Following a stroke , 55% of the patients do not recover any traction of the upper limb and 30% a residual motricity not allowing a functional grip. For this last group of patients, there are major therapeutic issues to restore a functional grip.

The aim of the study is to relieved the spastic cocontractions before and after usual injection of botulinum toxin A at stroke patient.

Descriptive study of spastic cocontraction index before and after botulinum toxin A injections during active elbow extension in chronic vascular hemiplegic patients.

The spastic cocontraction score will be compared between T1 (before the Botulinum toxin A injection) and T2 (4 weeks after the botulinum toxin A injection in the elbow flexors).

There is no control group. The patient is his own witness: the non-paretic side is considered as the physiological reference in terms of the level of spastic cocontractions.

Botulinum toxin A injections are performed in routine clinical practice in the Physical Medicine and Rehabilitation Department, following the recommendations in force. This treatment has been shown to be effective on spasticity in several high-level studies. The reduction of spasticity, evaluated clinically (Tardieu and Ashworth scale), is a criterion of efficacy of botulinum toxin A injections.

The evaluation of the effectiveness of botulinum toxin A injections on the other components of muscular hyperactivity, such as the reduction of spastic cocontraction during active movements, is poorly performed in clinical and clinical research. This protocol includes specific assessments to evaluate the evolution of spastic cocontraction.

Inclusion Criteria:

• Having notified his non-opposition to participate in the search
• Ischemic or hemorrhagic stroke of more than 6 months, cortical and / or subcortical;
• Indication to the realization of an injection of Botulinum Toxin A in the flexor muscles of the elbow according to the usual clinical criteria: presence of a functional complaint or aesthetic expressed by the patient and related to hyperactivity muscular (spasticity or cocontraction) on the flexor muscles elbow, which is a focal treatment by injection of botulinum toxin;
• Possibility of active extension of elbow> 20 °;
• Patients naive to Botulinum Toxin A or more than 4 months of a first injection of Botulinum Toxin A, having targeted the elbow flexors.

Exclusion Criteria:

• Passive limitation of elbow extension> 30 °;
• Pain when performing active movements of flexion / extension of the elbow
• Cognitive impairment limiting the comprehension of three basic instructions (proof test of the 3 papers of the MMS);
• Evolutionary or decompensated neurological pathology; Ischemic or haemorrhagic stroke of less than 6 months;
• General contraindication to the production of botulinum toxin; history of myasthenia gravis, Lambert Eaton syndrome; history of neuromuscular disease; surgery with curarization for less than 1 month; treatment with aminoglycoside, aminoquinoline or cyclosporine
• Legal incapacity (safeguard of justice, guardianship).

Patient with Ischemic or hemorrhagic stroke of more than 6 months, cortical and / or subcortical and an who can have a Botulinum Toxin A injection.