Diagnostics
In diagnostics, the search for the pathogen is in the foreground, since therapies against different pathogens sometimes differ fundamentally. For this purpose, cerebrospinal fluid, also known as liquor, is collected and examined during a lumbar puncture. A suitable treatment can often be found under the microscope or after cultivation on growth plates.
In addition, a PCR (polymerase chain reaction) can be used to detect the pathogen directly in the cerebrospinal fluid. Since the results of laboratory diagnostics are not immediately available, additional physical examinations and imaging procedures such as CT (computed tomography) and MRI (magnetic resonance imaging) of the brain are performed. The physical examination focuses on neurological symptoms such as loss of motor functions or sensory disturbances, disturbances of consciousness, and unusual pain sensation.
In meningitis, the latter causes a meningismus sign or a defensive tension in the patient when the head is passively tilted towards the chest in a lying position. The physical examination can be used to determine the location of the inflammation in the brain. The EEG (electroencephalogram) is also used as a diagnostic tool.
The excitation in the brain is measured and the functional capability or restriction is assessed. A very good diagnostic tool in the case of suspected inflammation of the brain is the examination of cerebrospinal fluid, also called liquor. The cerebrospinal fluid surrounds the central nervous system and has many functions, such as damping vibrations, disposing of waste products and many others.
If an inflammation of the brain now occurs, certain substances and cells can be detected in increased numbers in the cerebrospinal fluid. These include an increased number of white blood cells (neutrophil granulocytes) and an increased lactate and protein level. As a rule, the cerebrospinal fluid is removed for such an examination by means of a lumbar puncture. This involves sticking a needle in the cerebrospinal fluid space surrounding the spinal cord with a needle on the lumbar spine, from which the cerebrospinal fluid can be extracted.