Difficult diagnosis

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The first symptoms of multiple sclerosis are often mild, temporary and do not force you to see a doctor. Only subsequent, stronger attacks of the disease make the patient remember about previous episodes of malaise.

As much as about 85 percent. patients initially experience only one symptom of the nervous system. This is due to the fact that in the white matter of the central nervous system there was only one point of demyelination. This clinical picture is called a clinically isolated symptom. It is supposed that this is how the relapsing-remitting form of the disease develops, i.e. one in which there is a temporary exacerbation of symptoms called relapses and improvement in health, i.e. remission. In the remaining 15 percent. patients experience a gradual, slow deterioration in functioning. This group is usually affected by the primary progressive form of the disease.

Disturbing symptoms

– The first symptoms of Multiple Sclerosis can vary greatly. The most common are:

– Sensory changes in the limbs or face (33%)

– Deterioration of visual acuity, retrobulbar optic neuritis (16%)

– Double vision (7%)

– Weakness, chronic fatigue syndrome (13%)

– Difficulty moving

– Balance problems, dizziness (3%).

These health problems can be so nonspecific that, as long as they are mild, the patient rarely reports them to a doctor. If he mentions them to the general practitioner, he will receive a prescription for vitamins or other fortifying preparations, rather than a referral to a specialist. Usually, it is only an acute attack of the disease that the patient goes to a neurologist or to a hospital, to a neurological ward, only then and has a chance to be diagnosed.

Diagnostic difficulties

Multiple sclerosis is not an easily diagnosed disease. There is no single specific diagnostic test for “MS”. The neurologist usually starts with a detailed interview in which he or she determines the current symptoms and current health status. In the course of your interview, you may find that some previous symptoms may suggest multiple sclerosis. However, a complete neurological examination as well as medical tests and examinations are needed to confirm the diagnosis.

A neurological examination checks the proper functioning of the nervous system. The neurologist checks for any deviations from the normal operation of the nerve connections that send signals from the brain to other organs and parts of the body. Checks, among others the occurrence of changes in the movement of the eyeballs, motor coordination, muscle strength, maintaining the balance of the body, functioning of the sense organs, speech and reflexes. This test may also reveal symptoms that indicate MS, although it cannot be used to determine the cause of any problems you are having. Other diseases that give symptoms similar to those of MS must be eliminated.

Diagnostic tests

There are no specific tests for for multiple sclerosis, scientists are constantly modifying the diagnostic criteria for multiple sclerosis. The most important diagnostic factors are: magnetic resonance imaging (MRI), examination of the cerebrospinal fluid and examination of evoked potentials (analysis of the electric potential of a selected nervous structure in response to a visual, auditory or sensory stimulus).

Magnetic resonance imaging (Ang. MRI – magnetic resonance imaging) of the brain and spinal cord is a completely non-invasive, painless test. In order to obtain better visibility of the diseased areas, sometimes a contrast agent is administered intravenously before the examination – gadolinium. Magnetic resonance imaging allows, for example, to determine whether there are areas of demyelination in the CNS (devoid of the protein coat of the nerve – myelin), which indicate multiple sclerosis. These lesions are sometimes called posters. It sometimes happens, however, that the MRI result is ambiguous. In this case, additional tests are used: examination of the cerebrospinal fluid, visual evoked potentials.

Examination of the cerebrospinal fluid requires the collection of this fluid by inserting a puncture needle into the spinal canal (subarachnoid space). The most common puncture is done in the lumbar region. The examination is performed under local anesthesia. As it is an invasive activity, the patient has to sign the consent. After taking the fluid for an hour, the patient should lie on his stomach, then he can lie down on his back. You must not look up. The bed regime is valid for 24 hours. On the first and second day after the examination, you should drink more fluids (about 2 – 3 liters of water, tea or juices).

The analysis of the cerebrospinal fluid allows to determine, among others whether there is inflammation in the central nervous system. In addition, the level of immunoglobulin is determined. The correct IgG index is below 0,72, and the values ​​above 0,72 indicate intra-fluid synthesis of immunoglobulins. IgG index values ​​exceeding 0,72 occur in over 73% of people with MS. It is also important to determine oligoclonal crustaceans, as up to 98% of people with MS have oligoclonal bands in the cerebrospinal fluid.

Other tests used in the diagnosis of multiple sclerosis are test of evoked potentials, i.e. examination of visual, auditory and somatosensory potentials. They are performed to measure the speed at which signals from the brain travel through the nerves. The time it takes the nerves to transmit signals from the brain is an indicator of the state of the nervous system and helps to recognize whether demyelination (breakdown of the myelin sheath) has occurred. In the event of multiple sclerosis, the information transmission time is extended. The speed of signal transmission through the nervous system is measured by placing small electrodes on the head that monitor the brain waves generated in response to visual, auditory or sensory stimuli. The most useful of the three types of tests is the visual potential (VEP) test. The above tests are not invasive or painful, and therefore do not require a hospital stay, and can be performed on an outpatient basis.

Unfortunately, it happens that even the performance of all these tests does not give a clear diagnosis, because in many neurological diseases similar changes occur in the nervous system and thus similar test results, including MRI results, are obtained. In such situations, tests are carried out to exclude other possible symptoms of the disease. It is worth saying that currently, in order to establish the so-called The Mc Donald criteria introduced in 2000 are used for a clinically certain diagnosis of MS. They use the results of both clinical trials and diagnostic tests. In 2005, these criteria were subject to some clarifications and revisions. Briefly speaking, clinically, certain multiple sclerosis is when there are at least two demyelinating lesions in the CNS, scattered over time and space.

Text: Iza Czarnecka

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