[Aphasia: evidence-based therapy approaches].

Speech and language therapy is essential in the rehabilitation of aphasic disorders following a stroke. Due to the predicted increase of aphasia and limited resources within the healthcare system, the development of efficient and sustainable treatment methods is of exceptional importance. The effectiveness of both traditional and innovative approaches needs to be evaluated against the standards of evidence-based medicine. Class I evidence has been established for high-intensity speech and language therapy in subacute and chronic stages of aphasia. Innovative training-based approaches have so far only been evaluated in small studies but promising results have been shown for computer-based naming, video-based exercises for verbalization of complex contents and approaches modeled according to "forced-use" principles with standardized contents. Adjuvant training therapies are being developed to increase and prolong the impact of training alone, most notably non-invasive brain stimulation and pharmacological modulation. Transcranial direct current stimulation has been shown to effectively enhance training in several small randomized controlled trials but several questions still remain to be answered, including the location of electrode placement as well as the length and intensity of stimulation. Mixed evidence has been collected for the effectiveness of pharmacotherapy on speech learning and further randomized controlled trials are also needed to allow more firmly based recommendations.