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Research paper
Auditory training changes temporal lobe connectivity in ‘Wernicke’s aphasia’: a randomised trial
  1. Zoe VJ Woodhead1,2,3,
  2. Jennifer Crinion4,
  3. Sundeep Teki5,
  4. Will Penny2,
  5. Cathy J Price2,
  6. Alexander P Leff2,4
  1. 1 Department of Brain Repair and Rehabilitation, University College London, London, UK
  2. 2 Wellcome Trust Centre for Neuroimaging, University College London, London, UK
  3. 3 Department of Experimental Psychology, University of Oxford, Oxford, UK
  4. 4 Institute of Cognitive Neuroscience, University College London, London, UK
  5. 5 Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
  1. Correspondence to Dr Zoe VJ Woodhead, Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London WC1N 3BG, UK; z.woodhead{at}ucl.ac.uk

Abstract

Introduction Aphasia is one of the most disabling sequelae after stroke, occurring in 25%–40% of stroke survivors. However, there remains a lack of good evidence for the efficacy or mechanisms of speech comprehension rehabilitation.

Trial Design This within-subjects trial tested two concurrent interventions in 20 patients with chronic aphasia with speech comprehension impairment following left hemisphere stroke: (1) phonological training using ‘Earobics’ software and (2) a pharmacological intervention using donepezil, an acetylcholinesterase inhibitor. Donepezil was tested in a double-blind, placebo-controlled, cross-over design using block randomisation with bias minimisation.

Methods The primary outcome measure was speech comprehension score on the comprehensive aphasia test. Magnetoencephalography (MEG) with an established index of auditory perception, the mismatch negativity response, tested whether the therapies altered effective connectivity at the lower (primary) or higher (secondary) level of the auditory network.

Results Phonological training improved speech comprehension abilities and was particularly effective for patients with severe deficits. No major adverse effects of donepezil were observed, but it had an unpredicted negative effect on speech comprehension. The MEG analysis demonstrated that phonological training increased synaptic gain in the left superior temporal gyrus (STG). Patients with more severe speech comprehension impairments also showed strengthening of bidirectional connections between the left and right STG.

Conclusions Phonological training resulted in a small but significant improvement in speech comprehension, whereas donepezil had a negative effect. The connectivity results indicated that training reshaped higher order phonological representations in the left STG and (in more severe patients) induced stronger interhemispheric transfer of information between higher levels of auditory cortex.

Clinical trial registration

This trial was registered with EudraCT (2005-004215-30, https://eudract.ema.europa.eu/) and ISRCTN (68939136, http://www.isrctn.com/).

  • Wernicke’s aphasia
  • speech comprehension
  • phonological training
  • pharmacological trial
  • magnetoencephalography

This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/

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Footnotes

  • Funding This work was supported by the Wellcome Trust and the James S McDonnell Foundation (conducted

    as part of the Brain Network Recovery Group initiative). APL and ST were supported by personal fellowships from the Wellcome Trust (ME033459MES and 106084/Z/14/Z, respectively).

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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