Page 631 - Concise Pathology for Exam Preparation ( PDFDrive )

616 SECTION II Diseases of Organ Systems

CSF findings:
- Cloudy/frankly turbid CSF
- Elevated CSF pressure (above 180 mm water)
- Presence of polymorphs (10–10,000/µL)
- Raised CSF protein (.50 mg/dL)
- Decreased sugar (,40 mg/dL)
- Positive bacteriologic examination (Gram stain or culture)
Complications:
- Cerebral abscess formation
- Obstructive hydrocephalus
- Subdural empyema
- Cerebral infarction
- Epilepsy
(b) Acute lymphocytic (viral, aseptic) meningitis:

Affects children and young adults.

Causative viruses: Enteroviruses, mumps, ECHO virus, coxsackie virus, EBV
and HSV II
Gross pathology: No distinctive change; sometimes swelling of brain
Microscopy: Mild lymphocytic infiltrate in the leptomeninges
Clinical features:
- Acute meningeal symptoms and fever
- Benign and self-limiting, usually ends in complete recovery
- Life-threatening complications of bacterial meningitis usually not seen
CSF findings:
- Clear or slightly turbid fluid
- CSF protein normal or slightly raised
- CSF sugar normal
- CSF bacteriologically sterile
(c) Chronic tuberculous/cryptococcal meningitis

Tuberculous meningitis:
- Affects children and adults
- Usually due to haematogenous spread (miliary tuberculosis)
- Less commonly, spreads directly from tuberculosis of the vertebral body
Cryptococcal meningitis:
- Seen in debilitated or immunocompromised persons (eg, with AIDS)
- Usually due to haematogenous dissemination from a pulmonary lesion
Gross pathology:
- Thick exudate in subarachnoid space, more abundant in sulci and base of
brain
- Tubercles are 1–2 mm in diameter, and located adjacent to blood vessels
- Exudate in cryptococcal meningitis is scanty, translucent and gelatinous
Microscopy:
- Acute and chronic inflammatory cells
- Granulomas (with or without caseation)
- AFB/capsulated cryptococci
Clinical features:
- Headache, confusion, malaise and vomiting
- May have a fulminant (few weeks) or an indolent (months or years) course
CSF findings:
- Mild turbidity; may form fibrin web on standing (due to increased protein
including fibrinogen)
- Raised CSF pressure (.300 mm of water)
- Mononuclear leucocytosis (100–1000 cells/µL); mainly lymphocytes and
macrophages
- Increased protein

- Decreased glucose

- Demonstration of AFB/cryptococcus

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