Sensory Deficits in Neonatal Brachial Plexus Palsy: A Cross-Sectional Study of Clinical, Electrophysiological, and Functional Correlates.

Abstract

To systematically assess tactile sensibility in children with right-sided Neonatal Brachial Plexus Palsy (NBPP) using a standardized approach, and to investigate whether (1) sensibility is reduced in the affected, non-dominant hand compared to the non-dominant hand of matched controls, (2) sensory thresholds correlate with electrophysiological findings (SNAP), and (3) diminished sensibility in digits 1-3 is associated with impaired hand motor performance. Cross-sectional study with a control group. Tertiary university hospital NBPP care unit. A total of 76 left-hand-dominant children aged 6-23 years: 31 with right-sided NBPP and 45 age- and sex-matched typically developing (TD) controls. All participants underwent Semmes Weinstein monofilament sensory testing (SWM), motor assessment (BOT-2, Purdue Pegboard Test). NBPP participants also underwent electrodiagnostic examination of sensory nerve action potential (SNAPs). NBPP participants demonstrated significantly impaired tactile sensibility in digits 1-5 of the affected hand compared to TD controls (p = .006-.040). Sensory thresholds in digits 2-5 were also significantly worse than in the contralateral hand. Although SNAP abnormalities increased with lesion severity, SWM and SNAP results were only weakly correlated (φ=-0.325 - +0.110), highlighting the complementary nature of perceptual and electrophysiological testing. Within the NBPP group, reduced tactile sensibility in digits 1-3 was significantly associated with lower scores on the BOT-2 manual dexterity subscale (β = -0.302, p = .030) and Purdue Pegboard Test (β = -0.309, p = .015). Tactile sensory deficits are prevalent in children with right-sided NBPP and are functionally relevant, as reduced sensibility in digits 1 to 3 is associated with impaired fine motor performance. The partial dissociation between perceptual and electrophysiological findings highlights the complexity of sensory involvement and supports multimodal assessment. These results advocate for routine sensory evaluation to guide early neurorehabilitation and inform long-term management in NBPP.