History
- Headache (onset, location, duration, severity, characteristics, alleviating/aggravating factors, radiation, symptoms associated – N/V, fever, neck stiffness, seizures, altered sensorium, photophobia, lethargy, poor feeding)
- Previous URTI, otitis media, sinusitis, odontogenic
- Previous neurosurgical procedures, penetrating head trauma
- Infectious contacts
- Immunocompromised states (cancer, EtOH, etc)
Physical exam
- ABCs
- Head and neck (neuro)
- Neck – nuchal rigidity, lymphadenopathy
- Look for focal neurologic signs (full neurological exam): CN (3,4,6,7 primarily affected), motor, sensory, reflexes, coordination
- Eyes – papilledema
- Ears – otitis media
- Dermatological: look for nonblanching petechiae and cutaneous hemorrhages
- Special signs
- Kernig’s sign: with hip at 90O, patient will resist passive knee extension
- Brudzinski’s sign: with passive neck flexion, patient will flex both hips
Differential diagnosis
- Fever with neurological findings
- Brain Abscess
- Encephalitis (i.e. HSV)
- Pediatric febrile seizures
- Seizures
- Delirium Tremens
- Pediatrics, Febrile Seizures
- Intracranial pathology
- Neoplasm
- Subarachnoid Hemorrhage
Etiology
- Bacterial
- Neonates: Listeria, E.coli, GBS
- Pediatrics: H.influenza, S.pneumoniae, N.meningitidis
- Adolescents/Adults: S.pneumoniae, N.meningitidis
- Elderly: S.pneumoniae, N.meningitidis, Listeria
- Immunocompromised: Listeria
- Viral: Enterovirus, HIV, HSV-2, West Nile
- Fungal: Cryptococcus, Coccidioidomycosis
- Other: TB, Borrelia (Lyme), Treponema pallidum (neurosyphilis)
Investigations
- Bloodwork: CBCD, electrolytes
- CT head: R/O differential diagnosis, R/O increased ICP
- LP (gram stain, C&S, cell count, glucose, protein, PCR +/- serology)
Bacterial | Viral | |
Appearance (clear) | May be cloudy | May be cloudy |
Opening pressure (5-15 cmH2O) | Increased | Normal or slightly increased |
Glucose ratio (CSF:plasma >0.5) | <0.3 | Normal |
Protein (45-60 mg/dL) | 100-500 | Normal |
WBC (<5) | Thousands | Hundreds |
Predominant WBC | Neutrophils | Lymphocytes |
Treatment
- Initiate treatment empirically if you suspect meningitis
- Neonates
- Ampicillin (age 0-7 d: 50 mg/kg IV q8h; age 8-30 d: 50-100 mg/kg IV q6h)
- Cefotaxime 50 mg/kg IV q6h
- Infants, children, adults
- Ampicillin
- 3rd generation cephalosporin
- Vancomycin
- Adjust antibiotics when gram stain and C&S results come back
- If CSF is cloudy, + gram stain or leukocytes >1000
- Dexamethasone 10 mg q6h X 4 days
- First dose given 20 minutes prior to, or with first dose of antibiotics
- Associated with better outcomes and lower mortality
Prevention
- Immunization
- Pediatrics – Pentacel (H.influenza), Prevnar (S.pneumoniae), Menjugate (N.meningitidis)
- Adults – Pneumovax (pneumococcus)
- Immunocrompromised (asplenia, HIV) – Menjugate (meningococcus)
- Prophylactic treatment in close contacts