Randomized trial of iReadMore word reading training and brain stimulation in central alexia

Journal article

Central alexia is an acquired reading disorder co-occurring with a generalised language deficit (aphasia). We tested the impact of a novel training app, ‘iReadMore’, and anodal transcranial direct current stimulation of the left inferior frontal gyrus, on word reading ability in central alexia. The trial was registered on www.clinicaltrials.gov (NCT02062619).

21 chronic stroke patients with central alexia participated. A baseline-controlled, repeatedmeasures, crossover design was used. Participants completed two 4-week blocks of iReadMore training, one with anodal stimulation and one with sham stimulation (order counterbalanced between participants). Each block comprised 34 hours of iReadMore training and 11 stimulation sessions.

Outcome measures were assessed before, between and after the two blocks. The primary outcome measures were reading ability for trained and untrained words. Secondary outcome measures included semantic word matching, sentence reading, text reading and a self-report measure. iReadMore training resulted in an 8.7% improvement in reading accuracy for trained words (95% CI [6.0, 11.4]; Cohen’s d = 1.38) but did not generalise to untrained words. Reaction times also improved. Reading accuracy gains were still significant (but reduced) three-months after training cessation.

Anodal transcranial Direct Current Stimulation (compared to sham), delivered concurrently with iReadMore, resulted in a 2.6% (CI [-0.1, 5.3]; d = 0.41) facilitation for reading accuracy, both for trained and untrained words.

iReadMore also improved performance on the semantic word-matching test. There was a nonsignificant trend towards improved self-reported reading ability. However, no significant changes were seen at the sentence or text reading level.

In summary, iReadMore training in post-stroke central alexia improved reading ability for trained words, with good maintenance of the therapy effect. Anodal stimulation resulted in a small facilitation (d = 0.41) of learning and also generalised to untrained items.

Authors: Woodhead, Z; Kerry, S; Aguilar, O; Ong, Y; Hogan, J

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Brain
• Volume: 141
• Issue: 7
• Pages: 2127–2141
• Publication date: 2018-06-15
• Acceptance date: 2018-04-03
• DOI: 10.1093/brain/awy138
• EISSN: 1460-2156
• ISSN: 0006-8950
• Keywords: aphasia; central alexia; transcranial direct current stimulation (tDCS); computer-based rehabilitation; reading therapy