Investigating the relationship between cerebral blood flow and cognitive function in hemodialysis patients

Findlay, M. D., Dawson, J. , Dickie, D. A. , Forbes, K. P., McGlynn, D., Quinn, T. and Mark, P. B. (2019) Investigating the relationship between cerebral blood flow and cognitive function in hemodialysis patients. Journal of the American Society of Nephrology, 30(10194), pp. 147-158. (doi: 10.1681/ASN.2018050462) (PMID:30530658) (PMCID:PMC6317612)

Abstract

Background: The immediate and longer-term effects of hemodialysis on cerebral circulation, cerebral structure, and cognitive function are poorly understood. Methods: In a prospective observational cohort study of 97 adults (median age 59 years) receiving chronic hemodialysis, we used transcranial Doppler ultrasound to measure cerebral arterial mean flow velocity (MFV) throughout dialysis. Using a well validated neuropsychological protocol, we assessed cognitive function during and off dialysis and after 12 months of treatment. We also used brain magnetic resonance imaging (MRI) to assess atrophy, white matter hyperintensities (WMHs), and diffusion parameters, and tested correlations between MFV, cognitive scores, and changes on MRI. Results: MFV declined significantly during dialysis, correlating with ultrafiltrate volumes. Percentage of decline in MFV correlated with intradialytic decline in cognitive function, including global function, executive function, and verbal fluency. At follow-up, 73 patients were available for repeat testing, 34 of whom underwent repeat MRI. In a subgroup of patients followed for 12 months of continued dialysis, percentage of decline in MFV correlated significantly with lower global and executive function and with progression of WMH burden (a marker of small vessel disease). Twelve of 15 patients who received renal transplants during follow-up had both early and follow-up off-dialysis assessments. After transplant, patients’ memory (on a delayed recall test) improved significantly; increased fractional anisotropy of white matter (a measure of cerebral diffusion) in these patients correlated with improving executive function. Conclusions: Patients undergoing hemodialysis experience transient decline in cerebral blood flow, correlating with intradialytic cognitive dysfunction. Progressive cerebrovascular disease occurred in those continuing dialysis, but not in transplanted patients. Cognitive function and cerebral diffusion improved after transplant.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Findlay, Dr Mark and Dickie, Dr David Alexander and Mark, Professor Patrick and Dawson, Professor Jesse and Forbes, Dr Kirsten and Quinn, Professor Terry
• Authors: Findlay, M. D., Dawson, J., Dickie, D. A., Forbes, K. P., McGlynn, D., Quinn, T., and Mark, P. B.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Journal of the American Society of Nephrology
• Publisher: American Society of Nephrology
• ISSN: 1046-6673
• ISSN (Online): 1533-3450
• Published Online: 07 December 2018
• Copyright Holders: Copyright © 2018 American Society of Nephrology
• First Published: First published in Journal of the American Society of Nephrology 2018
• Publisher Policy: Reproduced in accordance with the publisher copyright policy