Spinal Stenosis: Narrowing of the Spinal Canal. Symptoms and Treatment

Spinal stenosis is a technical term for a narrowing of the spinal canal. This is a condition with a long development in which the lumen of the openings through which the spinal cord or spinal nerves is reduced.

As a result of the narrowing, various neurological problems arise, which are associated with pain.

Although it is a chronic disease based on degenerative spinal changes, it may not only affect retirees.

Difficulties usually arise around the age of 50. However, this does not rule out the possibility that the disease will not manifest itself sooner. Often its course is hidden and one does not show any symptoms = it is asymptomatic. However, over time, as a result of aging, it will.

Narrowing can affect any part of the spine, but most sources list two main types. It is a cervical and lumbar spinal stenosis.

Alternatively, there is a mention of a suprasacral lesion, ie above the sacral and subacral lesions, and thus below the sacral spine.

The incidence increases with age.

The figures for stenosis of the lumbar region are as follows: In 60-year-olds, the prevalence is 20%, in the age of 70, 30%, and in people over 80, up to 40%.

Briefly About the Spinal Cord and Spinal Canal

The spinal cord is the link between the brain and the rest of the human body. Conducts nerve impulses, information and provides some reflexes = transmission and reflex function.

It runs through the spinal canal - canalis vertebralis, which is formed by vertebrae. The vertebral foramen (foramina vertebralia) of the cervical, thoracic and lumbar vertebrae are the passageway of the spinal cord.

The vertebra is made of several anatomical structures: the body, the arch and the processes.

The spinal cord is located in...

From the first cervical vertebra - C1 to the 2nd lumbar vertebra - L2. A bundle of nerves, called the cauda equina, i.e. the so-called horse's tail, leaves the final part of the spinal cord.

It is about 40 - 50 cm long. 
It is about 1 cm wide. 

The spinal cord, like the brain, is made up of white and gray matter, and enclosed by spinal cord membranes. White matter is superficial and inside it is a gray mass which is arranged in the shape of the letter H.

Due to this arrangement of neurons, i.e. nerve cells, the spinal processes can be anterior, lateral and posterior.

The anterior processes have a motor function, they conduct nerve impulses from the brain to the muscles. The posterior ones are sensory, they conduct nerve information to the brain. Lateral processes contain vegetative neurons. Together they form the spinal nerves.

Accordingly, the spinal cord is divided into segments, where 1 spinal segment = 1 spinal nerve composed of anterior and posterior spinal roots.

The spinal cord segments are:

• 8 cervical
• 12 thoracic
• 5 lumbar
• 5 sacral
• 1 coccygeal

A total of 31 pairs of spinal nerves.

The spinal nerves exit the spinal cord at a site called the spinal root - fila radicularia. Spinal root compression is referred to as pinched nerve - radiculopathy.

The anterior and posterior spinal roots protrude from the spinal cord - radices anteriores and radices dorsales. These subsequently connect to said spinal nerve.

The spinal roots pass through the vertebra through an opening, which is technically referred to as the foramen intervertebrales.

Stenosis can affect:
spinal canal at the level of the vertebral holes - foramina vertebralia,
but also in the foramen intervertebrales - nerve root canal, the spinal root transition site.

Definition of Spinal Stenosis

Spinal stenosis is a reduction in the space due to nerve and vascular structures of the spine. It is based on a degenerative process on the spinal or root canals.

These are pathological (disease) changes in the sense of spondylosis, or the cause is a congenital narrow spinal canal. Spondylosis is a degenerative process that affects the entire segment, from the vertebrae, small joints, through the disc, to the ligaments and other structures.

Learn more about spondylosis.

Nerve compression due to the intervertebral disc bulging out - the hernia disc is not referred to as spinal canal stenosis.

Classification:

1. Clinically manifest form - manifests itself through symptoms.

2. Narrow spinal canal - there is narrowing, but no manifestations.
Stenosis is not manifested.

There is also an anatomical classification.

1. central stenosis, which has several subtypes
   • a narrowing of the central part of the spinal canal
2. lateral spinal stenosis, also referred to as lateral stenosis due to canal narrowing
   • that is, a narrowing at the point of nerve root withdrawal from the spinal cord
   • several subtypes
   • also known as foraminal stenosis

The literature also provides a breakdown by cause, which we present in the following section of the article.

