What Is Lateral Recess Stenosis?

Lateral recess stenosis (LRS) is the narrowing of the space within the spinal canal that is located toward the sides. Called the lateral recess, or Lee's entrance, this passageway for nerves is close to the spinal nerve root.

As this type of spinal stenosis worsens, the nerve structures in the lateral recess have less and less clear space around them. Nerves may come in contact with bone, putting pressure on disc material or other tissue, which can cause pain and other symptoms.

Read on to learn more about this area of the spine, how it is affected by lateral recess stenosis, what causes it, and how the condition is diagnosed and treated.

Lateral Recess Stenosis Causes

Lateral recess spinal stenosis is also known as foraminal stenosis. That's because the condition occurs when one or more of the intervertebral foramen narrows and compresses or pinches the nerve roots within it.

Age-related changes in bones, facet joints, and/or ligaments might cause the affected spinal structures to in some way occupy and therefore narrow space called the lateral recess, as well as the other passageways made by interconnecting spinal bones.

And due to their proximity, these imposing (and generally abnormal) tissues may “bump into” the nearby spinal nerve root and/or the spinal cord that normally passes through the lateral recess structure in your spine unimpeded.

This is called encroachment or impingement. When encroachment occurs, it may cause pronounced pain and other symptoms.

Symptoms of Lateral Recess Stenosis

Lateral recess spinal stenosis symptoms may include:

• Radiating lower back pain
• Claudication (cramping that occurs when you walk)
• Weakness and numbness and/or electrical sensations that go down one leg or arm

In some cases, more serious symptoms that disrupt bowel or bladder may occur, as well.

Because the lateral recess is part of the spinal canal, when stenosis develops there, it is categorized as central canal stenosis. In this case, myelopathy symptoms may ensue. Myelopathy symptoms result from irritation or compression of the spinal cord.

As an example, the development of lateral recess stenosis may occur when age-related changes in the ligamentum flavum occur. Such changes may include thickening, loss of strength, and loss of elasticity to the point where a buckling toward the inside of the spinal canal occurs.

A thickened ligamentum flavum creates a narrower spinal canal—the hallmark sign of central canal stenosis. If the buckling impinges on the spinal cord, it may cause myelopathy symptoms.

 Diagnosis of Lateral Recess Stenosis

Diagnosis for lateral spinal stenosis begins with a physical examination, in which your healthcare provider will test your reflexes and look for signs of pain, weakness, and loss of sensation.

Should your provider suspect a spinal abnormality, they may order an X-ray of your spine. The X-ray will show if there are bone growths (spurs) that are pushing on your spinal canal or causing it to narrow.

To help your provider confirm their diagnosis, they will likely order magnetic resonance imaging (MRI), or a computed tomography scan (CT scan). These imaging tests will give them a more detailed look at your spinal canal and nerves.

The combination of a physical exam and imaging tests is often sufficient to make a diagnosis. Sometimes, a healthcare provider will order other studies to confirm their diagnosis, including:

• Myelogram, in which you will be injected with a dye that makes your spinal structures stand out better during a CT scan
• Bone scan, to check for fractures, arthritis, tumors, and infections
• Electromyography (EMG), in which electrode stickers are attached to your skin to measure the speed and strength of your spinal nerve signals

 Treatment for Lateral Recess Stenosis

There is no cure for lateral recess spinal stenosis, nor can the condition be slowed. However, there are lateral stenosis recess treatments and therapies that can help relieve symptoms.

The goals of treatment include:

• Easing pain and inflammation
• Maintaining and improving mobility and flexibility
• Relieving pressure off of the spinal nerves

In some cases, a person with spinal stenosis will have no symptoms, in which case their healthcare provider may take a watch-and-wait approach to their care by monitoring their condition and making routine follow-up appointments.

A provider also may recommend lifestyle changes, such as nutrition and stress management education.

Medications

For people who do present with pain, healthcare providers can prescribe medications, including:

• Pain relievers, such as prescription strength Advil or Motrin (ibuprofen), Aleve (naproxen), and Tylenol (acetaminophen)
• Tricyclic antidepressants, such as amitriptyline, which can help ease chronic pain by calming nerve signals that trigger pain
• Anti-seizure drugs, such as Neurontin (gabapentin), and Lyrica (pregabalin), which reduce pain caused by damaged nerves
• Opioids, such as Oxycontin (oxycodone) and Vicodin (hydrocodone) for short-term pain relief. Your healthcare provider may not prescribe them for long-term pain, however, as they can be habit-forming.

Steroid Injections

Corticosteroid injections will not fix the spinal stenosis but can be given to ease pain and inflammation. The steroid medication may be injected into the neck, mid-back, or lower back/buttocks, depending on where the pain is centered.

Often, steroid injections may be used with other interventions as part of an overall treatment plan.

Physical Therapy

In an effort to avoid pain, some people with lateral recess avoid physical activity. Doing so does not actually help with symptoms, though, as the lack of activity only tends to increase weakness, and subsequently, pain.

Physical therapy is therefore recommended for any person with lateral recess spinal stenosis, regardless of the severity of their symptoms. Your physical therapist will work with you to maintain and improve strength and mobility in a safe way with lateral stenosis recess exercises and stretches.

For example, you may learn how to modify exercises done in a standing position, which can increase pressure on your compressed spinal nerve(s). Instead, your physical therapist will show you how to stretch while lying down.

Physical therapy will also help you improve your balance to protect you from falling and improve the stability of your spine.

Surgery

Finally, if non-surgical treatments are not effective enough to relieve pain or if you are disabled by your symptoms, your healthcare provider may recommend a surgical procedure to relieve pressure on your spinal cord and nerves.

The main surgical option for foraminal stenosis is foraminotomy: The area around the affected bone in your spinal column is enlarged to make space for the compressed nerves and take pressure off of them.

For this procedure, a surgeon will make an incision in your back or neck to expose the affected vertebrae. They will then widen the intravertebral foramen and remove any blockages that are compressing nerves.

Summary

Lateral recess spinal stenosis, also called foraminal stenosis, can cause lower back pain, weakness in the arm or leg on one side of the body, and in some cases, more serious symptoms involving bladder or bowel control. It occurs when changes in the spinal structure have impacts on nerves that run through the narrow passages of the lateral recess portion of the spinal canal.

In most cases, a physical exam along with imaging can support a diagnosis. Depending on the severity, your healthcare provider may take a wait-and-see approach or recommend over-the-counter pain relievers. Prescription drugs, steroid injections, physical therapy, and surgery may be necessary.