By Helen Garey
Marina Pellicciari is a force to be reckoned with, both on and off the basketball court. At age 11, she is an all-around athlete whose hero is Kobe Bryant. She also has cerebral palsy, a neuromuscular condition that occurs in more than one in 300 children.
So it was no surprise to see Marina shooting hoops in her driveway just months after a complex neurosurgical procedure to reduce muscle spasticity in her legs. Nearly 80 percent of children with cerebral palsy have spasticity, an involuntary stretching reflex that stiffens muscles, making it difficult to coordinate movement.
Children with lower-limb spasticity usually walk on their toes, knees pointed inward.
“Kids with spastic CP spend significantly more energy coordinating their movement, which results in pain, fatigue, and postural problems,” explains Richard Anderson, MD, associate professor of neurological surgery at CUMC.
Intensive physical and occupational therapy can produce functional improvements in children with spasticity, but commitment to this therapy usually wanes during adolescence. Other nonsurgical treatments, such as Botox injections and muscle relaxants, offer temporary relief. A longer-lasting therapy—an implantable pump that delivers a steady dose of the muscle relaxant baclofen to the theca, or space surrounding the spinal cord—is an option for those with severe spasticity. But the need to refill the medication and replace the battery every so often, along with a nearly 20 percent complication rate, can be a deterrent.
And, as Dr. Anderson points out, most of these treatments do not address the underlying cause of spasticity.
Old Procedure, New Techniques
One treatment, a procedure known as selective dorsal rhizotomy (SDR), gets to the root, or rather, the nerve rootlets of the problem. In SDR, the neurosurgeon identifies tiny, spaghetti-like strands of sensory nerve fibers, which are bundled together at the base of the spinal cord along with motor nerve rootlets. Sensory nerve rootlets tell muscles to contract when stimulated by touch or other stimuli. In cerebral palsy, the neurons that normally prevent muscles from overreacting to these signals are damaged, causing them to stiffen at the least provocation. Disconnecting 60 percent to 70 percent of these fibers can significantly reduce spasticity.
SDR was first proposed in 1911 by Dr. Otfried Foerster at a meeting for the Royal Society of Medicine. But the procedure fell out of favor due to the risk of disconnecting too many sensory nerve roots, including those involved in bladder sphincter function. Worse was the risk of severing motor nerve roots, which would irreversibly impair movement.
Interest in SDR was renewed in the 1970s, when the use of intraoperative neurophysiologic monitoring allowed doctors to identify the sensory nerves involved in spasticity with greater precision, improving safety.
While SDR is safe and effective, some hurdles remained. Surgeons typically make a large incision in the lumbar region near the spine, removing a six-inch piece of lamina, the bone that covers the spinal cord. But removing this much bone can increase the risk of spinal instability after surgery, making recovery longer and more painful. In addition, SDR is only effective when spasticity is the main feature of a patient’s condition, before orthopedic complications have manifested.
“Marina was a great candidate because she had significant spasticity and pain that were not adequately addressed with other therapies, including Botox injections and intensive physical therapy,” says Dr. Anderson. “Plus, her positive mindset would allow her to get through the postop rehabilitation required to learn how to walk again in a more physiologic way.”
At NewYork-Presbyterian’s Morgan Stanley Children’s Hospital, candidates for SDR are selected by a multidisciplinary team of specialists, including physiatrists, physical and occupational therapists, pediatric neurologists, neurosurgeons, orthopedic surgeons, orthotists, and nurses.
Using preoperative MRI and intraoperative ultrasound to identify the start of the nerve roots, Dr. Anderson makes a relatively tiny (one-and-a-half-inch) incision and removes a single shingle of bone. This technique is currently performed at only a few medical centers in the United States.
While the patient is under anesthesia, the surgeon electrically distinguishes between motor and sensory nerve roots, then separates the individual sensory rootlets and applies mild electrical stimulation to each one. “Less current is required to activate a dramatic response in motor nerves compared with sensory nerves, so we are able to guide the surgeon toward the sensory rootlets, and away from motor rootlets, with great confidence,” says Edward Gallo, technical supervisor of clinical neurophysiology at Columbia’s Comprehensive Epilepsy Center, who refers to himself as “The Electrician.”
Mr. Gallo measures the muscle’s electrical response, known as compound muscle action potential, to identify the sensory nerve rootlets that are eliciting more spasticity and to avoid those involved in bladder sphincter function. These results are confirmed clinically by physical and occupational therapists in the operating room, who palpate each muscle group as it is stimulated. Only with their feedback can the surgeon decide which nerve rootlets can be safely disconnected.
The Test of Time
In a large retrospective matched cohort trial, patients treated with SDR had significantly better outcomes in terms of reduced spasticity, improved range of motion in the joints, and overall function compared with those who received an intrathecal baclofen pump. In addition, the need for orthopedic surgery was significantly lower in those who had SDR compared with patients who used a pump.
But perhaps the best endorsement comes from Marina, whose determination to get beyond spasticity may be linked with her outcome and speedy recovery. On average, recovery from SDR can take up to a year. In Marina’s case, her functional abilities surpassed her baseline after just four months, including the seven weeks she spent in intensive rehabilitation to learn how to walk again. But the grueling work was worth it, she says, because the pain in her legs is gone and not once has she resorted to using a walker or cane.
“Marina’s recovery and progress have been exceptional,” says Dr. Anderson. “I think this shows that considering a patient’s positive attitude is important when we select the ideal candidate for this procedure.”
THIS JUST IN: Marina goes to her first Lakers game and gets the surprise of a lifetime.