Spinal stenosis is therefore a narrowing of the spinal or nerve root canal.

stenosis = narrowing of the spinal canal = vertebral canal/spinal cavity.

This narrowing occurs for several reasons. In some cases, it is a congenital defect. It represents a group of acquired stenosis.

Classification of stenosis according to etiological (causal) classification:

• congenital - since birth, in 3 - 13 % affected by stenosis (narrowing), which can be:
  • idiopathic
  • achondroplastic
• acquired, represents approximately 75% of all cases of stenosis
  • degenerative, based on spondylosis, osteophyte formation - bony projections and spondyloarthropathy
  • in spondylolisthesis
  • rheumatism and excessive bone density
  • iatrogenic, caused by a medical procedure, for example during disc surgery
  • after an accident - post-traumatic
  • metabolic - Paget's disease
  • ankylosing spondyliti (Beckterev's disease)
  • tumour
• combination of congenital and acquired form, up to 12% of all stenoses

As mentioned, in most cases it is an acquired form. The degenerative process mainly affects the intervertebral cartilage, facet joints (small intervertebral joints), ligaments, especially in terms of hypertrophy of the yellow ligaments and other soft structures.

Furthermoree...

Alternatively, the already present spinal stenosis will worsen the whole situation. Faulty statics and dynamics of the spine also play an important role in the development of difficulties.

=

Reduced space for nerves and blood vessels
+ mechanical compression of nerve roots 
+ long-term inflammatory changes
+ impaired blood flow
- arterial (arterial oxygenated) blood supply
and outflow of venous (venous, deoxygenated with metabolic products) blood.

A constriction of the spinal canal can be found in any part of the spine. However, it is most often in the lumbar or in the cervical spinal segments. Likewise, it can affect multiple segments at once.

The forms are named after the affected segment.

Lumbar spinal stenosis - LSS. In this case, it occurs mainly at the level of L4 - L5 and L3 - L4 (90% of all cases).
It is more common after the age of 60.

The minimum size of the channel in the lumbar region is 11 millimeters.
Relative stenosis below 12 mm and absolute below 10 mm.
The height of the root hole is approximately 20 - 23 mm.
Approximate area is 40 - 160 mm². 
The nerve root fills approximately 30% of the hole.

Cervical spinal stenosis, and thus narrowing in the neck. This type is also risky for the development of so-called cervical myelopathy.

And this is damage to the spinal cord in the cervical spine. It is caused by the compression of the nerve and blood vessels and insufficient blood supply.

As a result, symptoms such as weakness of the motor functions (mobility) and impaired sensitivity in the upper limbs occur. At a later time, muscle atrophy and paresis - limb paralysis. Other severe neurological problems may occur in serious conditions.

The size of the neck can be, for example, from 18 mm incrementally to 15 mm - 12.5 mm.
Minimum cervical canal diameter 11 millimetres.

The initial symptoms, as might be expected, are painless. Pain may be experienced, but it is not so decisive for the diagnosis.

Lumbar Spinal Stenosis

1. The first manifestation is neurogenic claudication = limping.

This symptom is reported to be present in an average of 62% of those with stenosis.

In addition to neurogenic claudication, vascular claudication occurs in vascular disease and in cases of insufficiency of blood circulation.

This symptom is characteristic of the spinal part of the spine and is a condition...

After a certain period of walking in an upright position, there is pain, tingling or other unpleasant sensations - paraesthesia, weakness in the lower limb, which can be manifested by limping, from which the name is derived.

These difficulties force the person to stop and rest. After a while (a few minutes) he/she is able to walk again. There may be discomfort in the thighs, calves or legs and feet. The weakening of lower limbs may cause falls and an injury.

In addition, bending backwards is difficult and worsen existing symptoms. Walking downhill is uncomfortable and difficult.

However, they are typically alleviated when bending forward. Being in a supine or sitting position have similar effects.

Typical postures of affected persons:

• bending forward with slightly bent knees
• leaning on a shopping cart in order to relieve the pain.

