Meningitis - Symptoms, Causes, and Treatment PDF

MENINGITIS Meningitis is an inflammation of the meninges, the protective membranes covering the brain and spinal cord. It can be caused by infections (bacterial, viral, fungal, parasitic) or non-infectious factors (autoimmune diseases, cancer, drug reactions). ...

MENINGITIS Meningitis is an inflammation of the meninges, the protective membranes covering the brain and spinal cord. It can be caused by infections (bacterial, viral, fungal, parasitic) or non-infectious factors (autoimmune diseases, cancer, drug reactions).  Types of Meningitis Bacterial Meningitis o Pathogens: Commonly caused by Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type B (Hib), Listeria monocytogenes. o Severity: Life-threatening and requires urgent treatment. o Mode of Transmission: Respiratory droplets or direct contact. Viral Meningitis o Pathogens: Most often caused by enteroviruses, but also by herpes simplex virus, varicella-zoster virus, or arboviruses. o Severity: Less severe than bacterial; usually self-limiting. o Mode of Transmission: Fecal-oral route, respiratory droplets, or insect bites.  Fungal Meningitis o Pathogens: Commonly caused by Cryptococcus neoformans or Histoplasma capsulatum. o Risk Factors: Immunosuppressed individuals (e.g., HIV/AIDS). o Transmission: Rare, usually through environmental exposure. Parasitic Meningitis o Rare and caused by parasites like Naegleria fowleri (amoebic meningitis). o Often fatal and associated with exposure to warm freshwater.  Non-infectious Meningitis Causes: Autoimmune diseases, malignancies, medications (e.g., NSAIDs, antibiotics), and trauma. Pathophysiology Pathogens invade the central nervous system (CNS) through the bloodstream or direct extension from infected adjacent structures. Inflammatory cytokines increase blood-brain barrier permeability, leading to: o Edema (swelling of the brain) o Increased intracranial pressure (ICP) o Altered cerebral perfusion o Neurological dysfunction Risk Factors Demographics: o Age (infants and elderly at higher risk) o Community living (e.g., dormitories, military barracks) Medical Conditions: o Immunosuppression (e.g., HIV/AIDS, cancer) o Recent neurosurgery or head trauma Vaccination Status: o Lack of vaccination for pathogens like Hib, meningococcal, or pneumococcal bacteria.  Clinical Features Classic Triad: oFever oNeck stiffness (nuchal rigidity) oAltered mental status (confusion, drowsiness) Other Symptoms: oSevere headache oPhotophobia (sensitivity to light) oNausea and vomiting oSeizures (in severe cases) Signs in Infants: oBulging fontanelle oPoor feeding oIrritability oHypotonia  Diagnosis Clinical Examination: oKernig’s Sign: Pain with knee extension when hip is flexed. oBrudzinski’s Sign: Involuntary hip and knee flexion upon neck flexion.  Lumbar Puncture:  Analyzes cerebrospinal fluid (CSF) for:  White blood cell count  Glucose levels (decreased in bacterial meningitis)  Protein levels (elevated in bacterial meningitis)  Pathogens (via Gram stain, PCR, or culture) Imaging: o CT or MRI to rule out brain abscess or elevated ICP before lumbar puncture.  CSF Findings in Meningitis Parameter Bacterial Viral Fungal Tuberculous Appearance Turbid Clear/Cloudy Clear/Cloudy Clear/Cloudy WBC Count High (PMNs) Moderate (lymph) Moderate (lymph) Moderate (lymph) Glucose Low Normal Low Low Protein High Normal/Mildly High High High  Management Bacterial Meningitis: oEmpiric Antibiotics (based on age and risk factors):  Neonates: Ampicillin + Cefotaxime or Gentamicin.  Adults: Ceftriaxone + Vancomycin. oAdjunct Therapy:  Dexamethasone to reduce inflammation  Viral Meningitis: o Supportive care (hydration, pain relief, fever management). o Antivirals (e.g., acyclovir for herpes-related cases). Fungal Meningitis: o Antifungal therapy (e.g., Amphotericin B + Flucytosine).  Prevention: oVaccination: Hib, pneumococcal, meningococcal. oProphylactic antibiotics for close contacts (e.g., rifampin for meningococcal exposure).  Complications  Seizures  Hydrocephalus  Hearing loss  Cognitive impairment  Death (in severe cases of bacterial meningitis)  Prevention Vaccinations: o Hib vaccine o Pneumococcal conjugate vaccine (PCV) o Meningococcal vaccines (MenACWY, MenB) Hygiene Measures: o Frequent handwashing. o Avoiding close contact with infected individuals. Prophylaxis: o Antibiotics for exposed individuals in meningococcal outbreaks.  Prognosis Bacterial Meningitis: o High mortality without treatment; survivors may have lasting neurological deficits. Viral Meningitis: o Generally good prognosis; resolves within 7–10 days. Fungal/Chronic Meningitis: o Variable prognosis; depends on timely treatment and underlying immune status.