Infection- CHRONIC BACTERIAL MENINGOENCEPHALITIS

Question 1

CHRONIC BACTERIAL MENINGOENCEPHALITIS

Answer 1

• Tuberculosis
• Neurosyphilis
• Neuroborreliosis (Lyme Disease)

Question 2

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

Each of these is briefly described next.

Answer 2

** M. tuberculosis, T.**
pallidum, and

**Borrelia species. **

Question 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.

Answer 3

Tuberculosis

Question 4

On macroscopic examination what is the appearance of Tuberculosis?

Answer 4

• 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.

Question 5

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

Answer 5

diffuse meningoencephalitis.

Question 6

What is the microscopic finding in tuberculosis?

Answer 6

• 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.

Question 7

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

The infectious process may spread to the ____________.

Answer 7

choroid plexus and ependymal surface, traveling through the CSF

Question 8

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

Answer 8

a dense, fibrous adhesive arachnoiditis

Question 9

What are the other manifestation of TB?

Answer 9

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

Question 10

What is a tuberculoma?

Answer 10

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 necrosissurrounded by atypical tuberculous granulomatous reaction;calcification
may occur in inactive lesions.

Question 11

Patients with tuberculous meningitis usually have symptoms of ______________

Answer 11

headache, malaise, mental
confusion, and vomiting.

Question 12

What is the CSF finding in TB?

Answer 12

• 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.

Question 13

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

Answer 13

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

Question 14

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

Question 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.

Answer 15

M. aviumintracellulare,

Question 16

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

Answer 16

Neurosyphilis

Question 17

What is the major patterns of CNS involvement in neurosyphyllis?

Answer 17

• 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).

Question 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.

Question 19

What is Meningovascular neurosyphilis is a

Answer 19

It is a chronic meningitis involving the base
of the brainandmore variably the cerebral convexitiesand thespinal 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.

Question 20

What is Paretic neurosyphilis?

Answer 20

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 insevere dementia (general
paresis of the insane).

Question 21

What is the microscopic apperance of neurosyphyllis?

Answer 21

• 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.

Question 22

What is granular ependymitis.

Answer 22

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,

Question 23

What is Tabes dorsalis?

Answer 23

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.

Question 24

What is the microscopic finding in Tabes Dorsalis?

Answer 24

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*

Question 25

What is Lyme disease?

Answer 25

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

Question 26

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

Answer 26

neuroborreliosis.

Question 27

What are the neurological manifestation of neuroborreliosis?

Answer 27

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 cellsin the brain as well asscattered extracellular
organisms (identified by Dieterle stain).

Question 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____________).

Answer 28

** Dieterle stain**