Overview
Meningitis is the infection of the membranous tissue (the meninges) surrounding the brain and the spinal cord. The meninges are composed of three layers; The Dura mater, the Arachnoid mater, and the Pia mater. In meningitis, the inflammation is basically of the Arachnoid and Pia mater, which are collectively known as the leptomeninges.
Causes
Meningitis is usually an infectious disease, of either bacterial, viral, or fungal origin. The organisms that can cause meningitis are listed below:
Bacteria:
- Streptococcus pneumoniae
- Neisseria meningitidis
- Haemophilus influenzae
- Listeria monocytogenes
- Mycobacterium Tuberculosis (Chronic meningitis)
Viral:
- Enteroviruses
- Herpes simplex virus
- HIV
- Mumps virus
- West nile virus
Symptoms
Initially, the symptoms of this health condition may mimic flu, but eventually, over the course of a few hours, to a few days, some of the following symptoms develop (in patients older than 2 years):
- High-grade fever
- Neck stiffness
- Severe headache
- Nausea or vomiting
- Confusion or difficulty concentrating
- Seizures
- Sleepiness
- Sensitivity to light
- No appetite or thirst
- Skin rash (sometimes, such as in meningococcal meningitis)
In infants, however, the symptoms are a little different:
- High fever
- Constant crying
- Excessive sleepiness or irritability
- Inactivity or sluggishness
- Poor feeding
- A bulge in the soft spot on top of a baby’s head (this soft spot is called the anterior fontanelle)
- Stiffness in a baby’s body and neck
Diagnosis
These are some of the diagnostic tests that can be conducted:
- Blood cultures
- CT scan
- MRI
- Spinal tap
Treatment
Treatment is dependent on the cause;
- Bacterial – I/V antibiotics and corticosteroids
- Viral – Bed rest, Fluids, Over the counter pain meds
