The diagnosis of meningitis is made through clinical observation of the symptoms of the disease and confirmed by means of an examination called a lumbar puncture, which consists of the removal of a small amount of CSF from the spinal canal. This test can show if there is inflammation in the meninges and which causative agent is essential for the diagnosis and to guide the treatment of the disease.
The tests and exams that can be ordered by the doctor are:
1. Assessment of symptoms
The initial diagnosis of meningitis is made through the evaluation of symptoms by the doctor, observing if the person feels pain or difficulty in moving the neck, has a high and sudden fever, dizziness, difficulty concentrating, sensitivity to light, lack of appetite, thirst and mental confusion, for example.
Based on the assessment of the symptoms presented by the patient, the doctor may request other tests to complete the diagnosis. Know other symptoms of meningitis.
2. CRL culture
CSF culture, also called cerebrospinal fluid or CSF, is one of the main laboratory tests requested for the diagnosis of meningitis. This examination consists of taking a sample of the CSF, which is a liquid found around the central nervous system, through a lumbar puncture, which is sent to the laboratory for analysis and research of microorganisms.
This test is uncomfortable, but quick, and usually causes headache and dizziness after the procedure, but in some cases it can relieve the symptoms of meningitis by lowering the cranial pressure.
The appearance of this liquid can already indicate whether the person has bacterial meningitis because in this case, the liquid can become cloudy and in the case of tuberculosis meningitis it can become slightly cloudy, in the other types the appearance can continue to be clean and transparent like water.
3. Blood and urine tests
Urine and blood tests may also be ordered to help diagnose meningitis. The urine test can indicate the presence of infections, due to the visualization of bacteria and countless leukocytes in the urine, and, thus, the urine culture can be indicated to identify the microorganism.
The blood test is also very requested to know the general condition of the person, which may indicate an increase in the number of leukocytes and neutrophils, in addition to being able to identify atypical lymphocytes, in the case of the CBC, and an increase in the concentration of CRP in the blood, being indicative of infection.
Normally when there is a sign of infection by bacteria, bacterioscopy can be recommended and, if the person is hospitalized, blood culture, which consists of culture of the blood sample in the laboratory to check for the presence of infection in the blood. In the case of bacterioscopy, the sample collected from the patient is stained by Gram stain and then analyzed under a microscope to check the characteristics of the bacterium and, thus, help in the diagnosis.
According to the results of the microbiological tests, it is also possible to check which antibiotic the microorganism is sensitive to, being the most recommended for the treatment of meningitis. Find out how meningitis is treated.
4. Imaging exams
Imaging tests, such as computed tomography and magnetic resonance imaging, are only indicated when brain damage or sequelae left by meningitis are suspected. There are suspicious signs when the person has seizures, changes in the size of the pupils of the eyes and if tuberculous meningitis is suspected.
When diagnosing the disease, the patient must remain in the hospital for a few days for the treatment to begin, based on antibiotics in case of bacterial meningitis or medications to lower the fever and reduce discomfort in case of viral meningitis.
5. Cup test
The cup test is a simple test that can be used to assist in the diagnosis of meningococcal meningitis, which is a type of bacterial meningitis characterized by the presence of red spots on the skin. The test consists of pressing a transparent glass cup on the arm and checking if the red spots remain and can be seen through the glass, which can characterize the disease.
