Meningitis

1. DR LNR GONZÁLEZ
KHC,RSA
ACUTE BACTERIAL
MENINGITIS

2. Objectives
Definition
Epidemiology
Clinical Presentation
Diagnosis
Treatment
Prognosis

3. Meninges

4. Meninges

5. Definition
Bacterial meningitis is an acute purulent
infection within the subarachnoid space. It is
associated with a CNS inflammatory reaction
that may result in decreased consciousness,
seizures, raised intracranial pressure (ICP), and
stroke. The meninges, the subarachnoid space,
and the brain parenchyma are all frequently
involved in the inflammatory reaction
(meningoencephalitis).

6. Epidemiology
Adult to age 60
S. pneumoniae (51%-60%)
N meningitidis (20-37%)
L. monocytogenes (4-6%)
H. influenzae, Streptococci, S.
aureus, and gram-neg
bacilli
Quagliarello, Vincent. Epidemiology of bacterial meningitis in adults. Uptodate. 26
May 2009.

7. Epidemiology
Adults over age 60
S. pneumoniae (70%)
L. monocytogenes (20%)
N. meningitidis (3-4%)
Group b strep (3-4%)
H. influenzae (3-4%)
Quaglierello, Vincent . Epidemiology of bacterial meningitis in adults.
Uptodate. 26 May 2009.

8. Predisposing Factors
Recent exposure
Recent respiratory or otic infection
Recent travel to endemic areas
Recent head trauma
Immunosuppression
 Asplenia
 Complement deficiency
 Corticosteroid excess
 HIV Infection

9. Clinical Features
Classic Triad
Fever (77%-95%)
Nuchal Rigidity (83%-88%)
Change in Mental Status (69-78%)
Headache (87%)
Severe and generalized
Van de Beek D et al. Clinical features and prognostic features in adults with
bacterial meningitis. NEJM. 28 October 2004.

10. Other Clinical Features
Symptoms lasting < 24 hours (48%)
Focal Neurologic Deficit (33%)
Rash (26%)
 Petechiae
 Palpable purpura
Coma (14%)
Seizure (5%)
Van de Beek D et al. Clinical features and prognostic features in adults with
bacterial meningitis. NEJM. 28 October 2004.

11. Examination
Exam for signs of infection
Kernig’s Sign
Brudzinski’s sign
Glasgow Coma Scale
Kaplan, Sheldon L. Epidemiology, clinical features and diagnosis of acute
meningitis in children. UpToDate. 27 May 2009.

12. Examination
Kernig’s Sign

13. Examination
Brudzinski’s Sign

14. Possible Complications
Neurological
Seizures (15-30%)
Focal neurologic deficit
(20-50%)
CN Palsies (III, VI, VII,
VIII) 5-11%
Sensorineural hearing
loss (12-14%)
Hemiparesis (4-13%)
Intellectual impairment
Systemic
Septic shock
DIC
ARDS
Septic or reactive
arthritis
Tunkel, Allan R. Clinical Features and diagnosis of acute bacterial
meningitis in adults. UpToDate. 16 June 2009.

15. Investigations
Leukocytosis or leukopenia
Possible thrombocytopenia
+Blood cultures (40-75%)
Chest Radiography
CSF studies
Kaplan, Sheldon L. Epidemiology, clinical features and diagnosis of acute
meningitis in children. UpToDate. 27 May 2009.

16. CT Scan
 Immunocompromised?
 New onset seizure
 Papilledema
 Abnormal level of consciousness
 Focal neurological deficit
Get Treatment with ab’s/steroids
Tunkel, Allan R. et al. Practice guidelines for the
management of bacterial meningitis. Clin Infect
Dis. 1 November 2004

17. Reference Range
Constituent SI Units Conventional Units
Chloride 116–122 mmol/L 116–122 meq/L
Glucose 2.22–3.89 mmol/L 40–70 mg/dL
Total protein 0.15–0.5 g/L 15–50 mg/dL
CSF pressure 50–180 mmH2O
CSF volume (adult) ~150 mL
Red blood cells 0 0
Leukocytes
Total 0–5 mononuclear cells per L 0–5 mononuclear cells per mm3
Differential
Lymphocytes 60–70%
Monocytes 30–50%
Neutrophils None

