Anatomical and Neuropathological Changes in Schizophrenia Patients
Gross Anatomy by Brain Imaging
Advances in brain imaging technology, especially magnetic resonance imaging, have established that there are significant, although not very robust, anatomical changes in brains of patients with schizophreniaImaging studies of chronic schizophrenia patients have detected enlarged ventricles (figure 1A) accompanied by volume decreases in amygdala, parahippocampal gyrus, and temporal lobes.4,8,9 Enlarged lateral and third ventricles and decrease in whole brain, hippocampal, basal ganglia, and thalamic volumes are present in first-episode patients with schizophrenia.10,11 There has been a debate about how long these changes continue after the onset of the disease. Recent longitudinal studies have suggested continuously progressive decreases in volumes of brain tissue and increases in volumes of lateral ventricles up to at least 20 years after the first symptoms. Progressive volume loss after the onset of the disease seems most pronounced in the frontal and temporal gray matter areas.12 Focusing on the frontal lobe, progressive volume decreases have been repeatedly reported.13–15 The progression of cortical gray matter deficits could arise from pathological disease progression, drug effect,16 or possibly in some cases comorbidity such as alcoholism.17Evaluation of the integrity of white matter fiber tracts by diffusion tensor imaging has shown abnormalities in the prefrontal and temporal lobes, cingulum, and corpus callosum.18
The normal human brain is anatomically and functionally asymmetrical. A meta-analysis of anatomical asymmetry in schizophrenia found abnormal brain torque and decrease of asymmetry favoring the left planum temporal and left Sylvian fissure. Because asymmetries in these areas are strongly related to cerebral dominance, the decreased temporo-parietal asymmetries may contribute to the decreased language dominance in schizophrenia.19