Genetic polymorphisms and post-stroke upper limb motor improvement - A systematic review and meta-analysis

Area of Science:

• Neuroscience
• Genetics
• Rehabilitation Medicine

Background:

• Post-stroke upper limb (UL) motor improvement relies on neuroplasticity and motor learning.
• Genetic factors, including polymorphisms in BDNF, APOE, and COMT, can influence recovery.
• The specific impact of these polymorphisms on UL motor improvement post-stroke requires elucidation.

Purpose of the Study:

• To investigate the influence of genetic polymorphisms on post-stroke upper limb motor improvement.
• To analyze the association between specific genetic variations and motor recovery outcomes.

Main Methods:

• Systematic review and meta-analysis of relevant literature.
• Assessment of study quality using the modified Downs and Black checklist.
• Meta-analysis of upper limb motor impairment (Fugl Meyer Assessment) and activity scores.

Main Results:

• Studies with BDNF val66met and met66met polymorphisms showed lower motor impairment (large ES) compared to those without.
• Individuals without COMT val158met or met158met polymorphisms exhibited lower impairment and higher activity scores (large ES).
• The APOEε4 polymorphism did not significantly affect upper limb motor improvement.

Conclusions:

• Polymorphisms in BDNF and COMT, specifically the presence of 1 or 2 met alleles, negatively impact upper limb motor improvement after stroke.
• These findings highlight the role of genetic factors in stroke rehabilitation outcomes.