The effects of low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) and sham condition rTMS on behavioural language in chronic non-fluent aphasia: Short term outcomes

Article type: Research Article

Authors: Barwood, Caroline H.S.^{a; *} | Murdoch, Bruce E.^a | Whelan, Brooke-Mai^a | Lloyd, David^{a; b} | Riek, Stephan^b | O'Sullivan, John^c | Coulthard, Alan^d | Wong, Andrew^{c; e; f} | Aitken, Phil^{f; h} | Hall, Graham^{f; g}

Affiliations: [a] Centre for Neurogenic Communication Disorders Research, School of Health and Rehabilitation Sciences, University of Queensland, Australia | [b] School of Human Movement Studies, University of Queensland, Australia | [c] Department of Neurology and Neurosurgery, Royal Brisbane and Women's Hospital, Queensland, Australia | [d] Department of Medical Imaging, Royal Brisbane and Women's Hospital, Queensland, Australia | [e] Department of Neurology, Princess Alexandra Hospital, Queensland, Australia | [f] Acute Stroke Unit, Princess Alexandra Hospital, Queensland, Australia | [g] Department of Medicine, Princess Alexandra Hospital, Queensland, Australia | [h] Department of Geriatric Medicine, Princess Alexandra Hospital, Queensland, Australia

Correspondence: [*] Corresponding author: Caroline Barwood, Centre for Neurogenic Communication Disorders Research, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane St Lucia, QLD 4072, Australia. Tel.: +617 3365 6162; Fax: +617 3365 1877; E-mail: [email protected]

Abstract: Introduction:The application of low frequency (1 Hz) Repetitive Transcranial Magnetic Stimulation (rTMS) to right hemisphere (RH) language homologues in non-fluent aphasic populations has yielded improvements in behavioural language function, up to 43 months post stimulation [32]. Functional imaging studies have demonstrated RH language homologue “overactivation” post left inferior frontal gyrus (IFG) damage, in chronic non-fluent aphasia. The effects of low frequency (inhibitory) rTMS are postulated to be as a result of a reduction of overactivation in RH language homologues, facilitating the reorganisation of neural language networks. Methods:Low frequency (1 Hz) rTMS was applied to the anterior portion of a Broca’s area homologue (pars triangularis), for 20 minutes per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent aphasic patients (six real stimulation and six sham), 2–10 years post stroke were stimulated. Behavioural language outcome measures were taken at baseline and 1 week post rTMS. Results:Comparisons between the real stimulation and sham conditions indicated significant main effects between the stimulation and sham groups to 1 week post stimulation for naming accuracy, latency and repetition. Conclusions:This study indicates that rTMS has the capacity to modulate neural language networks, to facilitate improvements in behavioural language function, 1 week post TMS.

Keywords: Transcranial Magnetic Stimulation (TMS), aphasia, stroke rehabilitation, language

DOI: 10.3233/NRE-2011-0640

Journal: NeuroRehabilitation, vol. 28, no. 2, pp. 113-128, 2011