Eye-tracking the effect of word order in sentence comprehension in aphasia: evidence from Basque, a free word order ergative language

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.

Aim: To determine the types, severity and evolution of aphasia in unselected, acute stroke patients and evaluate potential predictors for language outcome 1 year after stroke. Methods: 270 acute stroke patients with aphasia (203 with first-ever strokes) were included consecutively and prospectively from three hospitals in Copenhagen, Denmark, and assessed with the Western Aphasia Battery. The assessment was repeated 1 year after stroke. Results: The frequencies of the different types of aphasia in acute first-ever stroke were: global 32%, Broca’s 12%, isolation 2%, transcortical motor 2%, Wernicke’s 16%, transcortical sensory 7%, conduction 5% and anomic 25%. These figures are not substantially different from what has been found in previous studies of more or less selected populations. The type of aphasia always changed to a less severe form during the first year. Nonfluent aphasia could evolve into fluent aphasia (e.g., global to Wernicke’s and Broca’s to anomic), whereas a fluent aphasia never evolved into a nonfluent aphasia. One year after stroke, the following frequencies were found: global 7%, Broca’s 13%, isolation 0%, transcortical motor 1%, Wernicke’s 5%, transcortical sensory 0%, conduction 6% and anomic 29%. The distribution of aphasia types in acute and chronic aphasia is, thus, quite different. The outcome for language function was predicted by initial severity of the aphasia and by the initial stroke severity (assessed by the Scandinavian Stroke Scale), but not by age, sex or type of aphasia. Thus, a scoring of general stroke severity helps to improve the accuracy of the prognosis for the language function. One year after stroke, fluent aphasics were older than nonfluent aphasics, whereas such a difference was not found in the acute phase.