In order to work properly, muscles need to both contract and relax. But in children with spasticity, the signal to relax a muscle doesn’t get through. Instead, the sensory nerves keep telling the muscles they need to be tighter, so they contract even when they don’t need to.
Selective dorsal rhizotomy (SDR) is designed to disrupt this harmful feedback loop by cutting some of the sensory nerves, allowing muscles to relax when they need to.
©CATHERINE DELPHIA 2002
SDR is performed under general anesthesia and normally takes about 4 hours. The surgery requires a stay in the hospital of 4 to 5 days.
What happens during SDR surgery?
SDR surgery is done on an inpatient basis, and normally takes about four hours. General anesthesia is required, and after the child is asleep:
Next, the surgeon tests each sensory nerve root in turn by stimulating it electrically, while an electrophysiologist monitors the response in the leg muscles. If the nerve responses are abnormal, these nerve roots may be selectively cut.
Selective dorsal rhizotomy usually requires a child to stay in the hospital for four to five days.
Who will be helped most by SDR surgery?
Each child is evaluated by our cerebral palsy team to determine whether he or she qualifies for selective dorsal rhizotomy. The procedure is most effective in children whose cerebral palsy is the result of being born prematurely, and whose spasticity mainly affects their legs. (Children with spasticity in all their limbs, or who are affected more on one side of the body, may get more benefit from an intrathecal baclofen pump).
Children are good candidates for the operation if they:
Have spasticity mainly in their legs
Can walk on their own or with the help of a walker or braces, or have the potential to do so
Are motivated and able to follow instructions
Are physically and mentally able to participate in intensive physical therapy after the operation, to maintain its benefits.
Children with a great deal of spasticity in their arms, or who require support to sit up, may benefit less from SDR surgery.
SDR surgery is best done as soon as it becomes clear that a child will have trouble walking (typically between ages 3 and 6) and is no longer improving with other treatments like Botox injections or physical therapy alone. The earlier children are treated, the more normally their muscles and limbs will develop, the less stigma they will experience in school and the more independence they can enjoy. However, older children and young adults can also have very good results.
What is the recovery like after SDR surgery?
During the hospital stay:
The evening after surgery, children are closely watched in the intensive care unit and given a strong IV medication to minimize pain and discomfort. Pain is closely monitored. It’s important to lie flat in bed immediately after surgery to allow the wound to start healing and prevent spinal fluid from leaking out.
On the second day, children can usually move to a regular room. On the third day, they can discontinue the IV medications, switching to oral pain medications. Most children are also allowed to sit up in bed.
Over the next week, patients may experience numbness, tingling and a feeling of heaviness in their legs. This is normal, though rare.
Once spasticity is reduced, however, the underlying muscle weakness becomes more obvious. This means that the child will feel weaker at first and will need to gradually regain muscle strength through intensive physical therapy.
What results could we expect?
Selective dorsal rhizotomy can permanently reduce spasticity in children with cerebral palsy. Many children are able to transition from walkers to crutches or a cane, and they are less likely to need orthopedic surgery, particularly if they have SDR surgery at a young age.
Results depend on the child’s medical status before the operation and adherence to physical therapy afterward. But overall:
Although the reasons for this aren’t clear, many parents report that children speak better, do better on mental tasks and interact better socially after SDR surgery.