Selective Dorsal Rhizotomy in Cerebral Palsy- Selection and Physiotherapeutic Management

Selective Dorsal Rhizotomy (SDR) is a neurosurgical procedure that aims to:

• Reducing spasticity that interferes with motor function in children with spastic Cerebral Palsy.
• Improve function and mobility
• Increase independence
• Increase range of motion and improve positioning

(Verity, 2017 and Nordmark et al., 2008)

Funding in the UK:

The SDR procedure is not currently available on the NHS as funding for the surgery has been withdrawn whilst NHS England examines its effectiveness via a process called Commissioning Through Evaluation.  There are 7 funded centres: Alder Hey Children’s NHS Foundation Trust; The Portland Hospital for Women and Children; Great Ormond Street Hospitals NHS Foundation Trust; Leeds Teaching Hospitals NHS Trust; Nottingham University Hospitals NHS Trust; University Hospitals Bristol NHS Foundation Trust; The Robert Jones and Agnes Hunt Orthopaedic Hospital NHS (Scope UK, 2018). They undertake approximately 120 SDR cases a year (NHS England, 2014) with selected children to gather detailed information about clinical outcomes to produce a final report in Autumn 2018. Despite this SDR can be self-funded in the UK through the NHS hospital treatment top-up scheme. (Verity, 2017). In the UK the procedure costs between £30,000- £40,000 (The Portland Hospital, 2015).

Clinically relevant anatomy:

Two groups of nerve roots leave the spinal cord through the intervertebral foramen: the ventral and dorsal spinal roots (St. Louis Children’s Hospital, 2018). The ventral nerve roots are efferent motor roots and are responsible for control of muscular contractions, hormone synthesis and gland secretion. The dorsal nerve roots are afferent sensory roots and are responsible for the transmission of sensory stimulation to the CNS (Laser Spine Institute, n.d.). The SDR procedure decreases sensory stimulation to the CNS by dividing the dorsal nerve roots whilst preserving voluntary movement (NHS England, 2013).

Procedure:

The operation takes place under general anaesthetic and lasts approximately 5 hours (NICE, 2006). The procedure involves dividing some of the lumbar sensory nerve roots in order to reduce the sensory input to the sensory–motor reflex arcs which are responsible for increased muscle tone. A laminectomy of one or more vertebrae from L1 to S1 vertebrae  is performed to expose the dural sac (Funk and Haberl, 2016), which is opened to display the spinal conus with or without the cauda equina. The sensory nerve roots are identified intraoperatively using electrical stimulation, those that generate unusual electrical activity are thought to be those which contribute to spasticity. The selected sensory rootlets are divided, preserving some sensory supply and the motor roots responsible for voluntary movements (NICE, 2010). Up to 50% of the sensory nerve at each level is divided. (The Robert Jones and Agnes Hunt Orthopaedic Hospital, 2014). SDR is common in North America however there are significant variations between centers in the way the procedure is carried out (Steinbok, 2007).

Editing in process.

21/05/18