Bns 1 Exam- Pathology Of Fungal And Parasitic Cns Infections

Front 1

Routes for CNS infection

Back 1

Hematogenous spread (arterial as well as retrograde venous spread, i.e. from face)
Direct implantation (i.e. traumatic)
Local extension (i.e. sinuses, osteomyelitis, tooth abscess)
Transport along peripheral nerves (i.e. rabies, herpes zoster)

Front 2

Sites of CNS infection

Back 2

Meningitis – inflammatory process of leptomeninges and cerebrospinal fluid (CSF)in the subarachnoid space
Meningoencephalitis – inflammation of the brain parenchyma also occurs
Focal suppurative infections (i.e. brain abscess)

Front 3

Mechanisms of CNS injury from infection

Back 3

Direct cellular injury by the infectious agent
Indirect injury by microbial toxins, inflammatory response or immune-mediated response

Front 4

Some common bacterial causes of meningitis

Back 4

Neonates - E. coli, group B steptococci
Streptococcus pneumoniae
Listeria monocytogenes in older individuals
Neisseria meningitidis in adolescents

Front 5

Some causes of chronic bacterial meningitis

Back 5

Tuberculosis
Neurosyphilis (T. pallidum)
Lyme disease (Borrelia species)

Front 6

What disease?
Headache, neck pain/stiffness, photophobia, irritability, decreasing level of consciousness, fever

Back 6

bacterial meningitis

Front 7

What disease?
CSF appears cloudy or frankly purulent shows elevated neutrophil count
CSF has increased protein level and decreased glucose level
CSF gram stain and culture

Back 7

bacterial meningitis

Front 8

what cause Waterhouse-Friderichsen syndrome ?

Back 8

N. meningitidis

Front 9

Most common organisms in Fungal CNS infections

Back 9

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

Front 10

Most common organisms in Fungal CNS infections in endemic areas?

Back 10

Coccidioides immitis, Histoplasmosis capsulatum and Blastomyces dermatitidis

Front 11

Fungal CNS infections occurs mainly in who?

Back 11

immunocompromised patients

Front 12

How Fungal infection spreads?

Back 12

Fungal infection spreads to brain by hematogenous route mostly but invasion form sinuses may occur with some species, i.e. Mucor

Front 13

Infections occur of skin and mucous membranes in otherwise healthy people but diabetics are more susceptible
Esophagitis is common in AIDS patients
Disseminated systemic infection to various sites including brain and meninges may occur in neutropenic patients (leukemia, chemotherapy, bone marrow transplantation)
Benign commensals usually, seldom producing severe disease

Back 13

Candida

Front 14

What is the most common form of human fungal infection?

Back 14

C. albicans

Front 15

Central nervous system infection usually manifests as _____ and _________

Back 15

microabscesses
meningitis

Front 16

candida morphology

Back 16

Blastoconidia (budding yeast)
Pseudohyphae – budding yeast cells joined end to end
Easily seen on H&E , silver stains (GMS or Gomori methenamin-silver) and PAS (Periodic acid-Schiff)

Front 17

Commonly seen in AIDS, patients on high dose steroids and other immunosuppressed states

Back 17

Cryptococcal meningitis

Front 18

Environment – soil and bird (especially pigeons) droppings

Back 18

Cryptococcal meningitis

Front 19

How Cryptococcal meningitis transmitted?

Back 19

Infection is through inhalation

Front 20

What is the major virulence factor of Cryptococcal meningitis and how it works?

Back 20

capsular polysaccharide, glucuronoxylomannin
Inhibits phagocytosis by alveolar macrophages and other inflammatory processes
Undergoes phenotypic switching to evade immune responses

Front 21

How Cryptococcus neoformans**** is visualized in CSF?

Back 21

5 to 10 um yeast with thick gelatinous capsule
In CSF, cryptococcus visualized in India ink preparations (the thick capsule is seen as a clear halo in a dark background) or an antibody agglutination assay test

Front 22

Cross sections of brain of Cryptococcus neoformans look like:

Back 22

“soap bubble “
small cysts due to tissue destruction with spread of organisms along the perivascular space

Front 23

What does Meninges contain of C. neoformans?

Back 23

chronic inflammatory cells and fibroblasts with cryptococci

Front 24

What occur in immunocompetent individuals as well as suppuration in C. neoformans ?

Back 24

Chronic granulomatous inflammation

Front 25

How Cryptococci visualized?

Back 25

in tissues with mucicarmine, PAS (periodic acid Schiff) or silver stains

Front 26

69 year old healthy man with severe headaches for five weeks and sudden hearing loss 4 days prior to admission can caused by what?

Back 26

Cryptococcal meningitis

Front 27

What is the most common species of fungi that cause disease?

Back 27

Aspergillus fumigatus

Front 28

What predispose to disease Aspergillus?

