Lucy modelling paper CCF and VR final 040320.pdf (394.69 kB)
An objective method to identify non-responders in neurovascular coupling testing.
Version 2 2020-05-20, 08:30
Version 1 2020-05-20, 08:29
journal contribution
posted on 2020-05-20, 08:30 authored by Lucy C Beishon, Claire Al Williams, Kannakorn Intharakham, Angus P Batterham, Samuel C Barnes, Victoria J Haunton, Thompson G Robinson, Ronney B PaneraiBACKGROUND: Neurovascular coupling (NVC) can be assessed using transcranial Doppler (TCD) measured task-activation of cerebral blood flow velocity (CBFv). However, not all individuals show consistent responses. The aim of this study was to develop a robust, objective, method to identify non-responders to task-activation. NEW METHOD: Using five-minute seated resting (non-stimulated), bilateral CBFv data from 135 healthy participants, the cross-correlation function peak (CCF) between the population coherent average and each individual was obtained for a randomly selected segment of data (40 s) for both hemispheres (n = 270). The variance ratio (VR) was calculated by comparing the variance in CBFv data pre- and post-random mark. The 90th percentile for non-stimulated data was used to determine the upper confidence limit of normal variation in the CCF peak value (0.53), and VR (2.59). These criteria were then applied to task-activated CBFv from 69 healthy participants for five cognitive tasks (attention, verbal fluency, language, visuospatial, memory). RESULTS: Data were accepted as responders if either CCF ≥ 0.53 or VR ≥ 2.59. The number of cases accepted as responders for each task were as follows: attention, 54-59 (78-86%); verbal fluency, 42-48 (60-70%); language, 51-53 (74-77%); visuospatial, 54 (78%); memory, 40-47 (58-68%). COMPARISON WITH EXISTING METHOD: Currently, there are no objective criteria for the identification of non-responders in studies of NVC. This is a new method to objectively classify non-responders to task-activation. CONCLUSIONS: Using a large sample of resting CBFv data, we have set objective criteria to differentiate between responders and non-responders in task activation protocols.
Funding
LB is a research training fellow funded by the Dunhill Medical Trust (RTF180627). Professor Robinson is a National Institute for Health Research (NIHR) Senior Investigator. The views expressed in this article are those of the author(s) and not necessarily those of the NIHR, or the Department of Health and Social Care.
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Citation
Journal of Neuroscience Methods Volume 341, 15 July 2020, 108779Version
- AM (Accepted Manuscript)
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Journal of Neuroscience MethodsVolume
341Pagination
108779Publisher
Elsevier BVissn
0165-0270eissn
1872-678XAcceptance date
2020-05-11Copyright date
2020Available date
2020-05-15Publisher DOI
Publisher version
https://www.sciencedirect.com/science/article/pii/S0165027020302028Language
engUsage metrics
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