Selective dorsal rhizotomy (SDR) is a permanent neurosurgical procedure which reduces muscle tone (spasticity) in the legs of children with cerebral palsy (CP).
What does it involve?
Selective dorsal rhizotomy involves opening the back of one or more vertebrae in the lower spine to expose the spinal cord. Using electrophysiological monitoring, the neurosurgeon selectively cuts the sensory nerve fibres which send messages from leg muscles back to the spinal cord to reduce spasticity in the legs.
The operation takes several hours and children are usually required to stay in the neurosurgical ward for one week before being transferred to the rehabilitation ward for a further two to three weeks.
After the procedure, a period of intensive therapy and exercise is required to regain pre-operative strength and improve function. These improvements can continue for up to two years after the procedure.
Who is suitable for SDR?
Current research suggests that children with cerebral palsy aged between four and eight years with typical spastic diplegia will most benefit from SDR. They should also have:
- a history of prematurity and MRI brain scans which are normal or show periventricular leukomalacia (PVL)
- high levels of spasticity affecting multiple muscles in both legs
- spasticity which interferes with their walking and transfers
- tried other treatments (e.g. Botulinum Toxin, casting, orthoses, medications) and are not getting sufficient positive improvement with these alone
- good underlying strength and motor control for individual isolated movements.
Children who are less likely to be suitable for SDR include those with:
- a diagnosis other than CP
- different motor patterns (e.g. dystonia)
- excessive weakness
- significant fixed contracture
- previous major orthopedic surgery.
Assessment process for SDR
Our multi-disciplinary team of specialists work closely with families when determining if their child is a suitable candidate for SDR. This is based on a thorough assessment of their child’s condition as well as their ability to participate in intensive therapy over a several months in Brisbane.
As SDR is an irreversible procedure, it is important to ensure that it is the best option for your child at their current stage of development.
During the assessment process, you will meet with the rehabilitation team to discuss treatment goals and expectations. The team will also conduct clinical assessment including, gait, strength and spasticity/dystonia and review X-rays or MRI scans.
Further assessment may involve multi-level Botulinum Toxin (Botox) intervention and a therapy block with our team to help determine how your child will respond when spasticity is reduced.
Are there any risks?
As with all neurosurgical procedures, there are potential risks with SDR surgery. Complications after SDR, although uncommon, include infection, leak of cerebrospinal fluid from the wound, development of a fluid collection below the skin, severe leg weakness and loss of bladder control.
Long-term risks include sensory changes in the legs, spinal curvature, gait deterioration and/or limited endurance due to underlying weakness or dystonia.
What is the outcome for children who have had SDR?
A reduction in spasticity may be noticed immediately after the procedure, however SDR will unmask weakness and difficulties with coordinating movements common in CP. For strength in the legs to return and new movement patterns to be learnt, it will take hard work over time. Children will not gain strength typical of children without CP, as weakness is part of the neurological impacts of CP.
The procedure does not cure cerebral palsy and will not change your child’s gross motor function classification level (GMFCS). For example, if your child mostly walks with a walker before SDR, they are still likely to use an aide after SDR but their walking pattern may improve.
SDR may reduce the need for soft tissue surgery (muscle lengthening) in the future, however many children still require bony orthopaedic surgery later in life.
Referral and more information
A medical referral to the Queensland Paediatric Rehabilitation Service (QPRS) at Queensland Children’s Hospital is required for patients to be seen in a SDR Physical Assessment Clinic. After assessment, suitable children are referred to the neurosurgeon. The QPRS team can also meet with families who are planning to have the surgery performed privately (including overseas) to discuss the procedure and rehabilitation.
