Hemodynamic monitoring of middle cerebral arteries during cognitive tasks performance

Abstract

Aim:The aim of this study was to obtain temporal pattern and hemispheric dominance of blood flow velocity (BFV) changes and to assess suitability of different cognitive tasks for monitoring of BFV changes in the middle cerebral arteries (MCA). Results: A significant increase of BFV in both MCA was obtained during performance of all cognitive tasks. Statistically significant lateralization was found during performance of Stroop test with incongruent stimuli, while TMTB was found to have the best activation potential for MCA. Methods Conclusion:Our findings specify TMTB as the most suitable cognitive test for monitoring of BFV in MCA.

The assessment of neurovascular coupling with the Addenbrooke’s Cognitive Examination: a functional transcranial Doppler ultrasonographic study

“…Moody et al (2005) demonstrated changes in the subcomponents of small-vessel resistance during cognitive testing, possibly representing the metabolic and myogenic components of cerebrovascular resistance . In addition to the findings reported in this article, two recent functional TCD studies both demonstrated a fast and slow phase to the CBFv response during cognitive tasks (Boban et al 2014b;Szirmai et al 2005). The fast phase most likely represents rapid neurogenic control, and the slow phase increasing metabolic demands (Boban et al 2014b;Szirmai et al 2005).…”

“…In addition to the findings reported in this article, two recent functional TCD studies both demonstrated a fast and slow phase to the CBFv response during cognitive tasks (Boban et al 2014b;Szirmai et al 2005). The fast phase most likely represents rapid neurogenic control, and the slow phase increasing metabolic demands (Boban et al 2014b;Szirmai et al 2005). In a recent functional near-infrared spectroscopy study by Tan et al (2016), the Sternberg task demonstrated reduced amplitude of responses in the frontal and parietal areas with high cognitive load, indicating a vasodilatory response.…”

“…However, measuring changes in the frontal cortex during cognitive testing has its own challenges, particularly because anxiety is mediated through the frontal lobe and can potentially distort apparent changes in CBFv (Silvestrini et al 1994;Stroobant and Vingerhoets 2000). Indeed, a number of studies have demonstrated increases in HR with more cognitively stressful paradigms (Boban et al 2014b;Szirmai et al 2005). Furthermore, measuring flow through the posterior circulation has limited clinical application for the early detection of cognitive deficits due to MCI or AD, which are more likely to be due to early functional and structural changes in the medial temporal lobe, supplied by the MCA (Li et al 2015;Wierenga and Bondi 2007).…”

“…Heart rate and blood pressure increases are seen with all cognitive paradigms, and changes in CBFv could therefore reflect those occurring peripherally, rather than small vesselmediated myogenic or metabolic responses to NVC. This has been challenged by the results of several functional TCD studies (Boban et al 2014b;Moody et al 2005;Panerai et al 2005;Szirmai et al 2005). Moody et al (2005) demonstrated changes in the subcomponents of small-vessel resistance during cognitive testing, possibly representing the metabolic and myogenic components of cerebrovascular resistance .…”

“…A number of previous studies have demonstrated that lateralization of CBFv responses varies between different cognitive tasks and is therefore an important consideration in studies examining task-activated CBFv responses (Boban et al 2014b;Stroobant and Vingerhoets 2000;Vingerhoets and Stroobant 1999). Certainly, when investigating the utility of paradigms to elicit CBFv responses, it is important to determine the symmetry of the response between hemispheres in a healthy population before examining those changes in a cognitively impaired population.…”