Broca's Area Damage is Necessary but not Sufficient to Induce After-effects of cathodal tDCS on the Unaffected Hemisphere in Post-stroke Aphasia

Brain Stimulation

卷:7

S. Ferrieux¹  R. Valabregue²  Y. Samson²  C. Arbizu³  P. Vargas⁴  V. Perlbarg⁵  S. Lehéricy⁵  J.C. Corvol⁶  B. Alshawan⁷  A. Leger⁸  S. Meunier⁹  C. Rosso⁹  C. Zavanone¹⁰ 

[1] APHP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France;

[2] CNRS, UMR 7225, Paris, France;

[3] COGIMAGE, UPMC Paris 6, Paris, France;

[4] Corresponding author. APHP, Urgences Cérébro-vasculaires, Hôpital Pitié-Salpêtrière, 47-83 Bd de l’Hôpital, 75013 Paris, France. Tel.: [phone];

[5] Inserm, U975;

[6] Inserm, UPMC Univ Paris 06, UMRS 678, Laboratoire d'Imagerie Fonctionnelle, Paris, France;

[7] Univ Paris 11, IFR49, DSV/I2BM/NeuroSpin, Bat 145, Gif-sur-Yvette F-91191, France;

[8] fax: [phone].;

[9] CRICM – Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, UPMC Paris 6, Paris, France;

关键词: Stroke;    Language;    tDCS;    Diffusion tensor;    Resting state functional magnetic resonance imaging;   

DOI  :  

来源: DOAJ

【 摘 要 】

Background: The inter-individual variability of behavioral effects after tDCS applied to the unaffected right hemisphere in stroke may be related to factors such as the lesion location. Objective/hypothesis: We investigated the effect of left Broca's area (BA) damage on picture naming in aphasic patients after cathodal tDCS applied over the right BA. Methods: We conducted a study using pre-interventional diffusion and resting state functional MRI (rsfMRI) and two cross-over tDCS sessions (TYPE: sham and cathodal) over the right homologous BA in aphasic stroke patients with ischemic lesions involving the left BA (BA+) or other left brain areas (BA−). Picture naming accuracy was assessed after each session. Inter-hemispheric (IH) functional balance was investigated via rsfMRI connectivity maps using the right BA as a seed. Probabilistic tractography was used to study the integrity of language white matter pathways. Results: tDCS had different effects on picture naming accuracy in BA+ and BA− patients (TYPE × GROUP interaction, F(1,19): 4.6, P: 0.04). All BA− patients except one did not respond to tDCS and demonstrated normal IH balance between the right and left BA when compared to healthy subjects. BA+ patients were improved by tDCS in 36% and had decreased level of functional IH balance. Improvement in picture naming after cathodal tDCS was associated with the integrity of the arcuate fasciculus in BA+ patients. Conclusions: Behavioral effects of cathodal tDCS on the unaffected right hemisphere differ depending on whether BA and the arcuate fasciculus are damaged. Therefore, IH imbalance could be a direct consequence of anatomical lesions.

【 授权许可】

Unknown