Abstract WP193: Genetic Polymorphisms Negatively Impact Upper Limb Motor Recovery After Stroke - A Meta-analysis

Abstract

Upper limb (UL) hemiparesis is one of the most disabling consequences of a stroke. In addition to spontaneous recovery, post-stroke motor recovery is associated with adaptive neuroplasticity and motor learning. Factors affecting motor learning and adaptive neuroplasticity include the presence of genetic polymorphisms. Evidence is emerging that these polymorphisms can influence UL motor recovery. However, the implications of these polymorphisms on rehabilitation are unclear. Using a systematic review and meta analysis, we examined the influence of genetic polymorphisms on post-stroke UL motor recovery. We conducted a systematic review of the published literature in English language. The Down’s and Black checklist helped evaluate the quality of the published studies. We compared changes in UL motor impairment and activity levels between groups with and without the polymorphisms using standardized mean differences and derived summary effect sizes. Seven studies that examined the effects of genetic polymorphisms on UL motor recovery were obtained. The studies examined the effects of polymorphisms (presence of met alleles) in brain derived neurotrophic factor (BDNF, 5 studies) and Catechol- O -Methyltransferase (COMT, 1 study). One study assessed the effects of Apolipoprotein polymorphism (ApoE ε4). The Fugl Meyer Assessment and Wolf Motor Function Test outcomes assessed motor impairment and activity levels respectively. The quality of the published studies ranged from fair to good. The meta analysis revealed that presence of met allele in BDNF negatively influenced the recovery of motor impairment (moderate effect size -0.47). In addition, recovery of activity levels for people with moderate and high levels of motor ability (effect sizes -1.39 and -7.37 respectively) were also negatively impacted by the presence of met allele in BDNF. The met allele in COMT also negatively influenced recovery of motor impairment (effect size -2.66). Presence of ApoE ε4 did not influence UL motor recovery. In conclusion, the presence of genetic polymorphisms negatively influences the recovery of UL motor impairment and activity. These factors need to be considered while selecting rehabilitation interventions to maximize levels of UL motor recovery post-stroke.