La stenosis of the cervical canal it is due to the narrowing of the cervical portion of the spinal canal, or vertebral, resulting in compression of the spinal cord inside 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 flexible structure, in which the cervical spine corresponds to the neck area. This is made up of seven vertebrae: between each of these there are the intervertebral discs, which allow the spine to move fluidly. Inside the column there is the spinal canal, formed anteriorly by the vertebral body, while the laminae constitute its posterior arch. The canal is responsible for protecting the spinal cord and the nerve bundles. The spinal cord is in turn immersed in cerebrospinal fluid and is further protected by the three layers of the meninges. At each vertebral level, two spinal nerves emerge through the foramina, allowing the Central Nervous System (which also includes the brain) to communicate and receive information from the body's tissues, muscles, and skin.
Causes of cervical canal stenosis
As in the case of lumbar spinal stenosis, it is above all advancing age to cause cervical stenosis. In fact, over time, the vertebral discs end up dehydrated (disc disease) and are no longer able to perform their function as shock absorbers and the mobility of the cervical spine. This is why the available space between the vertebrae decreases, causing protrusions of the discs in the spinal canal and sometimes a misalignment or even a real abnormal movement between the vertebrae (spondylolisthesis). At the same time, the ligaments that form the spine lose flexibility and become stiff and thick, while new bone tissue develops abnormally (arthrosis).
All these changes contribute to causing a narrowing of the spinal canal, which occurs especially in subjects with over 50 years of age. In addition to natural aging, there may be other causes of cervical canal stenosis:
- cervical disc herniation
- spinal trauma
- spinal tumors, which can compress the spinal cord
- ossification of the posterior longitudinal ligament (more common in Japan)
- Paget's disease, which manifests itself with skeletal deformities
- congenital malformations, in which the spinal canal is already narrow from birth
Risk factors to take into account include heavy work, involving heavy lifting, repeated gestures, bad back postures, theobesity, diabetes mellitus and smoke.
A serious complication: cervical myelopathy
Cervical stenosis itself is a primary cause of cervical myelopathy, a pathology involving the first part of the spinal cord. However, this is not the only possible origin: myelopathy can also be caused by cervical spondylosis, slipped disc, spinal inflammation, or vascular disease in the same area. Its development is slow and gradual and does not necessarily lead to a typical symptom of stenosis: neck pain. However, it is essential to recognize its presence, also to avoid damage to the nerve cells in the spinal cord.
Cervical canal stenosis and myelopathy: symptoms and consequences
It should not be underestimated that cervical stenosis can be both symptomatic and asymptomaticIn the first case, symptoms may be constantly present and gradually become more intense, but they may also appear acutely 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 symptoms of cervical myelopathy related to stenosis are:
- 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 may lose control of the anal or bladder sphincter (incontinence). It can also occur together with tetraplegia, a form of paralysis affecting the torso and limbs.
Diagnosis of cervical canal stenosis
A fundamental step in starting a diagnosis is a physical examination by the doctor, based on the symptoms described by the patient, combined with a study of their health, family history, and lifestyle. But the role of diagnostic imaging is especially crucial, through the following tests:
- spine x-ray 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 provides extremely detailed images at the bone level of the area, seeing the osteophytes (arthrosis)
Cervical canal stenosis: treatment and surgery
Based on each individual situation, the neurosurgeon evaluates which type of treatment is most effective for cervical stenosis. Surgery is not necessarily the first choice. If the patient is elderly, does not suffer from serious illnesses, and symptoms are not disabling, it is actually 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 therefore be administered NSAIDs or corticosteroids, as recommended specific exercises for strengthening the muscles and increasing the flexibility of the cervical spine. Also very useful is the functional rest, that is, abstaining from all movements that precede the painful sensation.
However, if conservative treatment fails to achieve its aim or if the symptoms are disabling, the neurosurgeon may recommend proceeding with a surgeryIn particular, surgery is indicated if progressive neurological symptoms in the limbs or balance and gait disorders occur. Various surgical methods are available:
- laminectomy decompression
- laminoplasty
- vertebral arthrodesis (spinal fusion)
- anterior discectomy and arthrodesis
- foraminotomy
After surgery, it is advisable for the patient to make changes to his or her lifestyle, especially if he or she is a smoker or overweight.
