This study evaluates cognitive-motor interference in stroke patients who is responsible an alteration of spatio-temporal gait parameters. It's proved in the literature but the underlying pathophysiological mechanisms remain poorly understood. fNIRS is a functional imaging technique that evaluates this interference under optimal conditions. The purpose of this study is to evaluate the hemodynamic activity of the CPF in walking post-stroke patients under different DT conditions.

Walking is a motor task that involves cognitive functions. The parameters of walking and brain activity are modified in situations requiring significant attentional and cognitive demand. fNIRS is an interesting functional neuroimaging technique for studying cortical activity when performing a Dual Task (DT). To our knowledge, no studies have examined cerebral oxygenation levels in post-stroke patients based on different cognitive loads during walking. Understanding cognitive contributions in a dual-task walking situation is necessary to providing targeted interventions and preventing falls.

Patients included in the study will be evaluated in single cognitive task, with two levels of difficulty, single walking motor task, and dual task with two levels of cognitive difficulty. The fNIRS will record the hemodynamic activity of the prefrontal cortex for the cognitive slope and the GAITRite will record the walking parameters.

Inclusion Criteria:

• patient between 55 and 75 years old
• First stroke
• ischemic sylvian or hemorrhagic lobar deep respecting the frontal lobe, subacute phase (J15-J90),
• patient walking 10 meters.

Exclusion Criteria:

• Heminegligencia,
• a history of neurological pathologies, orthopedic pathologies, aphasia, cognitive disorders preceding stroke (dementia, head trauma), acute cardiovascular or respiratory pathologies.