Anomalous lateral sulcus asymmetry and cognitive function in first-episode schizophrenia

This study examines the cognitive functioning of first-episode schizophreniform patients within several weeks of hospitalization and at 2 years into the illness. Differences between patients and controls are also reported for measurements of the length of the lateral sulcus, which borders the planum temporal, an area of the brain integral to language function. Neuropsychological test results are also correlated to magnetic resonance imaging structural variables at the time of first hospitalization. Findings on neuropsychological summary scales reveal a diffuse pattern of cognitive impairment in schizophreniform patients compared to controls, which appears to improve over time. An atypical pattern of anatomic lateral symmetry is found in female schizophreniform patients, with female appearing to have a reduction in the normally occurring left greater than right length of the lateral sulcus. Such atypical asymmetry of the lateral sulcus is also associated with better cognitive function, particularly in schizophreniform patients. These findings suggest that atypical lateralization in an area critical to language function may be related to cognitive function in schizophreniform illness.