Meningitis, Introduction, Types, Pathophysiology and treatment

Meningitis, Types of Meningitis, sign & Symptoms of meningitis, pathophysiology of meningitis, diagnosis of meningitis, treatment of meningitis, prevention of meningitis.

1. MENINGITIS
Dr. V. Ganapathi Nayak
AssistantProfessor
PrathistaInstitute of Pharmaceutical
Sciences

2. INTRODUCTION TO MENINGITIS
●Meningitis is an inflammation of the protective membranes (meninges) surrounding the brain
and spinal cord. It can be caused by bacterial, viral, fungal, or parasitic infections, and in
some cases, non-infectious causes (such as cancer, medications, autoimmune diseases).
●Transmission: Bacterial and viral meningitis spread through respiratory droplets, close
contact, or contaminated food/ water.
●Fungal meningitis is not contagious and usually affects people with weakened immune
systems.
●Importance of Early Diagnosis: Meningitis can progress rapidly and may lead to severe
complications such as brain damage, hearing loss, seizures, or even death. Early recognition
of symptoms and prompt treatment are crucial in improving outcomes.
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3. TYPES OF MENINGITIS
●Bacterial Meningitis – The most severe form, requiring urgent medical treatment. Common
causes include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus
influenzae.
●Viral Meningitis – More common and usually less severe, often caused by enteroviruses,
herpes simplex virus, or mumps virus.
●Fungal Meningitis – Rare but serious, mostly affecting immunocompromised individuals (e.g.,
Cryptococcus).
●Parasitic & Non-Infectious Meningitis – Caused by parasites, autoimmune diseases, cancer,
or drug reactions.
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4. TYPES OF MENINGITIS
1. Bacterial Meningitis (Most Severe)A life-threatening infection requiring urgent medical
attention.
●Causes: Streptococcus pneumoniae (Pneumococcal meningitis)
●Neisseria meningitidis (Meningococcal meningitis)
●Haemophilus influenzae (Hib meningitis)
●Listeria monocytogenes (Affects newborns, elderly, immunocompromised)
●Transmission: Spread through respiratory droplets or bloodstream
●Symptoms: High fever, stiff neck, severe headache, confusion, seizures.
●Treatment: Intravenous (IV) antibiotics and corticosteroids.
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5. TYPES OF MENINGITIS
2. Viral Meningitis (Most Common & Milder)
●Usually self-limiting and less severe than bacterial meningitis.
●Causes: Enteroviruses (Coxsackievirus, Echovirus) – Most common.
●Herpes simplex virus (HSV-2)Mumps virus
●Varicella-zoster virus
●Transmission: Spread through fecal-oral route, respiratory droplets, or direct contact.
●Symptoms: Fever, headache, photophobia, mild neck stiffness, nausea.
●Treatment: Supportive care (fluids, pain relievers); antiviral therapy for HSV (Acyclovir).
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6. TYPES OF MENINGITIS
3. Fungal Meningitis (Rare but Serious)
●Occurs mainly in immunocompromised individuals (HIV/AIDS, organ transplant patients).
●Causes: Cryptococcus neoformans (Common in AIDS patients)
●Histoplasma capsulatum
●Candida species
●Transmission: Inhalation of fungal spores from the environment (not contagious).
●Symptoms: Slow onset of headache, fever, confusion, nausea.
●Treatment: Amphotericin B + Flucytosine, followed by long-term Fluconazole therapy.
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7. TYPES OF MENINGITIS
4. Parasitic Meningitis (Rare & Fatal)
●Caused by parasites infecting the brain through contaminated water or food.
●Causes: Naegleria fowleri (Brain-eating amoeba from freshwater)
●Angiostrongylus cantonensis (Rat lungworm)
●Transmission: Swimming in contaminated water or consuming infected food.
●Symptoms: Rapid-onset headache, fever, coma, death in severe cases.
●Treatment: Limited; supportive care and antifungal/antiparasitic drugs.
