Lingraphica co-founder and Chief Scientist, Dr. Richard Steele, summarizes an article from Germany on the factors that contribute to neuroplasticity and functional improvement in people with chronic aphasia. Read on for the details.
In this overview article, Professor Bettina Mohr, from the Department of Psychiatry at the Charité Universitätsmedizin in Berlin, discusses the clinical science that sheds light on factors contributing to neuroplasticity-related functional improvement in persons with chronic aphasia, follwing intensive regimens of language therapy.
First, Mohr sets working definitions for this discussion. In persons with chronic aphasia, she regards “any changes in behavior and brain activity across short-term intervals as treatment-induced,” since “non-therapy-related neuronal changes are highly unlikely” in chronic patients. She characterizes intensive therapies as those that last for at least 1-2 hours a day over a period of 2-4 weeks. To account for the effectiveness of such interventions, she points to cortical plasticity being promoted by “correlated neuronal activity and by strengthening of synaptic contacts between neurons.” In the peer-reviewed literature, Mohr identifies three therapeutic regimens with positive outcomes that have been intensively administered, according to her criteria: constraint-induced aphasia therapy (CIAT), intensive anomia treatment (IAT), and intensive melodic intonation therapy (IMIT).
In the case of CIAT, activities showing improvement and their associated cortical areas with contemporaneous activity changes include: lexical decision tasks/right-frontal area; passive word reading/left-temporoparietal area; and passive auditory processing/right-frontotemporal area. Following IAT, the analogous associations were improved naming (trained & untrained items)/left- frontotemporal perilesional areas. And following IMIT, researchers found improved expression/increase in fiber density and volume of the right hemisphere arcuate fasciculus. From these reports, Mohr concludes that “intensive aphasia treatment in chronic post stroke aphasia leads to reorganization of the functional and structural language network in both hemispheres.”
In conclusion, Mohr notes the importance of therapy method choices in furthering research, asserting that “choosing appropriate language tasks is essential when investigating changes in brain activation.” Subject engagement modes thus require careful attention in planning and assessing future research.
For further reading: B. Mohr, 28 June 2017. Neuroplasticity and Functional Recovery After Intensive Language Therapy in Chronic Post Stroke Aphasia: Which Factors Are Relevant? Frontiers in Human Neuroscience, vol. 11, article 332.