Spasticity refers to an abnormal increase in muscle tone in the extremities that hinders normal movement such as walking.
The most common cause of spasticity in children is cerebral palsy from premature birth or other perinatal problems. Other children may develop spasticity after later insults to the brain such as meningitis or trauma.
Children with spasticity are evaluated at Rainbow by a multidisciplinary team that includes pediatric neurology, orthopedics, neuroradiology, physical and occupational therapy. Mild spasticity can often be treated successfully with an aggressive physical therapy program and oral medications. More severe spasticity often improves with braces or casting, and botulinum toxin (botox) injections in the affected muscles.
Surgical treatment of spasticity is considered when a child has failed to have sufficient improvement with nonoperative treatment. If a child has reached a plateau in his or her progress, it may be an opportune time to consider surgical therapy.
Selective dorsal rhizotomy is an excellent surgical option for children have spastic diplegia (spasticity of the legs only) from periventricular leukomalacia (PVL), are (or have the potential to be) ambulatory with assistive devices, and are cooperative with physical therapy. Children with PVL lack an inhibitory signal from the brain that suppresses the spinal feedback loop between the motor and sensory roots regulating muscle tone. Through a small incision in the upper lumbar spine, a small window of bone (one laminar level) is removed where the leg nerve roots exit the spinal cord. After electrophysiological testing, each dorsal sensory root is divided into several rootlets, each rootlet is tested for abnormal spread from the feedback loop, and about 60-70 percent of the most abnormal rootlets are cut. The location and number of rootlets cut is individualized for each child. The risks and morbidity are quite low. The typical hospital stay is 4-5 days. Children begin an intensive six-week physical therapy course one week after the surgery. On average, children improve one level of assistive devices after the surgery, e.g. progress from ambulating with a walker to ambulating with canes. Long-term follow-up studies have shown the improvement in function persists over many years.
Insertion of an intrathecal baclofen pump is a surgical option for children with severe spasticity affecting all four limbs (spastic quadriplegia) from a variety of causes. These children are typically not ambulatory. Using xray guidance, a tiny catheter is inserted in the cerebrospinal fluid space (intrathecal) in the spine, and connected to a refillable pump inserted in the abdominal wall. Intrathecal baclofen is quite effective at relieving spasticity in the arms and legs, without the sedative effects that often accompany oral baclofen. The dose is easily adjusted through a wand held over the pump. Generally, children should weigh at least 30 pounds to tolerate placement of the pump. On average, the pump must be refilled every 2-3 months, and the pump replaced every 5-7 years.
What Can Be Done? Botox Therapy; Selective Dorsal Rhizotomy
Botox Therapy
Children with cerebral palsy have increased muscle tone (spasticity) that limits their ability to walk normally. The diagnosis of cerebral palsy is typically made when the child is a toddler and has difficulty learning to walk. Many children with cerebral palsy show significant improvement with physical therapy and oral medications. For children who still have increased muscle tone, botulinum toxin (botox) injected directly into the involved muscle groups can provide some improvement in muscle tone for a few months. The injections can be repeated, but for most children the repeat injections are less effective.
Selective Dorsal Rhizotomy
Children with cerebral palsy have increased muscle tone (spasticity) that limits their ability to walk normally. The diagnosis of cerebral palsy is typically made when the child is a toddler and has difficulty learning to walk. Many children with cerebral palsy show significant improvement with physical therapy and oral medications. For children who still have increased muscle tone, botulinum toxin (botox) injected directly into the involved muscle groups can provide some improvement in muscle tone for a few months. The injections can be repeated, but for most children the repeat injections are less effective.
Although non-surgical treatments are successful in many children, others continue to have problems walking normally due to spasticity. These children may benefit from a surgical procedure called selective dorsal rhizotomy. The term dorsal rhizotomy is used to describe cutting of the posterior sensory nerve roots after they exit from the spinal cord. Selective means that we use special electrophysiological monitoring during the procedure to identify and cut only those nerve roots that are abnormal.
The goal of selective dorsal rhizotomy is to help normalize the feedback loop that causes increased muscle tone in the leg muscles. Normally, muscle tone is determined by a feedback loop through the spinal cord between the motor and sensory nerves to each muscle. The feedback loop in the spinal cord receives messages from the brain descending through nerve bundles in the spinal cord. These messages from the brain suppress the spinal cord feedback loop, and thus limit the tone in the muscles. Children who have cerebral palsy do not have enough of these suppressive signals from the brain, and thus have too much muscle tone. In addition, children with cerebral palsy have increased spread of muscle tone to nearby muscle groups. This leads to increased muscle tone in larger areas. Selective dorsal rhizotomy surgery helps make the feedback loop between the motor and sensory nerves more normal by cutting a portion of the sensory roots at each spinal level in the lumbar and upper sacral areas. The decreased sensory portion of the feedback loop helps reduce the abnormal muscle tone without affecting sensation.