Editors' Note: Association of Sleep, Neuropsychological Performance, and Gray Matter Volume With Glymphatic Function in Community-Dwelling Older Adults.

Abstract

In their analysis of 84 community-dwelling elderly adults, Dr. Siow et al. evaluated the relationship between diffusion tensor imaging along the perivascular space (DTI-ALPS), sleep, and cognitive performance. As an emerging surrogate indicator of glymphatic function, the DTI-ALPS was strongly associated with sleep in this analysis. The investigators also found that higher DTI-ALPS indices were associated with better language and memory recall scores and concluded the DTI-ALPS could serve as an imaging biomarker for cognitive disorders. Dr. Piantino contests the notion that DTI-ALPS is a validated indicator of glymphatic function, which exhibits regional variability and lacks a gold standard test for quantitating glymphatic function. Furthermore, distinguishing between perivascular and nonperivascular spaces may be challenging on DTI. This exchange highlights the potential shortcomings of DTI as surrogate markers of glymphatic function. Additional studies are necessary to validate imaging markers of glymphatic activity and to better understand the relationship between the glymphatic system, sleep, and cognitive dysfunction. In their analysis of 84 community-dwelling elderly adults, Dr. Siow et al. evaluated the relationship between diffusion tensor imaging along the perivascular space (DTI-ALPS), sleep, and cognitive performance. As an emerging surrogate indicator of glymphatic function, the DTI-ALPS was strongly associated with sleep in this analysis. The investigators also found that higher DTI-ALPS indices were associated with better language and memory recall scores and concluded the DTI-ALPS could serve as an imaging biomarker for cognitive disorders. Dr. Piantino contests the notion that DTI-ALPS is a validated indicator of glymphatic function, which exhibits regional variability and lacks a gold standard test for quantitating glymphatic function. Furthermore, distinguishing between perivascular and nonperivascular spaces may be challenging on DTI. This exchange highlights the potential shortcomings of DTI as surrogate markers of glymphatic function. Additional studies are necessary to validate imaging markers of glymphatic activity and to better understand the relationship between the glymphatic system, sleep, and cognitive dysfunction.