Diagnostic guidelines | Diagnosis of polyneuropathy

Diagnostic guidelines

In order to diagnose polyneuropathy, doctors often proceed after certain examinations. Different examinations can indicate a polyneuropathy or, depending on the results, exclude it and another disease is responsible for the symptoms. Since different forms and manifestations of polyneuropathy are known, the examinations can also provide information about it.

In the foreground of the diagnosis is a detailed anamnesis of the symptoms. This is followed by the clinical findings, which provide conclusions about the extent of the symptoms and thus make an important contribution to classification. Here signs of acute or chronic, symmetrical or asymmetrical polyneuropathy can be clarified.

(see: symptoms of polyneuropathy)Next, the damage to the nerves is considered. For this purpose, electrophysiological examinations such as the measurement of nerve conduction velocity are performed. They provide information about the type of damage to the peripheral nerves.

A distinction is made between an inner (axonal) and an outer (demyelinating) pattern of damage.It can also be used to check whether the nerve still transmits excitation or whether it no longer reaches muscle areas and therefore no longer innovates. Blood tests and liquor tests are performed to search for possible causes. Different values can give an indication of a basic disease or an acute inflammation.

The laboratory offers the possibility to consider many factors and can also be expanded. Since polyneuropathies also have genetic factors, a genetic examination should be done if, especially if polyneuropathies are already known in the family. A reliable diagnosis can be made by a nerve biopsy. It is performed especially if there is a suspicion that the polyneuropathy is treatable. (see: Polyneuropathy therapy)

Laboratory for a polyneurpathy

Laboratory tests are used to search for the cause of polyneurpathies. Therefore, the laboratory chemical examination includes basic diagnostic tests and those with suspicion of a certain disease. The basic diagnostics include parameters such as the blood sedimentation rate and CRP.

Both values serve to clarify an inflammation. Furthermore, the individual electrolytes such as calcium and magnesium are checked as well as the typical values for checking liver and kidney function. Since polyneuropathy can also be caused by diabetes mellitus, the blood is also searched for indications of diabetes.

In most cases, fasting blood glucose is checked and a daily blood glucose profile is created and a glucose tolerance test is performed. In the blood the HbA1C value gives first indications of a sugar rank. This is a non-enzymatic saccharification of hemoglobin in the blood when the sugar content is particularly high. In order to exclude or detect other diseases, various vitamins, antibodies and immunoglobulins are tested. Alcohol abuse can also be the cause of polyneurpathies, so the transaminases in the blood are also tested, which are usually greatly increased when alcohol is consumed frequently and excessively.