18. Cause Appearance
Polymorphonuclear
cells
Lymphocytes Protein Glucose
Pyogenic bacterial
meningitis
Yellowish, turbid
Markedly increased
>1000. More than
85% of total
number of white
cells.
Slightly increased or
Normal
Markedly increased Markedly Decreased
Viral meningitis
Clear fluid, can be
hemorrhagic in HV
Increased Polys
have been described
in HV.
Increased
<100. More than
85% of total
number of white
cells.
Slightly increase or
Normal
Normal
Tuberculous
meningitis
Initially clear then
Turbid and viscous
Can be increased in
early stages.
<500
There are
descriptions of TBM
with no cells in
CSF@ initial stages.
Markedly increase
>100. More than
85% of total
number of white
cells.
Increased
>2g
Decreased
Fungal meningitis
Clear or Turbid and
viscous
Less than 25% of
total number of
white cells
Markedly increased.
More than 85% of
total number of
white cells.Cells can
be absent in
cryptococcal
infection.
Slightly increased or
Normal
Normal or
decreased

19. Gram Stain
Gram + Diplococci (S. pneumo)
Gram – Diplococci (N. meningiditis)
Gram + Bacilli (Listeria)
Gram – bacilli
Tunkel, Allan R. et al. Practice guidelines for the management of
bacterial meningitis. Clin Infect Dis. 1 November 2004

20. Treatment
Start empirical therapy and then examine CSF within 30
minutes.If focal neurological deficit is present, give empiric
treatment, do a CT Brain , then decide on LP.
Frequent aetiological agents: S. pneumonia,N.
meningitidis,H. influenzae
Sugested Empiric Regimes:
Ceftriaxone 2g IV q 12 h or cefotaxime 2g q 4h IV x 10-14
days.
Dexametasone 10mg IV q 6h x 4 days.Give with or just
before 1st
dose of antibiotics.

21. Treatment
Alternative Drugs;Meropenem 2g IV q 8 h x 10-14
days.
Penicillin Allergy:
Chloramphenicol 50mg/kg/d IVI div q 6h
+TMP/SMX 15-20mg(TMP)/kg/d div q6h+
vancomycin 500 mg q 6h IV x 10-14 days

22. Treatment
Penicillin g 24 mu /day remains the antibiotic of
choice for meningococcal meningitis caused by
susceptible strains. A 7-day course of intravenous
antibiotic therapy is adequate for uncomplicated
meningococcal meningitis.

23. Duration of antimicrobial therapy for
bacterial meningitis based on isolated pathogen
A 2-week course of intravenous antimicrobial
therapy is recommended for pneumococcal
meningitis.
 L. monocytogenes, meningitis due to this
organism is treated with ampicillin 2g q4h for at
least 3 weeks.
A 3-week course of intravenous antibiotic therapy is
recommended for meningitis due to gram-negative
bacilli.

24. Treatment
Non-Typhoidal Salmonellas (common in HIV
infection) treatment must be commenced with a
combination of Ceftriaxone 2g q 12 h IV +
Ciprofloxacin 750mg q 12h IV, three weeks of IV
antibiotics is recommended.

25. Post neuro surgery or post head
trauma:
Frequent aetiological agents:S. pneumonia, S.
aureous, P. aeruginosa, coliforms.
Sugested Treatment: Vancomycin 1g q 6-12h IV
(until known not MRSA)+ceftazidime 2g q 8h IV.
Alternative Treatment :Meropenem 1g q 8h IV+
vancomycin 1g q6h IV(until known not MRSA)
If S.pneumona is identified switch to
ceftriaxone/cefotaxime.

26. Prognosis
Mortality is 3–7% for
meningitis caused
by H. influenzae, N.
meningitidis, or group
B streptococci.
15% for that due to L.
monocytogenes.
20% for S.
pneumoniae.

27. Prognosis
The risk of death from bacterial meningitis
increases with
1-Decreased level of consciousness on
admission.
 2- Onset of seizures within 24 h of
admission.
 3- Signs of increased ICP.
 4- Age >50.
5-The presence of comorbid conditions
including shock and/or the need for
mechanical ventilation.
 6- Delay in the initiation of treatment

28. Prognosis
Decreased CSF glucose concentration [<2.2 mmol/L (<40 mg/dL)] and markedly
increased CSF protein concentration [>3 g/L (>300 mg/dL)] have been predictive of
increased mortality and poorer outcomes in some series.
Moderate or severe sequelae occur in ~25% of survivors, although the exact
incidence varies with the infecting organism.
Common sequelae include decreased intellectual function, memory impairment,
seizures, hearing loss and dizziness, and gait disturbances.

29. More on Central Nervous
System infections
available on request.
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