Of these, only SDR can permanently reduce spasticity in many patients with spastic diaplegia or quadriplegia.

SDR begins with a 1-2 inch incision along the centre lower back just below the rib cage. The tip of the spinal cord is located with ultrasound and other methods. A back portion of a single lumbar vertebra is removed to expose the spinal cord and nerve roots. After sensory nerves are exposed, the neurosurgeon divides each of the dorsal roots into 3-5 rootlets and stimulates each rootlet electronically. Muscle contraction responses from muscles in the lower extremities are tested by electrical stimulation to identify the rootlets that cause spasticity. The abnormal rootlets are selectively cut, leaving the normal rootlets intact. SDR is a complex neurosurgical procedure but the risk of surgery is minimal. In over 1100 patient treated at St Louis, only patient-developed leakage of the spinal fluid and no other complication occurred.

A significant differentiator between St Louis Children’s Hospital, and other worldwide centres that offer SDR,is that bone from only a single lumbar vertebra is removed and this is believed to prevent SDR-related spine problems in patients. At other hospitals, it is not unusual for bone from at least 3 lumber vertebra to be removed.

This is one of the reasons why we have chosen St Louis Children’ Hospital as the preferred assessment centre for Sarah, along with the fact that surgery is performed by Dr T.S. Park, MD, neurosurgeon-in-chief at St Louis Children’s Hospital, Shi H. Huang, Professor of Neurosurgery at Washington University School of Medicine and one of the United States’ leading pediatric neurosurgeons. Dr Park began performing the surgery in 1987 and has performed surgery on more than 1,600 patients ranging in age from 2 to 39 years. SDR is an available option for adults, although the recommended age is 2-6.

After surgery (about 3 hours), patients can expect to spend about 24 hours in the pediatric intensive care unit PICU) then be transferred to the hospital’s neurology/neurosurgery unit for bed rest until at least day 3 post-op. Gentle physical therapy then follows until discharge (days or weeks depending on individual patient recovery), followed by intensive physical therapy once home, for several months.

Outcome of SDR

SDR does not cause permanent weakness and does not result in floppy extremities. 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.

SDR results in improvements in sitting, standing, walking, and balance control in walking. Typically, improvements in motor function are most noticeable during the first 6 months after SDR. After that, improvements are slow but steady. In children, these improvements can continue up to 10 years of age. Some CP-related deformities can be improved by SDR. In most patients, SDR can halt the progression of hip subluxation and it does not exacerbate or increase the risk of this occurring.

Physical therapy post-SDR appears to be key to the whole procedure, as the muscle weakness that was hidden by the spasticity is unmasked by the Rhizotomy, and strength development needs to occur. Individual results can vary depending on the degree of spasticity pre-SDR.

Sarah’s Status at end of April 2008

Getting to assessment by St Louis Children’s Hospital has involved a raft of forms being completed, a video taken of Sarah undertaking various physical actions, and supplying recent hip x-rays. We have almost completed all at time of writing and hope to send everything off to the U.S. in May. From all the research to date, it would appear Sarah will be a good candidate for the procedure. Having no US medical insurance, or NZ insurance coverage for the pre-existing condition of CP, any US-based surgery would have to be self-funded and we have been provided an indicative cost by St Louis Children’s Hospital already.

We have discovered only one other New Zealander to date who has had SDR performed. Luckily the young lady lives only 10 minutes from us and we have recently met her. She has spastic quadriplegia and had the surgery performed in Auckland at Starship Hospital, in 1996, at age 6, by a surgeon who travelled from the U.S. We cannot find anywhere in Australia where SDR is being performed at this time but note that SDR is being reviewed by the Australian Government’s Medical Service Advisory Committee, so perhaps it will be also be available in Australia in the near future.

This article is a very condensed account of SDR and I would recommend that anyone who is interested in finding out more, refer to the reference sites below, both of which provide excellent information about SDR as a treatment for CP spasticity, for both children and adults.

Further updates on Sarah’s path to possible SDR will be provided in future editions of The Review.

Dave Colquhoun

References:

Park, T.S. (Date Unknown). Selective Dorsal Rhizotomy - An Excellent Treatment Option For Spastic Cerebral Palsy In Children and Young Adults. Retrieved April 29, 2008, from http://www.aaippt.org/SelectiveDorsal.html

St Louis Children’s Hospital. (2008). Cerebral Palsy Spasticity – Selective Dorsal Rhizotomy. Retrieved April 29, 2008 from the World Wide Web: http://www.stlouischildrens.org/tabid/89/itemid/1539/Cerebral-Palsy-Spasticity--Selective-Dorsal-Rhiz.aspx