The aim is to determine predictors of treatment response, i.e gain from rehabilitation training, in post stroke upper limb deficits. The investigators will like to answer the following question: "What is this patient's potential for recovery, given his profile?" The investigators propose to conduct a longitudinal physiopathological study on the stroke patients with motor deficits who entered the rehab center of Pitié Salpêtrière hospital. The investigators will benefit from the organization, which is already in place (clinical asssessments and training) to add MRI, TMS and EEG recordings, as well as genotype analysis before the training offered in the rehabilitation unit. The investigators will repeat these assessments after the training (immeadiately and 6 weeks after).

The protocol is based on 10 visits. The three main one are V1, V9 and V10. V1, V9 and V10 are the assessments visits with clinical scores, MRI TMS and EEG recordings. These are made before the training (V1), immediately after the 6 weeks of training (V9) and 6 weeks after (V10) V5 is a visit where the investigators will clinically assess the patients at three weeks of the training.

The other visits (V2, V3, V4, V6, V7, V8) consist in recording an EEG while patients are under training each week during six weeks.

Inclusion Criteria:

(i) First-ever stroke patients (ii) Upper limb motor impairment (Fugl Meyer scale) (iii) post stroke delay between 7 and 42 days (iv) affiliated to french health care (v) Suitable for task based oriented training in the rehab center

Exclusion Criteria:

(i) age < 18 or > 85 years (ii) Hemianopia (iii) contra-indications to MRI or TMS assessments (iv) life threatening conditions (v) patients under legal protection (vi) pregnancy