The reason for either worsening or relief is spatial changes at a given location.
In retroflexion of the spine, i.e. when bending, there is an additional narrowing.
Conversely, when leaning to partially release the oppression.

Table: Difference between neurogenic and vascular claudication

2. These symptoms are accompanied by other difficulties such as:

• chronic pain, possibly recurrent, one that recurs
• Low back pain
• stiffness of the lower limbs
• lower limb weakness
• possible pain at rest, but it is usually exacerbated when walking and standing
• radicular symptoms - manifestations of nerve irritation
• sometimes sphincter symptoms and urinary disorder (problem with standing urination)
• erectile dysfunction, rarely unwanted erection when walking - severe damage in the central type
• reflex disorders
• skin sensitization disorder
• chronic cauda syndrome - multiple root damage
  • long-term pain with paresthesias
  • lower limb weakness
  • paresis - paralysis of muscles to various degrees
  • sphincter and erection disorders

A condition called Cauda equina syndrome can also be a serious consequence of the narrowing.

Cervical Spinal Stenosis

This type of damage is at the level of the cervical spine. The risk is spinal cord compression, which can be followed by a number of neurological problems. The severity depends on the location and extent of the damage.

Symptoms:

• weakness in the limbs
• motor disorder
• up to paresis (partial paralysis) or plegia (complete paralysis) of the upper limb
• tingling and other discomfort
• sensitivity disorders
• myelopathy, spinal cord injury
• paralysis of the body under the place of oppression - in complete stenosis, ie absolute
• breathing problem

Thoracic Spinal Stenosis

It occurs less often in this section.

The reason is better stability of the thoracic spine and limited mobility due to the ribs and the chest. However, other degenerative processes in this section also have a lower frequency.

There is pain in this area, radiating to the chest, the abdomen. They are accompanied by paresthesia - tingling or other unpleasant sensations, but also bladder, defecation or sexual function disorders.

In the event of severe injury, paralysis may occur below the affected area.

The diagnosis usesthe patient's medical history, evaluates the clinical picture using a questionnaire, and classifies the difficulties. Neurological examination is important when a specialist examines the spine, posture, gait, reflexes in order to detect nerve root irritation - radiculopathy.

Imaging methods used:

• X-ray
• CT
• MRI - magnetic resonance
• EMG - electromyography
• PMG - contrastive perimyelography

Differential diagnosis is important to reveal another cause of the problem. Examples are pseudoradicular syndrome, low back pain, sciatica, disc herniation, vascular type claudication, psychiatric disorder, arthrosis in other places (hip - coxarthrosis, knee gonarthrosis), polyneuropathy, tumour and others.

Learn more:
Gonarthrosis
Coxarthrosis

The course of the disease is hidden from the long-term degenerative process until about the age of 50. However, this does not rule out the occurrence of difficulties in younger people.

Changes due to the aging of the body begin at the age of 20 to 30 as osteochondrosis or spondylosis.

How this type of disease manifests depends on several factors. This is the overall nature, degree of development, extent, site of narrowing and other risk effects, such as congenital stenosis, which has not been detected before.

There may be pain, tingling and other discomfort in the spine radiating towards the limbs. The lumbar type is characterized by neurogenic claudication (described in the section on symptoms).

Pain does might not always be a significant symptom, but limping and the need to stop walking are.

Rest alleviates pain, but so do bending forward, sitting or lying.

The pain may be generally mild at first, and exacerbated by the progression of the stenosis. In that case, there may be an unpleasant burning sensation that spreads to the upper limb, chest or lower limb.

Radiculopathy refers to nerve compression when it is associated with a sensitivity disorder or muscle weakness in a given dermatome. The dermatoma is the innervation area of the damaged nerve.

Absolute stenosis of the spinal cord or nerve is a serious condition in any part of the spine. In that case, it means a sudden deterioration of health and serious neurological problems, from loss of sensitivity to paralysis of a body part under damage.

The course of the disease is individual and depends on several factors.
The development of difficulties cannot be expected.
Neither improvement nor deterioration can ruled out.
In severe cases, the disease can lead to disability.