A type of spinal stenosis, neural foraminal stenosis, does not always cause symptoms. But if a nerve gets compressed in the gap, this will be painful.
Over-the-counter pain relief, such as non-steroid anti-inflammatory drugs (NSAIDs), may help, and doctors can prescribe medication that can modify nerve pain.
Contents of this article:
- Nerve cells are part of the nervous system, and they carry messages to the brain from all over the body.
- If a spinal nerve gets compressed, a pain signal is sent to the brain.
- Symptoms can include pain that may depend on where in the spine the nerve has been compressed.
- Treatment includes spinal injection of steroids or local anesthetic in long-term cases.
What is neural foraminal stenosis?
Nerves run through the vertebrae of the spine, up towards the brain. Neural foraminal stenosis is when these nerves get trapped in the spine.
Nerves run from all parts of the body to the spinal canal. The nerve roots pass through gaps in the vertebrae, called foramen and continue up the spinal cord to the brain.
The nervous system responds to information from the senses and triggers reactions.
For example, when a person feels pain, the nerves send information that makes the muscles move away from the source of pain, while at the same time informing the brain that there is pain.
Each nerve or neuron has a cell body and several extensions, called dendrites and an axon. The dendrites receive signals, which travel along the axon, which can be up to a meter long. All the signals reach the brain via the network of spinal neurons.
Neural foraminal stenosis occurs when the foramen of the neck (cervical stenosis), the upper part of the back (thoracic stenosis), or the lower back (lumbar stenosis), compress or narrow, trapping the nerve root.
Not everyone with neural foraminal stenosis will develop symptoms. If a nerve gets trapped, however, the symptoms tend only to affect one side of the body and can include:
- pain in the back or neck
- muscle weakness
- numbness or weakness in the arm, hand, or leg
- burning sensations
- problems walking
- issues with balance
If the nerve root becomes compressed on both sides, both sides of the body will likely be affected. This is called bilateral foraminal stenosis.
What causes it?
Neural foraminal stenosis may be caused by a range of conditions.
The risk of neural foraminal stenosis, which can be caused by general wear and tear, increases with age.
The most common cause of neural foraminal stenosis is a degenerative spine.
This expands into the foraminal canal, narrowing the spaces and openings where nerves leave between the vertebrae.
A degenerative disk is where a vertebral disc degenerates and slips out of place putting pressure on the exiting nerve. It is most common in the lumbar spine, but can also happen in the thoracic or the cervical spine.
Also known as a slipped or prolapsed disk, a herniated disk means one of the discs of cartilage that sits between the vertebrae is damaged.
Spondylolisthesis is where one vertebra slides in front or back of the vertebra below it. It commonly occurs in the lumbar spine but can occur elsewhere in the spine. This can cause narrowing of the exiting nerve in the foramen.
Rheumatoid arthritis and osteoarthritis
Arthritis develops when cartilage breaks down, and this can also happen to the discs of cartilage that sit between the vertebrae
This is a bone spur growth in the back quite common in those aged over 60 and usually caused by osteoarthritis.
Repetitive trauma to the spine damages the vertebrae and cause it to slip. This is more common in athletes such as gymnasts and weightlifters. A sudden injury can also make a disc slip.
How is it treated?
Treatment varies depending on the severity of the condition.
Usually, cycling is easier than walking for those with spinal stenosis. Cycling on a static bike for a couple of minutes a day is recommended, as a way to begin improving spinal mobility.
The British Association of Spinal Surgeons recommend improving spinal mobility and overall strength and fitness as a first step, adding that weight loss may help if applicable.
The organization add that cycling is often less painful than walking for people with spinal stenosis and suggest riding a static bike, starting with 2 to 3 minutes twice a day and building up from there.
It also suggests a person walks until they reach their pain threshold, resting, then walking a little further.
If exercise does not improve the symptoms, a doctor may recommend an epidural, which is an injection into the spinal canal. Epidurals tend to be more successful in easing leg pain than back, pain.
Studies show about 60 percent of people respond well to this kind of treatment.
If a person still experiences unbearable pain, a doctor may consider surgery. The doctor will have to take certain factors into account: These factors include:
- the person's general state of health, and whether they have any other conditions or health problems
- their general fitness
- whether the problem is in one or multiple areas of the spine
The surgical options include:
- Interspinous distraction device: This procedure involves implanting a device in the space between the vertebrae to widen the gap and relieve pressure on the nerves.
- Foraminotomy: A surgeon removes the bone that is causing the compression to give the nerves more room.
Everyone responds differently to treatment. But as a general rule of thumb, 20 percent of people will improve with time while 20 percent will worsen. The remainder will stay around the same.