Back 28

Neutropenia and corticosteroids
RARE IN AIDS pt's

Front 29

Transmission of Aspergillus

Back 29

Portal of entry into lungs by inhaling spores which then germinate into hyphae

Front 30

Virulence factors of Aspergillus

Back 30

adhesins, antioxidants, enzymes and toxins

Front 31

Severe invasive infections primarily in the lung but spread hematogenously to brain, heart valves most commonly
Allergic bronchopulmonary in asthma
or “fungus ball” (coloniziation of preexisting lung cavity)

Back 31

aspergillus

Front 32

Gross Morphology of Aspergillus

Back 32

Hemorrhagic infarction

Front 33

Septate hyphae, 5 to 10 um wide, display acute-angle branching, ~45 degree angle
Angioinvasive
Necrotizing inflammation

Back 33

Morphology of Aspergillus

Front 34

Predisposing factors to infection include neutropenia, corticosteroid use, diabetes mellitus, iron overload and skin breakdown (burns, trauma, surgical wounds, etc.)

Back 34

Zygomycosis (Mucormycosis)

Front 35

Numerous disease causing species of zygomycetes such as...

Back 35

Mucor, Rhizopus,

Front 36

transmission of Mucormycosis

Back 36

Routes of infection is usually inhalation but may also be ingested or percutaneous exposure

Front 37

Three primary sites of invasion of Mucormycosis

Back 37

are sinuses, lungs, and gastrointestinal tract

Front 38

Occurs in diabetics
Fungus in sinuses invades orbit and brain
eating the face off

Back 38

Rhinocerebral mucormycoisis

Front 39

Gross Morphology of mucormycosis

Back 39

Hemorrhagic infarcts

Front 40

Nonseptate hyphae, irregularly wide, 6 to 50 um in width, with frequent right angle branching
Angioinvasive
Necrotizing inflammation

Back 40

mucormycosis

Front 41

What region Histoplasma capsulatum endemic?

Back 41

Endemic to Ohio, Missouri, and Mississippi River valleys

Front 42

Transmission of histoplasma

Back 42

Acquired by inhalation of spores in dust from soil contaminated by bird or bat droppings

Front 43

Pulmonary infection of Histoplasma resembles what?

Back 43

TB, granuloma formation

Front 44

Histoplasma infection effect what pt population?

Back 44

CNS infection in immunocompromised or have a history suggestive of heavy exposure to histoplasma

Front 45

60 yo healthy male who worked in the poultry industry fertilized his garden with chicken feces and had gradually progressive 3 month Hx of headache, N & V, low grade fever, lower extremity weakness. He became unable to walk and had L 6th CN palsy. Bx of lesion
diagnose and treat!

Back 45

histoplasmosis. Recovered with amphotericin B and fluconazole

Front 46

50 yo healthy woman with several
weeks history of fever, night sweats,
weight loss. PE showed weakness
of right arm and leg, difficulty walk-
ing with a tendency to fall to the left.
Initially thought to be metastatic CA. . Lung also showed multiple
small bilateral lung nodules.
HIV was positive.

Back 46

Histoplasmosis resolved with Rx with
Amphotericin B, Itraconcazole and
Antiretroviral therapy.

Front 47

Where is Coccidioides immitis endemic?

Back 47

Southwest US (particularly Arizona and California’s San Joaquin Valley)

Front 48

How is Coccidioides immitis aquired?

Back 48

inhalation

Front 49

what % of people in endemic areas have positive skin test for Coccidioides immitis ?
And how many develop the actual disease?

Back 49

80% and <1% develop the disease

Front 50

Morphology: thick double contour wall, size~15 um, broad based buds
May be multinucleated
Suppurative granulomas

Back 50

Blastomyces Dermatiditis

Front 51

What area in tha USA do you find Blastomyces Dermatiditis?

Back 51

Central SE USA

Front 52

Where do you find Blastomyces Dermatiditis?

Back 52

soil

Front 53

Trasmission of Blastomyces Dermatiditis

Back 53

inhalation or direct inoculation of skin

Front 54

Well-circumscribed verrucous ulcerated lesions of facial skin The lesions have irregular raised borders with crusting and purulent discharge.

Back 54

Blastomyces

Front 55

26 year old with 3 month history of HA fatigue, cough , fever and hemoptysis and spreading facial rash. Empiric Rx with antibiotics. Declin in cognitive funciton. Worked on a farm hit by Katrina. Neuo exam ataxia and L sided weakness and he required 20 to 45 seconds to ansewer quesitons
CXR showed infiltrates.

Back 55

Blastomyces

Front 56

List Parasites Causing CNS Infection

Back 56

Toxoplasma gondii
Plasmodium falciparum
Taenia solium
Echinococcus granulosis
Trypanosoma(T. brucei rhodesiense and T. brucei gambiense)
Acanthamoeba
Naegleria fowleri

Front 57

How can you get Infection by ingesting Toxoplasma gondii?

