How is neuropathy diagnosed?
History and physical exam: First, your doctor will conduct a thorough history and physical exam. You doctor will review your symptoms and ask questions including your current and past medications, exposure to toxic substances, your history of trauma, your line of work or social habits (looking for repetitive motions), family history of diseases of the nervous system, your diet and alcohol use.
Neurologic exam: During a neurologic exam, your doctor will check your reflexes, your coordination and balance, your muscle strength and tone, and your ability to feel sensations (such as light touch or cold).
Blood work and imaging tests: Your doctor may also order blood work and imaging tests. Blood work can reveal vitamin and mineral imbalances, electrolyte imbalances (indicator of kidney problems, diabetes, other health issues), thyroid problems, toxic substances, antibodies to certain viruses or autoimmune diseases. Magnetic resonance imaging (MRI) can detect tumors, pinched nerves and nerve compression.
Genetic testing: A genetic test may be ordered if your doctor suspects a genetic condition is causing your neuropathy.
Electrodiagnostic assessment (EDX): Your doctor might send you to a nerve specialist for an EDX to find the location and degree of nerve damage. EDX includes two tests:
- Nerve conduction study (NCS): During this test, small patches – called electrodes – are placed on the skin over nerves and muscles on different parts of your body, usually your arms or legs. A brief pulse of electricity is applied to the patch over a nerve to be studied. The test measures the size of the response and how quickly the nerve is carrying the electrical signal. Both motor and sensory nerves can be studied in this way.
- Needle electromyography (EMG): An EMG can determine the health of a muscle, and determine if there is any disconnection between the nerve and muscle by measuring the electrical activity within the muscle while it is in use. During an EMG, a very thin needle electrode is inserted through the skin into the muscle. The muscle is then used for a specific movement and the electrical activity of the muscle is recorded on a graph called an electromyogram.
Tissue biopsies: In some cases, a nerve, muscle or skin biopsy is needed to confirm the diagnosis. During a biopsy, a small sample of your tissue is removed for examination under a microscope.
Other tests: Other tests include a test to measure your body’s ability to sweat (called a QSART test) and other tests to check the sensitivity of your senses (touch, heat/cold, pain, vibration).