Tests and diagnosis

By Mayo Clinic Staff

Peripheral neuropathy isn't a single disease, but rather damage to nerves that produces symptoms with many potential causes. Your doctor will need to determine where the nerve damage is and what's causing it.

Besides a physical exam, which may include blood tests, diagnosis usually requires:

  • A full medical history. Your doctor will review your medical history, including your symptoms, your lifestyle, exposure to toxins, drinking habits and a family history of nervous system (neurological) diseases.
  • Neurological examination. Your doctor may check your tendon reflexes, your muscle strength and tone, your ability to feel certain sensations, and your posture and coordination.

Your doctor may order tests, including:

  • Imaging tests. CT or MRI scans can look for herniated disks, tumors or other abnormalities.
  • Nerve function tests. Electromyography, a nerve function test, records electrical activity in your muscles to determine if your symptoms, including weakness, are caused by muscle or nerve damage.

    For nerve conduction studies, a probe sends electrical signals to a nerve, and an electrode placed along the nerve's pathway records the nerve's response to the signals. Nerve conduction studies record signals from both motor and sensory nerves.

  • Other nerve function tests. These may include an autonomic reflex screen that records how the autonomic nerve fibers work, a sweat test that records how you sweat, and sensory tests that record how you feel touch, vibration, cooling and heat.
  • Nerve biopsy. Your doctor may recommend removing a small portion of a nerve, usually a sensory nerve, to examine for abnormalities to determine the cause of your nerve damage.
  • Skin biopsy. Your doctor removes a small portion of skin to examine the number of nerve endings. A reduction in nerve endings indicates neuropathy.
Dec. 02, 2014