Absence of neurodegeneration in the thalamus and caudate of elderly patients with schizophrenia

The cognitive and functional deterioration observed in many 'poor-outcome' patients with schizophrenia suggests an ongoing neurodegenerative process. Diagnostic neuropathologic studies have excluded known neurodegenerative di seases as the cause of this dementia, and in a previous quantitative invest igation of neurodegeneration and neural injury in this population we found no abnormalities in the cerebral cortex. However, it is possible that the d eterioration observed in these patients could be due to subcortical neurode generative processes. Neurodegeneration and neural injury in the caudate nu cleus and mediodorsal nucleus of the thalamus were investigated in a postmo rtem study of 11 prospectively accrued, clinically well-characterized elder ly people with schizophrenia, 11 elderly control subjects with no neuropsyc hiatric illness, and 12 subjects with Alzheimer's disease. Traditional and immunohistochemical staining and unbiased computerized counting methods wer e used to quantify common markers of neurodegeneration and neural injury (n euron loss, neurofibrillary tangles, astrocytosis, microgliosis). No statis tically significant differences were found between schizophrenia and contro l subjects for the densities of any markers. There is no evidence that abno rmal neurodegeneration occurs in these two important subcortical structures . (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.