Botulinum toxin injections is very frequently used in the treatment of spasticity after central neurological damage (stroke, multiple sclerosis, spinal cord injury, head trauma). The injections may be painful and the tolerance of the injections varies from one patient to another. The pain felt during the injection causes in most patients great stress during the injection.~Virtual reality is a video technique with 360 ° vision simulating the physical presence of the patient in an existing environment outside the hospital setting. This technique has been used in painful procedures but only one publication, in pediatrics, has shown a decrease in pain and agitation during botulinum toxin injections.~The hypothesis of this research is that an immersive virtual reality system can, in adults, reduce stress and the painful experience of botulinum toxin injections.
The main objective of the study is to investigate the effect of exposure to a virtual reality session during botulinum toxin injections on injection-induced stress.~The secondary objectives are to study the effect of exposure to a virtual reality session during botulinum toxin injections, on the pain induced by the injection. And study the evolution of the effects of virtual reality with the repetition of the sessions.