Developmental language disorder associated with polymicrogyria

Subtle disorders of neuronal migration occur in the brains of some dyslexic patients who presented developmental language disorder (DLD) during early childhood.

To investigate a possible neuroanatomical substrate based on neuroimaging evaluation in children with DLD.

The authors obtained psychological assessment, language evaluation, neurologic examination, and neuroimaging investigation. Inclusion criteria were as follows: children should be at least 4 years of age; primary complaint of language delay; normal hearing; IQ >70; and an informed consent form signed by parents or guardians. Exclusion criteria were severe motor and cognitive handicap.

Fifteen children met all inclusion criteria. Ages ranged from 4 to 14 years and 11 were boys. Six patients presented diffuse polymicrogyria (PMG) around the entire extent of the sylvian fissure on MRI, and they had severe clinical manifestation of DLD: they did not speak at all or had mixed phonologic-syntactic deficit syndrome. Six children presented PMG restricted to the posterior aspects of the parietal regions, and they had a milder form of DLD: mainly phonologic programming deficit syndrome. The other three children had different imaging findings.

Developmental language disorder can be associated with polymicrogyria and the clinical manifestation varies according to the extension of cortical abnormality. A subtle form of posterior parietal polymicrogyria presenting as developmental language disorder is a mild form of perisylvian syndrome.