What is selective dorsal rhizotomy?
Selective Dorsal (or Posterior) Rhizotomy is a neurosurgical technique used to treat spasticity (increased muscle tone) in the lower limbs.
The procedure requires intensive post-operative physiotherapy. It is major, invasive surgery and is irreversible so we recommend that you gain as much information as possible before proceeding and speak to your/your child’s medical team.
What selective dorsal rhizotomy is not:
SDR is not a cure for cerebral palsy, nor is it suitable for the treatment of abnormal movements or balance problems therefore it is unlikely to be suitable for other types of cerebral palsy such as dystonic or athetoid.
It is important to note that SDR does not resolve fixed lower limb deformities (1) and for children in these circumstances, other forms of orthopaedic surgery may be considered.
What does the surgery involve?
Selective Dorsal Rhizotomy describes a surgical procedure carried out to the lower vertebrae usually between L2 – S2 (lumbar and sacral area). The vertebrae are opened to reveal the spinal cord which contain the neurones of the central nervous system. These neurones (bundles of nerve fibres) channel messages between the brain and different areas of the body.
Electrical stimulation is used to identify and sub-divide sensory and motor nerves. This process continues until the specific nerves and nerve roots affecting the spastic muscles and which may not be “transmitting” properly are identified and cut. Due to the size of the nerves and rootlets, this is a very precise procedure and therefore the surgery can last several hours and requires a general anaesthetic.
Principally, the surgery aims to:
- reduce spasticity
- improve function
- improve walking in those who already have some form of independent mobility, such as crawling or walking
- increase range of motion and improve body positioning in those who do not walk and require assistance with personal care
Who is suitable?
Factors which appear to contribute to success include:
- age two years plus although in the UK it is rare for children under five to be operated on
- spastic diplegia or quadriplegia
- premature birth
- upon MRI examination, no severe damage to the basal ganglia part of the brain
- some form of independent mobility. Good muscle tone and weight bearing is important this can be demonstrated by supporting full weight on the feet, holding a posture against gravity, make reciprocal movements for crawling or walking or moving quickly from one posture to another
- ability to participate in long term post-operative therapy. Patients will require long-term physiotherapy
- most likely to benefit children in Gross Motor Function Levels lll and lV
- in younger children, may reduce need for orthopaedic surgery later.
- For adults considering the surgery, most of the above will apply may be more helpful in a diagnosis of spastic diplegia and again, patients who currently ambulate independently.
Who is not suitable?
Factors likely to inhibit success, especially where the aim is to improve walking, include:
- mixed cerebral palsy with significant dystonia, athetosis or ataxia
- muscle-tendon contractures (fixed tightness)
- scoliosis (curvature of the spine)
- people who have experienced meningitis, congenital brain infection, hydrocephalus or head trauma
- previous surgery (especially multiple operations)
- hip displacement.
- In cases of mild spasticity a less extensive procedure, such as a tendonotomy (surgical cutting of a tendon), botulinum toxin, or intrathecal (ITB) may be more appropriate and should be considered prior to surgery.
Assessment and post operative procedures
Potential candidates participate in a rigorous assessment by an expert, multi-disciplinary team drawn from the fields of neurosurgery, neurology, physiotherapy and occupational therapy. The criteria used comprises a combination of clinical, laboratory and behavioural guidelines. Gait (walking) analysis and MRI scans are possible components.
Assurance of the parent/carer to adhere to the follow-up programme is also sought, as post-operative physiotherapy is crucial to the success of the treatment.
Intensive physiotherapy will be required for around three months to one year. In effect, the patient who was previously able to walk has to learn to walk again. Other potential post-operative procedures may include bracing and further surgery such as hip osteotomies (cutting of the bone) or tendonotomies.
Studies have shown that SDR and physiotherapy together produced a greater improvement in overall muscle function. SDR can also significantly decrease muscle spasticity and improve walking in children who were largely immobile prior to treatment. However reducing spasticity will not always help patients move or walk better. (2)
Risks and possible problems
It is important to remember that this procedure is irreversible and involves major surgery so we would strongly advise parents to consider very carefully whether or not this is suitable for their child and talk to the medical professionals involved in your child’s care. Not all patients with spastic cerebral palsy will benefit from SDR and some patients will see no benefit or even deterioration in their condition following surgery.
Side-effects can include:
- severe pain after surgery (58%)
- unpleasant feelings in the skin (40%)
- constipation (20%) and urine retention
- experiencing increased spasticity during times of stress months or years after surgery (40%)
- weakness in legs
- dislocation of joints.
% figures based on study of 250 children who underwent SDR (2)
Discouragement in the patient, due to the long follow-on process, has also been reported.
SDR can highlight weaknesses elsewhere, for example, where muscles working alongside the spastic muscles have adapted to compensate for the increase in muscle tone.
What else should I consider?
As stated, we would fully recommend discussing your interest in this surgery with your or your child’s medical advisors. You may want to ask the following questions:
- What does the procedure involve in detail?
- What are the benefits to me/my child?
- What is the likelihood of achieving those benefits?
- Could this procedure make things worse?
- What are the risks?
- Are there any alternatives?
- What care will I/my child need after the operation?
- What happens if something goes wrong? (this could be very important if you are having the surgery overseas)
- What may happen if I/my child does not have the procedure?
Where and how is SDR available?
Obviously SDR is a very specialised and expensive procedure and as such is rarely funded in the UK by the NHS.
The only centre in the UK currently offering SDR is the Robert Jones and Agnes Hunt Orthopaedic Hospital in Oswestry although it is possible the Frenchay Hospital in Bristol will offer the procedure in the near future. We believe that Oswestry take children from the age of six upwards whereas in the USA children as young as two years of age will be considered. Referrals to Oswestry must be made through your GP.
The procedure is also available in the USA, mainly at the St Louis Children’s Hospital where Dr TS Park has many years experience and has performed a large number of procedures with positive results.
The procedure is slightly different in America in that there is a difference in the proportion of nerves which are cut and more extensive surgery being carried out than in the UK. Many parents in the UK are very interested in the work being carried out at St Louis although the cost of taking your child to America for the procedure and follow-up treatment can be in the region of £30-£40,000.
Scope would recommend parents read the Guidelines on Treatment of Spasticity in Cerebral Palsy by Selective Dorsal Rhizotomy published byNICE (National Institute for Health and Clinical Excellence).
Further information and references
(1) What’s the Evidence? Selective Dorsal Rhizotomy published by Cerebra. This document also lists a number of research papers and clinical trials which have been published around SDR.
(2) Treatment of Spasticity in Cerebral Palsy by Selective Dorsal Ehizotomy published by National Institute for Health and Clinical Excellence (NICE).
Grunt S, Becher JG, van Schie P, van Ouwerkerk WJ, Ahmade M, Vermeulen RJ. Childs Nerv Syst. 2009 Oct 13. (Epub ahead of print). Preoperative MRI findings and functional outcome after selective dorsal rhizotomy in children with bilateral spasticity.
Engsberg JR, Ross SA, Collins DR, Park TS. Predicting functional change from preintervention measures in selective dorsal rhizotomy. J Neurosurg. 2007 April;106 (4Suppl):282-7www.ncbi.nlm.nih.gov/pmc/articles/PMC2678243/odf/nihms52698.pdf
The Robert Jones and Agnes Hunt Orthopaedic and District Hospital NHS Trust
Telephone: 01691 404000
Fax: 01691 404239
St Louis Children's Hospital
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