Medical Problems Co-Occur with Autism Spectrum Disorders and Affect the Clinical Presentation

Background:  

Medical conditions, including, sleep, eating and gastrointestinal (GI) problems and the presence of minor neurological dysfunction (MND), have been reported in autism spectrum disorders (ASD). Few studies have investigated the relationship between these medical problems and clinical manifestations in ASD.

Objectives:  

1. To describe the frequencies of sleep, eating and GI problems and MND in a large cohort with ASD; 2. To examine the relationship between these medical conditions and autism severity and adaptive functioning

Methods:  

Of 637 participants evaluated in a tertiary autism center, 529 were diagnosed with ASD and 108 received other diagnoses (developmental delay, specific language impairment, ADHD, and more). Medical histories were obtained from parents and a comprehensive neurological examination was performed by a pediatric neurologist. Evaluations of autism severity were based on the Autism Diagnosis Observation Schedule (ADOS) and the new ADOS severity scale. Adaptive skills were assessed using the Vineland Adaptive Behavior Scales. Non-parametric tests were used for nominal variables and MANCOVAs controlling for age were used for scale variables (adaptive skills, autism severity).

Results:  

Sleep problems were not significantly different in the ASD cohort (N=185; 38.3%) in comparison to the non-ASD group (38.8%). In the ASD cohort, the group without sleep problems had better adaptive functioning than the group with sleep problems. Differences were noted in three adaptive domains: communication (p<.01), daily living (p<.05) and socialization (p<.05). Autism severity scores did not differ in these groups. Eating problems were significantly more common in the ASD cohort (N=191; 38.7%) than in the non-ASD group (28%), χ² (3)=43.4, p<001. Eating problems in the ASD cohort included minor food selectivity (N=112; 22.7%), major food selectivity (N= 69; 14%) and motor related eating problems (N=10; 2%). The group with no or minor eating problems had better adaptive functioning only in the daily living skills domain than the group with major eating problems (p<.05). Autism severity scores were not different in these groups. GI problems were documented in 16.7% of the ASD cohort and in 23.8% of the non-ASD group with no significant difference between the groups. Adaptive functioning and autism severity scores were not different in these groups. Having MND was very common in the ASD cohort (N= 274; 57%), but not significantly different than the rate in the non-ASD group (47%). The most common MND in the ASD cohort were: hyperlaxity of joints (34.8%), abnormal deep tendon reflexes (30.3%), hypotonia (27.9%), cerebellar dysfunction (17.2%) and hypertonia (2.3%). Comparison of adaptive skills functioning revealed that the group with intact examination had better motor skills (85.9±13.5) than the group with MND (80.0±16.9) [F(1,343)=11.5, p<.001, µ²=.032]. Autism severity scores were not different in these groups.

Conclusions:  

Eating, GI and sleep problems and minor neurological dysfunction co-occur frequently in ASD and in other developmental disabilities. However, only food selectivity problems are more common in ASD. These medical problems affect adaptive functioning but not autism severity. Assessment and treatment of these medical problems in ASD is of great importance.