The surgery Selective Dorsal Rhizotomy SDR involves sectioning (cutting) of some of the sensory nerve fibres’ that come from the muscles and enter the spinal cord.

Two groups of nerve roots leave the spinal cord and lie in the spinal canal. The ventral spinal roots send information to the muscle; the dorsal spinal roots transmit sensation from the muscle to the spinal cord

At the time of the operation, the neurosurgeon divides each of the dorsal roots into 3-5 rootlets and stimulates each rootlet electrically. By examining electromyographic (EMG) responses from muscles in the lower extremities, the surgical team identifies the rootlets that cause spasticity. The abnormal rootlets are selectively cut, leaving the normal rootlets intact. This reduces messages from the muscle, resulting in a better balance of activities of nerve cells in the spinal cord, and thus reduces spasticity.

In 1991, they developed a less invasive surgical technique, which requires removal of the lamina from only 1-2 vertebrae. We refined the technique further and currently remove the lamina from a single lumbar vertebra.

Advantages of our technique over other techniques for SDR

We believe that our SDR procedure has these significant advantages over others:

1.     Reduced risk of spinal deformities in later years

2.     Decreased post-rhizotomy motor weakness

3.     Reduced hip flexor spasticity by sectioning the first lumbar dorsal root

4.     Shorter-term, less intense back pain

5.     Earlier resumption of vigorous physical therapy

In patients with spastic quadriplegia, however, SDR can fail to reduce spasticity. Recurrence of spasticity is relatively common in severely involved no ambulatory patients with spastic quadriplegia. In patients who can walk with an assistive device, the risk for recurrent spasticity is less than in no ambulatory patients, and even if it does recur, it is less severe than before the operation.

It is our opinion that patients with CP do not depend on spasticity for any activities. Their case is different from that of patients with spasticity associated with spinal cord injury, in whom the spasticity sometimes does help with standing and taking steps.

Strength: SDR does not cause permanent weakness.  However, patients will experience transient motor weakness that may last a few weeks to months after SDR. It should be remembered that a varying degree of motor weakness is always present in CP. When spasticity is reduced or eliminated, the motor weakness underlying spasticity becomes more noticeable, but the impression that SDR produces motor weakness is incorrect.

Patients who walk independently always resume independent walking within a few weeks after SDR. Patients who walk with crutches will also resume crutch walking within several weeks after SDR. Patients who walk well with a walker prior to SDR resume assisted walking within several weeks. Patients who use a walker and assistance require much longer to resume the level of walking they were capable of before SDR.