Intracerebral Hemorrhage: An Acute Manifestation of Small Vessel Disease?

Although intracerebral hemorrhage (ICH) and cerebral small vessel disease (cSVD) have long been considered distinct clinical entities, emerging evidence reveals significant overlap in their etiologies and imaging markers. This review aims to explore the relationship between ICH and cSVD, suggesting that ICH may represent an acute manifestation of small vessel disease. ICH is primarily caused by cerebral amyloid angiopathy and hypertension, while cSVD is mainly attributed to cerebral amyloid angiopathy and arteriolosclerosis. Hypertension-induced arteriolosclerosis is one of the most common pathologic changes in cSVD. This overlap in etiology suggests a close relationship between ICH and cSVD. In patients with ICH, multiple imaging markers of cSVD are often observed. Recent studies suggest that enlarged perivascular spaces, one of the imaging markers of cSVD, may serve as a pathway for hematoma expansion. Additionally, diffusion-weighted imaging lesions are frequently observed in patients with ICH. These lesions are likely to be based on underlying cSVD and may evolve into other cSVD markers, such as white matter hyperintensity, lacunar infarctions, or microbleeds. These findings highlight the complex interplay between ICH and cSVD, suggesting that ICH could be considered an acute expression of cSVD rather than an entirely separate entity.