Normal intrasylvian anatomical asymmetry in children with developmental language disorder.

Symmetry of posterior intrasylvian cortices (e.g., planum temporale, planum parietale) has been suggested to represent a risk factor for developmental disorders of language and reading. Using high-resolution magnetic resonance morphometry, we studied 21 right-handed children with developmental language disorder of the phonologic-syntactic type, and found normal left-right asymmetry of the planum temporale and planum parietale when compared with 21 matched controls. The planum temporale was bilaterally smaller in the affected children, a finding accounted for by their approximately 7% smaller forebrain size. Our data do not support a role of gross visible unilateral or bilateral abnormalities of posterior intrasylvian ontogenesis in this disorder.