Aphasia therapy early after stroke: behavioural and neurophysiological changes in the acute and post-acute phases

Abstract

Background: There is reasonable evidence to suggest that speech and language therapy can be effective in the chronic stages of stroke recovery. However, the active ingredients remain unknown and several variables can influence therapy outcome, such as content, type, and amount of therapy. Neurophysiological measures, event-related brain potentials such as the N400 and P300, have shown to be sensitive markers of therapeutic effects. As a supplement to the usual behavioural evaluation methods, neurophysiological measures might help to further disentangle the effect of content, type, and/or amount of therapy.Aims: The present single case study aims to investigate the effect of language therapy by combining behavioural and neurophysiological outcome measures in a patient with aphasia during the acute and post-acute stage after stroke. By further subdividing the therapy period into different therapy blocks, possible influences of content, type, and/or amount of therapy are investigated.Methods & Procedures: RL is a 47-year-old man with a moderate non-fluent aphasia, who received three periods of therapy in the first four months after his stroke. The initial evaluation moment occurred 10 days post-stroke. First, he received an intensive language treatment of 30 hr in 3 weeks, which was followed by a conventional treatment of 30 hr in 7 weeks. Then, RL received a second, intensive language therapy of 30 hr in 3 weeks. This was followed by a period of 6 months without any form of language treatment. Behavioural and neurophysiological measures were collected after every therapy and therapy-free period. The effect of therapy was examined by comparing the whole therapy period with the therapy-free period, without differentiating between the intensive and conventional treatment. In a second analysis, a comparison was made between the intensive therapy periods and the conventional therapy programme.Outcomes & Results: RL showed a general improvement on both behavioural and neurophysiological measures after the whole therapy period, which was preserved throughout the therapy-free period. Intensive treatment yielded better language outcomes as indicated by a behavioural and neurophysiological improvement in contrast with the behavioural deterioration of auditory discrimination of pseudowords and decline of the N400 neurophysiological marker, after the conventional therapy.Conclusions: The present study demonstrates the outcome of early language treatment after stroke in which intensity can play an important role. In addition, the use of neurophysiological outcome measures provides added value to the behavioural evaluations in the context of therapeutic follow-up.