Meningitis
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1- Introduction
2- Pathophysiology
3- Symptoms
4- Treatment
Introduction
Meningitis is a medical condition characterized by inflammation of the protective membranes (meninges) surrounding the brain and spinal cord. It can be caused by infectious agents such as bacteria, viruses, fungi, or parasites, as well as non-infectious causes like certain medications, cancer, or autoimmune disorders. Meningitis often presents with symptoms such as severe headache, fever, sensitivity to light, stiff neck, and altered mental status. Prompt diagnosis and treatment are crucial as bacterial meningitis, in particular, can be life-threatening without timely medical intervention. Treatment varies depending on the cause and may include antibiotics, antiviral medications, or supportive care to manage symptoms and prevent complications.
Pathophysiology
Meningitis refers to inflammation of the meninges, the protective membranes covering the brain and spinal cord. This condition can be caused by various infectious agents such as bacteria, viruses, fungi, or parasites. These microorganisms can enter the bloodstream and reach the central nervous system, leading to an immune response that triggers inflammation of the meninges. This inflammatory process can impair the normal function of the brain and spinal cord, affecting their ability to regulate bodily functions and processes.
Physiologically, meningitis disrupts the blood-brain barrier, allowing inflammatory cells and substances to accumulate in the cerebrospinal fluid (CSF), which bathes the brain and spinal cord. This accumulation leads to increased pressure within the skull, causing symptoms such as severe headache, fever, and sensitivity to light (photophobia). Stiff neck (neck stiffness) is another hallmark symptom, reflecting irritation of the meninges and limited flexibility of the neck muscles.
In more severe cases, meningitis can progress rapidly, causing confusion, altered mental status, seizures, and even coma if left untreated. Bacterial meningitis, in particular, can be life-threatening due to the rapid spread of bacteria and the potential for serious complications such as brain damage, hearing loss, or even death
Symptoms
Severe Headache: Often sudden and intense, accompanied by sensitivity to light (photophobia) and sound.
Fever: High body temperature, sometimes with chills.
Stiff Neck: Neck stiffness or pain, especially when trying to touch the chin to the chest.
Nausea and Vomiting: Especially common in bacterial meningitis.
Sensitivity to Light (Photophobia): Discomfort or pain in the eyes when exposed to light.
Altered Mental Status: Confusion, irritability, difficulty concentrating, and in severe cases, seizures or coma.
Skin Rash: In some cases of meningococcal meningitis caused by Neisseria meningitidis, a characteristic purple or red rash may develop that does not fade with pressure (petechiae).
Seizures: Especially in young children or infants.
Decreased Appetite: Loss of appetite or refusal to eat.
Stiffness or Pain in Joints or Muscles: Particularly in viral meningitis.
Sleepiness or Difficulty Waking Up: In severe cases, individuals may become lethargic or difficult to rouse.
In infants: Symptoms may include irritability, poor feeding, high-pitched cry, and bulging fontanelle (soft spot on the top of the head).
Treatment
Bacterial Meningitis:
- Antibiotics: Immediate administration of antibiotics is essential once bacterial meningitis is suspected or diagnosed. The choice of antibiotics depends on the suspected bacterial species and local resistance patterns. Commonly used antibiotics include third-generation cephalosporins (e.g., ceftriaxone or cefotaxime) in combination with vancomycin or ampicillin until the specific bacteria are identified.
- Supportive Care: Supportive measures such as intravenous fluids, oxygen therapy, and medications to reduce fever and manage seizures are also provided.
- Isolation: Patients with bacterial meningitis may need to be isolated until they are no longer contagious.
Viral Meningitis:
- Antiviral Medications: In cases of viral meningitis caused by herpesviruses or other specific viruses, antiviral medications such as acyclovir or ganciclovir may be used to reduce viral replication and symptoms.
- Supportive Care: Similar to bacterial meningitis, supportive care including hydration, pain relief, and monitoring of neurological status is important.
Fungal Meningitis:
- Antifungal Medications: Treatment of fungal meningitis involves antifungal medications such as amphotericin B, flucytosine, or fluconazole, depending on the specific fungal species causing the infection. Treatment duration is often prolonged and requires careful monitoring.
Other Causes (Non-infectious Meningitis):
- Treatment for non-infectious causes of meningitis (e.g., autoimmune, chemical) may involve corticosteroids to reduce inflammation and other medications tailored to the underlying condition.
Supportive Care:
- Regardless of the cause, supportive care plays a critical role in managing meningitis. This includes close monitoring of vital signs, neurological status, and hydration levels. Pain relief, fever management, and addressing complications such as seizures are also part of supportive care.
Vaccination:
- Prevention through vaccination is key, especially for bacterial meningitis caused by vaccine-preventable pathogens such as Haemophilus influenzae type b (Hib), Neisseria meningitidis, and Streptococcus pneumoniae. Vaccination programs have significantly reduced the incidence of meningitis in many countries.