From the Guidelines
For peripheral neuropathy screening, I recommend a comprehensive approach that includes a careful history, assessment of temperature or pinprick sensation, and vibration sensation using a 128-Hz tuning fork, as well as annual 10-g monofilament testing to identify feet at risk for ulceration and amputation 1. When it comes to lab tests, the focus should be on identifying underlying causes of peripheral neuropathy, with a particular emphasis on diabetes, given its high prevalence as a cause of peripheral neuropathy.
- A hemoglobin A1c test is crucial for assessing glycemic control in diabetic patients, as it can help prevent diabetic peripheral neuropathy (DPN) and cardiac autonomic neuropathy (CAN) in type 1 diabetes and may modestly slow their progression in type 2 diabetes 1.
- Additional tests such as vitamin B12 level, folate level, thyroid-stimulating hormone (TSH), and complete blood count (CBC) can help identify other potential causes of peripheral neuropathy, including vitamin deficiencies and thyroid dysfunction.
- It's also important to consider the patient's overall clinical presentation and risk factors when deciding which tests to order, as some cases may require more specialized testing. The goal of these screenings is not only to diagnose peripheral neuropathy but also to identify and manage underlying conditions that can improve symptoms, reduce sequelae, and enhance quality of life, as the early recognition and appropriate management of neuropathy in people with diabetes is critical 1.
From the Research
Screening Lab Tests for Peripheral Neuropathy
The following lab tests are recommended for screening peripheral neuropathy:
- Complete blood count 2, 3, 4
- Comprehensive metabolic profile 2, 3, 4
- Fasting blood glucose 2, 3, 4
- Vitamin B12 levels 2, 3, 4
- Thyroid-stimulating hormone levels 2, 3, 4
- Serum protein electrophoresis with immunofixation 3
- Erythrocyte sedimentation rate 2
- HbA1c 4
- Renal and liver function tests 4
Specialized Tests
Specialized tests may be ordered if clinically indicated, such as:
- Electrodiagnostic studies, including nerve conduction studies and electromyography 2, 3
- Nerve biopsy 2
- Lumbar puncture and cerebrospinal fluid analysis for diagnosis of Guillain-Barré syndrome and chronic inflammatory demyelinating neuropathy 2
- Specific antibody assays 3
Note that study 5 is not relevant to the question of screening lab tests for peripheral neuropathy.