From the Guidelines
To check for neuropathy, a comprehensive metabolic panel, complete blood count, hemoglobin A1C, and fasting glucose are essential to check for diabetes, which is a leading cause of neuropathy, as recommended by the most recent guidelines 1. When assessing for neuropathy, it's crucial to consider the underlying causes, as no single blood test definitively confirms neuropathy itself.
- A comprehensive metabolic panel can help identify metabolic disorders that may contribute to neuropathy.
- A complete blood count can reveal anemia or other blood-related conditions that may cause nerve damage.
- Hemoglobin A1C and fasting glucose tests are vital for diagnosing and managing diabetes, a primary cause of neuropathy, as emphasized in the 2023 standards of care in diabetes 1.
- Vitamin B12 and folate levels should be measured, as deficiencies in these vitamins can cause nerve damage.
- Thyroid function tests, including TSH, T3, and T4, are important, as thyroid disorders can lead to neuropathy.
- Inflammatory markers like ESR and CRP may help identify inflammatory conditions causing nerve damage.
- Specific tests for autoimmune conditions, such as ANA, rheumatoid factor, and anti-MAG antibodies, can be useful in certain cases.
- Screening for infections like HIV, hepatitis C, and Lyme disease may be necessary in relevant cases, and testing for heavy metals like lead, mercury, and arsenic may be required if toxin exposure is suspected.
- Protein electrophoresis can help identify monoclonal gammopathies associated with neuropathy, as noted in the guidelines for microvascular complications and foot care 1. These tests can help identify treatable causes of neuropathy, allowing for targeted treatment of the underlying condition rather than just symptom management, ultimately improving morbidity, mortality, and quality of life.
From the Research
Blood Tests for Neuropathy
To check for neuropathy, several blood tests can be conducted, including:
- Complete blood count
- Comprehensive metabolic profile
- Fasting blood glucose
- Vitamin B12 levels [ 2 ]
- Thyroid-stimulating hormone levels
- Serum protein electrophoresis with immunofixation [ 2 ]
Specific Tests for Nutritional Deficiencies
Nutritional deficiencies, such as vitamin B12 deficiency, can cause neuropathy. Studies have shown that:
- Low levels of vitamin B12 are associated with peripheral neuropathy [ 3 ]
- Elevated methylmalonic acid and homocysteine levels are also associated with peripheral neuropathy [ 3 ]
Laboratory Evaluation
Initial laboratory evaluation for neuropathy should focus on identifying treatable causes, such as: