Hypoperfusion of Wernicke's area predicts severity of semantic deficit in acute stroke

Based on earlier findings that the presence of word comprehension impairmen t (a deficit in the meaning of words, or lexical semantics) in acute stroke was strongly associated with the presence of hypoperfusion or infarct in W ernicke's area, we tested the hypothesis that the severity of word comprehe nsion impairment was correlated with the magnitude of delay in perfusion of Wernicke's area on magnetic resonance perfusion-weighted imaging. Eighty p atients were prospectively studied within 24 hours of onset or progression of acute left hemisphere stroke symptoms, with diffusion-weighted imaging, perfusion-weighted imaging, and detailed language tests. For 50 patients wi thout infarct in Wernicke's area, we found a strong Pearson correlation bet ween the rate of errors on a word comprehension test and the mean number of seconds of delay in time-to-peak concentration of contrast in Wernicke's a rea, relative to the homologous region on the right. These results add furt her evidence for the crucial role of Wernicke's area (Brodmann's area 22) i n word comprehension and indicate that the magnitude of delay on PWI may be a gross indicator of tissue dysfunction.