The medical examination
What is a Lumbar puncture?
What is a Nerve Conduction Velocity test?
What is an Electromyogram?
What is an MRI-scanning?
What is an Electrocardiogram?
What is a nerve biopsy?
Problems getting a diagnosis?
Is GBS related to Multiple Sclerosis?
Further reading

If you suspect that you have Guillain-Barré syndrome (GBS), it is extremely important that you seek qualified medical attention as soon as possible. The sooner you are diagnosed and treated, the faster recovery begins, thus reducing the risk of permanent physical damage.

The medical examination
It is important that the patient is thoroughly examined by a physician, in order for the diagnosis to be made correctly. There are a number of other diseases with symptoms that resemble GBS, that the physician has to exclude from the list of probables, before the patient can begin treatment. It can therefore take some time to make a correct diagnosis.

The diagnosis is based on a clinical examination of the symptoms and their distribution. Among other things, the physician checks whether the symptoms are symmetrical, i.e. appear on both sides of the body, if there are signs of increasing weakness, loss of tendon reflexes and signs of preceding infection.

In order to facilitate the ruling-out process, the patient is asked if he or she has been in contact with poisons (pesticides, chemicals, toxins, etc.), about his or her alcohol consumption, recent infections, other diseases (diabetes, family history of nerve disease, etc.), tick bites, etc. The physician also asks about the course of the disease so far, and can often diagnose the disease on the basis of all these factors. In some cases, further examinations may be required to confirm the diagnosis.

These examinations may include one or more of the following laboratory tests and electrodiagnostic studies: Blood and urine tests, x-rays, scans, lumbal puncture, Nerve Conduction Velocity test (NCV), electromyogram (EMG). An electrocardiogram (ECG) may be undertaken to confirm or rule out irregular heartbeat. A stool test may be done to check for the presence of stomach infections that triggered the attack.
These tests are explained below. They can, in some cases, indicate whether the disease is of the demyelinating or the axonal type, indicating what the course of the disease is likely to be.
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What is a lumbar puncture?
A lumbar puncture is an examination of the patient's spinal fluid. It is also known as a spinal tap.
The cerebrospinal fluid (CSF) surrounds the brain and spinal cord, and acts as a buffer. It is normally clear and colourless, and changes in its colour, quantity or composition may be an indication of neurological damage or disease. If the patient has GBS, the CSF will contain more protein than normal, with no increase in the number of white blood corpuscles or the pressure. A lumbar puncture is done to check if this is the case.
The patient lies still, in the foetal position, while a local anaesthetic is administered to his or her lower back. A needle is carefully inserted into the patient's spinal column, between the third and fourth vertebrae, into the fluid-filled area that surrounds the nerve roots. A little liquid is sucked out for testing. Nervous patients may be given a mild sedative or sleeping pill, and the examination carried out while they are asleep.

Some patients complain about headaches, hours or days after the examination. Patients are advised to lie down for 1-3 hours after the spinal tap. Very rare side effects include bleeding and infection.

A test undertaken early in the course of the disease can sometimes show very little, and it may be necessary to repeat it after some days, during which time the protein level may increase.
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What is a Nerve Conduction Velocity test?
The Nerve Conduction Velocity test (NCV) is a test that investigates how well the nerves function. Nerves with damaged myelin transmit signals slower than undamaged nerve cells, while nerves with destroyed axons cannot transmit signals at all.
An NCV reveals whether the ability of the tested nerves to transmit signals is reduced, i.e. if there are signs of myelin damage, as well as how advanced the damage is. The test can, in some cases, also indicate what may have caused the disease.
If the symptoms are displayed in a very slow manner, the first examination may show very little, and it can be necessary to repeat it after a couple of weeks.

During the test, flat electrodes are placed on the patient's skin, at intervals, above the nerve to be examined for damage. One of the electrodes stimulates the nerve by transmitting a very weak electrical impulse through it. The other electrodes pick up and measure the strength of the impulse that reaches them. See diagram.
The conduction velocity of the nerve is calculated from the distance between the electrodes and the time it takes for the impulse to move between them. The speed of transmission is related to the diameter of the nerve and its myelination. The result is therefore compared with the speed of transmission of an undamaged nerve.

The impulse may feel a little like an electric shock, and depending on how strong it is, it will be felt by the patient in varying degrees and may be uncomfortable for some patients.
The test carries no risk of electrical shock.
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What is an electromyogram?
A myogram or electromyography (EMG) examines the activity in the muscles for any signs of slowing down or blocking of response to nerve signals. It is used to differentiate between muscle disorders and muscle weakness caused by neurologic disorders.
When a nerve is stimulated with a brief electrical impulse, that feels like a tiny jolt, it creates activity in the adjoining muscle. This activity can be measured.

