Article

Measurement of plastic brain changes induced by a novel
rehabilitative approach is a key requirement for validating its biological
rationale linking the potential therapeutic gains to the changes in brain
physiology. OBJECTIVE: Based on an emerging notion linking cortical plastic
changes to EEG sleep slow-wave activity (SWA) regulation, we aimed to assess the
acute plastic changes induced by an imitation-based speech therapy in individuals
with aphasia by comparing sleep SWA changes before and after therapy. METHODS: A
total of 13 left-hemispheric stroke patients underwent language assessment with
the Western Aphasia Battery (WAB) before and after 2 consecutive high-density
(hd) EEG sleep recordings interleaved by a daytime session of imitation-based
speech therapy (Intensive Mouth Imitation and Talking for Aphasia Therapeutic
Effects [IMITATE]). This protocol is thought to stimulate bilateral connections
between the inferior parietal lobule and the ventral premotor areas. RESULTS: A
single exposure to IMITATE resulted in increases in local EEG SWA during
subsequent sleep over the same regions predicted by the therapeutic rationale,
particularly over the right hemisphere (unaffected by the lesion). Furthermore,
changes in SWA over the left-precentral areas predicted changes in WAB repetition
scores in our group, supporting the role of perilesional areas in predicting
positive functional responses. CONCLUSIONS: Our results suggest that SWA changes
occurring in brain areas activated during imitation-based aphasia therapy may
reflect the acute plastic changes induced by this intervention. Further testing
will be needed to evaluate SWA as a non-invasive assessment of changes induced by
the therapy and as a predictor of positive long-term clinical outcome.

Langue : ANGLAIS