Cognitive function and language of a child with an arachnoid cyst in the left frontal fossa.

The authors inspected the cognitive function of a boy with a congenital arachnoid cyst in the left frontal fossa. Neuropsychological tests described his cognition, including language, memory, and frontal functions, as mildly retarded overall. The boy's verbal ability was delayed, but his frontal function was intact. We supposed that the cyst would not affect his cognitive function. SPECT images showed low perfusion in the left temporal lobe. Dysfunction of the left temporal lobe should cause delayed language leading to learning difficulty. Neuropsychological evaluation of cognitive function concurrent with rCBF imaging was necessary not only for describing the influence of the cyst but also in discriminating its psychological aspects.