A woman with a paralyzed arm had movement completely restored after a delicate nerve transplant

• A woman was left partially paralyzed after a neck surgery.
• She couldn't lift her left arm, and her shoulder often popped out of its socket.

A 45-year-old woman who had an operation to remove a compressed disc from her neck woke up from surgery with a new problem: she couldn't lift her left arm.

The patient first came to the emergency room at 4 AM complaining of excruciating pain that radiated from her neck into her left arm, according to a case report published Monday.

An MRI revealed that a stretch of her spinal cord in her neck was compressed, squishing her nerves and causing the pain. This kind of wear-and-tear commonly occurs with age in patients over the age of 40, according to the American Academy of Orthopaedic Surgeons.

Three days after her ER visit, the patient had surgery to repair her cervical spine, or the spinal cord in her neck. The procedure, known as anterior cervical discectomy and fusion (ACDF) surgery, involved taking out flattened discs that used to cushion her spine and fusing together some of the bones in her neck.

Like any medical procedure, cervical spinal surgery is not without its risks. Between 5-10% of patients who undergo this type of neck operation report nerve pain or muscle weakness after surgery, according to studies cited in the case report. But the surgery had more more severe consequences for this patient.

Nerve damage from the surgery left her unable to move her arm

After her first surgery, the woman had a week of rehabilitation in-hospital and three months of physical therapy. But her progress stalled. Although she was able to move her wrist and fingers, she couldn't bend her elbow or shoulder to fully lift her left arm.

The patient also described how her left shoulder regularly dislocated from its socket, and she had grown accustomed to popping it back in, according to the case report. She reported some left arm pain after the surgery as well.

A scan of her muscles and the nerve cells that control them, known as electromyography (EMG), revealed that the muscles in her left shoulder and upper arm had atrophied — grown smaller — in the three months after her neck surgery. The corresponding nerves in her cervical spine appeared to be damaged, namely in the section of her neck where doctors had fused her spine.

A surgeon used the patient's healthy nerves to replace damaged ones

Dr. Rahul K. Nath, a surgeon at the Texas Nerve and Paralysis Institute who co-authored the case report, performed multiple surgeries to replace the patient's damaged nerves 5 months after her original procedure.

First, he took a stretch of healthy nerve fiber from the median nerve, which controls the forearm, and transferred it to replace the damaged part of the nerve that flexes the muscles in the upper arm, the musculocutaneous nerve.

In a second surgery, Nath harvested two nerve branches from the patient's triceps and moved them to replace the damaged nerves meant to stabilize the shoulder joint.

While operating on nerves, the surgical team had to be certain of the fibers' functions. By stimulating the nerves throughout the procedure, the surgeons were able to identify where specific nerve endings were located, and which connections needed to be extinguished as they moved the nerves around.

The patient wore a sling for three weeks after surgery, then was prescribed physical therapy five times a week for three months. At a check-up 17 months after the nerve transfers, the patient's arm function was nearly back to normal.

"Distal nerve transfers are a powerful treatment option," Nath wrote in the case report.