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The Effects of Acute Aerobic Exercise on Cerebral Blood Flow and Cognition in Persons with Multiple Sclerosis
Alexander Jacob Rosenberg1, Sang Ouk Wee1, Elizabeth C. Shroeder1, Georgios Grigoriadis1, Brian M. Sandroff2, Kanokwan Bunsawat1, Thessa I. Hilgenkamp1,3, Garett J. Griffith1, Robert Motl4 and Tracy Baynard1
Author Affiliations
1University of Illinois at Chicago, Chicago, IL
2Kessler Foundation, East Hanover, NJ
3Erasmus MC University Medical Center Rotterdam, 3015 CE Rotterdam, Netherlands
4University of Alabama at Birmingham, Birmingham, AL
Abstract
Multiple sclerosis (MS) is a chronic autoimmune disease associated with neurological symptoms leading to muscular weakness, pain, and cognitive decline. Cognitive impairment affects 40–70% of individuals with MS and has been associated with reduced physical independence and overall quality of life. Cerebral blood flow (CBF) decreases with aging and is associated with cognitive decline in healthy aging adults. Individuals with MS have an attenuated response in CBF velocity to a head-up tilt stimulus, independent of age. Exercise and physical activity improves CBF dynamics and cognitive function in older individuals without disease; however, this relationship has not been demonstrated in an MS population.
Purpose
To investigate the effects of acute moderate intensity aerobic exercise on cognitive function and CBF velocity in persons with MS.
Methods
Fourteen individuals with MS (Age = 42 ± 9 yrs, BMI = 26.3 ± 6.3 kg/m2) had aerobic capacity (VO2peak) assessed via a treadmill test. They were then randomized to either 20 min of treadmill walking at 60% of VO2peak or a control condition (20 min quiet rest). Participants completed both conditions in a counterbalanced order (i.e., within-subjects design). The modified flanker task (inhibitory control, mental processing speed) was administered at baseline, 1-minute post-condition, and 30-minutes post-condition. The flanker task involves a set of 5 flanking arrows of congruent (>>>>>) and incongruent (>> < >>) orientation and measures reaction time (RT) and accuracy of indicating the direction of the middle arrow. Continuous beat-to-beat CBF velocity (CBFv), end-tidal CO2, and heart rate (HR) measurements were recorded during the entire visit by transcranial Doppler, and CO2/O2 gas analyzer, and wireless three-lead ECG. Carotid artery beta-stiffness index and arterial compliance (AC) were measured by ultrasonography and carotid blood pressure (cSBP, cDBP, cMAP) measurements were obtained using applanation tonometry at the same time points as the flanker task.
Results
See table (http://www.fasebj.org/content/31/1_S...nt/842.4.short). Both conditions improved reaction time at 1-minute post (p<0.05), but only the exercise condition maintained the reduction at 30-minutes (p<0.05). Mean CBFv did not change following either condition, however, CBFv pulsatility increased following exercise (p<0.05) and returned back to baseline at post 30-min. HR, cSBP, cDBP, cMAP, Beta-stiffness, and end-tidal CO2 increased following exercise, while AC decreased (p<0.05).
Conclusion
These data demonstrate the beneficial effect of acute aerobic exercise on mental processing speed and accuracy, independent of CBF dynamics, carotid artery stiffness and carotid blood pressures in persons with MS. Therefore, acute improvements in reaction time following aerobic exercise seems to be attributed to other factors not assessed. Further investigation is required to fully elucidate the effects of aerobic exercise on cognition in MS, given there is no FDA approved treatment available for cognitive impairment in this population.
Alexander Jacob Rosenberg1, Sang Ouk Wee1, Elizabeth C. Shroeder1, Georgios Grigoriadis1, Brian M. Sandroff2, Kanokwan Bunsawat1, Thessa I. Hilgenkamp1,3, Garett J. Griffith1, Robert Motl4 and Tracy Baynard1
Author Affiliations
1University of Illinois at Chicago, Chicago, IL
2Kessler Foundation, East Hanover, NJ
3Erasmus MC University Medical Center Rotterdam, 3015 CE Rotterdam, Netherlands
4University of Alabama at Birmingham, Birmingham, AL
Abstract
Multiple sclerosis (MS) is a chronic autoimmune disease associated with neurological symptoms leading to muscular weakness, pain, and cognitive decline. Cognitive impairment affects 40–70% of individuals with MS and has been associated with reduced physical independence and overall quality of life. Cerebral blood flow (CBF) decreases with aging and is associated with cognitive decline in healthy aging adults. Individuals with MS have an attenuated response in CBF velocity to a head-up tilt stimulus, independent of age. Exercise and physical activity improves CBF dynamics and cognitive function in older individuals without disease; however, this relationship has not been demonstrated in an MS population.
Purpose
To investigate the effects of acute moderate intensity aerobic exercise on cognitive function and CBF velocity in persons with MS.
Methods
Fourteen individuals with MS (Age = 42 ± 9 yrs, BMI = 26.3 ± 6.3 kg/m2) had aerobic capacity (VO2peak) assessed via a treadmill test. They were then randomized to either 20 min of treadmill walking at 60% of VO2peak or a control condition (20 min quiet rest). Participants completed both conditions in a counterbalanced order (i.e., within-subjects design). The modified flanker task (inhibitory control, mental processing speed) was administered at baseline, 1-minute post-condition, and 30-minutes post-condition. The flanker task involves a set of 5 flanking arrows of congruent (>>>>>) and incongruent (>> < >>) orientation and measures reaction time (RT) and accuracy of indicating the direction of the middle arrow. Continuous beat-to-beat CBF velocity (CBFv), end-tidal CO2, and heart rate (HR) measurements were recorded during the entire visit by transcranial Doppler, and CO2/O2 gas analyzer, and wireless three-lead ECG. Carotid artery beta-stiffness index and arterial compliance (AC) were measured by ultrasonography and carotid blood pressure (cSBP, cDBP, cMAP) measurements were obtained using applanation tonometry at the same time points as the flanker task.
Results
See table (http://www.fasebj.org/content/31/1_S...nt/842.4.short). Both conditions improved reaction time at 1-minute post (p<0.05), but only the exercise condition maintained the reduction at 30-minutes (p<0.05). Mean CBFv did not change following either condition, however, CBFv pulsatility increased following exercise (p<0.05) and returned back to baseline at post 30-min. HR, cSBP, cDBP, cMAP, Beta-stiffness, and end-tidal CO2 increased following exercise, while AC decreased (p<0.05).
Conclusion
These data demonstrate the beneficial effect of acute aerobic exercise on mental processing speed and accuracy, independent of CBF dynamics, carotid artery stiffness and carotid blood pressures in persons with MS. Therefore, acute improvements in reaction time following aerobic exercise seems to be attributed to other factors not assessed. Further investigation is required to fully elucidate the effects of aerobic exercise on cognition in MS, given there is no FDA approved treatment available for cognitive impairment in this population.