What is Peripheral neuropathy?
Peripheral neuropathy is a condition caused by the damage to the peripheral nervous system which is outside the brain and the spinal cord. The peripheral nervous system consists of three key types of nerves; the automatic nerves which control the internal organs, the motor nerves which control muscles, and the sensory nerves which pass sensation to the skin. The symptoms depend on the type of the nerve that is damaged.
The most common symptoms include temporary numbness and tingling sensations in the hands and feet, sensitivity to touch and temperature, a burning sensation or stabbing pain, loss of coordination, or muscle weakness, sexual dysfunction in men, digestive problems, diarrhea and abnormal sweating.
What are the causes of peripheral neuropathy?
There are various factors and underlying disorders that can cause this condition. Some of the causes are;
Physical trauma from car accidents, sports accidents, or repeated stress injury can damage the nerve or compress it under increased pressure. This is as a result of inflammation or swelling of ligaments and tendons leading to increased pressure on the nerve. This leads to a common type of peripheral neuropathy known as carpal tunnel syndrome.
Patients who have type 1 diabetes or type 2 diabetes may develop diabetic polyneuropathy. This condition is probably caused by high blood sugar levels that cause damage to the small blood vessels that supply the nerves, causing nerve damage. The risk is higher for patients whose blood sugar levels are poorly controlled, smoke, are over 40 years, are overweight or have high blood pressure.
The early signs of diabetic neuropathy include are usually numbness, tingling or pain in the hands and feet. These may progress to a loss of sensation, muscle weakness and loss of reflexes. It is therefore essential for people with diabetes to examine their feet regularly for sores that may become infected.
Some chronic diseases may manifest with focal peripheral neuropathy. Kidney disease can lead to a build-up in levels of toxins in the body leading to nerve damage. Similarly, hypothyroidism causes fluid retention and swelling of body tissues which pressure surrounding nerves.
Infections and Autoimmune diseases
Many viruses and bacteria can cause damage to the sensory nerves like zoster virus, the Epstein-Barr virus, HIV and Herpes simplex virus causing episodes of intense pain.
Some bacterial diseases like Lyme disease, leprosy and diphtheria can also cause nerve damage and pain.
Various autoimmune diseases like lupus and rheumatoid arthritis manifest with peripheral neuropathy. This results from chronic inflammation around the nerve which may cause pressure to the nerve or involve the nerve as well, leading to severe pain.
Alcohol and Toxins
Alcohol abuse is a common cause of peripheral neuropathy. Alcohol neuropathy leads to permanent nerve damage.
Cancer therapy drugs, anti-retroviral therapy, and anticonvulsants are known to produce peripheral neuropathy a condition which improves once the treatment stops.
Exposure to toxins, such as heavy metal poisons arsenic, lead and mercury, and pesticides can cause nerve damage.
Some mutations and inherited disorders like amyloid polyneuropathy or Charcot-Marie-Tooth disease can cause nerve disorders which lead to weakness and wasting of the muscles of the lower limbs.