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8. TYPES OF MENINGITIS
●5. Non-Infectious Meningitis (Non-Contagious)
●Caused by autoimmune diseases, cancer, or medications.
●Causes: Autoimmune diseases (lupus, sarcoidosis)
●Cancer-related (leukemia, lymphoma)Drug reactions (NSAIDs, antibiotics)
●Symptoms: Similar to infectious meningitis but without fever.
●Treatment: Treat the underlying cause (e.g., immunosuppressants, steroids).
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9. SYMPTOMS OF MENINGITIS
●- Severe headache
●- Stiff neck
●- High fever
●- Nausea or vomiting
●- Sensitivity to light (photophobia)
●- Confusion or difficulty concentrating
●- Seizures (in severe cases)
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10. PATHOPHYSIOLOGY
1. Pathogen Entry into the Body
●Bacterial/Viral Entry: Pathogens enter the bloodstream through the respiratory tract, gastrointestinal tract, or skin.
●Direct Invasion: Trauma, neurosurgical procedures, sinusitis, or otitis media can allow direct spread to the meninges.
●Neural Spread: Some viruses (e.g., herpes simplex virus) travel via peripheral nerves to the central nervous system
(CNS).
2. Blood-Brain Barrier (BBB) DisruptionNormally, the blood-brain barrier (BBB) protects the CNS from infections
●Pathogens release toxins or provoke an immune response that increases BBB permeability, allowing bacteria,
viruses, or fungi to invade the cerebrospinal fluid (CSF).
3. Inflammatory Response in the CNS
●Once inside the CNS, pathogens trigger immune activation: Cytokines (IL-1, IL-6, TNF-α) and inflammatory
mediators are released.
●Neutrophils and macrophages migrate to the CSF, leading to increased permeability of blood vessels. This results in
vasodilation, edema, and increased intracranial pressure (ICP).
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11. PATHOPHYSIOLOGY
●4. Cerebral Dysfunction and Complications
●Increased Intracranial Pressure (ICP): Swelling of the brain due to inflammation leads to headache,
nausea, and altered consciousness.
●Reduced Cerebral Blood Flow: Inflammation can cause vasculitis and thrombosis, leading to ischemia
and infarction.
●Nerve Damage: Cranial nerve involvement can cause hearing loss, seizures, or paralysis.
●Hydrocephalus: Impaired CSF absorption due to inflammation can lead to fluid accumulation and
increased pressure on the brain.
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12. COMPLICATIONS
●Sensory-neural hearing loss
●Epilepsy/ seizures
●Memory loss
●Paralysis
●Learning difficulty
●Altered behavior
●Decreased intelligence
●Septicemia
●Death
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13. RISK FACTORS
1. Age;
●Infants & Young Children: Higher risk for bacterial and viral meningitis due to an immature immune
system.
●Elderly (65+ years): Increased risk, especially for Streptococcus pneumoniae and Listeria
monocytogenes.
2. Weakened Immune System
●HIV/AIDS, Cancer & Chemotherapy, Diabetes, Organ Transplant Recipients (Immunosuppressive
drugs)
●Long-term steroid use (e.g., in autoimmune diseases)
●Splenectomy (Surgical removal of the spleen) – Higher risk for Neisseria meningitidis infections.
3. Living in Close Quarters, College dormitories, Military barracks, Daycare centers, Prisons.
●Meningococcal meningitis spreads more easily in crowded settings.
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14. RISK FACTORS
4. Unvaccinated Individuals
●Lack of meningococcal, pneumococcal, Hib, or MMR vaccines increases the risk.
●Hib vaccine (Haemophilus influenzae type B) has significantly reduced bacterial meningitis in children.
5. Exposure to Infected Individuals, Respiratory droplets (coughing, sneezing, kissing, sharing utensils).
●Close contact with someone with bacterial or viral meningitis increases risk.
6. Skull or Spinal Cord Injuries, Head trauma or skull fractures – May allow bacteria to enter the meninges.
●Recent brain or spinal surgery – Increases risk of post-surgical meningitis.