During the test, a thin little electrode is pushed through the patient's skin, into the muscle to be examined. It is connected to a screen that shows the electrical activity being measured by the electrode. When the patient contracts the muscle, e.g. by bending it, the muscle fibres affected by the movement produce electrical activity that is measured and shown on the screen.
A muscle not in use produces no electrical impulses, and hence no signal will be seen on the screen to begin with. Inserting the electrode will cause electrical activity, that gradually dissipates, after which the screen gradually goes blank. Upon contraction of the muscle, activity will be seen on the screen, increasing as the patient contracts increasing numbers of muscle fibers.
The presence, as well as the form and size of the resultant reading provides information on the muscle's ability to respond to the nerve signals transmitted. See diagram.

The test takes approximately half an hour. Insertion of the electrodes may cause some pain. Exactly how much pain is involved depends on the extent of the patient's sensory disturbances. The muscle may also be tender for some days.
An electromyogram is often carried out together with the Nerve Conduction Velocity test described above.
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What is an MRI-scanning?
MRI stands for Magnetic Resonance Imaging. MRI forms "images" of the internal structures of the body. It uses radio waves, a powerful electromagnet and a computer to examine soft tissues, particularly those of the brain, spinal cord and nerves, in great detail, from any angle. It allows for quick diagnosis of many diseases without the need to extensive testing or exploratory surgery.

Tell your doctor before the MRI if you have metal objects inside your body. These include pacemakers, metal fragments such as shrapnel, metal implants, dental bridgework, intrauterine device, etc. They could stop working or even cause serious injuries during the MRI. Please also inform them if you are or might be pregnant, have recently been under surgery, or have any allergies.
You must leave jewelry, watches, coins, keys, and credit cards at home or in a locker at the MRI center. These objects can be damaged or inhibit radio waves from entering the body, thus distorting the images. Clothing with metal zippers, rivets, underwires and belt buckles are also incompatible for the same reasons. If your clothing contains metal, you will have to change into an imaging gown which contains no metal.

Your MRI exam may not proceed exactly as described here, but it will be similar enough so that this description will help you prepare for your exam.

The MRI is a large machine that has a circular tunnel built through it, approximately 60 cm (24 inches) in diameter. The technologist may place a special ring over the area to be scanned. The scanning table on which you are lying will slide into the magnet and all you have to do is relax and lie as still as you can.
If you are a patient who needs to have dye injected through the IV, this is usually done halfway through the scanning and rarely causes any side effects. The dye results in enhanced pictures.

Your exam will last between 30 and 60 minutes. You will need to lie still for periods of 3 to 10 minutes at a time while the series of images are collected. You will be asked to hold your breath for a few seconds for each picture that is taken.

The imaging session creates a series of loud thumping sounds, during which it is important not to move, as this will blur the pictures. You will be offered ear protection to block the noise, or you may be able to listen to music through special headphones during your scan.

You will be able to hear and talk to the technologist who will be in an adjacent control room constantly observing you through a window. If you become nervous in confined spaces or have trouble lying flat for a long time, please inform your doctor ahead of time and discuss whether you may require anti-anxiety or relaxing medication. Some MRI centres will allow a friend or relative to sit in the scan room while you are being imaged and talk with you.

MRI is a way of getting pictures of various parts of your body without the use of x-rays. A MRI scanner consists of a large and very strong magnet in which the patient lies. A radio wave antenna is used to send signals to the body and then receive signals back. These returning signals are converted into pictures by a computer attached to the scanner. Pictures of almost any part of your body can be obtained at almost any particular angle.

MRI is painless and quite safe in the majority of patients. After your scan, you may resume you normal activities. If you have been given relaxing medication, you may not be able to drive or operate machinery for the rest of the day.

A radiologist will read the magnetic resonance images from your scan, and provide your physician with a report. Your physician will schedule a meeting with you to discuss the findings. For more information, see 'further reading' below.
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What is CT scanning?

CT scanning uses X-rays to study tissues.

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What is an electrocardiogram?
An electrocardiogram (ECG) records the electrical activity of the heart, and indicates any irregularities in the heart's rhythm.

To administer the test, the patient is asked to lie down, and the areas to which the electrodes are to be fastened are cleaned, shaved if necessary. Several electrodes are secured to the patient's skin and connected to a screen. The patient is asked to lie still and hold his or her breath briefly. The activity of the heart produces small electrical impulses that are picked up and measured by the electrodes, after which the heart rhythm can be seen on the screen. See diagram.

The test is sometimes undertaken on patients walking on an indoor running machine, or in some other way made to undergo light physical exertion. This is done to monitor changes in the heart's activity. The test is painless.
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What is a nerve biopsy?
In rare cases, a nerve biopsy may be necessary. This requires the removal of a tiny piece of nerve, under local anaesthesia. The section is examined under a microscope for signs of damage.
Some patients have complained of sensory disturbances in the area a long time after the biopsy was done.
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As mentioned earlier, it can take a while before the diagnosis can be made: the tests may show results that are inconclusive, and may therefore have to be repeated. The physician also has to rule out other diseases whose symptoms resemble those of GBS, before the treatment can begin.

