Inter-Session Reliability of Functional Near-Infrared Spectroscopy at the Prefrontal Cortex While Walking in Multiple Sclerosis

Abstract

Many established technologies are limited in analyzing the executive functions in motion, especially while walking. Functional near-infrared spectroscopy (fNIRS) fills this gap. The aim of the study is to investigate the inter-session reliability (ISR) of fNIRS-derived parameters at the prefrontal cortex while walking in people with multiple sclerosis (MS) and healthy control (HC) individuals. Twenty people with MS/HC individuals walked a 12 m track back and forth over 6 min. The primary outcomes were the absolute and relative reliability of the mean, slope coefficient (SC), and area under the curve (A) of the oxy-/deoxyhemoglobin concentrations (HbO/HbR) in the Brodmann areas (BA) 9/46/10. The SC and the A of HbO exhibited a fair ISR in BA10 in people with MS. For the mean and A of the HbR, almost all areas observed revealed a fair ISR. Overall, the ISR was better for HbR than HbO. A fair to excellent ISR was found for most BA of the prefrontal cortex in HC individuals. In total, the ISR of the analyzed fNIRS-derived parameters was limited. To improve the ISR, confounders such as fatigue and mind wandering should be minimized. When reporting the ISR, the focus should be on the mean/A rather than SC.

Mind wandering in people with Multiple Sclerosis: A psychometric study

“…This confirms that MW can, at times, be conceived of a beneficial state, as it has been associated with positive outcomes such as increased creativity 16 . Also, the percentage of 31.76% may indicate that, although engaged in a spontaneous MW, PwMS could experience and be aware of some degree of control over this frequent switch between thoughts whom contents are miscellaneous in line with 13 (item MW2-S: -When I mind-wander my thoughts tend to be pulled from topic to topic"). As expected, extraversion, defined as amount of external stimulation required to achieve optimal excitement, was not correlated with MW.…”

“…Attempts to investigate and evaluate MW in MS are very scarce 13 . This dearth of knowledge is an important omission and understanding the consequences of this ubiquitous thought process is needed, especially in a clinical population in which psychological aspects as personality traits and mood are often affected by the disease.…”

Effects of a 6-Min Treadmill Walking Test on Dual-Task Gait Performance and Prefrontal Hemodynamics in People With Multiple Sclerosis

“…The placement over the PFC was done with the fNIRS Optodes' Location Decider (fOLD) toolbox ( 33 ). The sensitivity of the channels was described in Broscheid et al ( 34 ). The cap was positioned with Cz centrally [according to the international 10–20 system for electroencephalography ( 35 )] between the nasion and inion and preauricular points on the left and right side.…”

Cortical hemodynamics as a function of handgrip strength and cognitive performance: a cross-sectional fNIRS study in younger adults

“…In the hmrDeconvHRRF_DriftSS function, the hemodynamic response function (HRF) is estimated by using a general linear model approach (GLM) that uses ordinary least squares [81]. As done in several previous publications [82][83][84][85][86][87][88][89][90], the HRF was modeled with a consecutive sequence of Gaussian functions with a standard deviation of 0.5 s and their means separated by 0.5 s over a specific regression time (used parameters in Homer 2: trange − 2.0 to 20; glmSolveMethod 1; idxBasis 1; par-amsBasis 0.5 and 0.5). To account for baseline drift, it was modeled using a third order polynomial fit [84,89,91].…”