Exercise Training Increases Parietal Lobe Cerebral Blood Flow in Chronic Stroke: An Observational Study.

Andrew D. Robertson,Susan Marzolini,Laura E. Middleton,Paul I. Oh,Vincenzo S. Basile,Bradley J. MacIntosh

doi:10.3389/fnagi.2017.00318

Abstract

Exercise is increasingly recommended as an essential component of stroke rehabilitation, yet uncertainty remains with respect to its direct effect on the cerebral vasculature. The current study first demonstrated the repeatability of pseudo-continuous arterial spin labeling (ASL) magnetic resonance imaging (MRI) in older adults with stroke, and then investigated the change in cerebrovascular function following a 6-month cardiovascular rehabilitation program. In the repeatability study, 12 participants at least 3 months post-stroke underwent two ASL imaging scans 1 month apart. In the prospective observational study, eight individuals underwent ASL imaging and aerobic fitness testing before and after a 6-month cardiovascular rehabilitation program. Cerebral blood flow (CBF) and the spatial coefficient of variation of CBF (sCoV) were quantified to characterize tissue-level perfusion and large cerebral artery transit time properties, respectively. In repeat scanning, intraclass correlation (ICC) indicated moderate test-retest reliability for global gray matter CBF (ICC = 0.73) and excellent reliability for sCoV (ICC = 0.94). In the observational study, gray matter CBF increased after training (baseline: 40 ± 13 vs. 6-month: 46 ± 12 ml·100 g−1·min−1, P = 0.036). The greatest change occurred in the parietal lobe (+18 ± 12%). Gray matter sCoV, however, did not change following training (P = 0.31). This study provides preliminary evidence that exercise-based rehabilitation in chronic stroke enhances tissue-level perfusion, without changing the relative hemodynamic properties of the large cerebral arteries.

Highlights

Aerobic exercise training after stroke impacts functional recovery (Duncan et al, 2003) and cognition (Zheng et al, 2016)
A magnetic resonance imaging (MRI) study with chronic stroke participants reported that medial temporal lobe perfusion, but not global Cerebral blood flow (CBF), was increased following a community exercise program involving aerobic, resistance, flexibility and balance training (Moore et al, 2015)
This study of individuals with chronic stroke characterized the repeatability of arterial spin labeling (ASL) CBF, and subsequently measured changes in cerebral hemodynamics after participation in a 6-month cardiovascular rehabilitation program

Summary

Introduction

Aerobic exercise training after stroke impacts functional recovery (Duncan et al, 2003) and cognition (Zheng et al, 2016). While these changes may be driven by improvements in cardiopulmonary fitness (Marsden et al, 2013) or cardiometabolic risk profile (Tang et al, 2014), less is known about the role of brain-specific effects. A magnetic resonance imaging (MRI) study with chronic stroke participants reported that medial temporal lobe perfusion, but not global CBF, was increased following a community exercise program involving aerobic, resistance, flexibility and balance training (Moore et al, 2015)

Methods

Results

Conclusion