What Is Spinal Canal Stenosis? (Lumbar Spinal Stenosis)

Spinal canal stenosis, medically known as lumbar spinal stenosis (LSS), refers to the narrowing of the spinal canal due to either congenital (present at birth) or acquired (degenerative) causes. This narrowing compresses the spinal cord, nerve roots, and the blood vessels that nourish these structures.

Compression may directly affect the nerves or indirectly impair them by disrupting blood circulation—particularly during physical activity, when the demand for blood flow increases but the narrowed canal cannot accommodate it. As a result, neurological symptoms may arise.

Where Does Spinal Stenosis Occur?

Spinal stenosis may involve one or more of the following regions:

• Central canal (the main spinal canal)
• Lateral recess (sides of the spinal canal)
• Foramen (openings through which nerve roots exit the spine)

In foraminal stenosis, only the nerve roots are compressed, resulting in distinct symptoms.

What Are the Symptoms of Spinal Canal Stenosis?

In the early stages, spinal stenosis may not cause symptoms. However, as the narrowing progresses and pressure increases, the following symptoms may develop:

• Low back and leg pain
• Pain that worsens with standing or walking
• Relief when bending forward or sitting
• Muscle weakness
• Numbness or tingling
• Leg fatigue or heaviness
• Loss of balance
• In severe cases: incontinence (loss of bladder or bowel control)

Symptoms can vary between patients and typically worsen with movement and improve with rest.

What Causes Spinal Canal Stenosis?

The most common causes of lumbar canal stenosis include:

• Age-related degenerative changes
• Disc degeneration and bulging
• Arthritic overgrowth of facet joints
• Thickening of spinal ligaments
• Lumbar disc herniation
• Spondylolisthesis (vertebral slippage)

These structural changes can gradually reduce the space in the spinal canal and compress nearby nerve tissue. The process may develop slowly with aging or be accelerated by trauma.

How Does Spinal Narrowing Develop?

• Dehydrated, shrinking discs lose height
• Spinal ligaments lose elasticity and may thicken
• Bone spurs and overgrowth of joints press inward
• These changes narrow the canal and cause nerve compression

If combined with disc herniation or vertebral slippage, symptoms may worsen significantly.

How Do Symptoms Present in Spinal Stenosis?

In some patients, symptoms may not be evident during initial examination—especially if the patient is at rest. For this reason, physicians often perform a second exam after walking or standing to provoke symptoms.

• Spinal extension (leaning back) typically worsens pain
• Flexion (bending forward) usually relieves discomfort
• Patients often report relief when squatting or sitting down

These findings are characteristic of spinal stenosis.

Stenosis vs. Disc Herniation or Spondylolisthesis

The severity of symptoms is closely related to canal width:

• A disc herniation or slippage may not cause symptoms in individuals with a normal-width canal
• The same condition may lead to severe symptoms in those with a narrowed canal

This is due to reduced space for nerves and loss of protective cerebrospinal fluid (CSF) around them. Narrow canals result in earlier and more intense symptoms.

How Is Spinal Stenosis Diagnosed?

Diagnosis typically includes:

Clinical Evaluation:

• Patient history
• Neurological examination
• Assessment of symptoms that change with movement

Imaging Tests:

• MRI (Magnetic Resonance Imaging)
• CT Scan (Computed Tomography)
• X-ray

These tests evaluate the spinal canal, nerve roots, discs, joints, and CSF spaces in detail.

Conditions That May Be Confused with Spinal Stenosis

Symptoms of lumbar spinal stenosis can mimic vascular conditions, such as peripheral artery disease. For this reason:

• Leg pulses should be examined
• Cardiovascular evaluation may be necessary

Differential diagnosis is crucial for accurate treatment planning.

Conclusion: Early Diagnosis Is Essential

Lumbar spinal stenosis is a progressive condition that may lead to significant pain, limited mobility, and reduced quality of life, especially in older adults. However, when detected early and managed appropriately, it can often be treated successfully with non-surgical or surgical methods.

???? If you are experiencing symptoms like lower back pain, leg numbness, or difficulty walking, consult a neurosurgeon or spine specialist for an accurate diagnosis and personalized treatment plan.