Brain activation can be studied using the Functional Near InfraRed Spectroscopy (fNIRS). It was shown that CPF activation during walking and during dual task could be different in stroke patients and in healthy subjects.

To date, fNIRS reliability is not completely established during walking and during dual task. Therefore, this study will examine the reproducibility of fNIRS parameters during simple walking and during dual task in healthy subjects and in stroke patients.

A fNIRS system will be used to measure the CPF activation. The subjects will walk at their preferred speed on 10 m 3 times and while doing a cognitive task (dual task) 3 times also (in a random order). The same test will be repeated five minutes later. The fNIRS system will be retired and the same test will be repeated 10 min later.

Inclusion Criteria:

• Acute stroke group, subacute stroke group, and control group:

  • Age 50 to 80 years
  • Affiliated with a social security plan
  • Able to walk 20 meters unassisted

• Acute Stroke and Subacute Stroke Group:

  • Stroke onset less than 14 days (for the acute stroke group) or between 14 days and 6 months (for the subacute stroke group)
  • Stroke located in the left or right middle cerebral artery.

Exclusion Criteria:

• Acute stroke group, subacute stroke group, and control group:

  • Person under guardianship or curatorship
  • Refusal to sign informed consent
  • Known rheumatologic or cardiologic history
  • Medication that alters the vigilance and may affect walking (high dose psychotropic drugs, antispastic drugs).

• Acute stroke group and subacute stroke group:

  • History of symptomatic stroke
  • Previous neurological disease limiting gait, aphasia or impaired cognitive function (mild cognitive dementia, Alzheimer's or Parkinson's disease)
  • Ambulatory functional category < 3

• Control group: neurological medical history