Meningitis Risk factors:

 Head injury – skull #, cranial or spine surgery

Causes:  Septic site – pneumonia, mastoiditis, sinusitis, OM
1. Viral  Immunosuppressed – CA, AIDS, hyposplenism, sickle-cell dz,
 Commonest cause hypogammaglobinaemia
 Usually benign and self-limiting  Host factor – complement or antibody deficiency
 Complete recovery w/o specific Rx is the norm.  Foreign body – CSF shunt/ VP shunt (prone to staph. Meningitis)
 Common organisms: echoviruses, mumps. Less commonly
HSV & zoster, coxsackie Causes of bacterial meningitis by population groups:
2. Bacterial – high mortality & morbidity Neonate 1. Group B strep
2. Gram negative bacilli (E coli, proteus)
3. Fungal 3. Listeria monocytogenes
4. Others – malignancies, drugs (NSAIDS, trimethoprim), intrathecal Pre-school 1. H. influenzae
drugs, sarcoidosis, SLE child 2. N. meningitides
3. Strep. Pneumoniae
4. M. TB
DDx: 1. N. Meningitidis
Older child /
1. Any acute infections eg malaria 2. Strep. Pneumoniae
Adults
2. Local infections causing neck stiffness 3. M. TB
3. Encephalitis 4. L. monocytogenes
5. H. influenzae
4. Subarachnoid hemorrhage
Elderly / DM/ 1. Strep. Pneumoniae
2. N. Meningitidis
debilitated
S/S: 3. H. influenzae
4. L. monocytogenes
Meningism  Headache  Kernig’s sign 5. M. TB
 Photophobia  Brudzinski’s sign (hip Immuno- 1. Strep. Pneumoniae
 Neck stiffness flexion on flexion of neck) compromised 2. N. Meningitidis
 Opisthotonus 3. H. influenzae
4. L. monocytogenes
 ICP  Headache  Fits 5. C. Neoformans
 Vomiting  Cushing’s reflex: BP & 6. Toxoplasma gondii
 Irritability pulse 7. S. aureus
 Drowsiness  Irregular respiration  Meningococcus: Spread by air-borne route. May result in meningococcaemia.
 consciousness/coma  Papilloedema  Cxs of meningococcaemia: meningitis, purpuric rash, shock,
 Focal neuro signs DIVC, renal failure, peripheral gangrene, arthritis (rxtive or
septic), pericarditis (rxtive or septic)
Septicaemia  Malaise  DIC
 H. influenzae: a/w ottitis media
 Fever  BP, pulse, tachypnoea  Pneumococcus: a/w ottitis media and pneumonia, esp in elderly, alcoholics &
 Rash – petechiae/purpura  Arthritis immunocompromised.
suggests meningiococcus.  Odd behaviour  TB: chronic or acute on chronic, a/w chronic headache, isolated CN6 palsy
due to ICP, and S/S of TB eg fever, nightsweats.

DGIM – Last updated March 2005

 Viral
Investigations:  Supportive treatment
CT head  Exclude ICP (eg cerebral abscess, head injury, brain tumour)  Completer recovery without specific therapy is the norm.
pre-LP.
LP  Exclude  ICP by CT head, fundoscopy & clinical signs. Bacterial
 Tubes  IV penicillin stat on suspicion of bacterial meningitis
1. Cell count, cytospin for cell and differential count
2. Protein & glucose  Modify ABx regimen according to CSF invx results
3. Microbiology – gram stain, C&S, AFB smear, TB culture, Meningococcal Benzyl penicillin (2.4g/4hr slow IV)
Indian ink stain, fungal culture Pneumococcal Ceftriaxone (2g/12 hrly IV)
4. Cryptococcal antigen, bacterial antigens (S. pneumonia, N. H. influenzae Ceftriaxone
meningitides, H. influenzae, GBS) GBS/ Gram negative bacilli Ceftriaxone + Gentamicin + ampicillin
FBC (50mg/kg/6 hr IV)
L. monocytogenes Gentamicin + ampicillin
U/E/Cr M TB Pyrazinamide, isoniazid, rifampicin, ethambutol
DIVC screen  Especially if meningococcaemia is suspected. 6-12 mths
Blood glucose  To compare with CSF C. neoformans Amphotericin + flucytosine
Blood C/S
Urine C/S  Treatment for pyogenic meningitis of unknown cause
CXR  ?Lung abscess Neonate Ampicillin + Ceftriaxone or gentamicin
Infant Ampicillin + Ceftriaxone
Pre-school child Ceftriaxone
Typical CSF in meningitis Older child / adults Penicillin G (400K units/kg/day) + Ceftriaxone
Pyogenic TB Viral (‘aseptic’) Elderly (>50YO) Ampicillin + Ceftriaxone
Appearance Turbid Fibrin web forms Clear  Prophylaxis for close contacts--meningococcus:
on standing Children: 2 days of oral rifampicin (3-12mths 5mg/kg 12 hrly;
Predominant cell Neutrophils Lymphocytes Lymphocytes >1yr 10 mg/kg 12 hrly)
Cell count/ mm3 90-1000+ 10-1000 50-1000 Adults: single dose of 500mg ciprofloxacin OR rifampicin
Glucose  (< 1/2 plasma)  (< 1/2 plasma) N (> 1/2 plasma) 600mg 12 hrly for 2 days.
Protein (g/L)  (>1.5)  (1-5) N (<1)  Vaccination: available for groups A & C meningococci, but not group B.
Culture / smear Positive Usually not seen Negative
Complications of bacterial meningitis:
1) Hydrocephalus: pus causes adhesions which cause CSF flow
Treatment:
 Monitoring: BP, pulse, RR, temp, SpO2, conscious level obstruction. Rx: surgical drainage
 Supplemental O2 2) Cranial nerve damage
 ABx if bacterial (see below) 3) Secondary cerebral infarction: due to obliterative endarteritis of the
 Antipyretics and antiemetics leptomeningeal arteries passing through the meningeal exudates.
4) Cerebral venous sinus thrombosis
 Corticosteroids for ICP (controversial): 0.15mg/kg dexamethasone

DGIM – Last updated March 2005