Spinal stenosis

The spinal cord is a bundle of nerves that connects the central nervous system with the rest of the body. Its main purpose is to carry nerve signals throughout your body. These nerve signals control your body's movement (motor) and involuntary (autonomic) functions such as bowel and bladder control. They also send sense signals to the brain from the rest of the body.

The spinal cord is housed in the spinal canal, which is a protective tunnel running inside the spinal column – the stack of vertebrae that runs from the base of your skull to your pelvis.

Usually, there is enough room for the spinal cord and nerve roots to sit comfortably and function normally. However, various conditions can cause the spinal canal to become narrow and put pressure on the spinal cord. In some cases, this narrowing can compress and damage the spinal cord, interfering with the nerves and causing pain.

What causes spinal stenosis?

There are many conditions that can cause spinal stenosis. They can be split into two general groups: acquired and congenital causes.

An acquired cause is one that results in you developing spinal stenosis after birth, whereas a congenital cause is one that's present from birth, usually because of issues with the spine during foetal development or genetic conditions that affect bone growth.

Most people with spinal stenosis acquire it in later life, typically around 50 years old. Usually, this is a result of degenerative changes that occur in the spine as a natural part of ageing. Acquired causes of spinal stenosis include the following conditions:

• Thickened ligaments: Over time, arthritis can cause the bands (ligaments) that hold your spine together to thicken and bulge into your spinal canal. Together with facet arthropathy, which is joint inflammation and pain caused by them rubbing together roughly, this can lead to spinal stenosis.   
• Bulging discs: Vertebral discs are flat, round pads of gel that act as shock absorbers between each vertebra. Age can cause these discs to dry out and flatten, leading to cracks in the outer edge that the gel breaks through. This then presses on the nerves in the spinal canal near the edge of the disc.
• Spinal fractures and injuries: Broken bones in the vertebrae or near the spinal column can narrow the space in the spinal canal, as can injuries to the discs themselves
• Spinal cysts or tumours: Growths within the spinal canal or between the spinal canal and vertebrae can reduce space in the spinal canal.

What are the symptoms of spinal stenosis?

Spinal stenosis in the early stages may have no symptoms. In most cases, they gradually develop over time. In general, symptoms could include:

• Pain
• Numbness
• Tingling
• Weakness

The symptoms of spinal stenosis you experience depend on the severity of the condition and the section of the spine it's located in.

Symptoms of lumbar spinal stenosis

Common symptoms of lumbar spinal stenosis could include:

• Pain in the lower back
• Pain that begins in the buttocks and radiates down the leg and foot (sciatica)
• Pain that worsens when standing for long periods, walking or walking downhill
• Pain that lessens when leaning forward, sitting or walking uphill
• Numbness, tingling, cramping or weakness in the buttocks, leg or foot
• A feeling of heaviness, weakness or clumsiness in the legs
• A weakness in the foot that causes it to slap the ground when walking, called foot drop
• Loss of sexual ability

Pressure on nerves in the lumbar region can also cause cauda equina syndrome, the symptoms of which include:

• Loss of bowel control
• Severe numbness between the legs, inner thighs and back of the legs
• Numbness or tingling around the genital region and anus
• Severe pain and weakness that spreads into one or both legs, making it difficult to walk, stand or get up out of chairs

You should seek medical attention immediately if you experience any of the symptoms of cauda equina syndrome.

Symptoms of cervical spinal stenosis

Common symptoms of cervical spinal stenosis include:

• Neck pain
• Numbness or tingling in the arm, hand, leg or foot
• Weakness or clumsiness in the arm, hand, leg or foot
• Decreased hand function, including difficulty writing with a steady hand or fastening buttons
• Balance problems

Symptoms of thoracic spinal stenosis

Common symptoms of thoracic spinal stenosis include:

• Limited ability to rotate the torso
• Difficulty moving side to side
• Sharp pain in the mid-back that radiates to the lower back and the legs
• Pain in the ribs or internal organs
• Difficulty walking
• Balance problems
• Bowel or bladder dysfunction

Potential treatment options for spinal stenosis

The best treatment option for you depends on the cause of your spinal stenosis, where it's located and the severity of your symptoms.

