time series in bilateral visual area 17. Our hypothesis of reduced dorsal stream connectivity in autism was only in part confirmed. Functional connectivity with superior parietal areas was not significantly reduced. However, the autism group showed significantly reduced connectivity with bilateral inferior frontal area 44, which is compatible with the hypothesis of mirror neuron defects in autism. More generally, our findings suggest that dorsal stream connectivity in autism may not be fully functional.

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A partnership between pediatricians and autism specialists resulted in effective, systematic autism screening. Future studies should examine how to create effective systems of care.

There are no epidemiological data on autism for Mexico. This study was conducted to generate a first estimate of ASD prevalence in Mexico. We surveyed children age eight in Leon (Guanajuato). The sample was stratified in two strata: (1) children having special education and medical records (SEMR; N = 432) and (2) children attending regular schools (GSS; N = 11,684). GSS children were screened with the SRS and those with the highest scores were invited to a diagnostic evaluation. The final sample comprised 36 children (80.6 % male) who had confirmed ASD. A third had intellectual disability, 25 % were non-verbal, 69 % had co-occurring behavioral problems. The prevalence overall was 0.87 % (95 % CI 0.62, 1.1 %). This survey provides an estimate for ASD prevalence in Mexico that is consistent with recent studies.

BACKGROUND: Pediatricians, neurologists, and geneticists are important sources for autism surveillance, screening, and referrals, but practical time constraints limit the clinical utility of behavioral observations. We analyzed behaviors under favorable conditions (ie, video of autism evaluations reviewed by experts) to determine what is optimally observable within 10-minute samples, asked for referral impressions, and compared these to formal screening and developmental testing results.METHODS: Participants (n = 42, aged 15 to 33 months) were typically developing controls and children who screened positive during universal autism screening within a large community pediatric practice. Diagnostic evaluations were performed after screening to determine group status (autism, language delay, or typical). Licensed psychologists with toddler and autism expertise, unaware of diagnostic status, analyzed two 10-minute video samples of participants' autism evaluations, measuring 5 behaviors: Responding, Initiating, Vocalizing, Play, and Response to Name. Raters were asked for autism referral impressions based solely on individual 10-minute observations. RESULTS: Children who had autism showed more typical behavior (89% of the time) than atypical behavior (11%) overall. Expert raters missed 39% of cases in the autism group as needing autism referrals based on brief but highly focused observations. Significant differences in cognitive and adaptive development existed among groups, with receptive language skills differentiating the 3 groups.CONCLUSIONS: Brief clinical observations may not provide enough information about atypical behaviors to reliably detect autism risk. High prevalence of typical behaviors in brief samples may distort clinical impressions of atypical behaviors. Formal screening tools and general developmental testing provide critical data for accurate referrals. WHAT'S KNOWN ON THIS SUBJECT:Behavioral observations influence a clinician' s decision to diagnose or refer, and may even override formal screening results. In the case of autism spectrum disorder, an expected rate of atypical behavior during the span of a medical visit is unknown. WHAT THIS STUDY ADDS:We are the first to quantify the high base rates of typical behavior in young children who have autism and language delay. When observation times are brief, the preponderance of typical behaviors may negatively impact referral decision accuracy.