Departure of the principal investigator

Regardless of the cause of immobilization, within days or weeks there is rapidly a decrease in strength and muscle mass, which can lead to sarcopenia. In severe strokes, immobilization and neurologic damage may be added to promote sarcopenia. Several studies in Asian populations confirm rapid increases in sarcopenia rates after stroke, but there are only rare data in Western populations. The aim of this work is to monitor during the first 10 days after a severe stroke leading to a reduction in ambulation, the evolution of muscle strength (studied in dynamometry), body composition (studied by impedance measurement) and sarcopenia rates. Investigators will also look for factors that predict the occurrence of this sarcopenia (such as sex, age, initial deficiency, stroke volume, swallowing disorders, etc.).

In stroke patients, muscle damage combines many mechanisms such as immobilization, nutritional disorders , sympathetic activity, inflammation and denervation . These general factors explain that post-stroke sarcopenia is also observed on the side considered healthy .

Several meta-analyzes have been carried out on this subject . In the study by Inoue et al., which brings together 35 studies on the subject, the rates of sarcopenia observed were overall of the order of 15% before the stroke, of 30% in the 10 days post-stroke and of the order of 50% in the first semester . Only about 10 studies have been performed in the acute phase . However, the majority of these studies were performed in Asian populations (32 of them). But this is a population with demographic and physiological characteristics that are different from those in the West. Thus, body mass indices are lower and the representation of older people is higher in the population (the Japanese population is the oldest in the world).

Body composition may be a predictor of the course of recovery from stroke. In a cohort study it was thus shown by bioimpedance measurements that patients with the lowest muscle mass index had more severe neurological deficits at admission. They also had poorer functioning and longer hospital stays. Muscle mass is an independent variable in predicting what happens to people who have had a stroke.

Strokes cause motor deficits that reduce movement on the deficit side but also on the unaffected side. Sarcopenia (loss of strength and muscle mass) develops in the first few days after a stroke and worsens the consequences of neurologic damage. While immobilization rapidly leads to sarcopenia, sarcopenia has been poorly studied in acute stroke, especially in Asian populations, which are unrepresentative of Western populations.

The aims of this work are to:

1. Longitudinally determine rates of sarcopenia in the acute phase of stroke during follow-up over the first 10 days after stroke.
2. Determine the factors that predict the occurrence of sarcopenia (age, degree of initial deficiency, lesion volume, etc.)
3. Track body composition by segment (4 limbs and trunk) over time in impedance measurement, particularly by distinguishing between deficit and nondeficit. Investigators will distinguish the usual parameters (skeletal muscle mass, angle phase).
4. Monitor motor recovery of the deficient upper limb and determine whether muscle mass is a prognostic factor for recovery.

Measurement will be done at three time (T1, T2, T3) T1 corresponds to the first 72 hours post stroke T2 corresponds at 5 days (+/-1 days) T2 corresponds at 8 days (+/-1 days)

Inclusion Criteria:

• Acute stroke patient
• Over 18 years of age
• Functional Ambulation Categories (FAC) < 3
• NIHSS upper limb score ≥ 1
• Able to understand assessment instructions
• Non-objection to the study
• Affiliated with a social security scheme

Exclusion Criteria:

• Person under guardianship or curatorship.
• Person deprived of liberty
• Person under court protection
• Other neurological or rheumatological pathology limiting mobility
• Presence of a pacemaker or defibrillator.
• Pregnant or breast-feeding woman