This is the fourth of five in a series of blog posts on selective dorsal rhizotomy (SDR) in adulthood by Lily Collison — the inaugural author for Knowledge Translation Tuesday for the Cerebral Palsy Research Network (CPRN).  You can comment and discuss the article with Lily on MyCP.org.

Today I will explain a little more about selective dorsal rhizotomy (SDR) and then describe Tommy’s experience of SDR and early rehabilitation.

SDR only reduces spasticity, not other types of high tone. Of the various tone-reducing treatments (oral medications, botulinum neurotoxin injection, phenol injection, intrathecal baclofen, and SDR), SDR is the only irreversible tone-reducing treatment. What do the three words –“selective dorsal rhizotomy” mean?

• Selective: Only certain abnormal nerve rootlets are cut.
• Dorsal: “Dorsal” refers to the sensory nerve rootlets–it the sensory nerve rootlets that are cut. (The sensory nerve rootlets are termed “dorsal” because they are located toward the back of the body. The motor nerve rootlets are termed “ventral” because they are toward the front.)
• Rhizotomy: “Rhizo” means “root,” and “otomy” means “to cut into.”

Putting it all together, “selective dorsal rhizotomy” means that certain abnormal, dorsal nerve rootlets are cut. SDR is a major operation, and the better the rehabilitation, the better the outcome is likely to be. Just as the operation itself varies between institutions, different institutions have different rehabilitation protocols post-SDR. Typically patients undergo intensive physical therapy lasting approximately one year starting in the first days after surgery.

Tommy travelled to St. Paul on Wednesday February 5, 2020 for tests on Thursday followed by his SDR surgery on Friday. The plan was that he would spend four weeks in St. Paul for the initial intensive rehabilitation and then return to work/continue his rehabilitation back in San Francisco, where he lives. My husband and I travelled to St. Paul to support him there. Tommy was admitted on the morning of surgery and wasn’t unduly nervous. (He even pitched the idea of a career change to the anesthesiologist–“Hey come to Lambda School–lots of people are changing career and learning to code” [Tommy works at Lambda School, an online coding school] ?.)

There are two SDR techniques, the cauda and conus, named after the level of the spinal cord at which each procedure is performed. The choice of technique is provider-specific but also depends on the patient. The cauda technique was used in Tommy’s case. Dr. Kim (neurosurgeon) performed the surgery with Dr. Ward (Physical Medicine and Rehabilitation physician) monitoring. The surgery involved removal of the back of the vertebrae (the lamina) in order to access the spinal cord. The dorsal nerve roots were dissected into rootlets, and the rootlets were individually electrically stimulated to determine whether they triggered a normal or abnormal (spastic) response. If a rootlet triggered an abnormal response, it was cut. If not, it was left alone. 30% of dorsal nerve rootlets from L2 to S1 were cut during Tommy’s six hour surgery.

For the first three days post-op, Tommy was confined to lying on his back to allow healing of the dura–the cover of the spinal cord. His pain level was manageable; he did have some stiffness in his back and some unusual sensations in his feet–numbness and hypersensitivity (likely due to the handling of nerve rootlets which would have caused temporary nerve damage). Wound healing progressed well. Three days post-op he was gradually brought to a sitting position and closely monitored for headache (to ensure that the dura was fully healed–no cerebrospinal fluid leakage). He received physical and occupational therapies as an in-patient. He wore knee immobilizers 50% of the time as per plan. He left hospital using a rented wheelchair four days post-op, a day earlier than scheduled. (Indeed, he was well enough to have dinner that evening in the restaurant of our hotel–a goal of Tommy’s.) Over the next three weeks, he attended twice daily out-patient physical therapy and did exercises at home. Posterior leaf-spring AFOs (PLOs) were prescribed and manufactured. During that time he progressed from using a wheelchair to walking with a walker and then to walking with two crutches. The altered sensations he felt in the immediate post-op period, diminished with time. Four weeks post-op (March 4th)–he returned home to San Francisco. Little did we know what was to unfold with COVID-19.

Here are some photos.

Day 4 post-op: Leaving hospital.