Page 632 - Concise Pathology for Exam Preparation ( PDFDrive )

23 The Central Nervous System 617

Late sequelae:

- Exudate and fibrous adhesions leading to obstructive hydrocephalus
�

- Tuberculous encephalitis
�
- Tuberculosis of the spine
�

The differentiating features different types meningitis are shown Table 23.1.
in
of
of
TABLE 23.1. Differentiating features of different types of meningitis
Acute pyogenic Acute lymphocytic Chronic (tuberculous)
Features Normal (bacterial) meningitis (viral) meningitis meningitis
Naked eye Clear and Cloudy or frankly purulent Clear or slightly Clear or slightly turbid,
appearance colourless turbid forms fibrin coagulum
on standing
CSF pressure 60–150 mm Elevated (.180 mm Elevated Elevated
water of water)
Cells 0–4 lymphocytes/ 10–10,000 neutrophils/µL 10–100 100–1000
µL lymphocytes/µL lymphocytes/µL
Proteins 15–45 mg/dL Markedly raised due to Raised Raised
• Increased permeability of
blood–CSF barrier
• Decreased removal of pro-
tein molecules at arach-
noid level
Glucose 50–80 mg/dL Markedly reduced due to Normal Reduced

• Impaired glucose transport

• Increased glycolysis in CNS

• Increased glucose utiliza-
tion by WBCs and micro-
organisms
Bacteriology Sterile Causative organism isolated Sterile Tubercular bacilli present

Q. Write briefly on neurosyphilis.

Ans. Neurosyphilis syphilis affecting central nervous system (CNS). Involvement of
s
i

o

CNS generally seen in the tertiary stage the disease, in approximately 10% f

o
f
s
i

untreated patients.
Major Patterns of CNS Involvement in Neurosyphilis
1.
Meningeal
Causes chronic meningitis
(a)

( ) Histopathology shows obliterative endarteritis (Heubner arteritis) with perivascular

b
inflammation rich in plasma cells

Occasionally gummas (masses rich in plasma cells) may be seen in the brain paren-
(c)
chyma and meninges
of
to
of
Paretic
2. neurosyphilis (general paresis the insane due invasion brain by
T. Pallidum)
Insidious and progressive loss of mental and physical functions with mood altera-
(a)
tions and dementia
Widespread individual cell death and brain atrophy
(b)
Loss of cortical neurons and glial proliferation
(c)
Tabes
3. dorsalis
(a)
Damage of dorsal root resulting in impaired position and vibration sense, ataxia
and loss of pain sensation
(b)
Loss of both axons and myelin in the dorsal roots
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