7. Traveling to High-Risk Areas
●Sub-Saharan Africa ("Meningitis Belt") – High rates of meningococcal meningitis. Hajj Pilgrimage (Saudi
Arabia) – Requires meningococcal vaccination.
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15. RISK FACTORS
8. Exposure to Contaminated Water or Food
●Swimming in warm freshwater lakes/rivers – Risk of Naegleria fowleri (brain-eating amoeba).
●Eating contaminated dairy products – Risk of Listeria infection.
9. PregnancyPregnant women are at higher risk of Listeria meningitis, which can infect the baby.
●Prevention: Avoid unpasteurized dairy products and undercooked meat.
10. Certain Medical Conditions: Chronic sinus infections or ear infections (Otitis media,
Sinusitis) – Can spread to the brain.
●Hydrocephalus & CSF shunts – Increases risk of bacterial meningitis.
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16. DIAGNOSIS OF MENINGITIS
●History taking
●Physical examination
●Lumbar puncture (CSF analysis): Identifies bacteria, viruses, or fungi.
●Blood cultures: Detects bacteria in the bloodstream.
●Imaging (CT/MRI scan): Helps rule out brain swelling or other causes.
●Polymerase Chain Reaction (PCR): Detects viral genetic material.
●Serology Tests: Identifies antibodies against specific pathogens.
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17. TREATMENT
●Empirical Therapy (Before culture results):
●- Adults & children: Ceftriaxone 2g IV every 12 hours OR Cefotaxime 2g IV every 6 hours
PLUS Vancomycin 15-20 mg/kg IV every 8-12 hours.
●- Neonates: Ampicillin 50-100 mg/kg IV every 6 hours PLUS Gentamicin 2.5 mg/kg IV every 8
hours.
●Specific Treatment (After culture results):
●- Streptococcus pneumoniae: Ceftriaxone or Cefotaxime for 10-14 days
●- Neisseria meningitidis: Ceftriaxone for 7 days
●- Haemophilus influenzae: Cefotaxime for 7-10 days
●- Listeria monocytogenes: Ampicillin for 21 days
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18. TREATMENT
●- Most cases are self-limiting and require supportive care.
●- Herpes Simplex Virus (HSV) Meningitis: Acyclovir 10 mg/kg IV every 8 hours for 10-14 days.
●- Enteroviral Meningitis: Supportive care, fluids, and pain management.
●- Severe cases (immunocompromised): Consider IV antivirals and hospitalization.
●- Cryptococcal Meningitis (HIV/AIDS patients):
● - Induction: Amphotericin B 0.7-1 mg/kg IV daily PLUS Flucytosine 100 mg/kg/day (divided
doses) for 2 weeks
● - Consolidation: Fluconazole 400 mg PO daily for 8 weeks
● - Maintenance: Fluconazole 200 mg PO daily for 6-12 months.
●- Other fungal infections: Specific antifungal based on culture results.
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19. PREVENTION OF MENINGITIS
●Vaccination:
● - Pneumococcal vaccine (PCV13, PPSV23)
● - Meningococcal vaccine (MenACWY, MenB)
● - Haemophilus influenzae type B (Hib) vaccine
●Prophylactic Antibiotics:
● - Close contacts of meningococcal meningitis patients: Rifampin 600 mg PO BID for 2 days
OR Ciprofloxacin 500 mg PO single dose.
●General Preventive Measures:
● - Hand hygiene, avoiding close contact with infected individuals, and boosting immune
health.
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20. CONCLUSION
●Meningitis can be life-threatening if not treated promptly.
●Bacterial meningitis requires urgent antibiotic treatment.
●Viral meningitis is usually self-limiting but may need antiviral therapy in severe cases.
●Vaccination and prophylaxis play a critical role in prevention.
●Early diagnosis and treatment significantly improve outcomes.
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21. THANK
YOU
Dr. V, Ganapathi
[email protected]
Assistant professor