Meningitis involves:
Bacterial or Viral Infection: Typically caused by bacteria (such as Neisseria meningitidis, Streptococcus pneumoniae) or viruses (such as enteroviruses). These pathogens invade the meninges, the protective membranes covering the brain and spinal cord.
Inflammatory Response: The infection triggers an inflammatory response in the meninges, leading to swelling (edema) and increased pressure on the brain.
Blood-Brain Barrier: Infection breaches the blood-brain barrier, allowing pathogens and inflammatory cells to enter the cerebrospinal fluid (CSF) surrounding the brain and spinal cord.
Complications: Severe cases can lead to neurological damage, seizures, coma, and death.
Clinical Evaluation
Symptoms: Assessment of symptoms such as sudden onset of fever, severe headache, stiff neck (meningismus), sensitivity to light (photophobia), nausea, and vomiting.
Physical Examination: Examination findings may include altered mental status, focal neurological deficits, and signs of meningeal irritation (Brudzinski's sign, Kernig's sign).
Diagnostic Tests: Lumbar puncture (spinal tap) to analyze CSF for pathogens, imaging studies (such as CT scan or MRI) to assess for complications like cerebral edema or abscesses.
Sudden onset of high fever and chills.
Severe headache, often described as "the worst headache of my life."
Stiff neck (neck stiffness) and pain when trying to touch the chin to the chest.
Nausea, vomiting, and sensitivity to light (photophobia).
Altered mental status, confusion, or difficulty concentrating.
Petechial rash (in some bacterial meningitis cases, like Neisseria meningitidis).
Early treatment is critical to reduce complications and mortality:
Antibiotic or Antiviral Therapy: Prompt administration of antibiotics for bacterial meningitis or antiviral medications for viral meningitis.
Supportive Care: Intravenous fluids, pain management, and medications to reduce brain swelling.
Isolation Precautions: Isolation of patients with bacterial meningitis to prevent spread.
Monitoring and Surveillance: Close monitoring in an intensive care unit (ICU) for vital signs, neurological status, and response to treatment.
Vaccination: Vaccination against common pathogens like Haemophilus influenzae type b (Hib) and meningococcus can prevent some forms of meningitis.