Published in UAB Insight, Spring 2008
Comprehensive Treatment for Brachial Plexus and Peripheral Nerve Injuries
Traction injuries to the brachial plexus are among the most common injuries neonates sustain during delivery, particularly when performed under emergent conditions. “Brachial plexus injuries result from lateral flexion of the baby’s neck combined with downward force on the shoulder, most often caused when the shoulder becomes lodged under the pelvic bone,” says pediatric neurosurgeon John C. Wellons III, MD. The extent of traction determines the severity of the trauma, which can range from a mild stretch injury to a stretch or tear causing formation of a neuroma to avulsion of individual nerves from the spinal cord.
“Most brachial plexus injuries resolve without surgery,” says Wellons, who sees patients at the Brachial Plexus and Nerve Injury Clinic at Children’s Hospital of Alabama, one of the region’s few high-volume centers for brachial plexus repair.
“Nuance is important in treating these injuries,” he says. “If interventions are done too early, babies who may have gotten better on their own are subjected to unnecessary surgery. If surgery is performed too late, target muscles atrophy and no anastomosis can reanimate them. The best judgments are made when we track functional changes within groups of muscular actions. Evaluation by at least 2 months of age is critical for establishing baseline shoulder abduction, arm rotation, elbow flexion, and hand function,” Wellons says.
The clinic’s physiatrist Charles R. Law, MD, and team of occupational therapists design at-home exercise programs and functional splints to help recovery. Wellons and Law evaluate function at 2-month intervals and typically make decisions about surgery when patients are aged 5 to 8 months.
About 80% of children attain normal or near-normal function without surgery. “Of the remaining 20%, half will achieve better function through rehabilitation than with surgery,” he says. “Surgical outcomes for the remaining 10% are determined by the presurgical pattern of arm function. The best candidates are those who have some degree of hand function despite an inability to raise their hand to their mouth.”
Wellons repairs most brachial plexus injuries with neurotization, commonly transferring the medial pectoral nerve to the musculocutaneous nerve for arm flexion and the spinal accessory nerve to the suprascapular nerve for shoulder abduction. Intercostal nerves or free nerve grafts to jump across injured areas are occasionally used. In the last 10 years, 82% of infants at the clinic who underwent medial pectoral nerve to musculocutaneous nerve transfer for birth injury achieved hand-to-mouth function.
“Intraoperative neuromonitoring and nerve mapping allow us to look for any function across neuromas in the plexus and map individual fascicles within each nerve. The medial pectoral nerve is a smaller nerve, and one of the reasons we have achieved good success is that we perform the microanastomosis transfers at a fascicular level,” he says.
If children do not achieve hand-to-mouth function through neurotization, Wellons refers them to orthopaedic colleagues who can discuss muscle and tendon transfers as children age.
“I encourage pediatricians to consult with us even if they think patients will not need surgery,” he says. “We offer many options to help children and their families reach our shared goal of a functional, independent hand.”
For more information:
John Wellons
1.800.UAB.MIST
mist@uabmc.edu