Clinically accessible neuroimaging predictors of post-stroke neurocognitive disorder: a prospective observational study

Abstract

Background: Neurocognitive disorder (NCD) is common in stroke survivors. We aimed to identify clinically accessible imaging markers of stroke and chronic pathology that are associated with early post-stroke NCD.

Methods: We included 231 stroke survivors from the "Norwegian Cognitive Impairment after Stroke (Nor-COAST)" study who underwent a standardized cognitive assessment 3 months after the stroke. Any NCD (mild cognitive impairment and dementia) and major NCD (dementia) were diagnosed according to "Diagnostic and Statistical Manual of Mental Disorders (DSM-5)" criteria. Clinically accessible imaging findings were analyzed on study-specific brain MRIs in the early phase after stroke. Stroke lesion volumes were semi automatically quantified and strategic stroke locations were determined by an atlas based coregistration. White matter hyperintensities (WMH) and medial temporal lobe atrophy (MTA) were visually scored. Logistic regression was used to identify neuroimaging findings associated with major NCD and any NCD.

Results: Mean age was 71.8 years (SD 11.1), 101 (43.7%) were females, mean time from stroke to imaging was 8 (SD 16) days. At 3 months 63 (27.3%) had mild NCD and 65 (28.1%) had major NCD. Any NCD was significantly associated with WMH pathology (odds ratio (OR) = 2.73 [1.56 to 4.77], p = 0.001), MTA pathology (OR = 1.95 [1.12 to 3.41], p = 0.019), and left hemispheric stroke (OR = 1.8 [1.05 to 3.09], p = 0.032). Major NCD was significantly associated with WMH pathology (OR = 2.54 [1.33 to 4.84], p = 0.005) and stroke lesion volume (OR (per ml) =1.04 [1.01 to 1.06], p = 0.001).

Conclusion: WMH pathology, MTA pathology and left hemispheric stroke were associated with the development of any NCD. Stroke lesion volume and WMH pathology were associated with the development of major NCD 3 months after stroke. These imaging findings may be used in the routine clinical setting to identify patients at risk for early post-stroke NCD.

Trial registration: ClinicalTrials.gov, NCT02650531 , Registered 8 January 2016 - Retrospectively registered.

Keywords: Cognitive impairment; Post stroke dementia; Stroke imaging; Stroke volume; White matter lesions.

Fig. 1

Study population overview

Fig. 2

Examples of WMH, MTA and stroke lesion volume for normal cognition, mild and major NCD. a.) Normal cognitive status after 3 months with normal MTA (medial temporal lobe atrophy) and WMH (white matter hyperintensity) score and an average stroke volume for this group; b.) mild NCD (neurocognitive disorder) with a relatively small stroke volume, pathologic MTA and pathologic WMH score; c.) Major NCD with a larger stroke volume, normal MTA and pathologic WMH score