Neuromuscular Scoliosis

Neuromuscular = involving the muscles and the nervous system (the brain, spine, and nerves)
Scoliosis = a side-to-side curvature of the spine

Scoliosis is a side-to-side curvature of the spine. Neuromuscular scoliosis is a particular type of scoliosis caused by problems with the muscles and the nervous system (the brain, spine, and nerves).

Compared with other forms of scoliosis, neuromuscular scoliosis is more likely to continue increasing in size over time. It is likely to involve the entire length of the spine and have a shape that looks like a tall “C.” It is often associated with a tilted pelvis, a condition known as pelvic obliquity. As in other forms of scoliosis, the spine is likely to rotate as well as the curve.

Neuromuscular scoliosis is most commonly diagnosed in children and adolescents. (The spinal curvature can continue to increase into adulthood.) More rarely, adults can be diagnosed with neuromuscular scoliosis.

Symptoms

Neuromuscular scoliosis can cause difficulty with balance, sitting, and (if the child walks) walking. Severe curves can interfere with breathing and with lung development.

Signs of neuromuscular scoliosis include increasing asymmetry (the difference between right and left sides) in the shoulders, rib cage, and hips. The waist may appear higher on one side.

In children who walk, signs include changes in posture, difficulty standing upright, or changes in gait.

In children who do not walk, signs include leaning to one side and needing to support a seated position with the arms.

In most cases, neuromuscular scoliosis does not cause pain.

Diagnosis

Neuromuscular scoliosis is diagnosed with X-rays of the spine from the side and the back. Whenever possible, the X-rays are taken in a standing or seated position without supports. Taking the X-rays without supports gives the best idea of the natural state of the curve because this allows gravity to affect the shape of the spine.

A doctor will use X-ray images to measure the degree of curvature and rotation in the spine and pelvis.

Risk Factors

Neuromuscular scoliosis is associated with underlying conditions like cerebral palsy, spina bifida, or other forms of spinal dysraphism, spinal tumors, syringomyelia, muscular dystrophy, connective tissue, and other genetic conditions, or paralysis due to spinal cord injury.

The curvature tends to be most severe in children who do not walk.

The exact mechanisms of the condition are not well understood. It is sometimes involved with muscle rigidity and sometimes with muscle looseness. The presence, severity, and course of the condition cannot always be predicted by the condition and the muscle involvement.

Treatments

There are non-surgical and surgical treatment options for neuromuscular scoliosis. In general, surgical treatment is appropriate for children and adults whose curve is large and progressive, whose curve causes pain or difficulty with walking, sitting or breathing, and who have the nutritional and overall health status to tolerate surgery.

The surgical treatment involves correcting the spinal curvature and then keeping the spine in the corrected position. Curves of neuromuscular scoliosis are generally long curves that involve much of the spine. The surgical treatment may extend along a large portion of the spine, down to the pelvis (see spinopelvic fixation).

In children who are still growing, curve correction and stabilization is accomplished with growing constructs (e.g. growing rods or VEPTRs). These adjustable metal rods are curved to fit the corrected spine and attached to screws that are implanted in bones of the spine or to ribs. Once the rods are inserted, they are lengthened with a minor procedure every 6-8 months while growth continues. In some cases, these lengthenings can be done magnetically without the need for surgery. In this way, the child’s spine can grow while the rods keep it stable. The use of hardware like screws and rods to keep the spine stable is called spinal fixation.

The rods alone are not a lifelong solution. Long-term stability is granted by bone fusion. In a bone fusion, small pieces of bone graft are placed like bridges to connect bones of the spine. The bones grow together into one solid bone, like when a fracture heals. The resulting section of spine is very stable and will not allow curvature. However, this procedure is usually not performed until the spine is finished growing.

In patients whose spinal growth is complete, a fusion and fixation procedure is performed. The bone fusion provides long-term stability. The fixation with hardware keeps the spine stable while the bones fuse. In patients who originally had growth rods, those rods are replaced with standard fixation rods during the fusion and fixation.