This document outlines a case study and provides information on meningitis and encephalitis, including their definitions, causes, clinical presentations, investigations, management, and complications. It discusses the classic triad seen in bacterial meningitis and notes that altered mental status is more common in bacterial versus viral meningitis. The top 5 causes of bacterial meningitis are mentioned. Diagnostic tests, treatment including the role of steroids and prophylaxis, and potential radiological findings are summarized. Encephalitis is also defined and its causes, presentations, and investigations are briefly covered.

1. Meningitis and Encephalitis
(clinical presentation & management)
Dr Ahmad Shahir Mawardi
Neurology Department
Hospital Kuala Lumpur
28th
May 2018

2. Outlines
1.Case illustration
2.Definition, causes
3.Clinical presentation
4.Management (History, Investigations,
Treatment, complications)
5.Algorithm

3. Case study 1

5. Role of Neurologist
• improvement in therapy
• proper isolation
• prophylaxis of contacts when required
• anticipation and management of the
neurologic complications

6. Definition
• fever
• headache
• meningismus with
inflammation in the
subarachnoid space
as evidenced by CSF
pleocytosis

7. Meningitis
• acute (hours to days), subacute, or chronic (>4/52)
• Infectious vs non-infectious (aseptic)
• The average age is 41.9 years.
• Acute meningitis is often infectious with a bacterial or
viral cause

8. *encephalitis, myelitis, or encephalomyelitis

9. Clinical presentation (1)
• The classic triad (fever, neck stiffness & altered mental
status) - 44%
• > 2/4 (headache, fever, stiff neck, or altered mentation) -
95%.
• An altered level of consciousness is present in 2/3 of
patients with bacterial meningitis
– absent in patients with viral meningitis unless coincident
encephalitis is present.

10. The absence of
nuchal rigidity,
Kernig sign, and
Brudzinski sign
should never be
used to exclude the
possibility of
meningitis

11. Clinical presentation (2)
• Lethargy or obtundation
• Coma - 20% (pnemocoocal > meningococcal)
• Seizures - 20 % (bact meningitis)
• Rash
– viral exanthem : enteroviruses, flaviviruses rash of
HFMD : Enteroviruses
– Hemorrhagic purpura: meningococcemia
• defined syndrome of otitis and upper respiratory
tract infection (in children)

12. Top 5 causes of bacterial meningitis

15. Viral & Culture-Negative (Aseptic) Meningitis

17. Prophylactic therapy
• meningococcal meningitis, rifampin prophylaxis, 600 mg
bd x 2/7, should be given to household contacts and
those with direct exposure to droplet secretions.

18. Within hours of antibiotic
administration, the yield of
bacterial culture falls(~
>50%), but other helpful CSF
parameters do not.
yield on Gram stain was reduced
by 16%
1.8 mmol/L
2.2 g/L

19. Investigations (1)
Blood
• FBC with differential
• Blood cultures (aerobic and
• anaerobic)
• CRP/ESR/procalcitonin
• HIV
• Rapid plasma reagent
• Serum for acute serology (store for
paired convalescent sample in 3 to
4 weeks)
• Heterophile antibodies
• (Epstein-Barr virus)
• Lyme disease tests
• Rickettsial serologies
CSF
• Opening pressure
• Cell count and differential
• Serum and CSF glucose
concentration
• Protein concentration
• Stains: Gram, India ink, AFB
• Cultures: aerobic, anaerobic,
acid-fast bacillus, fungal
• Cytology
• Antibody testing (arboviral)
• PCRs: enteroviral, West Nile virus,a
herpesvirus types 1 and 2)
• CSF lactate (posttrauma or
neurosurgical)

21. • A bloody tap will falsely elevate the CSF white cell count and
protein.
• To correct for a bloody tap,
– subtract 1 white cell for every 700 red blood cells/mm3
– 0.1 g/dl of protein for every 1000 red blood cells.

22. Question 1
Does all patients suspected with meningitis
will need CT brain prior to LP and what
are the reason(s)?

23. • Abnormal CT scans were found in 56 of 301 (24%) subjects in a
prospective study and were associated with
– age older than 60 years,
– immunocompromised states
– recent seizure
– focal neurologic deficits
– or inability to follow two consecutive commands or questions correctly
• The absence of these findings had a negative predictive value of
97%.

24. Question 2
• Role of steroid in bacterial meningitis?

25. • corticosteroids have been shown to reduce
morbidity and mortality in children and also
improve functional outcome when compared to
placebo in adults.
• Dexamethasone 10 mg IV 6 hourly x 4/7
– at the time of or immediately before the first dose of
antibiotics
• studies have only demonstrated the benefit in
higher-income countries.

26. Radiological findings
leptomeningeal enhancement

27. Radiological findings
• may be normal
• subtle hydrocephalus
• hyperdensity around basal cisterns
(especially in tuberculosis)
• leptomeningeal enhancement
• complications or sources of the meningitis

28. A: cerebral oedema
B: complete effacement of the
basal cisterns
C: communicating hydrocephalus
D: subdural collection

29. • hydrocephalus
• subdural empyema
• epidural empyema
• cerebritis and cerebral abscess
• infarction
• ventriculitis
• dural sinus thrombosis

30. SYSTEMIC COMPLICATIONS
• Hypotension, septic
shock and adult
respiratory distress
syndrome
• Hyponatraemia/Hyper
natraemia
• Arthritis
If gcs drop:
• Cerebral oedema
• Hydrocephalus
• Cerebral infarction
• Seizures

34. Encephalitis

35. • diagnosis that should
only be made if there
is tissue confirmation
• in practice:
– febrile illness, severe
headache reduced
consciousness
– surrogate markers of
brain inflammation
Encephalitis

36. Causes (1)

37. Causes (2)

38. • HSV- brain parenchyma in the temporal lobes,
sometimes with frontal or parietal involvement.
• Mumps virus - acute viral encephalitis, or a delayed
immune mediated encephalitis.
• Measles virus - post-infectious encephalitis, which can
sometimes have a acute haemorrhagic
leukoencephalitis.
• Influenza A virus - diffuse cerebral oedema
• Varicella zoster virus (VZV) -vasculitis

39. Infectious causes
of encephalitis

40. Non-infectious
causes of
encephalitis

42. • acute flu-like prodrome,
fever,
• severe headache
• nausea, vomiting
• altered consciousness
• seizures
• focal neurological signs
Clinical presentations
HSV-1 encephalitis
• febrile (91%)
• disorientation (76%)
• speech disturbances (59%)
• behavioural changes (41%)
• seizures (33%)
• Alterations in higher mental
function

44. History
• from family members
• rashes
• travel history
• occupation and recreational activities
• risk factors for HIV

45. Examinations
• GCS
• rashes, shingels, scar, bites, IVDU
• sign of immunocompromised state
• subtle seizure
• meningism, and look for focal neurological signs
• lower cranial neuropathies and myoclonus
(rhomboencephalitis or basal
meningoencephalitis)

46. Investigations

47. Investigations

48. EEG
• usually shows non-specific diffuse high
amplitude slow waves of encephalopathy,
• subtle epileptic seizures.
• Periodic lateralised epileptiform (HSV
encephalitis)

51. References
• Russell Bartt, Acute bacterial and Viral Meningitis,
Continuum Lifelong Learning Neurol 2012;18(6):1255–
1270
• Ewout S Schut, Jan de Gans, Diederik van de Beek,
Community-acquired bacterial meningitis in adults, Pract
Neurol 2008; 8: 8–23
• Tom Solomon, Ian J Hart, Nicholas J Beeching, Pract
Neurol 2007; 7: 288–305

52. Thank you