Problems getting a diagnosis?
Some patients may find it incredibly difficult to get a firm diagnosis. The reason for this can range from doctors with no experience of GBS/variants who will not refer the patient to a specialist to one's body reacting in a non-standard way to the syndrome thus leading to ambiguous results etc. Some medical systems do not permit the patient to get a second opinion. The reasons vary, and many case histories in the database at this website mention such issues.
The solutions found by resourceful patients are varied. Some have found that printing out relevant pages of this website for their health professional has helped initiate a more helpful dialog. For other solutions, please refer to the case histories.

Something that can be recommended is to write up your own 'case notes' in two copies, one for yourself and one for your doctor.
In section 1, state the various diagnoses and treatments undergone.
In section 2, state the current symptoms and any improvement/deterioration or new symptoms that have shown up.
In section 3, put in all the questions you have.

This format keeps all the relevant information together, makes sure you do not forget any symptoms or questions, and usually proves very helpful to the doctor. Don't forget to give your doctor his copy at the start of your consultation!

Is GBS related to Multiple Sclerosis?
I have had several queries about whether Multiple Sclerosis (MS) is related to GBS/CIDP, and whether it is common to have a diagnosis of GBS/CIDP changed to MS.

Many doctors believe that both conditions may have related mechanisms. However, MS targets the central nervous system (CNS) while GBS/CIDP targets the peripheral nervous system (PNS). In other words, they target different systems. So while both conditions may induce weakness, the weakness is actually caused by damage to different areas of the body.

Like GBS/CIDP, MS can be very difficult to diagnose in the early stages. MS is diagnosed very thoroughly, so CIDP may be considered initially during the process of diagnosis as a possibility and then be ruled out. It is highly unlikely that a patient would go the other way around, from a diagnosis of GBS/CIDP to MS, especially if there is evidence of lesions to the CNS. MS is also much more common than CIDP, which is a very rare condition.

Although possible, it is extremely rare for a patient to suffer from both conditions. In such a case, damage would be found in both the CNS and PNS. Such a case was reported several years ago by Dr. Glass at the Emery Neurology Clinic in the US.

Please refer to the section below for further reading on the issue.

Further reading

Diagnosing an autoimmune disease
An Algorithm for the Evaluation of Peripheral Neuropathy
The steps your doctor has to go through to distinguish one kind
of peripheral neuropathy from another.
Distinguishing acute-onset CIDP from Guillain–Barré syndrome with treatment related fluctuations
Patients diagnosed with GBS who do not show improvement after 9 weeks may need to be reclassified as CIDP.
Getting the Best Out of Medical Consultations
Have you ever come away from a visit to your doctor or the specialist feeling dissatisfied, frustrated, and thinking, 'Why didn't I ask about ...?' or 'Why didn't I ask her what she meant by ...?' Here are some tips to help you remain calm and to give you confidence in a successful outcome.
GBS - diagnosis and misdiagnosis
Common symtoms that may be misdiagnosed.

GBS/CIDP and MS
The differences between GBS and MS.
National Multiple Sclerosis Society. An easy read.
An Algorithm for the Evaluation of Peripheral Neuropathy.
A. Poncelet. 1998.
Technical description of how doctors go about differentiating one neuropathy from another.
Final Diagnosis -- Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with onion bulb formation in hypertrophic nerves and co-existent multiple sclerosis (MS)
D. Quan and B.K. Kleinschmidt-DeMasters
Very technical discussion on differentiation of CIDP and MS in a patient.

Difficult diagnosis?
Mayo Clinic
Mayo Clinic specialises in diagnosing difficult cases and have great experience with neuropathy.
Tips for getting a proper diagnosis of an autoimmune disease
How patients with confusing, undiagnosed symptoms can help obtain a correct diagnosis.

- Lumbar puncture
Medicine.Net: Lumbar Puncture
What, why, how.....
Harvard health Guide: Lumbar Puncture
More information.

- Patient examinations procedures
EMG & NCV
More information on the procedures and what they may indicate.
The basics of MRI
All you ever want to know about MRI!
What is MRI
More on MRI.
When Do I Need an MRI Study of My Body? [reg. required, free]
A discussion guide for patients and caregivers.
Harvard health guide: EMG
Click "know more about this test" for more info.
What is SSEP
In-depth explanation.

- Case histories
English and foreign-language case histories that inspire and support patients and their families. Many contain descriptions of examinations and diagnostic procedures, some describe the frustration of not being able to get a diagnosis.