Exercise intensity modulates the change in cerebral blood flow following aerobic exercise in chronic stroke

Abstract

The mechanisms supporting functional improvement by aerobic exercise following stroke remain incompletely understood. This study investigated how cycling intensity and aerobic fitness influence cerebral blood flow (CBF) following a single exercise session. Thirteen community-living stroke survivors performed 20 min of semi-recumbent cycling at low and moderate intensities (40-50 and 60-70 % of heart rate reserve, respectively) as determined from an exercise stress test. CBF was quantified by arterial spin labeling MRI at baseline, as well as 30 and 50 min post-exercise. An intensity-dependent effect was observed in the right post-central and supramarginal gyri up to 50 min after exercise (uncorrected p < 0.005, cluster size ≥10). Regional CBF was increased 18 ± 17 % and reduced 8 ± 12 % following moderate- and low-intensity cycling, respectively. In contrast, CBF changes were similar between sessions in the right lentiform nucleus and mid-frontal gyrus, as well as the left temporal and parietal gyri. Aerobic fitness was directly related to posterior cingulate and thalamic CBF, and inversely related to precuneal CBF at rest (R (2) ≥ 0.75); however, no relationship between fitness and the post-exercise change in CBF was observed. Divergent changes in regional CBF were observed in the right parietal cortex following low- and moderate-intensity exercise, which suggests that intensity of prescribed exercise may be useful in optimizing rehabilitation.

Assessment of the Effects of Aerobic Fitness on Cerebrovascular Function in Young Adults Using Multiple Inversion Time Arterial Spin Labeling MRI

“…Gauthier et al (2015) found both positive and inverse correlations between CVR and aerobic fitness in older adults, and this, along with the Robertson et al (2015) study adds to the evidence that aerobic fitness may have complex, regionally varying and age dependent effects on the brain. Although the direction of the correlation in stroke survivors in the thalamus and posterior cingulate cortex contradicts the current results, the current study and those of Robertson et al (2015) and Gauthier et al (2015) further suggest that aerobic fitness may exert localized effects on CBF (Thomas et al, 2013;Chaddock-Heyman et al, 2016). Given that participants in each of these cited studies have differed in age and health status, the fact that consistent findings have not been reported is unsurprising.…”

“…A study by Robertson et al (2015) in stroke survivors, using single inversion time PCASL, similarly found an inverse correlation between precuneus CBF and aerobic fitness, but a positive correlation between thalamic and posterior cingulate CBF and aerobic fitness. Gauthier et al (2015) found both positive and inverse correlations between CVR and aerobic fitness in older adults, and this, along with the Robertson et al (2015) study adds to the evidence that aerobic fitness may have complex, regionally varying and age dependent effects on the brain.…”

“…A study by Robertson et al (2015) in stroke survivors, using single inversion time PCASL, similarly found an inverse correlation between precuneus CBF and aerobic fitness, but a positive correlation between thalamic and posterior cingulate CBF and aerobic fitness. Gauthier et al (2015) found both positive and inverse correlations between CVR and aerobic fitness in older adults, and this, along with the Robertson et al (2015) study adds to the evidence that aerobic fitness may have complex, regionally varying and age dependent effects on the brain. Although the direction of the correlation in stroke survivors in the thalamus and posterior cingulate cortex contradicts the current results, the current study and those of Robertson et al (2015) and Gauthier et al (2015) further suggest that aerobic fitness may exert localized effects on CBF (Thomas et al, 2013;Chaddock-Heyman et al, 2016).…”

Assessment of the effects of aerobic fitness on cerebrovascular function in young adults using multiple inversion time arterial spin labelling MRI

“…2015) found both positive and inverse correlations between CVR and aerobic fitness in older adults, and this, along with theRobertson et al (2015) study adds to the evidence that aerobic fitness may have complex, regionally varying and age dependent effects on the brain. Although the direction of the correlation in stroke survivors in the thalamus and posterior cingulate cortex contradicts the current results, the current study and those ofRobertson et al (2015) andGauthier et al (2015) further suggest that aerobic fitness may exert localised effects on CBF …”

“…A study by Robertson et al (2015) in stroke survivors, using single inversion time PCASL, similarly found an inverse correlation between precuneus CBF and aerobic fitness, but a positive correlation between thalamic and posterior cingulate CBF and aerobic fitness. Gauthier et al Thomas et al, 2013).…”