Language rehabilitation in chronic aphasia and time postonset: a review of single-subject data.

BACKGROUND AND PURPOSE This article is a comprehensive review of aphasia treatment studies for the purpose of investigating the relationship between time postonset of aphasia and response to treatment for aphasia in chronic patients at >/=1 year after symptom onset. METHODS Studies that demonstrated treatment response (defined as a measurable change in task performance compared with a control task performance) through the use of single-subject design methodologies on measures of verbal output or auditory comprehension were selected. Individual subject data were extracted from the 23 studies that met criteria identifying the subjects as those who received direct continuous therapy for spoken language deficits and whose changes in response to therapy were measurable. Percent of maximum possible change was used as a measurement of outcome. RESULTS Nonparametric correlation statistics (Spearman rho) and comparisons of group means (Kruskal-Wallis) were used to compare the relationship between time postonset and improvement. Time postonset at which treatment was initiated did not correlate with response to treatment. No significant differences in response to treatment were found between groups of patients according to times postonset. CONCLUSIONS Time postonset is not related to response to treatment for aphasia in patients >1 year postonset of aphasia.