Head Circumference in Autism, Asperger’s Syndrome, and ADHD: a comparative study

Gillberg, C and de Souza, L, Developmental Medicine and Child Neurology 2002, 44: 296-300.

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This study was undertaken to test the hypothesis that children with autistic spectrum disorders often have macrocephalus, and that those without comorbid learning disability are most frequently affected. Fifty consecutive children with Asperger’s Syndrome (45 males, five females; mean age 9 years, range 1 year 6 months to 16 years) without indications of underlying medical disorders were matched for birth year and sex with 50 children (45 males, five females; mean age 6 years 4 months, range 1 year 4 months to 13 years 11 months) who met criteria for autistic disorder and with 50 children who met the criteria for attention deficit-hyperactivity disorder. Birth and neuropsychiatric follow-up records were examined and data relating to occipitofrontal circumference, weight and height were detailed. The group with Asperger’s Syndrome included a subset of individuals with macrocephalus recorded both at birth and at follow up after the first year of life. Another sub-group developed macrocephalus during early childhood. Autistic spectrum disorders include a subgroup with macrocephalus characterised by a relatively high level of functioning and a clinical presentation most often consistent with a diagnosis of Asperger’s Syndrome.

On the basis of the results obtained in this clinical study, it would appear that one in four to one in five of children with Asperger’s Syndrome, but only one in 10 of those with autistic disorder, have macrocephalus ascertained after age 16 months, which had been present from birth.

Contrary to some previous findings, there were indications in our study that about half of those with Asperger’s Syndrome (and 50 to 75% of those with autistic disorder) who were macrocephalic after 16 months of age had developmental macrocephalus, i.e. the large head was not present from birth. Nevertheless, a substantial proportion of all the patients with autistic spectrum disorders in our study also had developmental macrocephalus.