The NIH stroke scale can establish cognitive function after stroke.
BACKGROUND
Cognitive impairment is an important but underrecognised consequence of stroke. We investigated whether a subset of items from the NIH Stroke Scale (NIHSS) could yield valid information on cognitive status in a group of stroke patients.


METHODS
149 stroke patients from the Göteborg 70+ Stroke Study were investigated after 18 months. We extracted 4 items corresponding to the NIHSS items on orientation, executive function, language and inattention. Scores on this subset of 4 NIHSS items (Cog-4) and the Mini-Mental State Examination (MMSE) were evaluated against a reference diagnosis of severe cognitive impairment.


RESULTS
The area under the receiver-operator curve (AUC) plotted for the Cog-4 scale against the diagnosis of severe cognitive impairment was 0.78; the MMSE had a slightly better diagnostic precision, with an AUC of 0.84. Making the executive task more difficult increased the precision of the Cog-4, raising the AUC to 0.81.


CONCLUSIONS
A composite score based on 4 NIHSS items is almost as good as the MMSE in detecting severe cognitive impairment. Ideally, dedicated measures of cognition should be employed as a matter of course after stroke, but in their absence, the Cog-4 subscale provides an indication of cognitive functioning.
Cumming
Toby B
TB
National Stroke Research Institute, Melbourne, Vic., Australia.
Blomstrand
Christian
C
Bernhardt
Julie
J
Linden
Thomas
T
D000368:Aged; D019540:Area Under Curve; D001288:Attention; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D056344:Executive Function; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D009316:National Institutes of Health (U.S.); D009949:Orientation; D011237:Predictive Value of Tests; D011569:Psychiatric Status Rating Scales; D012372:ROC Curve; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis* / Q000401:mortality / Q000523:psychology; D013548:Sweden / Q000453:epidemiology; D014481:United States