PO106 / #1015 IS THE USE OF REPETITIVE TRANSCRANIAL MAGNETIC STIMULATION (RTMS) SYSTEMATICALLY SUCCESSFUL IN THE REHABILITATION OF CHRONIC SPATIAL NEGLECT AFTER STROKE?

International audienceIntroduction: Neglect represents a neurological condition consisting in the lack of awareness in the contralesional hemispace (generally the left, after a right hemisphere lesion), precluding the rehabilitation of patients' deficits. By targeting cortical nodes and their associated networks, non-invasive brain stimulation techniques are currently used in neglect rehabilitation, being based on the inter-hemispheric rivalry hypothesis (Kinsbourne, 1977), that posits the existence of mutual inhibitions between the two brain hemispheres. The main approach consists in the inhibition of intact systems in the contralesional structures in order to restitute the lost function. Materials / Methods: The present study is based on data acquired in the PHRC Regional NEGLECT, a multicentric double-blind clinical trial evaluating the efficacy and safety of a repetitive transcranial magnetic stimulation (rTMS) regime for 2 weeks, to improve visuo-spatial neglect in 21 stroke patients (10 men), at least at 2 months after the stroke. All patients performed neurological, neuropsychological (paper and pencil and computerbased reaction time target detection-localization tests) and neuroradiological evaluations, before and during the real or sham rTMS program, as well as 10 days, 14 days, 4 weeks and 24 weeks following the end of the rTMS. Based on the neuropsychological evaluation, a Spatial Bias Compound Score (SBCS) was computed. During the rTMS, the coil of a standard Magstim Superrapid machine was applied on the intact left posterior parietal cortex (PPC), at the posterior part of the intraparietal sulcus. In line with Kinsbourne's hypothesis, we aimed at decreasing the 'excess' of inhibitory information that is projected transcallosally from the intact left PPC onto the damaged right PPC. Specifically, we assessed the effects of rTMS in the treatment of neglect and we documented lesional patterns of patients, with the aim to characterize predictive factors of response to treatment. Results: Statistical analyses did not emphasize any changes in the SBCS between baseline and the four post rTMS treatment evaluations, between the sham and the rTMS groups (all p > 0.05). However, computer-based tests showed significant improvement in the rTMS group comparing with the sham group. The anatomical analysis emphasized heterogenous lesional patterns for both groups. Discussion: These results suggest that a reappraisal of the inter-hemispheric rivalry hypothesis and/or of inhibitory effects of rTMS is necessary. Conclusions: Future stimulation protocols should be individually designed, considering the presence of the lesion and of the impaired/ preserved networks, in order to efficiently rehabilitate neglect. Acknowledgements: Authors thank l'Assistance Publique-Hôpitaux de Paris for financial support in conducting this study. Learning Objectives: 1 To learn about the rehabilitation of neglect 2 To understand the physiological basis of neglect rehabilitation by using rTMS 3 To conceive future stimulation protocols individually designed