Guillain-Barré syndrome is a condition that rapidly causes muscle weakness in patients following a period of infection with a bacteria or virus. Some people with the syndrome are unable to carry out key functions involving movement due to the effects of the condition throughout the body.
The syndrome can temporarily leave patients unable to walk, swallow food, talk properly, breath, speak, or move their eyes, to name just a few complications of the syndrome. The full extent of the muscle weakness progression throughout the body can take around two weeks in some patients and up to about a month in others. Recovery with medical help can take months and there is 5% risk of death.
However, there are many diseases that can result in muscle weakness so the medical diagnosis team has to perform a thorough examination and ask the patient a variety of important questions to ensure that they make the correct diagnosis. Doctors will consider the symptoms that the patient is experiencing as well asrun some tests to confirm their diagnosis.
Nerve Conduction Studies and Electromyography (EMG)
A nerve conduction study, also known as a nerve conduction velocity test, analyses how well a nerve is functioning by measuring conduction as an electrical current travels through it. Two electrodes are attached to the skin of the patient at two different places of a nerve. One of the electrodes stimulates the electrical impulse and the other one reads it after its passage through the nerve. A reading indicating low function will suggest that the nerves have been affected by the syndrome. The test is performed by chiropractors, physiatrists, neurologists, and medical specialists in clinical physiology.
Another test used to analyze muscle function is called electromyography. Here, the medic places an electrode needle in the muscle under investigation to gain information about the function of the muscle. A low functional reading will show that the muscle has been affected.
The medical team performs a lumbar puncture, also known as a spinal tap, to analyze the cerebrospinal fluid as part of diagnosis of the syndrome. In this method, fluid is drawn from the patient’s spine using a needle and is tested for various parameters. Increase in protein levels combined with normal white blood cell count can be an indication of the syndrome. This is termed as albuminocytologic dissociation and is seen in most patients affected by the syndrome in the first week of onset of symptoms. However, an increased white blood cell count may rule out Guillain-Barré syndrome. The patient is usually under the influence of a local anesthetic during the test.
Doctors also use blood tests to rule out other diseases causing muscle weakness, to screen for genetic diseases, to detect any infections, and to obtain a general health assessment.
Reviewed by Susha Cheriyedath, MSc