Читать книгу Recent Advances in Dialysis Therapy in Japan - Группа авторов - Страница 56

WMHs comprising periventricular hyperintensity (PVH) and deep and subcortical WMH (DSWMH) are common radiographic findings on MRI in the elderly and hypertensive populations [7, 18]. WMHs are assumed to be caused by chronic hypoperfusion or ischemia due to arteriolosclerosis [7], but the pathogenesis remains to be fully elucidated. The incidence of WMHs among the middle-aged and elderly general population is 24.6–33% [18–21], and is higher in dialysis patients (52–76.7%) compared with healthy individuals [11, 22, 23]. WMHs have previously been assumed to be age-related changes with little clinical significance, but accumulating evidence has shown them to be markers of ischemic cerebral small-vessel disease and risk factors for future stroke, cognitive impairment, and dementia among the general population [7].

Fig. 2. Comparison of the prevalence of cerebral small-vessel disease between hemodialysis (HD) patients (n = 179) and the healthy control population (n = 58). * p < 0.0001 vs. HD patients. SBI, silent brain infarction; PVH, periventricular hyperintensity; DSWMH, deep and subcortical white matter hyperintensity; CMBs, cerebral microbleeds.

Despite their high prevalence, there have only been a few studies of WMHs in dialysis patients [11, 22, 23]. Our longitudinal study found that the presence of WMHs was a predictor of future cardiovascular events, including stroke, in HD patients [24].

While the pathological differences between PVH and DSWMH, which are regional subtypes of WMHs, have not been sufficiently elucidated, recent reports have shown that an age-related change, arteriolosclerosis, is the main factor in PVH, while vascular diseases are involved in DSWMH, in addition to age-related changes, indicating a condition of atherosclerosis in addition to arteriolosclerosis [25]. Some previous studies [26, 27] in the general population have also shown that PVH is a stronger predictor of stroke events. In contrast, Kobayashi et al. [6] found that DSWMH was a predictor of stroke events, but that PVH was not related to clinical stroke onset in neurologically normal adults with no history of stroke. Our study [24] revealed that PVH was a stronger predictor of cardiovascular events, including stroke, compared with DSWMH. Therefore, the differences in the clinical significance of PVH and DSWMH remain controversial and further accumulation of evidence is necessary.