Unravelling cossed wires : dysfunction in obstetric brachial plexus lesions in the light of intertwined effects of the peripheral and central nervous system

Abstract

Sensory function is impaired in adults with conservatively

treated OBPL. There

is widespread motor misrouting together with motor functional impairment in conservatively treated OBPL, not explained by muscle weakness. There were no differences in the degree of cocontraction between OBPL patients and healthy subjects for either the triceps or deltoid muscles during supramaximal biceps stimulation. However, elbow stiffness was approximately 1.7 times higher in OBPL patients than in control subjects during voluntary levels of contraction, suggesting a significant effect of misrouting in the patients. In children with OBPL the deficit during automatic arm abduction was not observed during voluntary movements and therefore cannot be explained by a peripheral deficit, suggesting a central component. In adults OBPL affected imagined but not actual elbow flexion suggested an impairment of motor planning.

Obstetric brachial plexus lesionErbs palsyConservative treatmentAdultsSensory functionMotor axonal misroutingCocontractionShort-range stiffnessfMRICentral motor programming