Mayo Clinic doctors diagnose Guillain-Barre syndrome (GBS) through comprehensive evaluation and tests. Guillain-Barre syndrome can be difficult to diagnose in the earliest stages, and other conditions may have similar symptoms. Your symptoms and signs help doctors identify the condition.
Your doctor will discuss your medical history, review your symptoms and perform a complete physical examination. Your doctor may order several tests to check for signs of GBS, including:
- Electromyogram (EMG). This test measures the tiny electrical signals in muscles. A doctor inserts a thin-needle electrode into the muscle to be tested. An instrument records the electrical activity in the muscle at rest and during contraction. An EMG helps to determine if stimulation between your peripheral nerves and muscles is adequate.
- Nerve conduction study. This test measures electrical nerve impulses and functioning in your muscles and nerves. A doctor places two electrodes on your skin, and electrical impulses in the nerve signals are measured when a small shock passes through the nerve.
- Spinal tap (lumbar puncture). In this procedure, a specialist inserts a needle into your spine, usually in your lower back (lumbar region), to withdraw a small sample of spinal fluid. Among other tests, your doctor will test the fluid's protein level, which commonly rises in people who have GBS.
Read more about electromyogram, nerve conduction study and spinal tap at MayoClinic.com.