Picking up a spoon to stir your coffee seems like a simple thing. But each time you do it, you activate an intricate bundle of nerves that starts in the spinal cord in your neck and reaches down into your shoulders and arms, combining and splitting off into branches. This network of nerves is called the brachial plexus—you have one on each side. When you decide you’re ready to mix that teaspoon of sugar into your coffee, these nerves carry the message from your brain to your hand.

Though it’s possible to injure your brachial plexus without even knowing you did so, the consequences can include temporary numbness to your arm, pain, loss of sensation or even paralysis. 

“What commonly happens is the patient has no idea they have a severe injury to the brachial plexus. They know their hand or arm is not working properly, but they often don’t know why, and that there may be a way to treat the problem. It’s important to consult with a hand surgeon as quickly as possible,” says Grant Thomson, MD, chief of hand and microsurgery within the Yale Medicine Plastic & Reconstructive Surgery. 

If a patient does need surgery, it should be scheduled within six months after the injury. “If you wait longer than six months, the chance of a successful repair goes way down,” he says.

Yale Medicine is one among just a handful of centers in the country offering a highly complex operation called nerve transfer surgery for brachial plexus. Dr. Thomson says nerve transfer surgery has a better prognosis than the traditional approach, which is reconstruction of the brachial plexus.

Many brachial plexus injuries occur when the arm is pulled down on one side of the body and the head is pushed to the other side. Pulling the arm forcibly overstretches it and suddenly you may notice your arm feels weak. This feeling can go away after a few minutes, or it may continue for days.

People injure the brachial plexus in a variety of ways. It may be compressed or cut in a serious car accident or other trauma. If the nerves are torn away from the spinal cord, the result could be permanent paralysis of the arm and hand. 

People who play high-energy sports, such as football or soccer have injured themselves this way, as well as people who have experienced blunt traumas or even gunshot wounds. Dr. Thomson says he sees more brachial plexus injuries during motorcycle season.

Other brachial plexus injuries are not related to a particular accident or event. A growing tumor can compress the nerves or inflammation can cause swelling. Though rare, some newborns suffer a brachial plexus injury during childbirth. It can happen if the baby’s shoulder crushes against its mother’s pubic bone, if its head and neck are pushed away from the shoulders, or if the baby’s shoulders are stretched too much during a normal vaginal delivery.

A brachial plexus injury usually affects only one side of the body. The severity of injury can depend on a number of factors, including the force of the injury and how many nerves are injured. Since nerves have different functions, which ones are injured also matters.

In general, symptoms may include:

• Loss of sensation
• A change in your ability to move one of your shoulders, arms or hands
• Weakness or paralysis in the arm or hand
• Pain in the neck, arm or hand
• A feeling like an electric shock going down one arm

Even if your symptoms seem minor, it’s important to talk to your doctor. If you wait too long and find you need surgery, the delay could make a difference in your recovery.

A hand surgeon will perform a physical examination of the arm and hand, and ask about your symptoms. Imaging with a CT scan or MRI is important. Another test called electromyography involves inserting a needle electrode into different muscles to check on electrical activity of any damaged nerves. Another test called a nerve conduction study may be used to measure the speed of an electrical impulse through those nerves, in order to determine the extent of damage.

Mild injuries may be correctable with physical therapy, which can help with range of motion and stiffness. Depending on the severity of your problem, you should be prepared for recovery to take weeks or months.

Since you may have some numbness, it’s important to be aware of any cuts, burns, bruises or other injuries to the area and seek treatment if necessary.

Severe injuries to the brachial plexus may require surgery, as they won’t heal on their own. If surgery is required, it should occur within six months of your injury. The longer you go without a nerve stimulating a particular muscle, the less chance there is that the muscle will ever function normally again.

Where the traditional surgery for a brachial plexus involves nerve grafting across the injured segments, Yale Medicine is among the few medical centers offering a new procedure called nerve transfer surgery, which involves more targeted nerve restoration away from the scarred area, and closer to the required muscle function.

This complex microsurgery is an open operation that can take seven hours or more, but the results may be better than the traditional approach. It involves harvesting available nerves from areas in the body that can function without them, and transplanting them directly into the nerve supplying the targeted muscle. 

For instance, a trapezius muscle may function safely with fewer nerves: “People can still shrug their shoulders without some of those nerve fibers,” Dr. Thomson says, and the extra nerve fibers can be used to reanimate other muscles in the area that control arm motion.

In nerve transfer surgery, the surgeon’s experience plays a vital role. “Nerve transfer surgery involves a lot of careful decision making,” Dr. Thomson says. 

The surgical team examines each nerve through a microscope and applies an electrode; if it makes a muscle twitch, the nerve is considered suitable to transplant. “We usually are going after specific functions. So, if the patient is missing elbow flexion, we will need to choose a nerve that is close by and has a duplicated function,” he says.

Recovery from this type of surgery depends on the severity of injury—if many nerves are injured, fewer nerves will be available to harvest and transplant and the outcome may not be perfect. “We usually can’t get the patient completely back to normal, but we would like to get some reasonable function of the hand, the elbow and shoulder,” Dr. Thomson says.

Nerves grow back slowly. While you may be able to start passively moving your arm or hand again after a few weeks, it may take three to six months before you notice a flicker of active motion. Some nerves take years to heal.

You must move your muscles during recovery to prevent your joints from becoming stiff. You will need physical therapy after surgery. Just as with nonsurgical approaches, it’s important to be aware of any cuts, burns, bruises or other injuries to the area.

Function begins to improve once the nerves are transplanted and have an opportunity to grow into the muscle, according to Dr. Thomson. He says nerve transfer surgeries can provide the patient with reasonable function the majority of the time.

Experienced Yale Medicine hand surgeons have the experience, tools and techniques to restore as much mobility as possible after a brachial plexus injury. Our surgeons are among a handful in the region who perform nerve transfer surgery, which has a higher success rate than traditional brachial plexus reconstruction.

Yale Medicine anesthesiologists, orthopaedists, neurosurgeons and other members of the care team also have a high-level of training and expertise in brachial plexus surgery. These different specialists consult on brachial plexus cases and often participate in the surgeries.

“The best care is at an academic medical center,” says Dr. Thomson. “The surgery teams have a high level of training and expertise in these procedures. We have the best people here.”