Published on Oct 30, 2019 - 5 min read
Any damage to the peripheral nerves, that is the nerves that carry signals from the brain to rest of the body, is called peripheral neuropathy. Learn about its causes, symptoms, diagnosis, and treatment.
The peripheral nervous system carries information from the brain and spinal cord to the rest of the body, and also send sensory information to the central nervous system. The nerves that make up the peripheral nervous system are called peripheral nerves. Damage to these peripheral nerves resulting in weakness, numbness, and pain, is called peripheral neuropathy. It commonly affects the nerves in hands and feet, but can also affect internal organs, mouth, and face.
Diabetes is the primary cause of this condition. Trauma, infections, genetics, metabolic problems, and toxins can all result in peripheral neuropathy. It causes stabbing, burning or tingling pain in the extremities. Medications and treating the underlying condition helps improve symptoms in most cases.
There are more than 100 different kinds of peripheral neuropathies. This condition usually affects people over 55 years of age. Depending on the type and number of nerves they affect, peripheral neuropathy can be divided into:
1) Mononeuropathy - When a single peripheral nerve is damaged, it is called mononeuropathy. Injury or trauma is the most common cause. It can also result from prolonged pressure on a nerve and repetitive motions. The common examples include:
Carpal tunnel syndrome - It occurs when the nerve in the wrist is compressed due to overuse strain injury. It is mostly seen in people who use computer keyboards for a long time every day and physical labors. It results in numbness, tingling, and pain in the first three fingers from the thumb.
Ulnar nerve palsy - It occurs when the nerve present in the elbow is damaged. It causes pain and numbness in the 4th and 5th digit of the hand.
Radial nerve palsy - When the humerus bone in the upper arm fractures, it damages the nerve that is present on the underside of the upper arm, resulting in radial nerve palsy.
Peroneal nerve palsy - It results from damage or compression of the nerve present in the calf.
2) Polyneuropathy - Polyneuropathy is when multiple peripheral nerves are damaged at the same time throughout the body. Most cases of peripheral neuropathy are of this type. It can result from exposure to toxins, alcohol abuse, malnutrition, and conditions like kidney disease and cancer. The common examples are:
Diabetic neuropathy - It is the type of nerve damage seen in diabetic patients. It commonly affects patients with uncontrolled blood sugar levels. The symptoms include loss of sensation, tingling, and burning sensation in the limbs.
Guillain-Barre syndrome - It is a severe and rare condition where the body's immune system attacks nerves in the body. The symptoms appear suddenly and progress rapidly. It can cause weakness and tingling sensation in the arms, blood pressure and heart rhythm problems.
The symptoms vary depending on the type of peripheral nerve damaged. The types of nerves are:
Sensory nerves - These nerves receive sensations from the skin like pain, vibration, touch, and hot or cold temperatures.
Motor nerves - These nerves control the movements of the muscles.
Autonomic nerves - Such nerves are in charge of functions like heart rate, digestion, and blood pressure.
Peripheral neuropathy can affect any of the above nerves and can result in the following signs and symptoms:
Numbness, prickling or tingling in hands and feet, which spreads gradually.
Sharp and throbbing kind of pain.
Some people have burning sensations.
Increased sensitivity to touch.
Pain during activities like putting weight on the feet.
Dropping things from the hands frequently.
Lack of coordination.
Hands and feet of the patients feel as if they are wearing gloves or socks.
Thinning of the skin.
Difficulty digesting food.
Diarrhea or constipation.
Blood pressure changes cause dizziness.
The causes of peripheral neuropathy are:
Exposure to toxins.
Trauma or injury.
Kidney and liver disease.
Bone marrow disorders.
Infectious diseases like Lyme disease, hepatitis B, leprosy, or AIDS.
Hereditary (Charcot-Marie-Tooth disease).
Idiopathic (the cause is unknown).
The factors that increase the risk of peripheral neuropathy are:
Exposure to environmental toxins.
Autoimmune diseases like rheumatoid arthritis and lupus.
Vitamin B deficiency.
Kidney, liver or thyroid problems.
If your symptoms are in line with nerve pathology, your doctor will take a full medical history, which will include your symptoms, lifestyle, family history, and history of exposure to any toxins. The doctor will conduct a neurological examination, where he or she will check tendon reflexes, muscle strength, and coordination.
You might need to get the following tests done:
Blood tests - To diagnose diabetes, vitamin deficiencies, autoimmune conditions, etc.
CT or MRI scans - To check for disc herniation and tumors.
Electromyography (EMG) - This test records electrical activity in the muscles, which is used to determine if there is any nerve damage.
Nerve conduction test - Here, nerves response is recorded after the nerves are stimulated with low electric currents.
Nerve function tests - It includes tests like an autonomic reflex screen, a sweat test, and sensory tests.
Nerve biopsy - A small portion of a nerve is removed to look for abnormalities.
Skin biopsy - A skin biopsy shows if there is any reduction in nerve endings.
The treatment options are:
Painkillers - Nonsteroidal anti-inflammatory drugs (NSAIDs), or for severe pain, opioid medications like Tramadol or Oxycodone are used.
Anti-epileptic medications - Gabapentin and Pregabalin.
Topical medicines - Cream containing Capsaicin or Lidocaine.
Antidepressants - Tricyclic antidepressants like Amitriptyline and Nortriptyline, serotonin and norepinephrine reuptake inhibitors like Duloxetine and Venlafaxine.
Transcutaneous electrical nerve stimulation (TENS) - Gentle electric current is placed on the skin.
Plasma exchange and intravenous immune globulin - Helps suppress immune system activity.
Physical therapy - Improves muscle weakness.
Surgery - Surgery might be needed to relieve pressure on nerves.
Some of the complications include:
Skin injury - Due to loss of sensation, you might not feel temperature changes, which results in injury to the skin in the toes.
Infection - Minor injuries can go unnoticed, which might become infected.
Lack of balance - Patients often fall due to a lack of balance.
To know more about peripheral neuropathies, consult a neurologist now.
Query: Hi doctor, I am diabetic and hypertensive. My problem is, if I touch anything with my fingers, I get a burning sensation and I drop it down. Please advise me on this. Read Full »
Query: Hello doctor, About a month ago, I developed what I thought was a pinched nerve in my neck. I had numbing and tingling in my left arm and my hand would go numb while sleeping. However, over the next couple weeks the numbing, tingling, moved to my right arm then my legs and feet to include muscle tw... Read Full »
Query: Hello doctor, I am feeling burning in my whole body, especially in ribs and sometimes shoulders. Why? Read Full »
Do you have a question on Peripheral Neuropathy or ?Ask a Doctor Online