Neuropathy is a medical term that identifies intense chronic pain usually associated with tissue injury. Neuropathy often develops when nerve fibers become dysfunctional, damaged, or injured and sent incorrect signals to the brain. The damage or dysfunction usually involves a significant change in how the nerve functions at the site of the injury and the surrounding area. Doctors often classify the neuropathy by the disease that caused it, like diabetic neuropathy.
- Who Is at Risk for Neuropathy?
- What Causes Neuropathic Pain?
- Diagnosing Neuropathy
- Neuropathy Treatments
The most common forms of neuropathy include:
- Peripheral Neuropathy – This type of nerve dysfunction involves the peripheral nervous system including the brain and spinal cord. Nerve damage or dysfunction typically occurs in the extremities involving the arms, hands, fingers, legs, feet, and toes.
- Proximal Neuropathy – This form of nerve dysfunction refers to the damage caused to the nerves in the buttocks, thighs, hips, and shoulders that display neuropathic pain.
- Cranial Neuropathy – There are twelve cranial nerves that leading out of the brain that when damaged or become dysfunctional can cause auditory (hearing) neuropathy or optic (sight) neuropathy. Auditory neuropathy develops when the nerve carrying signals from the inner ear is affected. Optic neuropathy involves disease or damage affecting the optic nerve that sends signals to the brain involving sight.
- Autonomic Neuropathy – This form of neuropathy involves the involuntary nervous system were nurse become damage that controls perspiration, bladder or bowel function, digestion, blood pressure, blood flow circulation, heart function, and sexual response.
- Focal Neuropathy – This form of neuropathic pain is restricted or focused to a specific group of nerves or single nerve in the body.
Who Is at Risk for Neuropathy?
While anyone can develop neuropathy, especially if an area of the body is injured by an outside force, there are specific risk factors that heighten the potential development neuropathic pain. These include:
- Diabetes mellitus
- Toxic exposure
- Thyroid, liver, or kidney disorders
- Multiple sclerosis
- Infections including hepatitis C, Epstein-Barr virus, HIV, shingles, and Lyme disease
- Alcohol abuse
- Repetitive motion
- Spine surgery
- Vitamin deficiency, especially B vitamins
- Autoimmune disease including Lupus, rheueumatoid arthritis and other conditions where tissue was attacked by the immune system
- Facial nerve problems
- Hip, leg, and back problems
- Skin and burn trauma
What Causes Neuropathic Pain?
No single disease causes peripheral neuropathy. In fact, any damage or dysfunction to the nerve can cause neuropathic pain, including:
- Alcoholism which causes vitamin deficiency, leading to neuropathic pain
- Diabetes – Nearly fifty percent of all individuals suffering from diabetes will dissolve some form of neuropathic pain.
- Autoimmune Disease including rheumatoid arthritis, Sjogren's syndrome, Guillain-Barre syndrome, Lupus necrotizing vasculitis, and chronic inflammatory demyelinating polyneuropathy
- Exposure to Toxic Substances including heavy metals, poisons, or chemicals
- Inherited Disorders including Charcot-Marie-Tooth Disease
- Medication Use including chemotherapy to treat cancer
- Tumors – Both noncancerous (benign) and cancerous (malignant) growths can cause neuropathy when a massive tissue presses on nerves
- Trauma including sports injuries, falls, and motor vehicle accidents can damage or sever peripheral nerves. This includes pressure on the nerve caused by walking with crutches or motion repetitiveness
- Bone Marrow including osteosclerotic myeloma (bone cancer), amyloidosis, lymphoma, and abnormal blood protein (monoclonal gammopathies).
- Vitamin Deficiencies including vitamin E, niacin, B-1, B-6 and B-12
- Infections caused by bacteria or viruses including Epstein-Barr virus, shingles, L yme disease, HIV, diphtheria, leprosy, and hepatitis C
Some individuals experienced idiopathic neuropathy where no direct cause can be identified.
The type of symptoms involving neuropathic pain depends on the nerves in the peripheral nervous system and its location. Neuropathic pain can occur in one of three parts of the nervous system that include:
- Sensory Nerves that receive the sensation of touch, pain, temperature, or vibration on the skin
- Anatomic Nerves that regulate blood pressure, digestion, heart rate, and bladder function
- Motor Nerves in charge of muscle movement
Neuropathic pain can involve mononeuropathy where one nerve is affected, multiple mononeuropathies were multiple nerves are affected in different areas of the body or polyneuropathy that involves many nerves.
The most common neuropathy symptoms involve:
- Extreme sensitivity in the skin and muscle affecting touch
- Gradually increasing numbness, tingling or prickling in the hands or feet which can spread or radiate to the arms or legs
- Shooting pain
- Burning, jabbing, throbbing, sharp or freezing pain
- Following caused by a lack of balance or coordination
- Digestive, bladder, or bowel problems
- Altered sweating and heat intolerance
- Lightheadedness or dizziness caused by a change in blood pressure
Any noticeable signs of the symptoms above require a visit to the doctor for an initial diagnosis to ensure treatment provides an optimal outcome.
Diagnosing peripheral neuropathy requires extensive testing to determine the potential cause in the affected areas. The doctor will typically perform a comprehensive physical examination and use blood tests to verify the diagnosis that involves:
- Complete Medical History – The patient must provide the doctor a complete medical history including their current and past symptoms, any exposure to toxic chemicals, their lifestyle, drinking habits and any neurological (nervous system) disease involved in their family history.
- Neurological Exam – Usually the doctor will check body reflexes including the tendons, muscle tone and strength, coordination, posture, and the ability of the patient to feel certain sensations.
Other parts of the diagnosis will include:
- Blood Tests to detect or identify vitamin deficiencies, abnormal new functions, diabetic conditions and other known causes of peripheral neuropathy.
- Nerve Biopsy where a small amount of nerve tissue is removed from the body to look for any abnormality.
- Imaging Tests using MRI (magnetic resonance imaging) scans and CT (computerized tomography) scans can identify abnormalities, tumors and herniated discs that might be causing neuropathic pain in the body.
- Nerve Conduction Velocity Tests including electromyography can identify nerve damage to the muscles. This might involve electronic signal probes that record the nerve pathways in responding to signals
- Skin Biopsy where a small amount of skin is removed to excise an affected nerve ending.
Based on the intensity or severity of the neuropathic pain, the doctor may simply prescribe and NSAIDs drugs like Motrin or Aleve to alleviate inflammation and ease the pain. However, stronger painkillers are often required including the use of antidepressants, anticonvulsants, and morphine that are known to diminish neuropathic pain.
Sometimes, the treatment of neuropathy involves treating the underlying cause. This includes diabetic patients who suffer neuropathic pain caused by their condition. Effectively managing diabetes can minimize further damage to the body's nervous system.
Sometimes, a pain specialist is required to treat difficult cases of neuropathy. The doctor may choose to use an implantable or invasive device that shows positive results in managing pain. Electric stimulation of the affected nerves can also minimize neuropathic pain and reduce or eliminate associated pain symptoms.
The most common forms of treatment used to minimize the symptoms of neuropathy include:
- Physical therapy
- Relaxation therapy
- Massage therapy
Most forms of neuropathic pain require more than standard pain treatments especially if the condition worsens over time. Without treatment, the neuropathy can lead to serious disabilities. Because of that, doctors often take a multidisciplinary approach by recommending various therapies that provide concomitant care as a treatment to provide relief associated with nerve damage.