Reaction Time and Visible White Matter Lesions in Subcortical Ischemic Vascular Cognitive Impairment

Abstract

Slowed behavioral reaction time is associated with pathological brain changes, including white matter lesions, the common clinical characteristic of subcortical ischemic vascular cognitive impairment (SIVCI). In the present study, reaction time (RT) employing Trails B of the Trail Making Test, with responses capped at 300 s, was investigated in SIVCI (n = 27) compared to cognitively healthy aging (CH) (n = 26). RT was significantly slowed in SIVCI compared to CH (Cohen's d effect size = 1.26). Furthermore, failure to complete Trails B within 300 s was also a characteristic of SIVCI although some ostensibly cognitively healthy older adults also failed to complete within this time limit. Within the SIVCI group, RT did not differ significantly with respect to whether the patients were classified as having moderate/severe or mild, periventricular white matter changes visible on their diagnostic CT/MRI scans. This, together with the high degree of overlap in RT between the two SIVCI subgroups, raises the possibility that using visible ratings scales in isolation may lead to the underestimation of disease level.

Reaction Time Decomposition as a Tool to Study Subcortical Ischemic Vascular Cognitive Impairment

“…This finding also indicates that a ‘normal’ RT measure might in fact be masking functional abnormality to which IIV measurement is more sensitive and that abnormally raised IIV in VCI is the result of changes in at least two component processes of a behavioral response. The fact that further analysis failed to reveal any significant correlation between white matter (ARWMC) [ 29 ] score and any of the RT or IQR measures indicates the possibility that using visible white matter rating scales in isolation may lead to the under estimation of disease level in VCI [ 10 ].…”

The assessment of cognitive and behavioural disturbances in vascular cognitive impairment (VCI) — recommendations of an expert working group

“…MoCA, DemTect). Also, the Trail Making Test is sometimes recommended in the short screening context [61]. VASCOG experts suggest also other test combinations for shorter and longer screening, with semantic fluency -animal naming being the most commonly recommended measure [62].…”

Lacking Pace but Not Precision: Age-Related Information Processing Changes in Response to a Dynamic Attentional Control Task

“…This is a crucial consideration as older adults with ostensibly normal cognition for their age and educational level, and some individuals with subjective cognitive decline (SCD) [55], can show considerable variation in RT and attention. Some individuals may even present with levels of detrimental functional change more typical of MCI, vascular cognitive impairment (VCI), and Alzheimer's disease (AD) [11][12][13][14].…”

“…Generally, in such tests, RT is measured over multiple sequential trials in which a response to the same given stimulus is required. Blocks of discrete trials are delivered, often with uniform task difficulty, and are analysed by focusing on each separate event or averaging responses over time [3,11,12,15]. However, the intricacies of visual perception in the real-world are far more complex than that represented by the measurement of RT in this way.…”

“…Executive function-related reaction time (RT) and its individual variability (IIV) are regarded as behavioural markers of central nervous system integrity [ 1 , 2 , 3 , 4 ]. In relation to ageing, RT slowing and increased IIV are commonly described behavioural characteristics of normal, healthy processes [ 1 , 5 ], with disproportionate levels of decline associated with functional deficits and disease, such as mild cognitive impairment (MCI), vascular cognitive impairment (VCI), and Alzheimer’s disease (AD) [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], as well as conditions such as mild traumatic brain injury (mTBI) [ 16 ]. It is common, therefore, for RT tests to be included in clinical diagnostic batteries.…”