Lessons About Brain Vascular Disease From Another Pulsating Organ, the Kidney

Abstract

See related article, pages 55–61. Because of similarities in the vascular supply to kidney and brain, information about vascular disease in one organ may inform us about vascular disease in the other, and such knowledge may shed light on ways to treat or prevent these diseases. Unlike most organs, both kidney and brain are low resistance end-organs and are exposed to high-volume blood flow throughout the cardiac cycle, explaining their pulsating nature.1 For the kidney, impairments from vascular disease manifest as problems with glomerular filtration, detected clinically by biochemical makers such as serum creatinine, urinary albumin, and serum cystatin C. For the brain, impairments manifest with overt focal neurological deficits, such as with stroke or transient ischemic attack, or as covert global deficits affecting cognition, mobility and mood, such as has been suggested with small-vessel disease. In humans, investigation of brain vascular disease and how it causes impairment of brain function often entails looking at the structure of the brain with MRI for infarctions, white matter lesions, and volumes of brain, ventricles and sulci. Given the difficulty in getting tissue, exploration of cause usually does not include microscopic examination of brain tissue, although microinfarcts inapparent on MRI can be identified.2 For investigation of vascular disease in the kidney, structural changes detectable on imaging are limited primarily to decrements in kidney size due to chronic fibrosis and atrophy. On the other hand, tissue is more …