Co-administration of prism adaptation and methylphenidate needs striatal integrity to alleviate spatial neglect

Context A previous study demonstrated a long-term functional improvement of spatial neglect after methylphenidate combined with prismatic adaptation in a group of patients suffering from left spatial neglect after a right stroke (RITAPRISM study). Objective we hypothesized that the functional improvement after MP combined with PA depends on striatal integrity in responders patients. Methods We conducted an MRI study in “MP+PA” program to identify lesional pattern in responders and non-responders patients in the RITAPRISM cohort. Using anatomical segmentation on morphological MRI, we compared lesional pattern in the striatum between responders and non-responders patients. Results The beneficial effect of MP+PA co-administration should require striatal integrity in neglect patients. More specifically, our results suggest that the short-term effect is mediated by the ventral striatum whereas the long-term effect is mediated by the posterior putamen. Conclusion Benefical effet of MP+PA could rely on reinforcement processes at early stage of the MP+PA program and visuospatial substrates at long-term. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by institutional grant from the Programme Hospitalier de Recherche Clinique (PHRC 2007). This work also benefited from institutional supports from Inserm, CNRS, UCBL, HCL, the Labex/Idex ANR-11-LABX-0042 and IHU CeSaMe ANR-10-IBHU-0003 and the James McDonnell Foundation. MBG salary was supported by ANR-18-CE17-0012 ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by Lyon Ethics Committee (CPP Sud-Est IV; EudraCT Number: 2008-000325-00). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors