The neurovascular unit and possible influences on cerebral small vessel disease

Introduction: Small vessel disease (SVD) is reflected by injury to the microvasculature. Once thought to be inert immobile conduits of blood flow in the central nervous system (CNS), cerebral microvessels have since been shown to be structures of considerable complexity, with dynamic functional responses as rapid as those of neurons. Defined as cerebral vessels less than 100 µm diameter, microvessels represent one limb of the neurovascular unit. There is a meager hold of information about the cerebral microvasculature beyond their ultrastructure and histology. SVD manifests in a variety of disorders of varying etiology, typified by lacunes, microhemorrhages, vascular cognitive impairment, and other conditions affecting microvessels and larger CNS vessels [1]. The precise targets for the initial injury may be obscured in the history of the tissue. Furthermore, there are significant limitations in our understanding of the molecular initiators of SVD, in part due to limitations in the resolution of the techniques at hand. However, considerations of the better-characterized acute and early alterations in the microvasculature evident during ischemia may be informative to the topic of SVD.