Brachial Plexus and Peripheral Nerve Center
Peripheral nerve injuries involve nerves that exit the brain and spinal cord to control the upper and lower extremity. The cause can be congenital (from birth), traumatic, or acquired (viral, radiation, or tumor-related). Peripheral nerve injuries can present in several different ways.
- Brachial Plexus Palsy: A network of nerves, termed the brachial plexus, travel through the neck to reach their targets in the hand and upper extremity. These nerves control movement at the shoulder, elbow, wrist, and hand as well as upper extremity sensation. When injured, patients demonstrate weakness or the inability with raising their arm from the side, bending their elbow, moving their hand, and/or numbness along the upper extremity.
- Common Peroneal Palsy: The common peroneal nerve travels along the outer part of the knee and leg. It controls lifting of the foot at the ankle and sensation along the outer part of the leg and top of the foot. When injured, patients demonstrate foot drop and numbness along the outer leg and top of the foot.
- Median Nerve Palsy: The median nerve is an important structure located in the center of the forearm, wrist, and palm of the hand. It controls bending at the wrist, bending of the finger joints, movement of the thumb across the palm, and sensation to the thumb, index, middle, and half the ring finger. In the setting of trauma, the median nerve can be cut at any level. In carpal tunnel syndrome, the median nerve remains intact but compressed as it passes underneath a fibrous tunnel in the wrist on its way to the hand. When injured, patients can demonstrate weakness with bending at the finger joints and moving the thumb across the palm and/or numbness along the thumb and majority of the fingertips. In carpal tunnel syndrome, patients will often report nighttime pain and numbness upon awakening in the morning of the thumb, index, and middle fingers.
- Ulnar Nerve Palsy: The ulnar nerve is another important structure located along the inner side of the elbow, forearm, wrist, and palm of the hand. It controls straightening of the finger joints, thumb key pinch, and sensation to half the ring and the entire small finger. In the setting of trauma, the ulnar nerve can be cut at any level. In cubital tunnel syndrome, the ulnar nerve can be compressed as it passes underneath a fibrous tunnel near the elbow joint. When injured, patients can demonstrate weakness with straightening of the finger joints, thumb key pinch, and/or numbness along half the ring and the entire small finger. In cubital tunnel syndrome, patients will often report nighttime pain and numbness upon awakening in the morning of the ring and small fingers.
In consultation with a plastic surgeon, an occupational therapist will complete a functional evaluation to determine the severity of the nerve injury. Muscular strength will be tested and graded on a scale form 0 to 7. Sensory testing will include two-point discrimination and pressure sensation. Sometimes a nerve and/or muscle study is performed to better understand the degree of injury. An MRI can sometimes shed light on the location and extent of injury.
Based on the functional analysis, your health-care team may suggest surgical and/or therapeutic solutions.
An occupational (hand) therapist can educate your child on different ways of performing activities that will help them be as independent as possible. This may include a stretching or splinting program to help improve movement across joints.
If the nerve has been completely cut or there has not been reasonable muscle recovery within 6 months, surgery is recommended. The timing is very important, as by 12-18 months the connections between the nerve and its muscular target may be permanently lost.
Nerves can be fixed in 1 of 3 ways. When cut and within weeks of the injury, the nerve ends can be brought together and repaired with suture. If ruptured, the nerve ends are typically too far apart and not able to be sown together. In those situations, the nerve can be reconstructed using either nerve grafts or nerve transfers. The nerve graft procedure involves cutting out the injured area and bridging the gap with sensory nerves taken from the calf or arm. The nerve grafts do not immediately turn the injured nerve back on. Instead, the grafts act like a bridge and allow the injured nerve to grow at 1 mm a day and connect with its other side. Little to no numbness is experienced at the site of the calf and/or arm where the nerve is taken from. The nerve transfer procedure involves identifying a working nerve that is redundant and expendable. This working nerve is cut and transferred to the end of the injured nerve, thereby bypassing the damaged segment. As compared to the nerve graft procedure, nerve transfers offer the possibility of shorter times to nerve regeneration and faster muscle recovery. Given that the nerve transfer uses an extra nerve, little to no weakness is observed at the donor site.
Following surgery, your child may be placed into a splint (“half-cast”) to protect the nerve repair or reconstruction. Depending on the type of surgery, the splint will stay in place between 3 and 6 weeks. Once the splint is removed, the skin incisions are checked to make sure they have adequately healed. Once healing has been confirmed, occupational therapy sessions resume.
Scheduling a Consultation
Your pediatrician or family doctor can make a referral to the plastic surgery clinic. Please contact the plastic surgery clinic at 323-361-2154 for more information about our services.