Neuropathy

Neuropathy (Dutch: neuropatie, Engels: neuropathy) is a condition characterized by damage, dysfunction or degeneration of one or more nerves. This results in various neurological symptoms such as numbness, tingling sensations, pain or weakness in the affected areas of the body. Depending on the cause and location of the damage, neuropathy can be classified as peripheral, autonomic, focal or radiculopathy [@Vdijc2018].

Causes

Neuropathy can have a variety of causes, ranging from genetic conditions to acquired disorders and diseases [@Vdijc2018]. Some common causes are:

1. Diabetes mellitus: High blood sugar levels can lead to nerve damage, resulting in diabetic neuropathy.
2. Chemotherapy: Certain chemotherapy drugs can damage the nerves, leading to chemo-induced peripheral neuropathy (CIPN).
3. Alcoholism: Chronic alcohol consumption can cause vitamin deficiencies that can lead to nerve damage.
4. Infections: Viral and bacterial infections, such as HIV, Lyme disease and Guillain-Barré syndrome, can cause neuropathy.
5. Nutritional deficiencies: Deficiencies in vitamins B1, B6, B12 and E can contribute to the development of neuropathy.
6. Autoimmune diseases: Conditions like lupus, rheumatoid arthritis and Sjögren's syndrome can cause inflammation and damage to the nerves.
7. Toxins and medications: Exposure to heavy metals (like lead) and certain prescription drugs (such as isoniazid and some anti-retroviral medications) can lead to nerve damage.
8. Hereditary factors: Certain genetic disorders, such as Charcot-Marie-Tooth disease and Friedreich's ataxia, can cause neuropathy.

Symptoms

The symptoms of neuropathy depend on the type and location of the nerve damage. Common symptoms include [@Vdijc2018]:

1. Numbness and tingling sensations in the hands and feet.
2. Pain or burning sensations in affected areas.
3. Weakness or muscle atrophy in affected muscles.
4. Hypersensitivity or increased sensitivity to touch, temperature or vibrations.
5. Loss of coordination or balance problems due to damage to sensory nerves.
6. Digestive problems caused by autonomic nerve damage (e.g., constipation, diarrhea, nausea).
7. Urinary retention or bladder problems due to damage to autonomic nerves controlling urination.
8. Changes in sweating patterns due to damage to autonomic nerves regulating perspiration.
9. Loss of hair, nails or skin discoloration due to damage to sensory nerves in the skin.

Classification and ICD9 codes

Neuropathy can be classified according to the type and location of the nerve damage as follows [@ICD9]:

1. Peripheral neuropathy (357) - Damage to the nerves outside of the brain and spinal cord. Examples include diabetes-related neuropathy (357.20) and Chemo-induced peripheral neuropathy (357.90).
2. Autonomic neuropathy (327) - Damage to the autonomic nervous system that controls involuntary functions such as heart rate, digestion, respiration, etc. Examples include diabetes-related autonomic neuropathy (357.21) and Parkinson's disease-related autonomic neuropathy (332.0).
3. Focal neuropathy (354) - Damage to a specific nerve or group of nerves that controls a specific function in a localized area of the body. Examples include carpal tunnel syndrome (354.0) and ulnar neuropathy (354.1).
4. Radiculopathy (723) - Damage to a spinal nerve root or its surrounding tissues, resulting in pain, weakness, numbness or other symptoms affecting a specific region of the body. Examples include cervical radiculopathy (723.0) and lumbar radiculopathy (723.1).
5. Mononeuropathies multiplex (MNM; 357.29) - Multiple focal neuropathies affecting different nerves at different locations within the body at the same time [@Vdijc2018].

Treatment options for neuropathy

Treatment for neuropathy primarily involves addressing the underlying cause if possible, managing symptoms and preventing further nerve damage [@Vdijc2018]. Some treatment options include:

1. Medications: Antidepressants (such as amitriptyline), anticonvulsants (such as gabapentin), topical agents (lidocaine patch), alpha-lipoic acid and capsaicin cream may help relieve pain associated with neuropathy [@MayoClinic].
2. Physical therapy: Regular exercise, stretching and massage can help manage pain and improve muscle strength [@Vdijc2018]. For example, foot neuropathy treatment massage can help alleviate discomfort in affected feet [@FootMedicineOnline].
3. Laser therapy: Low-level laser therapy (LLLT) has been shown to potentially reduce pain and improve nerve function in patients with peripheral neuropathy [@Vdijc2018]. However, research on LLLT for neuropathy is still ongoing [@Medscape].
4. Lifestyle modifications: Quitting smoking, limiting alcohol consumption, maintaining a healthy diet and exercising regularly can help slow the progression of neuropathy [@MayoClinic]. Good blood sugar control for diabetic patients is crucial in reducing the risk of developing diabetic neuropathy [@DiabetesSelfManagement].