Morphometry of structural preservation of tunica media in aged and hypertensive human intracerebral arteries

Abstract

Background and Purpose Medial smooth muscle cell necrosis has been reported as a lesion that may precede angionecrosis, which is a major cause of not only hypertensive brain hemorrhage but also lacunar infarct. We morphometrically studied a loss of smooth muscle cells in the media of cerebral arteries in relation to clinical risk factors. Methods The lateral striate, ie, perforating arteries and the medullary arteries in the subcortical white matter of the temporal lobe (100 to 400 μm in diameter) were histologically investigated in 121 autopsied brains. Medial area was measured quantitatively, and the number of nuclei of smooth muscle cells in the area was calculated in 1210 cross-sectional arteries of histological sections. The influence on the structural (ie, smooth muscle cell) preservation of the tunica media (ratio of number of smooth muscle cell nuclei to medial area [N-MA ratio]) of age, blood pressure, serum lipids, and presence or absence of extracerebral severe atherosclerosis was investigated. Results The N-MA ratio decreased slightly with age in both arteries. A reverse correlation between N-MA ratio and age was seen in groups both with and without hypertension. The mean N-MA ratio in the hypertensive group was significantly lower than that of the nonhypertensive group (P