title: Plastic changes following imitation-based speech and language therapy for aphasia: a high-density sleep EEG study.
abstract: BACKGROUND OBJECTIVE: 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.
authors: 1University of Wisconsin-Madison, WI, USA.
authors: Simone
authors: S
authors: Sarasso
authors: Sara
authors: S
authors: Määttä
authors: Fabio
authors: F
authors: Ferrarelli
authors: Rositsa
authors: R
authors: Poryazova
authors: Giulio
authors: G
authors: Tononi
authors: Steven L
authors: SL
authors: Small
mesh_terms: D000328:Adult; D000368:Aged; D001037:Aphasia / Q000209:etiology / Q000628:therapy*; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007100:Imitative Behavior; D007808:Language Therapy; D008297:Male; D008875:Middle Aged; D009473:Neuronal Plasticity; D012890:Sleep / Q000502:physiology; D013070:Speech Therapy; D020521:Stroke / Q000150:complications / Q000503:physiopathology
keywords: EEG; SWA; aphasia; sleep; stroke