Aim  The aim of this study was to improve the understanding of brain function in children with autism spectrum disorder (ASD) in relation to minor neurological dysfunctions (MNDs).

Method  We studied MNDs in 122 children (93 males, 29 females; mean age 8y 1mo, SD 2y 6mo) who, among a total cohort of 705 children (513 males, 192 females; mean age 9y, SD 2y 0.5mo) referred to a regional outpatient non-academic psychiatric centre in the Netherlands, were diagnosed with ASD after an extensive multidisciplinary psychiatric assessment. Children with clear neurological abnormalities (e.g. cerebral palsy or spina bifida) were excluded from the study. MNDs were assessed in all 705 children using the Touwen examination method. Special attention was paid to the severity and type of MND. Data of the children with ASD were compared with neurological morbidity data of children with other psychiatric disorders and with children in the general population, who were born at Groningen University Hospital between 1975 and 1978.

Results  Seventy-four percent of the children with ASD showed complex MNDs compared with 52% of the children with other psychiatric disorders and 6% of the reference group (χ2=18.0, p<0.001; χ2=937.5, p<0.001 respectively). Specific dysfunctions frequently encountered in ASD were dysfunctional posture and muscle tone, fine manipulative disability, dyscoordination, and excessive associated movements.

Conclusion  These findings suggest a contribution of dysfunctional supraspinal networks involving multiple parts of the brain in the pathogenesis of ASD. This is consistent with findings from neuroimaging studies, and highlights the importance of neurological examinations in paediatric psychiatric assessments.