Arterial Stiffness Associated With Processing Speed in Multiple Sclerosis

Meglio,Marco;

News

Article

June 1, 2023

NeurologyLive

August 2023

Volume6

Issue 4

Arterial Stiffness Associated With Processing Speed in Multiple Sclerosis

Author(s):

Marco Meglio

Investigators observed significant correlations between processing speed and arterial stiffness among patients with multiple sclerosis, but not in healthy controls.

Robert Motl, PhD

In a recently conducted study, patients with multiple sclerosis (MS) demonstrated significantly worse cognitive performance and greater arterial stiffness than healthy controls, suggesting an association between vascular and cognitive functions. Of note, patients with higher aortic augmentation index (AIx) were associated with slower processing speed.^1,2

Led by Robert Motl, PhD, professor, Rehabilitation Sciences, College of Applied Health Sciences, the study included 61 participants (MS: n = 45; healthy controls: n = 16) who completed the Brief International Cognitive Assessment (BICAMS). Vascular function was measured using the SphygmoCor XCEL System, with aortic AIx standardized to a heart rate of 75 beats per minute (AIx75). With participants still in a supine position, carotid to femoral pulse wave velocity (cfPWV) was derived from the waveform at the right common carotid artery and right femoral artery using the same strain gage transducer.

Presented at the 2023 Consortium of Multiple Sclerosis Centers (CMSC) Annual Meeting, held May 31 to June 3, in Aurora, Colorado, the MS group showed worse cognitive performance than controls (P <.05). Investigators observed specific mean differences of –12.1 (95% CI, –20.4 to –3.8), –11.6 (95% CI, –18.0 to –5.1), and –5.3 (95% CI, –9.4 to –1.4) points, respectively, on Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-II (CVLT-II), and Brief Visuospatial Memory Test-Revised.

When comparing vascular function, the MS group demonstrated significantly higher cfPWV than healthy controls (1.3 [95% CI, 0.3-2.3] m/s; P = .026). Although not significantly different from controls (P >.05), this group also registered higher mean values of aortic mean arterial pressure, pulse pressure, augmentation pressure, and AIx75. Most notably, investigators observed statistically significant correlations between SDMT scores with AIx75 (r_s = –0.45; P = .002) and cfPWV (r_s = 0.30; P = .045) in the MS sample.

In a simple linear regression model, there was a significant linear relationship between the SDMT score and aortic AIx75 in the MS cohort. Motl et al also used an additional simple regression (Model 2) and quadratic regression (Model 3) that included cfPWV and SDMT. Contrary to the non-significant ß coefficient in Model 2 (P = .24), both linear and polynomial terms of cfPWV were significant in model 3 (P <.05). Collectively, results of the model comparison suggested a better performance of the quadratic model (Model 3), and therefore confirmed the presence of nonlinear relationship between cfPWV and the SDMT score.

In 2022, data from a cohort of adults with neurologist-confirmed MS reported comorbidities indicated that the association between vascular comorbidity and lower cognitive function is partially mediated by changes in brain macrostructure and microstructure. The trial featured 105 participants, with 35.2%, 15.2%, and 8.6% reporting at least 1, 2, or 3 vascular comorbidities, respectively. All told, findings showed that he biggest contributors to the cognitive variate were the SDMT and CVLT-II, and to the MRI variate were gray matter mean diffusivity and thalamic volume. After adjusting for the MRI variate, vascular comorbidity was not associated with the cognitive variate.³

Click here for more coverage of CMSC 2023.