Long-term effects of strokes on bone mass

Area of Science:

• Neurology
• Orthopedics
• Bone Metabolism

Background:

• Stroke often results in hemiparesis, leading to muscle weakness and reduced limb use.
• The impact of this muscle weakness on bone mineral content in the long term is not fully understood.

Purpose of the Study:

• To investigate the long-term effects of stroke-induced muscle weakness on bone mineral content in the hemiparetic limb.
• To quantify bone demineralization progression and identify affected limbs.

Main Methods:

• Dual Energy X-ray Absorptiometry (DXA) was used to measure bone mineral content.
• Muscle strength was assessed using the Oxford scale.
• Measurements were taken within 7 days post-stroke and monthly for up to 6 months.

Main Results:

• Bone demineralization was observed on the paralyzed side, starting within the first month and progressing over 3-4 months.
• Upper limbs showed more pronounced demineralization (9.3% decrease) than lower limbs (3.7% decrease) after 4 months.
• No significant bone mineral loss occurred in healthy limbs, and demineralization plateaued after 4 months.

Conclusions:

• Stroke-induced bone demineralization occurs in the hemiparetic limb, peaking within 3-4 months.
• Arms are more susceptible to bone loss than legs following a stroke.
• Muscle weakness secondary to stroke significantly impacts bone health in the affected limb.