Progressive CKD Increases Prevalence, Severity of Cerebral Small Vessel Disease

Imaging findings suggest a significant relationship between patients with progressive chronic kidney disease (CKD) and cerebral small vessel disease (CSVD), according to a new study.

Researchers undertook the study, published in Renal Failure, with the hypothesis that since the kidney and brain share susceptibilities to vascular injury, kidney impairment might be predictive of the presence and severity of CSVD. Results show such a relationship, with progressive CKD patients exhibiting a greater degree of white matter degeneration and more cerebral microbleeds.

The reason behind the relationship is yet to be understood. Nevertheless, the authors said, there is the possibility that estimated glomerular filtration rate (eGFR) “may not only contribute to the evaluation of renal functions in patients with CKD but may also find utility in the prediction of cerebral small vessel disease. eGFR may reflect a more generalized process indicative of underlying cerebral damage, not limited solely to the kidney.”

The study evaluated 52 patients from December 2015 to December 2017 with chronic nephritis and CKD who were classified into a group with progressive disease (n = 17) and stable disease (n = 35). MRIs were performed to evaluate features of silent CSVD of both groups, including enlarged Virchow-Robin spaces (VRS; also known as perivascular spaces), white matter lesions (WML), lacunar infarcts (LI; small infarcts in the deep cerebral white matter, basal ganglia, or pons), and cerebral microbleeds (CMB).

Results showed WML and CMB in the progressive group worsened at follow-up (10-20 months) compared with initial exam (P = .004 and .020, respectively), while there was no significant change in the stable group. No significant difference was found at follow-up for those with VRS and LI.

In addition, the study found eGFR was significantly correlated with VRS, WML, and CMB at follow-up (P = .037, .041, and .009, respectively).

Researchers suspected the existence of a relationship because of similar blood flow, anatomical, and functional features of the kidney and brain. Both are low-impedance terminal organs that are exposed to high-flow blood shocks throughout the cardiac cycle.

The first lesions in the nervous system from CKD show up as damage to small blood vessels, including small arteries, arterioles, capillaries, and small veins. With poor redundancy in the vessel system to mitigate damage from a blockage, patients have increased susceptibility to stroke. Lesions to the brain affecting its ability to function or caused by pathologic changes in small blood vessels, which collectively are a sign of CSVD.

Given the findings, the authors recommended research into the possibility that when CSVD progresses, CKD may correspondingly decline, and when renal function declines, CSVD might progress.

WML, the progression of which correlates to that of CKD, is one manifestation of cerebrovascular disease and is closely related to cerebral ischemia, stroke, degeneration, and other neurologic diseases. WMLs with intracranial merged lesion can reflect the severity of CSVD in the elderly; their development can be regarded as the terminal changes in CSVD prognosis.

CMBs are the radiologic correlates of leakage of blood components through injured or fragile vascular walls or of frank small hemorrhage spots.

Reference

Yao T, Song G, Li Y, et al. Chronic kidney disease correlates with MRI findings of cerebral small vessel disease. Ren Fail. 2021;43(1):255-263. doi:10.1080/0886022X.2021.1873804