Chronic pain in children with obstetrical brachial plexus palsy
Kristen Davidge, MD, MSc, FRCS(C)
BACKGROUND: Obstetrical brachial plexus palsy (OBPP) is a condition where the nerves innervating the upper limb are injured during the birthing process, resulting in immediate and often persistent impairment in upper limb sensory and motor function. The fact that children with OBPP experience pain has only recently been recognized, because children with OBPP do not start reporting pain in their affected upper limb until late childhood or adolescence, a decade or more after the initial nerve injury.
GAP: Early data suggests that upper limb pain in older children and adolescents with OBPP is typically frequent, episodic, of low-to-moderate intensity and more common than initially recognized, with a point prevalence of 25% and lifetime prevalence of 66%. However, existing data are limited to operated patients and much remains to be understood regarding the nature of pain in this condition.
HYPOTHESIS: The goal of this proposal is to establish the overall prevalence, characteristics, impact and determinants of pain in children and adolescents with obstetrical brachial plexus palsy. We anticipate overall point and lifetime pain prevalence to approach 15% and 50%, respectively, and hypothesize that children with OBPP experience episodic upper limb pain, with mixed musculoskeletal and neuropathic symptoms that interferes with function when the intensity is severe.
METHODS: This study comprises a cross-sectional investigation of pain prevalence, characteristics, and interference, (Aims 1 and 2), and a retrospective cohort analysis of pain determinants (Aim 3). In the cross-sectional study, we will sample 1396 children and adolescents with OBPP, aged 8-18 years, at a single, high-volume, pediatric tertiary care center.
IMPACT: This research will generate key information to guide improved recognition and diagnosis of pain in OBPP, improved treatment strategies based on knowledge of pain mechanisms, and preliminary pain prevention strategies based on identified risk factors. In the long-term, research on pain in OBPP will have wide-ranging implications for our understanding of central and peripheral pain processing in the neonate.