narrow lumbar canal

Severe spinal stenosis: What to do? (Should we be worried?)

La spinal stenosis, also called narrow spinal canal is a pathology of the spine characterized by a narrowing of the spinal canal.

Generally, the symptoms of this pathology are more or less bearable and feel differently from one individual to another. However, some patients suffer from more severe and disabling symptoms, reflecting what is called severe spinal stenosis.

What characterizes severe spinal stenosis? should we be worried? how to handle it? Answers in this article.

Anatomical reminder 

The vertebral column or rachis represents a bony structure providing the junction between the head and the pelvis. It consists of 24 vertebrae which articulate with each other.

In addition to its role in static support, it is also responsible for protecting the spinal cord who walks in the spinal canal.

The vertebrae that form the spine are anatomically formed of three parts:

  • Le vertebral body ;
  • The vertebral canal or spinal canal;
  • Of the processes and structures forming the posterior part.

The spinal canal is the part of the spine that allows the passage of the spinal cord.

What is spinal stenosis? 

A decrease in the diameter of the Spinal canal causes a pathology called spinal stenosis and which causes irritation of the spinal cord or nerve roots.

narrow lumbar canal

All parts of the spine can be affected by this pathology, more particularly the joints C5-C6, C6-C7 at the cervical level (we speak of narrow cervical canal), L4-L5 and L5-S1 at the lumbosacral part (narrow lumbar canal).

There are different forms of spinal stenosis:

  • mild spinal stenosis: diameter of the spinal canal rather slightly reduced and almost asymptomatic:
  • Moderate spinal stenosis: moderately reduced spinal canal diameter causing mild symptoms;
  • Severe spinal stenosis : diameter of the very narrow spinal canal giving rise to significant and sometimes very disabling symptoms.

Causes of spinal stenosis 

Spinal stenosis is the consequence of a reduction in the diameter of the vertebral canal which can be of congenital origin or result from degenerative, traumatic or even tumoral processes.

The most important causes of spinal stenosis are:

  • Congenital origin: some people are born with a vertebral canal whose diameter is abnormally reduced, which with age causes sometimes severe spinal stenosis.
  • Degenerative causes: over the years, the vertebrae undergo inflammatory and degenerative phenomena such as osteoarthritis, which can lead to the formation of small bony prominences called "osteophytes", or thickening of the ligaments found inside the canal spinal. These abnormalities are the cause of a sometimes significant reduction in the diameter of the spinal canal which can lead to severe spinal stenosis.
cervical spondylosis
  • A herniated disc: when large, the herniated disc can significantly reduce the diameter of the spinal canal and be the cause of severe spinal stenosis.
herniated disc
  • Un spondylolisthesis : it is a shift forward from a vertebrate on the other which can cause sometimes severe spinal stenosis when it is important.
spondylolisthesis MRI
  • A trauma : a broken bone or vertebral compaction following a traffic accident or a fall from a height, especially when they are violent, give rise to severe spinal stenosis by acute and significant reduction in the diameter of the spinal canal.
  • Cancers: large primary or secondary vertebral tumors sometimes, although rarely, cause severe spinal stenosis.


Symptoms of severe spinal stenosis

When mild to moderate, spinal stenosis is in most cases asymptomatic. However, when they are severe, they sometimes cause quite noisy clinical pictures, with in particular:

back pain

This is one of the most specific signs of spinal stenosis. It is manifested by pain associated with numbness occurring in the legs when standing and accentuated by walking. This pain is relieved by sitting, leaning forward or squatting.

  • A pain 

The pain can appear in the neck and arms giving cervico-brachial neuralgia, or in the pelvis and lower limbs causing low back pain and / or sciatica.

  • Sensory disorders 

A type of numbness, paresthesia or sensations of electric shocks can also be felt by the patient.

  • walking disorders 

Such as a balance disorder or muscle weakness while walking.

When to worry


When the spinal stenosis is really important, it generates important clinical signs signing a serious neurological suffering that must be taken care of quickly. When these signs appear, it is necessary to worry about them and consult as soon as possible.

stethoscope representing a medical emergency
  • Severe sensory disturbances: such as anesthesia of the perineum with severe sphincter disorders such as urinary and/or intestinal incontinence and serious genital disorders.
  • A sciatica paralytic : causing what is called "foot drop", this symptom is a sign of severe nerve compression probably secondary to severe spinal stenosis.
  • Impairment of the fine motor skills of the hand : when spinal stenosis affects the cervical spine, what is more when it is severe, it sometimes induces a disturbance in the execution of fine tasks. In the extreme, it causes difficulty in holding a pen and writing.

Treatment options

The initial management of spinal stenosis is based on a conservative treatment combining physiotherapy, analgesic drugs at different levels or even sometimes cortisone injections.


Unfortunately, when spinal stenosis is severe, these initial measures alone are no longer sufficient and the use of more invasive procedures is necessary.

Although the management depends on the symptomatology and the clinical picture presented by the patient, surgery generally represents the most plausible treatment option in severe spinal stenosis.

Surgery for spinal stenosis involves reducing pressure on the spinal cord or vertebral nerves. This intervention is called decompression and it is divided into several procedures:

  • Laminectomy 

Laminectomy is the most frequently used surgery in spinal stenosis. It involves the removal of two spinal blades and spinous process (bony protrusion at the back of the vertebra) connecting them in order to decompress the spinal cord and nerve roots irritated by spinal stenosis.

lumbar laminectomy
Diagram showing the process of lumbar laminectomy

In some situations, parts of one or more facet joints may also be removed as part of a laminectomy.

  • Foraminotomy 

Less invasive than the previous one, it can only be offered when the spinal stenosis is not very extensive. It consists of removing part of the intervertebral foramen with more or less partial removal of the intervertebral disc.

When the primary cause of spinal stenosis is significant disc degeneration, intervertebral disc removal may be necessary. In this case, a discectomy followed by fusion of the adjacent vertebrae (arthrodesis) is proposed to ensure spinal stability and relieve pain.

spinal fusion

Other surgical techniques may be offered in rare situations such as corpectomy (complete removal of a vertebral body) or the micro endoscopic decompression.

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