Nerve compression (entrapment neuropathy) takes place when pressure is put on to a nerve in the body. This condition is sometimes called a trapped nerve, which can happen to the nerves in any part of the body. A compressed nerve is often very painful and there could also be muscle weakness, numbness and tingling.
The symptoms associated with sural nerve compression:
Causes Sural Nerve Compression
Many different incidents or situations can cause sural nerve compression, which will need medical treatment. Injury, trauma and surgery can all lead to sural nerve compression. Some causes of sural nerve compression, however, can be avoided by making simple changes, e.g. avoiding hazardous activities or sitting correctly with legs uncrossed.
One of the main causes of sural nerve compression is injury to the lower leg or ankle. Injuries such as fractures, sprains and muscle tears, often result in a swelling of the lower leg. This inflammation is the body’s way of protecting the injury, but it can compress the sural nerve at the same time.
Blunt trauma to the back of the calf, ankle or outside of the foot can also lead to sural nerve compression. These areas of the body are not designed to take heavy impacts and can become damaged. Protective footwear and calf sleeves are a useful way to help protect the nerves in these areas and avoid nerve compression.
Sitting in one position for long periods of time can cause sural nerve compression. The nerve is particularly prone to compression if you sit with your legs crossed for more than a few minutes. When one leg is on top of the other, the pressure on the supported calf can lead to compression. The pressure on the nerve can also weaken it, thus making it even more prone to compression than a healthy nerve.
Fascial thickening can also entrap the sural nerve and cause compression. When the fascia (soft tissue) in the foot thickens, it can trap nerves which will lead to complications. Medical studies have concluded that fascial thickening can cause sural nerve compression.
The sural nerve commonly becomes damaged during Achilles surgery and it can also become compressed following the operation. Due to the fact that the sural nerve is so close to the Achilles tendon, this is a complication that often occurs during the healing process. In some cases, the compression cannot be avoided in order to treat the original problem.
If surgery is carried out on the lower leg, ankle or foot, it may lead to sural nerve compression. The actual surgery will not damage the nerve, but the scar tissue that remains can cause post-operative issues.
Scar tissue forms to replace normal skin following an injury or surgery, which of course, is an essential part of the healing process. If scar tissue is causing sural nerve compression, it needs to be broken up to release the compressed sural nerve.
Tumors And Cysts
Tumors can also put pressure on a nerve which will then cause pain and discomfort. The majority of tumors are benign (non-cancerous) but they still cause problems and need attention. Most tumors are removed unless the operation is expected to damage other healthy tissue in the area.
Cysts can appear anywhere on the body and when they are growing in the lower leg or foot, complications can develop. Even though most cysts are harmless, they can put direct pressure on the sural nerve. If the cyst in not removed, it will continue to grow, and more pressure will be put on the nerve.
Leg Casts And Braces
When a leg is broken or fractured, it is almost always placed in a cast until the bones have had the time to knit together and can once again bear weight. Casts are very rigid, so the bones stay in place. However, this also leads to compression of the sural nerve. The nerve may also become compressed if the cast is too tight or ill-fitting.
Surgical braces are sometimes fitted to patients when they are recovering from fractures or other injuries. If the leg or ankle brace is too tight it can lead to sural nerve compression. The brace needs to be supportive but not so tight that it puts excess pressure on the leg or ankle. Fortunately, most leg braces are adjustable, and problems caused by tight braces can be avoided.
Badly Fitting Footwear
If you wear shoes or boots that are too tight, this will put unnecessary pressure on all parts of your foot and ankle. This will press on to the nerve and cause sural nerve compression. This situation can be avoided if you have your feet measured by a professional and only wear correctly sized footwear.
People who suffer from diabetes can be impaired by compressed sural nerves, because the nerve is not receiving an adequate supply of blood. High blood sugar can damage the nerves and weaken the walls of tiny blood vessels. When the sural nerve does not receive enough blood, it is more sensitive to pressure.
A nerve that is sensitive to pressure is more likely to become entrapped. Even small amounts of pressure can damage the sural nerve in people who have diabetes.
How Is Sural Nerve Compression Diagnosed?
If you are experiencing pain or discomfort in your calf, ankle or feet, a doctor will need to examine you. Doctors will usually carry out a Tinel’s test, which can detect sural nerve compression. The test involves percussion (light tapping) at the site of the pain. If the sural nerve is compressed, this will cause a sensation of tingling or ‘pins and needles’ in the affected area.
If the doctor suspects that the sural nerve is compressed, you will be referred for ultrasound imaging tests. The imaging tests will locate the problem and an appropriate course of treatment will be offered.
Imaging tests are the best way to locate the source of the problem because the sural nerve is so small. MRI and ultrasound scans are an effective way to look at small capillaries and nerves in the body.
What Does The Sural Nerve Do?
The sural nerve is a small sensory nerve; it has no motor function. The sural nerve is often harvested and used when nerve grafts are required to repair other nerves in the body.
The sural nerve innervates the back of the calf and the outside of the ankle. This nerve also provides sensation to the outside of the foot and the two outside toes. The sural nerve transmits sensory signals from these areas of the body to the brain.
Where Is The Sural Nerve?
The sciatic nerve divides into the tibial and fibular nerves and the sural nerves branches off these. The nerve is located in the calf and it runs from midway up the leg.
The nerve passes down the calf, through the ankle and Achilles tendon. The sural nerve then branches out through the foot running mainly at the sides. The nerve finishes at the 5th toe on both feet.
Are There Any Treatments For Sural Nerve Compression?
There are various treatments for sural nerve compression and a doctor will recommend a suitable option. When the doctor has diagnosed a compressed sural nerve, the treatment will depend on the diagnosis. Non-surgical treatments may be the best course of action to begin with.
Direct massage to the painful area is one way to break up scar tissue that can compress the nerve. Physiotherapy is also used to relax muscles and reduce scar tissue. Gentle stretching can also sometimes free a nerve that has been compressed by scar tissue.
In addition, anti-inflammatory drugs and corticosteroid injections can help to break up scar tissue. Corticosteroid injections will also help to relieve pain and reduce any inflammation and swelling in the affected area. If the scar tissue cannot be broken up, then other options will be discussed with the patient.
Surgery is another alternative and a surgeon is able to free the sural nerve to relieve the symptoms. When the compressed nerve is free it can be wrapped in collagen which will protect it from future compression. A further option is to remove the sural nerve. However, this is not recommended in most cases as the procedure will result in permanent numbness of the area.
Aside from an injury, illness or disease, most people will not suffer from sural nerve compression. Any accidental or surgical damage that causes nerve compression will require medical treatment. If you suspect you have sural nerve compression, this can be diagnosed and successfully treated by a qualified doctor.