Post-Mortem Comparison of the Incidence and the Distribution of Cerebrovascular Lesions Using Additional 7.0-Tesla Magnetic Resonance Imaging in Cognitive Normal Young, Middle-Aged, and Elderly Persons

Abstract

Regional brain atrophy and an escalation in vascular risk are associated to increasing age in normal cognitive healthy persons. The present post-mortem study compares the incidence of cerebrovascular lesions between young-aged, middle-aged, and elderly cognitive normal persons with additional 7.0-tesla MRI). The patients consisted of 10 young adults, 20 middle-aged adults, and 14 elderly ones. In addition to the macroscopic visible cerebrovascular lesions, a whole coronal section of a cerebral hemisphere was taken for the semi-quantitative evaluation of white matter changes (WMCs), cortical micro-infarcts (CoMIs), and cortical micro-bleeds (CoMBs). Three separate coronal sections of a cerebral hemisphere were submitted to T2 and T2* MRI sequences for semi-quantitative evaluation of the small cerebrovascular lesions. Arterial hypertension, hypercholesterolemia, and the use of anti-thrombotic agents were found to be more frequent in the elderly group, and to a lesser degree in the middle-aged group. The neuropathological examination showed more severe WMCs and an increased number of CoMBs in the elderly group. On NMR the increased severity of WMCs was only found in the frontal and occipital sections of the elderly brains. CoMIs were augmented in the central and occipital sections of the middle-aged and the elderly persons. CoMBs were increased in all coronal sections of elderly as well as middle-aged groups. CoMIs reflect most significantly the cerebrovascular involvement of the aging brain. The increase of WMCs is probably mostly related the aging related neurodegenerative progression. The increase of CoMBs is probably due to mixed cerebrovascular and neurodegenerative pathology.