Back 57

Raw or undercooked meat containing oocysts, particularly pork and lamb
Material contaminated with oocyst containing cat feces – changing litter box

Front 58

los guantes

Back 58

gloves

Front 59

What is TORCH?

Back 59

List that can cross BBB
TO-toxoplasma
R-rubella
C-CMV
H-Herpes

Front 60

Cerebral toxoplasmosis affect what pt population?

Back 60

immunocompromised patients, especially AIDS

Front 61

Transplacental transmission of toxoplasma can cause what?

Back 61

Stillbirth, abortion, microcephalus, hydrocephalus, cerebral calcifications, retinochorditis (most common manifestation)

Front 62

Gross Morphology of Cerebral Toxoplasmosis

Back 62

Brain abscesses in cerebral cortex near the gray-white junction, deep gray nuclei and rarely other locations

Front 63

Acute cerebral toxoplasmosis's micromorphology present with:******

Back 63

Central necrosis with tachyzoites and encysted bradyzoites at the periphery of necrotic foci
Surrounding acute and chronic inflammation, macrophages
May have vasculitis

Front 64

Which mosquito species causes most severe Malaria?

Back 64

Plasmodium falciparum

Front 65

List the four main malaria parasites (protozoa)

Back 65

Plasmodium vivax
Plasmodium ovale
Plasmodium malariae
Plasmodium falciparum

Front 66

what is the is the main cause of death due to malaria in children? ******

Back 66

Cerebral malaria, caused by P. falciparum,

Front 67

T/F
Cerebral malaria is caused by ischemia due to plugging of small blood vessels with parasite laden red cells

Back 67

True

Front 68

T/F
Plasmodium falciparum causes infected red cells to clump together and to stick to endothelial cells

Back 68

True

Front 69

Cysticercosis caused by what?

Back 69

Taenia solium/Tapeworm

Front 70

What routes Taenia solium infects the body?

Back 70

. Ingestion of undercooked pork containing larval cysts (cysterci)
Cysterci attach to intestinal wall
Adult tapeworms (up to meters in length can then develop)
. Ingestion of eggs in contaminated food or water
Larvae hatch and penetrate intestinal wall to disseminate hematogenously
The larvae encyst in many organs including brain
Viable T. solium cyst may not produce symptoms, producing substances which inhibit host defenses
When cystercerci die or degenerate, an inflammatory response develops

Front 71

Tanea solium larvea affects mainly what organ in the body?******

Back 71

Brain

Front 72

What is the most common cause of epilepsy?

Back 72

Neurocysticercosis

Front 73

What is the Most common neurological infection in the world

Back 73

Neurocysticercosis

Front 74

What organs does T. Solium infect? List 4 this time!

Back 74

brain, muscles, skin and heart but can be found in any organ

Front 75

Hydatid disease caused by what?

Back 75

Echinococcus

Front 76

what is Echinococcus?

Back 76

tapeworm

Front 77

What animals do you find Echinococcus?

Back 77

dogs (E. granulosis) or foxes (E. multilocularis, rare but most virulent)

Front 78

Transmission of Echinococcus?

Back 78

Ingestion of food (i.e. sheep)contaminated with eggs released by infected dogs (E. granulosis) or foxes (E. multilocularis, rare but most virulent)

Front 79

Where does Echinococcus eggs hatch and what organs does it invade?

Back 79

Eggs hatch in small intestine and release oncospheres which invade liver, lungs (5-15%), bones and rarely brain
USUALLY SINGLET!!!!

Front 80

Single cyst in the brain
What disease

Back 80

Echinococcal cyst (hydatid disease)

Front 81

Multiple cysts in the brain.
What disease?

Back 81

T. Solium/ Neurocystercicosis

Front 82

African trypanosomiasis (sleeping sickness) endmic to what region?

Back 82

Sub saharan Africa

Front 83

African trypanosomiasis trasmission by what?

Back 83

tsetse fly

Front 84

What species cause the E. African form of sleeping sickness ?

Back 84

T. brucei rhodesiense

Front 85

What species cause acute and virulent sleeping sickness? And Where?

Back 85

T. brucei rhodesiense
E. Africa

Front 86

What species cause chronic sleeping sickness? And Where?

Back 86

T. brucei gambiense
W. Africa

Front 87

How does african trypanosomiasis escape the immune system?

Back 87

by antigenic variation of parasite surface glycoproteins

Front 88

Symptoms of sleeping sickness

Back 88

Intermittent fevers, lymphadenopathy, splenomegaly

Front 89

local eye infection by ameba called

Back 89

Acanthamoeba

Front 90

Where do you find Acanthamoeba?

Back 90

water and soil

Front 91

CNs infection by Acanthamoeba in immunocomprimissed pt's cause almost always what?

Back 91

Death

Front 92

What is Naegleria fowleri?
Where do find it?
Cause what?

Back 92

Free living ameba
Water (lakes, swimming pools, tap water)
Immunocompromised
primary amebic meningoencephalitis (acute lethal CNS disease)