Selective dorsal rhizotomy (SDR)

Overview

Selective dorsal rhizotomy (SDR) is a surgical procedure designed to reduce muscle spasticity in children with cerebral palsy (CP). Spasticity, or muscle tightness, occurs when certain muscles contract involuntarily, affecting mobility and causing discomfort. The surgery involves cutting specific sensory nerve fibers in the lower spinal cord that are responsible for sending signals that cause this tightness. By targeting only the problematic nerve rootlets, SDR reduces muscle stiffness while preserving other functions. 

This procedure is mainly used for children with spastic diplegic cerebral palsy, where muscle tightness primarily affects the legs, or severe spastic quadriplegic cerebral palsy, which impacts all four limbs. Normally, the brain controls the reflexes in the spinal cord that regulate muscle tone, but in children with CP, this control is impaired, resulting in continuous muscle contraction. SDR helps restore better muscle function by addressing the faulty nerve signals, improving mobility, and preventing complications like contractures and bone deformities. 

After the surgery, children require intensive rehabilitative and physical therapy to achieve the best outcomes. SDR is not suitable for every child with spastic cerebral palsy, so careful evaluation is necessary to determine if this treatment is appropriate. With proper follow-up care, SDR can significantly enhance a child’s quality of life by improving movement and reducing pain.

Reasons for undergoing the procedure  

Healthcare providers sometimes use selective dorsal rhizotomy (SDR) to treat spasticity in children with cerebral palsy (CP), a condition that impairs muscle control due to brain damage or abnormalities in areas responsible for movement and coordination. Many individuals with CP experience spasticity, where certain muscles contract involuntarily during movement or even at rest. This spasticity can limit mobility, cause pain, and interfere with daily activities. 

Selective dorsal rhizotomy is primarily recommended for children with spastic diplegic cerebral palsy, where spasticity mainly affects the legs, or severe spastic quadriplegic cerebral palsy, where all four limbs are involved. The procedure helps reduce muscle tightness, potentially improving mobility and quality of life.

Risk 

The following are potential short-term risk of selective dorsal rhizotomy (SDR):  

• Infection.  
• Bleeding.  
• Cerebrospinal fluid (CSF) leak.

Permanent complications are rare but may include:  

• Increased sensitivity to touch (hyperesthesia), potentially causing pain  
• Loss of bladder control or urinary incontinence  
• Loss of bowel control or bowel incontinence  
• Weakness or loss of previous walking ability  

Your child’s healthcare team will discuss all potential risks before the surgery.

Before the procedure  

Selective dorsal rhizotomy (SDR) is only effective for certain children with cerebral palsy. To determine if your child might benefit from this surgery, they will undergo a thorough screening process involving several specialists: 

Evaluations by specialists: 

• Pediatric neurosurgeon: This specialist has experience performing SDR on children. They will assess your child’s lower extremities and evaluate the underlying muscle condition. 
• Pediatric orthopaedic surgeon: This specialist will examine your child to determine if any orthopedic surgeries are needed to address issues like bone deformities or contractures (severe muscle stiffness). 
• Physical therapist: They will measure the spasticity and muscle function in your child’s legs. 
• Occupational therapist: This specialist will evaluate your child’s current abilities and potential to perform everyday activities, such as walking, eating, dressing, and playing.

Once each specialist has completed their individual assessments, the team will discuss together whether SDR is a suitable option for your child. 

Further screening procedures: 

In-depth physical and occupational therapy evaluations: These will include videotaping your child performing movements and daily activities to help develop a post-surgery therapy plan. 

• Brain magnetic resonance imaging (MRI): To ensure there are no other underlying neurological issues that could affect the surgery. 
• Pediatric neurologist consultation: To address any neurological conditions that may impact the procedure or recovery. 
• Meeting with pediatric neurosurgeon: This session will go over the risks of the surgery and explain what to expect during the recovery process. 
• Anesthesiologist appointment: To confirm that general anesthesia is safe for your child during the surgery.

During the procedure  

The general steps of a selective dorsal rhizotomy (SDR) surgery are as follows:  

• Anesthesia: An anesthesiologist administers general anesthesia to ensure your child is asleep and pain-free during the procedure.  
• Incision: The neurosurgeon makes a small cut in the middle of your child’s lower back.  
• Exposure: Through this incision, the surgeon creates a small “window” in the spine, navigating through muscle, bone, and the dura (the spinal cord’s covering) to access the nerve fibers.  
• Nerve identification: The neurosurgeon separates the motor nerves from the sensory nerves, protecting the motor nerves throughout the surgery.  
• Electrode placement: Electrodes are attached to the sensory nerve roots. Electromyography (EMG) is used to stimulate the nerves and identify which ones are causing spasticity. Several stimulations help determine which nerves to cut.  
• Nerve cutting: The surgeon cuts a percentage of the identified abnormal sensory nerves. The exact nerves and the amount cut vary for each child.  
• Closure: After cutting the nerves, the surgeon closes the incision layer by layer.

After the procedure  

After the selective dorsal rhizotomy (SDR) surgery, your child will be transferred to a recovery room, often in the intensive care unit (ICU), for close monitoring. The surgery typically lasts about four to five hours.

Children generally stay in the hospital for approximately five days. During the first 24 to 48 hours, they will need to lie flat. Physical and occupational therapy usually begin within a few days after the surgery and are essential for recovery. Your child will likely engage in these therapies most days of the week for three to six months.

Before discharge, the healthcare team will discuss medications, incision care, permitted activity levels, and when your child can return to school. Regular follow-up appointments will be necessary, and the healthcare team will inform you about the schedule for these visits.

Outcome 

The success of selective dorsal rhizotomy (SDR) greatly depends on your child’s commitment to intensive physical therapy following the procedure, as well as the specific goals tailored to their individual needs. 

In children with spastic diplegic cerebral palsy, SDR has the potential to achieve:  

• Enhanced mobility and improved walking abilities  
• Increased stamina  
• Better balance with a reduction in falls  
• Improved sitting and standing posture  
• Reduced pain from spasticity 

For those with spastic quadriplegic cerebral palsy, SDR can boost independence by enabling:  

• More comfortable sitting for extended periods  
• Use of a potty seat  
• Operation of a wheelchair independently 

Additionally, SDR can simplify daily care for children with spastic quadriplegic cerebral palsy, making tasks like diaper changes or using adaptive feeding devices easier for caregivers.

Generally, children with spastic diplegic cerebral palsy experience more favorable outcomes from SDR compared to those with spastic quadriplegic cerebral palsy.

If you observe any signs of complications post-surgery, such as an infection at the incision site or issues with bladder control, contact your child’s healthcare provider immediately.