30430
Language Regression Is Associated with Faster/Normal Motor Development Among Toddlers with Autism
Objectives: To examine whether ASD children with LR differ from ASD children without LR in achieving early developmental milestones.
Methods: We studied 218 children with ASD who are part of the Negev Autism Center cohort (www.negevautism.org). ASD diagnosis was determined using DSM-5 criteria and confirmed by the Autism Diagnostic Observation Scale-2 (ADOS-2) test. Parents of all children in this sample completed a detailed intake questionnaire that included questions regarding language development, language regression (LR), and the timing of other developmental milestones. LR was further confirmed by examining the clinical report of the family’s initial intake meeting with a clinician and by an additional phone interview of the parents. Children with no regression (NR) were defined as cases where there was no indication of regression in the clinical history or intake form.
Results: Overall, 37 children with ASD (17.0%) had confirmed LR and 119 children with ASD (54.6%) did not have any concern of regression (NR). Examination of the birth records of these children revealed a remarkably higher rate of premature births (<35 weeks) among the NR group compared to the LR group (12.6% vs 2.7% respectively; p=0.12). Since premature birth is a known risk factor for both ASD and delayed motor development, we excluded these cases (1 LR and 15 NR) from our analyses. Diagnosis of ASD in the LR group took place 8.5 months earlier, on average, than in the NR group (32.1±9.1 vs. 40.6±15.6 months; p<0.005). Comparison of developmental milestones between the groups revealed that LR children developed faster than NR children exhibiting earlier crawling (7.41±2.06 vs. 8.90±3.24; p=0.02), walking (12.7±1.95 vs. 16.1±4.76; p<0.001), and use of words (12.4±3.67 vs. 19.9±11.4, p<0.001, even when excluding 27 non-verbal children from the NR group). Finally, 7 children in the NR group and 0 children in the LR group had hypotonia during the first year of life.
Conclusions: These findings suggest that ASD children with LR exhibit a variety of distinct early developmental characteristics in comparison to ASD children with NR. Stratifying ASD children into these groups is likely to be of great importance when assessing potential early markers of autism risk (such as premature birth, hypotonia, and motor difficulties), which do not seem to appear in the LR subgroup. Similarly, these differences motivate additional research into the potentially distinct etiology of ASD children with LR.