Longitudinal changes in muscle strength and mass after acute stroke

Area of Science:

• Neurology
• Rehabilitation Medicine
• Human Physiology

Background:

• Reduced mobility following a stroke can theoretically lead to muscle mass loss and increased disability.
• Investigating the impact of acute stroke on limb muscle characteristics is crucial for understanding long-term recovery and function.

Purpose of the Study:

• To examine longitudinal changes in muscle strength, lean cross-sectional area, and muscle mass across all limbs in patients following an acute stroke.
• To determine if reduced mobility post-stroke contributes to muscle deterioration.

Main Methods:

• Recruited 17 patients within 72 hours of hospital admission.
• Measured hand grip strength, knee extensor strength, and limb lean cross-sectional area at 6 intervals over 6 months.
• Assessed appendicular and total muscle mass using dual-energy X-ray absorptiometry at 3 weeks and 6 months post-stroke.

Main Results:

• No significant longitudinal changes were observed in arm or leg strength, lean cross-sectional area, or muscle mass.
• Muscle strength in all limbs was notably lower compared to established population norms.
• The findings did not support a link between reduced mobility and subsequent muscle decline.

Conclusions:

• Acute stroke did not lead to measurable declines in limb muscle strength or mass within the first six months.
• Pre-existing muscle weakness, potentially on the ipsilateral side, may be a more significant factor than post-stroke immobility.
• Further research is needed to explore the origins of muscle weakness in stroke survivors.