What is the sural nerve?
Your sural nerve is below your skin’s surface in the back of your lower leg (calf). It’s part of your peripheral nervous system, which helps your brain communicate with the rest of your body.
What type of nerve is the sural nerve?
Your sural nerve is a sensory nerve that enables you to detect:
- Foot position.
What is the function of the sural nerve?
Your sural nerve provides skin sensation to the:
- Back of your leg, below your knee.
- Outer side of your foot.
- Outer heel.
How else does the sural nerve contribute to my well-being?
Your sural nerve allows you to feel sensation and contributes to maintaining balance while on your feet. It can also serve as donor tissue to diagnose and repair other nerve disorders. These include:
A biopsy is a tissue sample that healthcare providers examine in a lab for signs of nerve disease. Your sural nerve is used because it lies close to your skin’s surface and is easy to find. It also heals well after surgery, with few — if any — complications.
You may need a sural nerve biopsy if you’re are showing signs of:
- AL (light chain) amyloidosis: Abnormal blood proteins that affect other body systems, like your nerves.
- Vasculitis: Inflammation in your blood vessels.
- Any peripheral nerve disorder that’s difficult to diagnose.
A nerve graft uses healthy tissue to repair or replace damaged nerves. Healthcare providers use your sural nerve because it provides a long tissue sample.
A sural nerve graft can be attached elsewhere within your body to relieve:
- Brachial plexus injuries, which affect your shoulder, arm or hand.
- Sciatic or peroneal nerve injuries, which affect your leg, ankle or foot.
- Erectile dysfunction, which is the inability of a penis to achieve or maintain an erection.
- Facial paralysis, which is nerve damage that may cause one side of your face to sag.
- Neurotrophic keratitis, which is a rare disease affecting nerves in your eye.
What does the sural nerve look like?
Your sural nerve starts in areas of your upper calf where two nerves join. It travels down the back outer part of your leg, curves at your ankle and ends before your toes.
The two nerves that contribute to the formation of your sural nerve are your:
- Tibial nerve, which enables sensation and movement in the back of your leg and foot.
- Common fibular nerve (common peroneal nerve), which provides sensory and movement capabilities to the area behind your knee and nearby leg tissue.
What is the sural nerve made of?
Your sural nerve contains tiny, string-like fibers (axons). A fatty substance, myelin, binds them together into nerve bundles. These bundles travel up your body to connect to your spinal cord. This network of nerve tissue makes it possible for nerve signals to travel quickly to and from your brain.
Conditions and Disorders
What conditions affect the sural nerve?
Conditions affecting this nerve include:
- Diabetes-related neuropathy: Nerve damage that occurs as a result of ongoing high blood sugar. Your sural nerve is one of the most commonly affected nerves by this condition.
- Sural nerve entrapment (pinched nerve): This condition occurs when nearby tissue thickens and presses on your nerve. Entrapment causes sural nerve pain.
- Sports injuries: Ankle sprains, which are a common sports injury, force your joint out of its natural position. Sprains can damage your sural nerve. Injury can also occur when ski boots or horse saddle ankle straps are too tight.
- Surgical complications: Surgical instruments sometimes injure your sural nerve. Complications also happen when hardware, like screws to repair a bad break, rub against your nerve.
How can I prevent sural nerve pain and injury?
Steps you can take to care for your sural nerve include:
- Keeping blood sugars within a healthy range if you have diabetes.
- Selecting athletic footwear that fits well and replacing it once it wears out.
- Quitting smoking or using other tobacco products.
- Eating a healthy diet with foods containing vitamin D and vitamin B12, which supports nerve health.
When should I call a healthcare provider about problems with my sural nerve?
You should call your healthcare provider if you experience discomfort in your lower leg or the top outside of your foot.
Symptoms may include:
- Lack of sensation.
- Sensitivity to touch.
- Sharp or throbbing pain.
- Tingling or numbness.
A note from Cleveland Clinic
Your sural nerve is part of your peripheral nervous system. It provides sensation to your lower leg and parts of your foot. Many health conditions can affect your nerve, including diabetes and sports injuries. Your sural nerve’s length and ability to regenerate make it ideal for a sural nerve biopsy or graft. If you experience sural nerve pain, it’s important to see your healthcare provider.
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