Treatment will start with lifestyle changes and non-surgical treatments – and in mild cases this can be sufficient to manage your symptoms. Your consultant may recommend surgery as a last resort, though, if these options aren't effective or in an emergency such as you developing cauda equina syndrome.

Non-surgical treatments for spinal stenosis

Your consultant will recommend non-surgical treatments to help you manage the symptoms of spinal stenosis. These typically include:

• Oral medications: Nonsteroidal anti-inflammatory drugs such as ibuprofen can help reduce inflammation associated with spinal stenosis and provide pain relief. Your consultant may also prescribe other medications for their pain-relieving properties or to help manage other symptoms you're experiencing such as muscle cramps.
• Physical therapy: A physiotherapist will work with you to develop an exercise programme to help you manage your symptoms and make your spine more resilient. Performing routine exercises can strengthen the muscles surrounding the spine, which may lead to improvements in mobility and core stability. Physical therapy can also help correct the forward-leaning posture which many people with spinal stenosis adopt to alleviate pressure on their nerves.
• Spinal injections: Some patients with spinal-stenosis-associated arm or leg pain may benefit from steroid or epidural injections directly into the inflamed area of the spinal canal. Steroid is a potent anti-inflammatory agent that can help relieve pressure on the spinal cord and nerves but the response to this treatment is variable. These injections are typically done under CT guidance with local anaesthetic or under sedation using image intensifiers in theatre.

Spinal stenosis surgery

Most people who have spinal stenosis don't need surgery. If non-surgical treatments fail to relieve your symptoms, though, then surgery could be the most effective treatment.

Spinal stenosis is a complex condition and the spinal cord and nerves are extremely delicate. Because of this, there are several types of surgery your consultant could recommend. These include:

• Laminectomy: Also known as decompression surgery, this procedure involves removing a portion of the vertebra called the lamina, which is the part of the vertebral arch that forms the backing of the spinal canal. This opens up the spinal canal, making more room for the spinal cord and nerve roots. This operation is commonly used to treat spinal stenosis in the lumbar spine but, in certain cases, it may also be needed to treat stenosis in the cervical or thoracic spine.
• Laminotomy: Surgery to remove a partial area of the lamina causing the most pressure on the spinal cord and nerves. Depending on the severity of your condition, a laminotomy could help create space in the spinal canal and relieve pressure on the nerves.
• Laminoplasty: Instead of wholly or partially removing the lamina, it can be moved into a more open position and fixed in place with a small metal plate and screws. This allows for greater strength and stability of the spine following the operation. This surgery is typically used to treat spinal stenosis in the cervical spine.
• Foraminotomy: This surgery involves removing bone or tissue around the foramen, which is the area in your vertebrae where the nerve roots exit the spinal canal to connect with the other parts of the body. There's normally enough room for the nerves to pass through the foramen but they can become narrow with spinal stenosis. A foraminotomy creates enough space for the nerves to pass through.
• Interspinous process spacer placement: This procedure involves the insertion of small devices called spacers between the spinous processes. The spinous process is the part of each vertebra that sticks out and forms a small bump along the back of the spine. Creating space between each spinous process can help open up the spinal canal and relieve the nerves from compression. This is a minimally invasive operation suitable for some people with lumbar spinal stenosis.
• Spinal fusion: Spinal fusion permanently joins together two vertebrae so that they heal as a single bone. The surgeon places bone or a bonelike material in the space between two vertebrae before inserting metal plates, screws or rods to hold them together. Your consultant will typically only recommend this surgery as a last option, to treat spinal stenosis if your spine is unstable, you suffer from severe radiating nerve pain, and other treatments haven't been effective.

Your consultant will suggest the treatment they think will be the most effective, depending on the specifics of your condition. They'll explain what the procedure involves in detail and any risks before you decide to go ahead.