Infection- CHRONIC BACTERIAL MENINGOENCEPHALITIS Flashcards Preview

2H. Pathology- CNS > Infection- CHRONIC BACTERIAL MENINGOENCEPHALITIS > Flashcards

Flashcards in Infection- CHRONIC BACTERIAL MENINGOENCEPHALITIS Deck (29)
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CHRONIC BACTERIAL MENINGOENCEPHALITIS

  • Tuberculosis
  • Neurosyphilis
  • Neuroborreliosis (Lyme Disease)

2

Chronic bacterial infection of the meninges and the brain may be caused by_____________

Each of these is briefly described next.

 M. tuberculosis, T.
pallidum, and

Borrelia species. 

3

__________ of the brain may be part of systemic disease or apparently isolated, the brain
having been seeded from a silent, usually pulmonary, lesion.

It may involve the meninges or the
brain, often together.

Tuberculosis

4

On macroscopic examination what is the appearance of Tuberculosis? 

  • the subarachnoid space contains a gelatinous
  • or fibrinous exudate, most often at the base of the brain, obliterating the cisterns and encasing cranial nerves.
  • There may be discrete, white granules scattered over the leptomeninges.

5

What is the most common pattern of involvement in tuberculosis is a _______________

 

diffuse meningoencephalitis. 

6

What is the microscopic finding in tuberculosis?

  •  there are mixtures of lymphocytes, plasma cells, and macrophages.
  • Florid cases show well-formed granulomas, often with caseous necrosis and giant cells
  • . Arteries running through the subarachnoid space may show obliterative endarteritis with inflammatory infiltrates in their walls and marked intimal thickening.

7

In TB, Organisms can often be seen with acid-fast stains.

The infectious process may spread to the ____________.

choroid plexus and ependymal surface, traveling through the CSF

8

 In cases of
long-standing duration iin TB, _____________may develop, most
conspicuous around the base of the brain. Hydrocephalus may result.

a dense, fibrous adhesive arachnoiditis 

9

What are the other manifestation of TB?

It is the development of a single (or often multiple)
wellcircumscribed intraparenchymal mass (tuberculoma)
, which may be associated with
meningitis. 

10

What is a tuberculoma?

A tuberculoma may be as large as several centimeters in diameter, causing
significant mass effect.

On microscopic examination, there is usually a central core of
caseous necrosis
surrounded by a typical tuberculous granulomatous reaction; calcification
may occur in inactive lesions.

11

Patients with tuberculous meningitis usually have symptoms of ______________ 

headache, malaise, mental
confusion, and vomiting.

12

What is the CSF finding in TB?

  • There is only a moderate CSF pleocytosis made up of mononuclear cells or a mixture of polymorphonuclear and mononuclear cells;
  • the protein concentration is elevated, often strikingly so;
  • and the glucose content typically is moderately reduced or normal.

 

13

What is the most serious complications of chronic tuberculous meningitis are _____________

  • arachnoid fibrosis
  • producing hydrocephalus,
  • and obliterative endarteritis producing arterial occlusion and
  • infarction of underlying brain.

14

Infection by Mycobacterium tuberculosis in individuals with acquired immunodeficiency
syndrome (AIDS)
is often similar to that in individuals not suffering from AIDS, but there may be
less host reaction

15

HIV-positive individuals are also at risk for infection by____________
usually in the setting of disseminated infection.

These lesions typically contain
confluent sheets of macrophages filled with organisms, with little or no associated
granulomatous reaction.

 M. aviumintracellulare,

16

____________is a manifestation of the tertiary stage of syphilis and occurs in only about 10% of
individuals with untreated infection.

Neurosyphilis 

17

What is the major patterns of CNS involvement in neurosyphyllis? 

 

  • meningovascular neurosyphilis,
  • paretic neurosyphilis,
  • and tabes dorsalis;
  • affected individuals often show incomplete or mixed pictures, most commonly the combination of tabes dorsalis and paretic disease (taboparesis).

 

 

18

Individuals infected with HIV are at increased risk for neurosyphilis, particularly as an acute syphilitic meningitis or meningovascular disease, because of impaired cell-mediated immunity. The rate of progression and severity of the
disease seem to be accelerated, possibly for the same reason.

19

What is Meningovascular neurosyphilis is a

 It is a chronic meningitis involving the base
of the brain
and more variably the cerebral convexities and the spinal leptomeninges.

In
addition, there may be an associated obliterative endarteritis (Heubner arteritis)
accompanied by a distinctive perivascular inflammatory reaction rich in plasma cells and
lymphocytes.

Cerebral gummas (plasma cell–rich mass lesions) may also occur in the
meninges and extend into the parenchyma.

20

What is Paretic neurosyphilis?

 It is caused by invasion of the brain by Treponema pallidum and is clinically manifested as insidious but progressive mental deficits associated with mood
alterations (including delusions of grandeur)
that terminate in severe dementia (general
paresis of the insane).

21

What is the microscopic apperance of neurosyphyllis?

  •  inflammatory lesions are associated with parenchymal damage in the cerebral cortex (particularly the frontal lobe but also affecting other areas of the isocortex)
  • characterized by loss of neurons, proliferations of microglia (rod cells), gliosis, and iron deposits.
  • The latter are demonstrable with the Prussian blue stain perivascularly and in the neuropil, and are presumably the sequelae of small bleeds stemming from damage to the microcirculation.
  • The spirochetes can, at times, be demonstrated in tissue sections.

22

What is granular ependymitis.

The spirochetes can, at times, be
demonstrated in tissue sections.

Granular ependymitis is when there is often an associated hydrocephalus with damage to
the ependymal lining and proliferation of subependymal glia, 

23

What is Tabes dorsalis?

It  is the result of damage by the spirochetes to the sensory nerves in the dorsal roots, which produces impaired joint position sense and resultant ataxia (locomotor
ataxia)
; loss of pain sensation, leading to skin and joint damage (Charcot joints); other
sensory disturbances, particularly the characteristic “lightning pains”; and absence of deep
tendon reflexes.
 

24

What is the microscopic finding in Tabes Dorsalis?

On microscopic examination there is loss of both axons and myelin in the
dorsal roots, with corresponding pallor and atrophy in the dorsal columns of the spinal cord.
Organisms are not demonstrable in the cord lesions

25


What is Lyme disease? 

It is a disease is caused by the spirochete Borrelia burgdorferi, transmitted by various species
of Ixodes tick;

26

What do you call the involvement of the nervous system iin Lyme disease?

 neuroborreliosis. 

27

What are the neurological manifestation of neuroborreliosis?

Neurologic
symptoms are highly variable and include aseptic meningitis, facial nerve palsies and other
polyneuropathies, as well as encephalopathy

The rare cases that have come to autopsy have
shown a focal proliferation of microglial cells
in the brain as well as scattered extracellular
organisms (identified by Dieterle stain).

28

The rare cases that have come to autopsy have
shown a focal proliferation of microglial cells in the brain as well as scattered extracellular
organisms
(identified by____________).

 Dieterle stain

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