Scoliosis means side-to-side curvature of the spine. Mostly it occurs during the growth period or just before puberty. Neuromuscular scoliosis (NMS) is one of the uncommon variants of scoliosis that occurs in children. Neuromuscular scoliosis results in loss of control over the muscles or dystrophic muscles that support the spine.
Neuromuscular scoliosis though not common, it is one of the important variants of scoliosis.
What Is Neuromuscular Scoliosis?
Neuromuscular scoliosis means – the curvature of the spine caused by problems with the muscles and the nervous system associated with the brain and spinal cord. It is the second most common type of scoliosis associated with conditions of the nerve or muscular systems such as muscular dystrophy, cerebral palsy, and spina bifida and commonly in India poliomyelitis. Compared to other types of scoliosis, neuromuscular scoliosis is more severe, more progressive and more morbid.
Some are ambulators and some are non-ambulators. In many patients who are non-ambulators, there is a unilateral or bilateral hip dislocation or subluxation along with fixed pelvic obliquity. In our country, we see more cases of neuromuscular scoliosis as sequelae of poliomyelitis.
In many cases of neuromuscular scoliosis, surgery is inevitable to fix the curvature and to stabilize the spine. Nerves and muscles in the spine and trunk are unable to maintain proper alignment. The spinal curves due to neuromuscular scoliosis are often associated with pelvic obliquity. This is a condition where the child’s pelvis is aligned one side higher than the other.
Signs & Symptoms Of Neuromuscular Scoliosis(NMS)
The signs and symptoms of neuromuscular scoliosis usually appear early in a child’s life. A spine doctor can diagnose the condition early during a physical exam. You also can observe scoliosis symptoms in your children when their spine tends to curve and also by observing changes in their overall body posture. In most of the cases, it doesn’t cause any pain. Some other symptoms that may indicate neuromuscular scoliosis include:
- Leaning or uneven seating posture
- Having trouble to sit in a chair
- Uneven shoulder heights
- Uneven structure of hips or buttocks
- Uneven arms height
Children may also face hygiene challenges. Children with this condition have poor balance and reduced coordination of the trunk, neck, and the head.
Causes Of Neuromuscular Scoliosis (NMS)
Neuromuscular scoliosis mainly occurs due to the underlying medical conditions which affect the body’s neurological or muscular system or both. Some of the underlying conditions associated with neuromuscular scoliosis are:
- Cerebral palsy
- Spina Bifida
- Myelodysplasia (thoracic level)
- Myelodysplasia (lower lumbar)
- Duchenne muscular dystrophy
- Spinal muscle atrophy
- Friedreich ataxia
- Spinal tumours
- Syringomyelia(a cyst that formed within the spinal cord)
- Muscular dystrophy
- Connective tissue disorders and other genetic conditions
- Other forms of spinal dysraphism(a spectrum of spinal disorders)
A spinal cord injury can also lead to neuromuscular scoliosis. The possibility of developing a spinal curve depends on the extent of nerves and muscles that are involved with the child’s neuromuscular condition. The spinal curve tends to be more severe in physically immovable children.
However, not every child with neuromuscular conditions develops scoliosis. A child may walk initially with some neuromuscular conditions, but upon reaching adolescence, the condition in some muscular dystrophies progresses and they can’t walk anymore. This means that the neuromuscular condition is developing into scoliosis, and it becomes a major growth spurt.
The exact mechanisms of this condition are yet to be understood. Sometimes, it may be due to muscle rigidity and sometimes due to muscle looseness. Early treatment can slow down the progression and improves the quality of life of your children with this scoliosis.
Treatment Options For Causes Of Neuromuscular Scoliosis (NMS)
There are both non-surgical(conventional) and surgical treatment options available for neuromuscular scoliosis. In general, surgical treatment is inevitable for children and adults who have a large and progressive spinal curve. Their spinal curve causes pain and limits activities like walking, sitting. They might experience difficulty in breathing too.
Nonoperative treatment for neuromuscular scoliosis is generally prescribed for mild scoliosis and at initial stages in order to prevent progression. For patients with smaller curves, braces are recommended to achieve proper balance while walking, sitting and moving around. Bracing also prevents your child’s spinal curve from becoming worse during their growth, but bracing can’t correct the existing spinal curve. Wheelchair modification, physical therapy, and a pleasant environment can help your child to improve mobility.
A spine surgeon considers several things before recommending a surgery to treat the spinal curve, which includes – the severity of the curve, the effects of the curve in limiting the functional abilities of your child. Some other things to consider are:-
- Significant spinal curve
- Is the patient experiencing Intense pain
- Problems with the functioning of the heart or lungs.
The surgical treatment for scoliosis helps to correct the spinal curvature. Neuromuscular scoliosis spinal curves are generally long and involve much of the spine down till the pelvis.
In conditions of neuromuscular scoliosis secondary to poliomyelitis, by stabilizing the spine and restoring the balance the upper limbs are freed for during routine work. Otherwise, the patient uses upper limbs to stabilize the trunk.
For growing children, correction of spinal curve and stabilization is achieved with growing constructs called growing rods. Spinal stabilization in young children is achieved with these growing rods which allow the spine, lungs, and chest to grow as much as possible. These growing rods aim to provide continuous growth while correcting the spinal curve.
These adjustable rods are implanted into the bones of the spine or to ribs and fixed with screws. Once the rods are implanted, they are lengthened for every 6-8 months with a minor procedure to keep up the child’s growth. In this way, the rods keep the growth of the spine stable. The growing rods can’t provide a lifelong solution in a child who has already undergone the procedure. When your child is fully grown, bone fusion is performed for long term stability.
The most common surgical method used to treat neuromuscular scoliosis is Spinal fusion. It is also called bone fusion, where small pieces of bone graft, (taken from a bone bank or made artificially) are placed between the vertebrae to connect bones in the spine.
The bones then grow together fuses into one solid bone, like when a broken bone heals. Metal rods are used to hold the spine still until the fusion happens. Once the fusion happens successfully, the spine becomes stable and doesn’t allow curvature in future. However, the procedure is performed after the spine is grown completely. Some patients are fraught with significant pelvic obliquity which causes imbalance while sitting. During surgery pelvic obliquity is usually reduced by instrumenting and fusing the scoliotic spine to the pelvis.