Infection- Fungal

Question 1

Fungal disease of the CNS is encountered primarily in _______________.

Answer 1

immunosuppressed individuals

Question 2

The
brain is usually involved when there is widespread hematogenous dissemination of the fungus,
most often ___________.

Answer 2

• Candida albicans,
• Mucor species,
• Aspergillus fumigatus, and
• Cryptococcus neoformans

Question 3

In endemic areas, pathogens such as _______________may involve the CNS after a primary pulmonary or
cutaneous infection; again, this often follows immunosuppression.

Answer 3

Histoplasma capsulatum, Coccidioides
immitis,

and

Blastomyces dermatitidis

Question 4

There are three main patterns of fungal infection in the CNS: _____________, _________ and ________

Answer 4

1. chronic meningitis,
2. vasculitis, and
3. parenchymal invasion.

Question 5

Vasculitis is most frequently seen with____________ and __________
both of which are characterized by direct fungal invasion of blood vessel walls, but it
occasionally occurs with other infections such as candidiasis.

The resultant vascular thrombosis
produces infarction that is often strikingly hemorrhagic and that subsequently becomes septic
from ingrowth of the causative fungus.

Answer 5

mucormycosis and aspergillosis,

Question 6

Parenchymal invasion, usually in the form of granulomas or abscesses, can occur with most of
the fungi and often coexists with meningitis.

Question 7

The most commonly encountered fungi invading the
brain are _______ and ____________.

Answer 7

Candida and Cryptococcus

Question 8

Candidiasis usually produces ____________.

Answer 8

multiple microabscesses,
with or without granuloma formation

Question 9

Although most fungi invade the brain by hematogenous
dissemination,direct extensionmay also occur, particularly inmucormycosis, most commonly in
_____________

Answer 9

diabetics with ketoacidosis.

Question 10

What is the most common fungal infecion associated in diabetics and ketoacidosis that cause direct invasion instead of hematogenous spread.

Answer 10

mucormycosis

Question 11

What is the common opportunistic infection in the setting of HIV/AIDS, may be
fulminant and fatal in as little as 2 weeks or indolent, evolving over months or years.

Answer 11

Cryptococcal meningitis

Question 12

What is the CSF appearance in Cryptococcus mengitis?

Answer 12

may contain few cells but usually has a high concentration of protein.

Question 13

The mucoid-encapsulated
yeasts can be visualized in the CSF by______preparations and in ______________

Answer 13

India ink

tissue sections by **PAS, **mucicarmine, and silver stains.

Question 14

With cryptococcal infection, the brain shows a_______________

Answer 14

• chronic meningitis affecting the basal leptomeninges,
• which are opaque and thickened by reactive connective tissue that may obstruct the outflow of CSF from the foramina of Luschka and Magendie, giving rise to hydrocephalus.

Question 15

Sections of the brain in cryptococcal infection disclose a ________________ which are especially
prominent in the basal ganglia in the distribution of the lenticulostriate arteries ( Fig. 28-28A ).

Answer 15

gelatinous material within the subarachnoid
spaceandsmall cysts within the parenchyma(“soap bubbles”),

Cryptococcal infection. A, Whole-brain section showing the numerous
areas of tissue destruction (“soap bubbles”) associated with the spread of organisms in the
perivascular spaces. B, At higher magnification it is possible to see the cryptococci in the
lesions.

Parenchymal lesions consist of aggregates of organisms within expanded perivascular
(Virchow-Robin) spaces associated with minimal or absent inflammation or gliosis ( Fig. 28-
28B ).

The meningeal infiltrates consist of chronic inflammatory cells and fibroblasts admixed
with cryptococci.