Selective Dorsal Rhizotomy

Selective dorsal rhizotomy (SDR) is a type of neurosurgical procedure used to treat spasticity. Spasticity is a condition in which muscles contract uncontrollably and remain tight. It results in pain and decreased range of movement in the arms and legs.

Spasticity happens when an injury to the brain or spinal cord results in abnormal stimulation signals being sent to the muscles of the body. In a basic sense, a faulty electrical circuit causes abnormal contraction of the muscles. Selective dorsal rhizotomy involves cutting small nerve roots in the spine (called “nerve rootlets”) to interrupt the faulty signals. This can reduce spasticity.

Selective dorsal rhizotomy is the only surgery that can potentially reduce spasticity permanently. It is a one-time procedure. The cut nerve rootlets do not grow back.

Before surgery, your child will have a comprehensive evaluation in the Surgical Spasticity Clinic. This includes a physical exam, gait analysis and other tests as necessary. The surgical spasticity team includes two kinds of doctors, a pediatric neurosurgeon and a pediatric rehabilitation specialist, and a physical therapist.

What Kind of Spasticity Does Selective Dorsal Rhizotomy Treat?

Selective dorsal rhizotomy offers the most benefit for children whose spasticity mostly affects their legs. Children who were able to bear weight on their legs and take steps before the surgery typically enjoy the best results.

What Are the Benefits of Selective Dorsal Rhizotomy?

Your child’s spasticity will improve significantly immediately after their selective dorsal rhizotomy. But this is just the beginning. Intensive physical therapy will help your child continue to benefit from surgery. (See the section, “Physical Therapy after Selective Dorsal Rhizotomy”).

Every child is different. Our team will help you know what to expect in the weeks and months after selective dorsal rhizotomy. Your child may gain better muscle strength and control, range of motion, posture and gait mechanics. These are most obvious in the first six months after the procedure. However, your child may continue to see gradual improvements for years after the surgery.

What Does Selective Dorsal Rhizotomy Surgery Involve?

Selective dorsal rhizotomy surgery takes about four hours. Your child will be under general anesthesia. A nurse will talk with you during surgery to let you know how things are going.

During the surgery, the neurosurgeon will make a one-inch incision to access the lower spine. This is a minimally invasive approach that results in a shorter recovery time as well as less pain and muscle weakness after surgery.

Next, the neurosurgeon creates a small “window” (called a laminectomy) in the bone of the spine. Now the surgeon can see all of the nerve roots involved with sensation and movement in the legs. A nerve root is the segment of the nerve that comes out of the spinal cord. Each nerve root is made up of about three to seven smaller nerve “rootlets.”

Selective dorsal rhizotomy focuses on nerve rootlets that affect sensation only. The neurosurgeon tests each sensory nerve rootlet to see which ones are conducting abnormal signals to the muscles. The neurosurgeon cuts the most abnormal nerve rootlets. (Learn more below in “How Does the Neurosurgeon Know which Nerve Rootlets to Cut?”)

The incision is then closed with dissolvable sutures. After surgery, the neurosurgeon will meet with you to talk about how everything went. You can see your child about 45 minutes after surgery, after they have started to wake up from anesthesia.

Most children leave the hospital four to five days after surgery. Some children stay in the hospital longer for inpatient physical therapy. Our team has found that outpatient physical therapy is just as effective in helping children benefit from a selective dorsal rhizotomy.

How Does the Neurosurgeon Know Which Nerve Rootlets to Cut?

The neurosurgeon uses a small electrical current to stimulate each sensory nerve rootlet, one at a time. Using technology called electromyography (EMG), the surgical team sees how the muscles of the legs respond to stimulation. Data appears on a large computer screen in the operating room.

The neurosurgeon and other specialists make decisions together about which nerve rootlets to cut. The physical therapist plays an important role in this process. (See next section, “How Does the Physical Therapist Help during Selective Dorsal Rhizotomy?”)

The neurosurgeon carefully cuts each sensory nerve rootlet that is transmitting abnormal signals resulting in spasticity. The quantity of nerve rootlets that is cut varies from child to child. Typically about half of the nerve rootlets get cut.

How Does a Physical Therapist Help During Selective Dorsal Rhizotomy?

During selective dorsal rhizotomy surgery at Cincinnati Children’s, a physical therapist is in the operating room. This physical therapist helps the neurosurgeon identify which nerve rootlets are resulting in spasticity. The physical therapist places his or her hands on the child’s legs. When a nerve rootlet is stimulated, the physical therapist can feel different muscles contract. The team compares that to the information they see on the EMG computer screen. They also consider what they know about the child from clinic appointments, gait analysis video and other tests.

This team approach in the operating room is unusual. It helps our doctors tailor the procedure to your child’s specific needs. Sometimes the neurosurgeon will stimulate a nerve rootlet multiple times. The goal is for everyone to be in agreement about whether it should be cut. This approach improves accuracy to ensure the best possible outcome.

What Are the Potential Risks of Selective Dorsal Rhizotomy?

Possible risks of selective dorsal rhizotomy include post-surgical infection and spinal fluid leakage. There is also a risk of injury to the spinal cord or nerve rootlets. This can result in bladder dysfunction, bowel dysfunction or new weakness. The risk of these problems occurring at Cincinnati Children’s is very low.

Physical Therapy after Selective Dorsal Rhizotomy

Your child will participate in intensive physical therapy about three or four times a week for a year after selective dorsal rhizotomy. This is essential to help your child permanently improve their muscle strength and control, range of motion, posture and gait mechanics.

Therapists will work with your child to improve muscle strength, control and coordination. This can involve exercises, games and assistive technologies. Physical therapy also will focus on improving balance, walking, sitting, standing and other gross motor skills. Your child’s therapist will also teach you how to do exercises at home. This will help your child continue working on muscle control and flexibility between visits.

If you do not live in the Cincinnati area, our physical therapists can provide your hometown therapist with resources, therapy goals and timelines. They can also work with local doctors and orthotists who are prescribing braces and other assistive devices for your child.

Long-Term Follow-Up

Selective dorsal rhizotomy helps many children experience big improvements in spasticity. However, many children need additional treatment such as orthopedic surgery to maximize their walking. Your child’s care team can provide long-term follow-up to address any concerns and additional needs. They will work with your child’s other doctors to help them reach their full potential.

Last Updated 05/2020

Reviewed By Amy Myhaver, RNII, BSN, RNC-NIC

Conditions and treatments.

The Surgical Spasticity Clinic in the Cerebral Palsy Program provides surgical solutions for your child’s spasticity.