Meningitis is an acute infection of the meninges presenting with:
• Pyrexia
• Headache
• Meningism
ETIOLOGY
1. INFECTIVE -Bacterial,Viral Protozoal and fungal
2. Non- INFECTIVE:
Malignancy- CA Breast, CA Bronchus, Leukemia Inflammatory- SLE, Sarcoidosis
Bacterial
• Neonates–Gram Negative bacilli, Group B Streptococcus • Preschool- Haemophilus, menningococcus, Streptococcus pneumonae, TB
Older-meningococcus, S pneumonae, TB, Staph, Haemophilus
Viral – Polio, mumps, influenza, Herpes, Varicella
Protozoa Cysticercus, Amoebic
Fungi. Cryptococcus, candida
FEATURES OF BACTERIAL MENINGITIS
1. Can be direct spread from CSOM, Fracture skull, Sinus
2. Air borne infection close contacts, epidemics
• Commonest organism -H influenza, S pneumonae
• Pia Mater and Archnoid are congested and inflammatory cellsare present. Pus may form.
• Adhesions may lead to Hydrocephalus and Cranial nerve damage.
• Cerebral infarcts may be present
CLINICAL FEATURES:
• Severe Headache
• Drowsiness
• Fever
• Neck stiffness
• Coma
• Focal neurological deficits
• Rash
FEATURES OF VIRAL MENINGITIS:
• Benign,self limiting, less serious • Severe headache, Meningism, high Pyrexia • No Focal neurological signs
• CSF shows lymphocytosis
COMPLICATIONS:
• Shock
• Renal failure
• Pericarditis
• Intravascular coagulation
INVESTIGATIONS:
1.CSF – pressure is raised, cloudy appearance, increased proteins Low Glucose levels, Raised WBC(Neutrophils).
2.CSF for gram stain and culture
3. CT Scan
4. Blood culture
5.PCR on blood and CSF
TB MENINGITIS
• Caeseous focus in brain/meninges
• Exudate is greenish and gelatinous • Presence of Tubercles
• Clinical features:
Headache, low grade fever, vomiting, behavioural changes, meningism, altered consciousness, focal signs
• Investigations:
1. CSF- increased pressure, clear appearance, cobweb formation Increased WBC (lymphocytes), high proteins, very low Glucose levels
2. CSF for Z N stain and culture
3. imaging- Hydrocephalus and tuberculoma