From the Research
Blood tests for neuropathic causes should include complete blood count, comprehensive metabolic panel, hemoglobin A1c, vitamin B12, folate, thyroid function tests, erythrocyte sedimentation rate, and C-reactive protein. These tests help identify common causes of neuropathy such as diabetes, vitamin deficiencies, thyroid dysfunction, inflammatory conditions, paraproteinemias, infections, and toxin exposure 1, 2, 3, 4. Additional specialized tests may include serum protein electrophoresis to detect monoclonal gammopathies, anti-nuclear antibody and rheumatoid factor for autoimmune conditions, HIV and hepatitis panel for infectious causes, and heavy metal screening if exposure is suspected. The specific panel should be tailored based on clinical presentation, with diabetes screening being particularly important as it's the most common cause of neuropathy. Early identification of the underlying cause is crucial for appropriate management and potentially halting progression of nerve damage.
Some key points to consider when evaluating neuropathic causes include:
- Vitamin B12 deficiency is a common cause of megaloblastic anemia and can lead to neurocognitive and other consequences if left untreated 1, 2
- Folate deficiency can also cause megaloblastic anemia, although its prevalence has decreased due to folate fortification 3, 4
- Other causes of neuropathy, such as thyroid dysfunction, inflammatory conditions, and infections, should also be considered and tested for accordingly 1, 2, 3, 4
- Genetic testing may be warranted for hereditary neuropathies, and the specific panel should be tailored based on clinical presentation. It's worth noting that while anaemia is common in critical illness, the treatment and management of anaemia in this context is different from that of neuropathic causes, and should be approached separately 5.