Aphasia in acute stroke: incidence, determinants, and recovery

Knowledge of the frequency and remission of aphasia is essential for the rehabilitation of stroke patients and provides insight into the brain organization of language. We studied prospectively and consecutively an unselected and community-based sample of 881 patients with acute stroke. Assessment of aphasia was done at admission, weekly during the hospital stay, and at a 6-month follow-up using the aphasia score of the Scandinavian Stroke Scale. Thirty-eight percent had aphasia at the time of admission; at discharge 18% had aphasia. Sex was not a determinant of aphasia in stroke, and no sex difference in the anterior-posterior distribution of lesions was found. The remission curve was steep: Stationary language function in 95% was reached within 2 weeks in those with initial mild aphasia, within 6 weeks in those with moderate, and within 10 weeks in those with severe aphasia. A valid prognosis of aphasia could be made within 1 to 4 weeks after the stroke depending on the initial severity of aphasia. Initial severity of aphasia was the only clinically relevant predictor of aphasia outcome. Sex, handedness, and side of stroke lesion were not independent outcome predictors, and the influence of age was minimal.