From the Guidelines
Peripheral neuropathy is primarily caused by diabetes, but other significant causes include toxins, neurotoxic medications, vitamin B12 deficiency, hypothyroidism, renal disease, malignancies, infections, and vasculitis, as identified in the most recent guidelines 1. The causes of peripheral neuropathy are multifaceted and can be attributed to various factors. According to the latest standards of medical care in diabetes-2022 1, diabetes is a leading cause of peripheral neuropathy, with high blood sugar damaging nerves over time. However, it is essential to consider other potential causes of neuropathy, including:
- Toxins such as alcohol
- Neurotoxic medications like chemotherapy
- Vitamin B12 deficiency
- Hypothyroidism
- Renal disease
- Malignancies like multiple myeloma and bronchogenic carcinoma
- Infections such as HIV
- Chronic inflammatory demyelinating neuropathy
- Inherited neuropathies
- Vasculitis These causes can be identified through simple clinical tests, including pinprick and temperature sensation for small-fiber function, vibration perception and 10-g monofilament for large-fiber function, and 10-g monofilament for protective sensation 1. Addressing the underlying cause of peripheral neuropathy is crucial for effective treatment, and early identification can help reverse some nerve damage, while chronic neuropathy may only be managed symptomatically with medications like gabapentin, pregabalin, or duloxetine 1. In clinical practice, it is vital to consider these various causes and to prioritize glycemic control, as it can effectively prevent diabetic peripheral neuropathy and cardiac autonomic neuropathy in type 1 diabetes and may modestly slow their progression in type 2 diabetes 1.
From the Research
Causes of Peripheral Neuropathy
The causes of peripheral neuropathy are varied and can be attributed to several factors, including:
- Diabetes mellitus, which is the most common cause of peripheral neuropathy worldwide 2, 3, 4, 5, 6
- Hypothyroidism 3
- Nutritional deficiencies, such as vitamin B12 deficiency 3
- Toxic causes, although the specific toxins are not mentioned in the provided studies
- Systemic and metabolic causes, including hyperglycemia and dyslipidemia 6
- Inflammatory mechanisms, which may contribute to acute diabetic neuropathies 6
Diabetic Neuropathy
Diabetic neuropathy is a major cause of disability and health care expense, and it is estimated that more than half of patients with diabetes have neuropathy 6. The most common form of diabetic neuropathy is distal symmetric polyneuropathy, which is characterized by a glove-and-stocking distribution of sensory or motor function loss 2, 5. Other forms of diabetic neuropathy include autonomic neuropathy, radiculo-plexopathies, and mononeuropathies 2.
Diagnosis and Treatment
The diagnosis of peripheral neuropathy requires careful clinical assessment, judicious laboratory testing, and electrodiagnostic studies or nerve biopsy if the diagnosis remains unclear 3. Treatment should address the underlying disease process, correct any nutritional deficiencies, and provide symptomatic treatment 3. In the case of diabetic neuropathy, improving glycemic control is essential, although it is more effective in type 1 than in type 2 diabetes 2. Duloxetine and pregabalin are commonly used to treat neuropathic pain in diabetic peripheral neuropathy 5.