Can virtual games retrain the brain to restore balance?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: \- Adult patient (18 years old or older) with motor disorders related to a deficit in postural stability (mini-BESTest ≤ 25) which may be associated with a deficit in the use of upper limbs and locomotion, consecutive to : 1) either acquired neurological impairments (ischemic or hemorrhagic stroke in sub-acute or chronic phase, head trauma, benign tumor operated on with complete removal, cerebral anoxia) , or 2) a neurodegenerative affection (Parkinson's disease, Multiple Sclerosis). OR * Child or teenager patient (6 to 17 years old) with motor disorders related to a deficit in postural stability (mini-BESTest ≤ 25) which may be associated with a deficit in the use of upper limbs and locomotion, consecutive to 1) either spastic, dyskinetic or ataxic cerebral palsy, or 2) a similar impairment without diagnosis or of another etiology. * Patient able to walk with or without technical aids and to perform voluntary upper limb movements. * Patient able to understand and follow instructions or adapted communication. * Patient having given written informed consent concerning his/her participation in the protocol OR (for children) whose parents have given their written informed consent. * Patient covered by social security. Exclusion Criteria: * Patient with a severe intellectual disability. * Patient with a severe attention deficit disorder. * Patient whose epilepsy is not stable. * Patient with pain preventing participation in the intended tasks of the protocol. * Patient with an illness, medical condition or treatment incompatible with participation in the protocol. * Patient with multiple sclerosis with relapse less than 3 months old. * Simultaneous participation in other interventional research (1) that may exclude participation in the present study or (2) for which the exclusion period has not ended and whose nature may possibly impact the results of the present research. In addition, the vulnerable persons mentioned in Articles L. 1121-5, L.1121-6 and L.1121-8 of the French Public Health Code are excluded from the study: * Pregnant, nursing or parturient women. * Persons deprived of their liberty by judicial or administrative decision, hospitalized without consent or admitted to a health or social institution for purposes other than research. * Adults under legal protection or unable to express their consent.