Meningitis

Infection causing inflammation of leptomeninges.

Incidence of bacterial meningitis with capsulated organisms has reduced with vaccination against S pneumoniae, N Meningitidis & H influenza, especially in developed countries.

Causes

 – Bacteria: S Pneumoniae, N Meningitidis, H influenza, Gr A Strep, Gr Neg bacilli, Mycobacterium

                 [In Newborn: E coli, Gr B Strep, Enterobacter, Listeria]

 – Viruses: Enterovirus, Parechovirus, Herpes Simplex, CMV

 – Rarely: Fungal, Toxoplasma, Lyme dis etc

High risk groups:

 – Those with VP shunt, post neurosurgery or head injury with CSF leak

 – Immunocompromised children (HIV, Aspleenism)

 – Unvaccinated

 – Endemic areas e.g. TB

 – Perinatal risk factors (PROM, Preterm, GBS colonization etc)

History

[Assess as for a child with fever or sepsis]

Febrile illness, often with a prodromal period with coryzal symptoms

Non-specific symptoms of poor feeding, sleepiness or irritability in young children.

Onset can be rapid with S. pneumoniae and N. meningitidis.

Symptoms of increased ICP includes irritability and bulging fontanelle in infants.

Older children present with vomiting, headache, lethargy and sometimes photophobia.

Non-blanching rash is sometimes seen if there is associated meningococcal septicaemia (but uncommon).

Enquire about recent head injury (if basal skull fracture); localized infections around face e.g. ear infection, sinusitis, dental abscess etc

Vaccination history; ask exposure to TB, or other ill contacts

Examination

 – ABCDE assessment as for a child with suspected sepsis

 – Circulatory shock? Apnoea?

 – Look for signs of meningeal irritation (Kernig and Brudzinski signs)- not reliable in infants if AF open

 – Raised ICP (Cushing’s Triad): bradycardia, hypertension, irregular resp; fontanelle may be bulging

 – ENT, sinuses, dental abcess?

 – Assess consciousness level, alertness, irritability

 – Cranial nerve palsy (esp 3^rd & 6^th), including pupillary reflexes

 – Papilloedema is a late sign and not a reliable indicator of raised intracranial pressure

 – Any abnormal posturing, seizures or focal neurological abnormality?

 – Non-blanching rash?

Investigations

 – As for child with sepsis (FBC, U&E, Coagulation, Blood cultures etc)

Do not delay antibiotics in a child with suspected meningitis

 – Neuroimaging (urgent CT Brain) should be done before lumbar puncture after infancy if AF closed (to exclude raised ICP and risk of herniation)

 – If meningitis is suspected, Lumbar Puncture should be performed early (if no contraindications)

 – CSF samples to be tested for cell count, microscopy, protein, glucose and gram stain

 – Request CSF virology PCR if initial analysis suggests possible viral meningitis

 – EEG may be performed in suspected encephalitis