Cognitive screening improves the predictive value of stroke severity scores for functional outcome 3–6 months after mild stroke and transient ischaemic attack: an observational study

Abstract

ObjectivesTo investigate the prognostic value of the neurocognitive status measured by screening instruments, the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE), individually and in combination with the stroke severity scale, the National Institute of Health Stroke Scale (NIHSS), obtained at the subacute stroke phase or the baseline (≤2 weeks), for functional outcome 3–6 months later.DesignProspective observational study.SettingTertiary stroke neurology service.Participants400 patients with a recent ischaemic stroke or transient ischaemic attack (TIA) received NIHSS, MoCA and MMSE at baseline and were followed up 3–6 months later.Primary outcome measuresAt 3–6 months following the index event, functional outcome was measured by the modified Rankin Scale (mRS) scores.ResultsMost patients (79.8%) had a mild ischaemic stroke and less disability (median NIHSS=2, median mRS=2 and median premorbid mRS=0), while a minority of patients had TIA (20.3%). Baseline NIHSS, MMSE and MoCA scores individually predicted mRS scores at 3–6 months, with NIHSS being the strongest predictor (NIHSS: R2 change=0.043, p<0.001). Moreover, baseline MMSE scores had a small but statistically significant incremental predictive value to the baseline NIHSS for mRS scores at 3–6 months, while baseline MoCA scores did not (MMSE: R2 changes=0.006, p=0.03; MoCA: R2 changes=0.004, p=0.083). However, in patients with more severe stroke at baseline (defined as NIHSS>2), baseline MoCA and MMSE had a significant and moderately large incremental predictive value to the baseline NIHSS for mRS scores at 3–6 months (MMSE: R2 changes=0.021, p=0.010; MoCA: R2 changes=0.017, p=0.021).ConclusionsCognitive screening at the subacute stroke phase can predict functional outcome independently and improve the predictive value of stroke severity scores for functional outcome 3–6 months later, particularly in patients with more severe stroke.

Poststroke Cognitive Decline is Independent of Longitudinal Changes in Cerebral Hemodynamics Parameters

“…Furthermore, in a previous study, we reported that brief cognitive tests (MMSE and MoCA) administered during the acute stroke phase might predict functional outcome and cognitive impairment determined by a formal neuropsychological evaluation at 3-6 months after stroke. 21,45 Fifth, we did not evaluate potential confounders for cognitive decline such as treatment with antihypertensive, statins, and antithrombotic drugs and duration of the vascular risk factors. Sixth, only 59 out of 100 baseline subjects completed both TCD investigation and cognitive tests.…”

Use of Montreal Cognitive Assessment in Patients With Stroke

“…In our study, MoCA baseline score was an independent determinant of PSCI with an odds ratio 1.4 for each test point lost. 20 MoCA score was also associated with poor functional status measured with the modified Rankin Scale at 3 to 6 months in patients with ischemic stroke or transient ischemic attack 14 and at 12 months in patients with subarachnoid hemorrhage.…”

“…10,11,14,[16][17][18][19] These exclusion criteria led to apply MoCA mostly in mild-to-moderate patients with stroke, usually with first-ever ischemic stroke, without other major disorders or severe aphasia. The fact that patients with severe neurological status or aphasia cannot be tested with MoCA is not necessarily a major limitation of this tool because these patients are already candidates for specific rehabilitation programs or long-term care strategies.…”

“…attack, 8,[10][11][12][13] hemorrhages, 10,14 severe stroke, 15 major physical disability, 14,[16][17][18] significant aphasia, 8,10,11,13,[16][17][18] inability to participate in rehabilitation activities, 8 prestroke cognitive impairment, [15][16][17] acute delirium, 17 and major psychiatric disorder. 10,11,14,[16][17][18][19] These exclusion criteria led to apply MoCA mostly in mild-to-moderate patients with stroke, usually with first-ever ischemic stroke, without other major disorders or severe aphasia.…”

“…The feasibility of the application of MoCA in patients with stroke at a 3-month follow-up was evaluated by Cumming et al 22 The test was completed by 87% of patients with mild stroke (baseline National Institutes of Health Stroke Scale, 0-7), 79% of those with moderate stroke (National Institutes of Health Stroke Scale, [8][9][10][11][12][13][14][15], and 67% of those with severe stroke (National Institutes of Health Stroke Scale, >16). 22 Sixty-five percent of patients examined were classified as affected by PSCI; the items most frequently impaired were those with attention and executive demands and word recall.…”