Pathology, Presentation, and Treatment of Meningitis

Meningitis by definition is the inflammation of the meninges, the three layered protective membrane that surrounds the central nervous system. The meninges are comprised of the Dura mater, the Arachnoid mater, and the innermost Pia mater. It is of utmost importance to determine if bacteria, virus, fungus, toxins, or parasites, caused the inflammation, and treat the microorganism quickly and efficiently to give the best prognosis. It is of utmost importance to determine the cause of inflammation (i.e. bacteria, virus, fungus, toxins). While viral or aseptic meningitis only need supportive treatment, bacterial meningitis is one of the ten most common causes of death by infectious disease killing approximately 135,000 people a year (Waghdhare, Kalantri, Joshi, & Kalantri, 2010).

Pathophysiology

In order to infect the meninges, pathogens must cross the blood brain barrier. According to Myers, Director of Infection Control at Scripps Mercy hospital (2000), pathogens enter through an open wound, surgical incision, or a mucus membrane. Systemic infections can also result in meningitis (Huether & McCance, 2012) with typical invasion occurring through the middle ear or during respiratory tract infections (Myers, 2000). Bacteria elude the body’s immune defenses with their capsule; viruses hide within the body’s own cells and invade the cerebrospinal fluid through the cerebral capillary system (Myers, 2000).

Once inside, the pathogens cause inflammation of blood vessels, infarcts (necrosis due to obstructed blood flow), edema, hydrocephalus caused by arachnoid villi obstruction (location that reabsorbs CSF) (Huether & McCance, 2012), and decreased cerebral blood flow (Myers 2000).

According to Huether and McCance, authors of Understandi...

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