Predicting Recovery of Cognitive Function Soon after Stroke: Differential Modeling of Logarithmic and Linear Regression

Abstract

Cognitive disorders in the acute stage of stroke are common and are important independent predictors of adverse outcome in the long term. Despite the impact of cognitive disorders on both patients and their families, it is still difficult to predict the extent or duration of cognitive impairments. The objective of the present study was, therefore, to provide data on predicting the recovery of cognitive function soon after stroke by differential modeling with logarithmic and linear regression. This study included two rounds of data collection comprising 57 stroke patients enrolled in the first round for the purpose of identifying the time course of cognitive recovery in the early-phase group data, and 43 stroke patients in the second round for the purpose of ensuring that the correlation of the early-phase group data applied to the prediction of each individual's degree of cognitive recovery. In the first round, Mini-Mental State Examination (MMSE) scores were assessed 3 times during hospitalization, and the scores were regressed on the logarithm and linear of time. In the second round, calculations of MMSE scores were made for the first two scoring times after admission to tailor the structures of logarithmic and linear regression formulae to fit an individual's degree of functional recovery. The time course of early-phase recovery for cognitive functions resembled both logarithmic and linear functions. However, MMSE scores sampled at two baseline points based on logarithmic regression modeling could estimate prediction of cognitive recovery more accurately than could linear regression modeling (logarithmic modeling, R2 = 0.676, P<0.0001; linear regression modeling, R2 = 0.598, P<0.0001). Logarithmic modeling based on MMSE scores could accurately predict the recovery of cognitive function soon after the occurrence of stroke. This logarithmic modeling with mathematical procedures is simple enough to be adopted in daily clinical practice.

Longitudinal Effect of Stroke on Cognition: A Systematic Review

“…The number of participants at baseline ranged from 5015 to 1187 16. Follow‐up ranged from 3 weeks17 to 6 years 15, 18, 19. The cohorts included stroke‐specific populations17, 20, 21, 22, 23 and population‐based studies 15, 16, 18, 19, 24, 25, 26, 27, 28.…”

“…Follow‐up ranged from 3 weeks17 to 6 years 15, 18, 19. The cohorts included stroke‐specific populations17, 20, 21, 22, 23 and population‐based studies 15, 16, 18, 19, 24, 25, 26, 27, 28. The majority of studies were conducted in the United States (n=4),16, 18, 25, 26 followed by the United Kingdom (n=2),20, 27 Israel (n=2),22, 23 the Netherlands (n=2),15, 24 Germany (n=1),19 India (n=1),28 Norway (n=1),21 and Japan (n=1) 17.…”

“…The cohorts included stroke‐specific populations17, 20, 21, 22, 23 and population‐based studies 15, 16, 18, 19, 24, 25, 26, 27, 28. The majority of studies were conducted in the United States (n=4),16, 18, 25, 26 followed by the United Kingdom (n=2),20, 27 Israel (n=2),22, 23 the Netherlands (n=2),15, 24 Germany (n=1),19 India (n=1),28 Norway (n=1),21 and Japan (n=1) 17. Stroke case ascertainment included hospital‐based diagnosis,20, 21, 22, 23, 27 self‐report,15, 25 general practitioner records,19 self‐report confirmed through medical records and/or expert review,16, 18, 24, 26, 28 and not specified 17.…”

“…The Mini Mental State Examination (MMSE; total,16, 17, 21, 24, 28 subtests scores,26 and modified MMSE [3MSE]25) was the most commonly used cognitive assessment. Other batteries for assessing global cognitive function included the Montreal Cognitive Assessment (MoCA),22, 23 the Cambridge Cognitive Assessment (CAMCOG),27 the revised CAMCOG (CAMCOG‐R),20 and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) 21.…”

“…The majority of cohorts were population based (n=8),15, 16, 18, 19, 24, 25, 26, 28 although 5 studies were hospital based,17, 20, 21, 22, 23 and the sampling framework was unclear in 1 study 27. The studies demonstrating cognitive decline tended to be population‐based cohorts with longer follow‐up (3 years28 to 6 years15, 18).…”