The relationship between homocysteine, cognition and stroke subtypes in acute stroke.

BACKGROUND: Elevations in plasma homocysteine (Hcy) have been associated with an increased risk of stroke and dementia. The mechanisms underlying these associations remain poorly understood.
OBJECTIVES: This study examines the relationships between Hcy, cognition, and stroke subtype. We hypothesize that: 1) Hcy levels are inversely related to cognition, 2) Hcy levels are unrelated to stroke subtype, and 3) stroke subtype affects cognition.
METHODS: We studied 169 consenting patients admitted for acute stroke during a 4 month period. Blood was drawn for Hcy levels and the Mini-Mental State Examination (MMSE) was administered within 9 days of admission. The Oxfordshire Community Stroke Project Classification was used to characterize stroke subtypes. Correlation between Hcy and MMSE scores was examined as was the relationships between Hcy and stroke subtype, and between stroke subtypes and MMSE scores.
RESULTS: A significant inverse correlation between Hcy levels and MMSE scores was demonstrated (r=-0.243, p=0.001). MMSE scores also differed according to the type of stroke, with Total or Partial Anterior Circulation Infarcts (TACI/PACI) scoring lowest (F=8.77, df=2, p<0.001). Hcy levels did not differ between the various stroke subtypes (F=0.21, df=2, p=0.81). Multivariate linear regression analysis showed that age, education, and stroke subtype, but not Hcy, were independent predictors of acute MMSE scores.
CONCLUSIONS: In this study sample, there was an inverse relationship between Hcy and cognition in acute stroke patients. However, Hcy was not an independent predictor for cognition in acute stroke after other factors such as stroke subtype and patient age were taken into account. These results suggest that during the acute stage of stroke, stroke subtype is a more important factor in determining cognition than Hcy levels.