La stenosis of the cervical canal is due to narrowing of the cervical tract of the spinal canal, or vertebral, resulting in compression of the medulla within it. This condition is in turn the most frequent cause of cervical myelopathy.
The structure of the neck and spinal canal
The vertebral column, or backbone, is a fundamental element of our body, as it passes through most of it. It is a ductile structure, in which the cervical spine corresponds to the neck area. This consists of seven vertebrae: between each of these there are i intervertebral discs, which allow the spine to move smoothly. Inside the column is the spinal canal, formed anteriorly by the vertebral body, while the laminae constitute its posterior arch. The channel is responsible for protecting the spinal cord and the nerve bundles. The medulla is in turn immersed in the cerebrospinal fluid and is further protected by the three layers of the meninges. At each vertebral level, two spinal nerves exit through the conjugation foramina, allowing the Central Nervous System (which also includes the brain) to communicate and receive information from the body's tissues, muscles and skin.
The causes of stenosis of the cervical canal
As in the case of stenosis of the lumbar canal, and especially advancing age to cause cervical stenosis. In fact, with the passage of time the vertebral discs eventually become dehydrated (disc disease) and are no longer able to fulfill their function as shock absorbers and the mobility of the cervical spine. This is why the space available between the vertebrae decreases, causing protrusions of the discs in the vertebral canal and sometimes a misalignment or even a real anomalous movement between the vertebrae (spondylolisthesis). At the same time, i ligaments that form the spine lose flexibility and become stiff and thick as new bone develops abnormally (osteoarthritis).
All these changes combine to cause a narrowing of the spinal canal, which occurs mainly in people with more than 50 years of age. In addition to natural aging, there may be other causes of cervical canal stenosis:
- Cervical disc herniation
- trauma to the spine
- spinal tumors, which can compress the spinal cord
- ossification of the posterior longitudinal ligament (more common in Japan)
- Paget's disease, which is manifested by skeletal deformities
- congenital malformations, in which the spinal canal is already narrow from birth
Among the risk factors to be considered are heavy work, with heavy lifting, repeated gestures, bad back postures,obesity, diabetes mellitus and smoke.
A serious complication: cervical myelopathy
Cervical stenosis is itself the primary cause of cervical myelopathy, a disease involving the first part of the spinal cord. However, it is not the only possible origin: myelopathy can also be caused by cervical spondylosis, slipped disc, inflammation of the marrow or vascular pathologies in the same area. Its development is slow and gradual and does not necessarily involve a typical symptom of stenosis: neck pain. But it is essential to recognize its presence, also to avoid injury to the nerve cells of the spinal cord.
Stenosis of the cervical canal and myelopathy: symptoms and consequences
We should not underestimate the fact that cervical stenosis can be both symptomatic and asymptomatic. In the first case, the symptoms can be constantly present and gradually more and more intense, but also present themselves in an acute way and then remain silent for a certain period. The characteristic symptoms are:
- neck pain
- burning or pain in the shoulders, upper limbs, lower limbs, buttocks
Typical of stenosis-related cervical myelopathy are these symptoms:
- tingling and numbness in the limbs
- weakness of the limbs and hands
- balance disorders
- difficulty walking
There are particularly serious cases in which cervical stenosis can negatively affect intestinal and urinary functions, so much so that the patient can lose control of the anal or bladder sphincter (incontinence). It can also occur with quadriplegia, a form of paralysis that affects the torso and limbs.
Diagnosis of stenosis of the cervical canal
Fundamental to start a diagnostic process is the physical examination by the doctor, based on the symptoms described by the patient, combined with the study of his health condition, family history and lifestyle. But above all the role of diagnostic imaging is essential, through these tests:
- x-ray of the spine to identify possible alterations of the vertebrae
- magnetic resonance, to study the tissues of the involved area, evaluate the compression of the spinal cord and nerves, and detect any hernias
- TAC, which guarantees extremely detailed images at the bone level of the area, seeing the osteophytes (osteoarthritis)
Stenosis of the cervical canal: treatment and intervention
Based on each subjective situation, the neurosurgeon evaluates which type of treatment is the most effective for addressing the stenosis of the cervical canal. Surgery is not necessarily the first choice. If the patient is in old age, does not suffer from serious diseases and the symptoms are not disabling, it is indeed advisable to opt for a conservative treatment, aimed at improving the quality of life, which can also keep the symptoms of cervical myelopathy under control. They can then be administered NSAID drugs or corticosteroids, as they are recommended specific exercises for strengthening the muscles and flexibility of the cervical spine. The functional rest, that is, refraining from all movements that precede the painful sensation.
However, if conservative treatment fails or if the symptoms are disabling, the neurosurgeon may recommend proceeding with a surgery. In particular, the operation is indicated if progressive neurological symptoms occur in the limbs or balance and walking disorders. Different intervention methods are available:
- laminectomy decompressive
- vertebral arthrodesis (spinal fusion)
- discectomy and anterior arthrodesis
After the operation, the patient should act on their lifestyle, especially if they are smokers or overweight.