Meningitis
Summary/Definition
The human central nervous system includes the brain and spinal cord, surrounded by three meninges. The meninges, also called “brain tunic”, are the integuments that line both the brain and spinal cord. Meningitis is an inflammatory disease of the meninges, consisting of three layers that cover and protect the brain and spinal cord. This disease can be caused by various factors, including infections, physical injuries, cancer, or side effects from certain medications. Although cases of meningitis with a mild case that passes without specific treatment have been described, caution should be exercised, since the meninges are located close to the brain and spinal cord. Inflammation in this area can cause serious neurological damage, which, if complicated, can lead to disability or even death.
Meninges
The meninges are also known as “brain tunic” and refer to the layers that cover the brain and spinal cord. Meningitis is an inflammation that occurs in this area.
Cerebrospinal fluid
Cerebrospinal fluid is a fluid located in the arachnoid membrane, which is the middle of the three meninges. It serves to protect the brain and spinal cord.
In most cases, meningitis is an infectious disease caused by microorganisms such as viruses, bacteria and fungi that enter the cerebrospinal fluid through the bloodstream. However, there is also a form of non-infectious meningitis associated with cancer, systemic lupus erythematosus, or a reaction to certain medications.
Infectious meningitis can be caused by various microorganisms. Viruses can enter the body through the nose or mouth and enter the central nervous system, causing inflammation. Usually such meningitis goes away naturally within a few days. Bacteria, for example, Meningococcus, Pneumococcus, Hemophilus bacillus type b and Staphylococcus aureus, can cause acute bacterial meningitis, in which bacteria enter the central nervous system, causing acute purulent inflammation. In the case of bacterial meningitis, it is important to start taking antibacterial drugs immediately, as a delay can lead to fatal consequences. Frequent causative agents of bacterial meningitis are meningococci, pneumococci and hemophilic bacillus type b.
Symptoms
Symptoms of irritation of the meninges
Symptoms of irritation of the meninges include three characteristic signs: rigidity of the muscles of the occiput, photophobia and headache. In addition, the symptoms of Kernig and Brudzinsky are also present in the clinical picture. The rigidity of the occipital muscles is manifested in the inability to tilt the head forward. Kernig’s symptom is characterized by pain that occurs when trying to straighten the leg from the position of flexion of the hip and knee joints. Brudzinsky’s symptom suggests a patient’s reaction in which, when passively trying to bend his head in a supine position, his legs involuntarily bend due to irritation of the meninges.
Petechiae as a sign of meningitis
Meningitis caused by meningococcal infection is often accompanied by a petechial rash that spreads rapidly over the skin. This rash manifests itself in the form of uneven red or purple spots spreading to the trunk, lower limbs and the mucous membrane of the eyes.
Diagnostics
To diagnose meningitis, an analysis of cerebrospinal fluid is performed. Cerebrospinal fluid is a fluid located in the space between the meninges and the spinal cord. Its collection and analysis provide a wealth of data necessary for the diagnosis of meningitis. The study of cerebrospinal fluid includes measuring its pressure, analyzing its composition and bacteriological examination. The collection of cerebrospinal fluid is performed by lumbar puncture, in which the patient is in a position resembling the position of the embryo, lying on his side, and a long and thin needle is inserted through the back to extract the cerebrospinal fluid.
In addition, meningitis is diagnosed using blood tests, MRI and CT.
Treatment and course of the disease
Bacterial meningitis requires immediate medical attention, so it is extremely important to conduct an express diagnosis and begin empirical antibiotic therapy within 1 hour. If bacterial meningitis is suspected, doctors immediately begin administering antibiotics without waiting for the results of laboratory tests. Adjuvant therapy with steroids is carried out to reduce mortality, severe hearing loss and other neurological complications.
In some cases, viral meningitis can be cured quickly, without the need for hospitalization, and in other cases, symptomatic treatment may be required when assessing the condition for a certain time after hospitalization. Since the virus cannot be destroyed with antibiotics, symptomatic treatment is usually used. Headaches can be relieved with painkillers. There are also cases when headaches decrease after performing a lumbar puncture. If it is known that the cause of meningitis is the herpes virus, the drug acyclovir is prescribed (there is no special treatment besides this).
Complications
The mortality rate from meningitis varies depending on the cause or type of pathogen bacteria.
High mortality is observed among elderly patients over 50 years old suffering from acute bacterial meningitis, which is accompanied by impaired consciousness during hospitalization, increased intracranial pressure, shock and the need for artificial lung ventilation. Approximately 25% of the surviving patients may have long-term consequences, such as decreased intellectual abilities, memory impairment, seizures, hearing loss, dizziness and walking disorders.
In most cases of acute viral meningitis, a relatively mild clinical course is observed for 7 days, and in most cases the disease passes naturally without serious complications. However, some patients may develop chronic headaches, mild mental disorders and general weakness, which may last several weeks or even months.
