Improving screening for vascular cognitive impairment at three to six months after mild ischemic stroke and transient ischemic attack.

BACKGROUND: The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were compared with and without the addition of a brief processing speed test, the symbol digit modalities test (SDMT), for vascular cognitive impairment (VCI) screening at three to six months after stroke. METHODS: Patients with ischemic stroke and transient ischemic attack were assessed with MoCA and MMSE, as well as a formal neuropsychological battery three to six months after stroke. VCI was defined by impairment in any cognitive domain on neuropsychological testing. The area under the receiver operating characteristic curve (AUC) was used to compare test discriminatory ability. RESULTS: One hundred and eighty-nine patients out of 327 (58%) had VCI, of whom 180 (95%) had vascular mild cognitive impairment (VaMCI), and nine (5%) had dementia. The overall AUCs of the MoCA and MMSE scores and performance at their respective cut-off points were equivalent in detecting VCI (AUCs: 0.87 (95% CI 0.83-0.91) vs. 0.84 (95% CI 0.80-0.88), p = 0.13; cut-offs: MoCA (≤23) vs. MMSE (≤26), sensitivity: 0.78 vs. 0.71; specificity: 0.80 vs. 0.82; positive predictive value: 0.84 vs. 0.84; negative predictive value: 0.72 vs. 0.67; and correctly classified 78.6% vs. 75.5%; p = 0.42). The AUCs of MMSE and MoCA were improved significantly by the SDMT (AUCs: MMSE+SDMT 0.90 (95% CI 0.87-0.93), p <0.001; MoCA+SDMT 0.91 (95% CI 0.88-0.94), p < 0.02). CONCLUSIONS: The MoCA and MMSE are equivalent and moderately sensitive, and can be supplemented with the SDMT to improve their accuracy in VCI screening.

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.

OBJECTIVES: To 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. DESIGN: Prospective observational study. SETTING: Tertiary stroke neurology service. PARTICIPANTS: 400 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 MEASURES: At 3-6 months following the index event, functional outcome was measured by the modified Rankin Scale (mRS) scores. RESULTS: Most 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: R(2) 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: R(2) changes=0.006, p=0.03; MoCA: R(2) 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: R(2) changes=0.021, p=0.010; MoCA: R(2) changes=0.017, p=0.021). CONCLUSIONS: Cognitive 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.

Brief screening tests during acute admission in patients with mild stroke are predictive of vascular cognitive impairment 3-6 months after stroke.

OBJECTIVES: To determine the prognostic value of brief cognitive screening tests administered in the subacute stroke phase (initial 2 weeks) for the detection of significant cognitive impairment 3-6 months after stroke, the authors compared the Montreal Cognitive Assessment (MoCA) and the Mini-Mental State Examination (MMSE). METHODS: Patients with ischaemic stroke and transient ischaemic attack were assessed with both MoCA and MMSE within 14 days after index stroke, followed by a formal neuropsychological evaluation of seven cognitive domains 3-6 months later. Cognitive outcomes were dichotomised as either no-mild (impairment in ≤2 cognitive domains) or moderate-severe (impairment in ≥ 3 cognitive domains) vascular cognitive impairment. Area under the receiver operating characteristic (ROC) curve analysis was used to compare discriminatory ability. RESULTS: 300 patients were recruited, of whom 239 received formal neuropsychological assessment 3-6 months after the stroke. 60 (25%) patients had moderate-severe VCI. The overall discriminant validity for detection of moderate-severe cognitive impairment was similar for MoCA (ROC 0.85 (95% CI 0.79 to 0.90) and MMSE (ROC 0.83 (95% CI 0.77 to 0.89)), p=0.96). Both MoCA (21/22) and MMSE (25/26) had similar discriminant indices at their optimal cutoff points; sensitivity 0.88 versus 0.88; specificity 0.64 versus 0.67; 70% versus 72% correctly classified. Moreover, both tests had similar discriminant indices in detecting impaired cognitive domains. CONCLUSIONS: Brief screening tests during acute admission in patients with mild stroke are predictive of significant vascular cognitive impairment 3-6 months after stroke.