Are cortical microvascular raspberries caused by cerebral hypoperfusion? An exploratory pathological study.

Abstract

This retrospective study investigated a cortical microvascular formation, termed a 'raspberry' due to its appearance under a bright-field microscope. We examined whether there is support for the hypothesis that raspberry formation is an angiogenic process induced by cerebral hypoperfusion. Raspberries were manually quantified in haematoxylin and eosin-stained cortical sections from the anterior frontal lobe of deceased individuals who had undergone a diagnostic neuropathological examination at the Department of Pathology, Lund, Sweden, during April 2019-January 2021. Subjects represented consecutively received cases during this 22-month period. The raspberry density was compared between subjects according to variables collected from medical records and autopsy reports: age, sex, hypertension, diabetes mellitus, atrial fibrillation, orthostatic hypotension, chronic heart failure, acute circulatory failure, aortic atherosclerosis, atherosclerosis of the basal cerebral arteries (referred to as 'cerebral atherosclerosis'), cerebral small vessel disease, cerebral amyloid angiopathy, cerebral infarction, and ischaemic white matter disease. 62 subjects were included. The mean age was 71.9 years (range 46-97 years). 21 subjects (33.9%) were female. Independent-samples t-test showed a higher raspberry density in subjects with cerebral atherosclerosis (p=0.029; 95% CI 0.7, 11.6 raspberries/cm²). The higher raspberry density in subjects with cerebral atherosclerosis remained in multiple linear regression (p=0.003; 95% CI 2.3, 11.1 raspberries/cm²). This exploratory study indicates that cortical raspberries could be associated with cerebral atherosclerosis. The remaining results were inconclusive but motivate further examination of variables such as acute circulatory failure.