MENINGITIS

PRERNA FOR IAS

MENINGITIS

1. Definition of Meningitis

Meningitis is the inflammation of the meninges, the protective membranes covering the brain and spinal cord. The three layers of meninges are the dura mater, arachnoid mater, and pia mater. Meningitis is most commonly caused by infections due to bacteria, viruses, fungi, or parasites, although certain drugs and autoimmune disorders may also trigger it. The inflammation increases pressure around the brain and spinal cord, leading to severe symptoms. Meningitis can affect people of all ages, but infants, young children, elderly individuals, and people with weakened immune systems are at higher risk. Early diagnosis and treatment are essential.

2. Meninges

The meninges are three protective membranes that surround and protect the brain and spinal cord. The outermost layer is the dura mater, a tough and fibrous membrane that provides mechanical protection. The middle layer is the arachnoid mater, a delicate membrane separated from the pia mater by the subarachnoid space, which contains cerebrospinal fluid (CSF). The innermost layer is the pia mater, a thin, highly vascular membrane closely attached to the surface of the brain and spinal cord. Together, these membranes protect the central nervous system, support blood vessels, and help circulate cerebrospinal fluid.

3. Causes of Meningitis

Meningitis can result from several infectious and non-infectious causes. Bacterial meningitis is the most severe form and requires emergency treatment. Viral meningitis is the most common type and is usually less severe. Fungal meningitis mainly affects people with weakened immune systems, while parasitic meningitis is rare but can be serious. Non-infectious causes include certain medications, autoimmune diseases, and cancers. The infection spreads through respiratory droplets, direct contact, or contaminated food, depending on the organism involved. Identifying the exact cause is important because treatment differs for bacterial, viral, fungal, and parasitic meningitis.

4. Symptoms of Meningitis