The nervous system consists of the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is comprised of the brain and spinal cord, while the PNS comprises of nerves that carry information to and from the brain to the rest of the body.
There are three types of nerves that are included in the PNS:
- Autonomic nerves that control BP, bladder functions and sweat levels.
- Motor nerves that control the muscles.
- Sensory nerves that transfer sensations like cold, heat or pain to the brain.
Peripheral neuropathy is a condition characterized by damaged nerves that cause pain. When this condition affects one nerve, it is called mononeuropathy; when several nerves are affected, it is polyneuropathy; and when 2 or more nerves are involved in different areas, it is termed as multiple mononeuropathy.
Peripheral neuropathy is a comparatively common disease that usually affects older people.
Causes of Peripheral Neuropathy
Diabetes is the most common cause of peripheral neuropathy. At least half of all diabetics develop some form of neuropathy during the course of the disease.
Other factors that can cause peripheral neuropathy are:
- Excessive alcohol intake, which leads to poor dietary choices.
- Autoimmune diseases like lupus and rheumatoid arthritis.
- Exposure to toxic substances like heavy metals and certain medications, like chemotherapy.
- Viral or bacterial infections.
- Trauma or compression of the nerves.
- Tumor on or surrounding the nerves.
- Vitamin deficiencies.
Signs and Symptoms of Peripheral Neuropathy
Symptoms depend on the type of the affected nerve. Common signs and symptoms include:
- Numbness and tingling sensation in the feet or hands that can slowly spread to the legs and arms.
- Burning or sharp electric pain.
- Sensitivity to touch or heat.
- Impaired coordination.
- Muscle weakness or paralysis.
- Bowel or bladder incontinence.
- Foot infection and ulcers.
Peripheral neuropathy involves the exact detection of nerve damage and its cause, which is difficult to diagnose. Your doctor will review your medical history and family history for neurological diseases, and will conduct physical and neurological examinations for muscle strength, sensation, posture and coordination.
Your doctor may order other tests including:
- Blood tests for vitamin, sugar and thyroid levels and liver and kidney function.
- Computed tomography (CT) scan or MRI to detect herniated disks or spinal tumors.
- Nerve function tests using electromyography to measure the electrical activity of the nerves.
- Nerve biopsy, in which a part of the damaged nerve is removed to test for abnormalities.
- Lumbar puncture to test cerebrospinal fluid in the lower back for signs of disease.
The main aim of treatment is to control the underlying cause of peripheral neuropathy and manage pain. Symptoms of peripheral neuropathy can be relieved with:
- Medications: Your doctor may prescribe pain killers, anti-seizure and antidepressant drugs, and topical medications.
- Neuromodulation (Spinal cord stimulation or peripheral field stimulation): Your doctor will pass a gentle electric current through two electrodes placed on the painful areas of your body. Your pain will reduce when the electric impulses travel along the nerves of the painful area, due to the stimulation of the affected nerves and production of endorphins (natural pain killers), which block the pain signals in the brain.
- Acupuncture. Your therapist will insert thin needles into the body close to the nerves. This will stimulate the nerves and release endorphins.
- Plasma exchange and intravenous immune globulin may be performed to suppress the activity of the immune system.
Peripheral neuropathy can be prevented by:
- Managing the underlying disease condition such as diabetes.
- Maintaining a healthy diet and lifestyle to keep your nerves healthy.
- Eating a vitamin B-12 rich diet or including supplements.
- Preventing nerve damage by avoiding repetitive motions, restricted positions, toxic chemicals, and excessive alcohol.