Prayson Infection

Question 1

Epidural abcess

Answer 1

Most common organsims: Streptococcus and Staphylococcus. Usually 2/2 extension from bones (trauma, osteomyelitis) > soft tissue
Spinal- Staph aureus, Lumbar and thoracic, more common than intracranial
Intracranial - extension from sinus infection

Question 2

Subdural abcess

Answer 2

1 Strep, #2 Staph. Bone/sinus infection via thrombophlebitis. Dorsolateral cerbrum, frontal pole, and interhemispheric fissure. Spinal rare

Question 3

Leptomeninges

Answer 3

Fever, HA, nausea, vomiting, confusion, nuchal rigidity, Kernig’s and Brudzinski’s signs.
Neonatal- Strep agalactiae (Group B, exudate over vertex) and E. coli (hemorrhage, necrotizing, arteritis, necrosis) are most common, Proteus, Listeria (microabcesses)
Children- Nisseria meningitidis (basal aspect of brain, Waterhous Friederichesen)
Adults- S. pneumonia, Listeria monocytogenes

Question 4

Abcess

Answer 4

#1 Streptococcus 
#2 gram-negative bacilli 
#3 Staphylococcus
frequently multiple organisms

Question 5

Mycobacterium tuberculosis

Answer 5

Necrotizing granulomas; Ziehl-Neelsen & Fite have low yeild (<50%)
CSF: lymphocyte predom
Epidural- extension from vertebral infxn (Pott’s), subdural- milliary or en-plaque, abcsess-tuberucloma, meningitis- base of brain, neutrophils, endarteritis.

Question 6

Mycobacterium avium

Answer 6

Perivascular macrophages with orgasisms

Question 7

Sarcoid

Answer 7

Non-casseating granulomas, base of brain post. fossa, Optic nerve and chiasm common, near vessels in meninges,

Question 8

Whipple’s dx

Answer 8

Tropheryma whippelii, gram + actinomyocete. Males, dementia, gaze palsies, and myoclonus. PAS+ organsims in perivascular macs

Question 9

Early Syphilis

Answer 9

Treponema pallidum; Steiner, Warthin-Starry, Dieterle stains. Subacute secondary lymphocytic meningitis, meningovascular lymhs, plasma cells, and gummata (central necrosis surrounded by epithelioid histiocytes, no organisms), arteritis, Heubner’s endarteritis obliterans, pachymeningitis cervicalis.

Question 10

General paresis Syphilis

Answer 10

Progressive dementia, Argyll Robertson pupils, late frotnal atrophy, subacute encephalitis, loss of neurons, astrocytosis, perivascular inflammation, microglial with iron. Spirochetes hard to identify. 3 year course

Question 11

Lissauer’s dementia

Answer 11

Cuased by syphilis (7-8 year course), variant of general paresis. Epileptic or aapoplectic attacks, temporal atrophy w/ pseudolaminar degenration.

Question 12

Tabes Dorasalis

Answer 12

Degeneration of spinal dorsal roots and columns, lumbosacral and lower thoracic cord, dorsal root ganglia unaffected.
Caused by syphillis. Pain, loss of reflexes, loss of pain sensation and joint position, ataxia, Charcot joints. Optic nerve atrophy

Question 13

Congenital syphilis

Answer 13

Meningovascular inflammation with obstructive hydrocephalus. Keratitis, chroiretinits, and deafness. cerebellar general paresis

Question 14

Lyme disease

Answer 14

Borrelia burgdorferi, spirochete transmitted by ioxodid tick. Lymphoplasmacytic leptomeningitis, crainial neuropathy. Erythema chroncia migrans, cardiac involvement, and arthritis.

Question 15

Actinomycosis

Answer 15

BT w/ fungal like morphology, thin filaments. Gram +, acid fast -. Sulfur granules, cervicofacial entry. Granulomas and basilar meningitis

Question 16

Nocardia

Answer 16

Nocardia asteroides most common. BT w/ fungal like morphology, thin filaments. Gram+, partial acid fast +. lung entry. Granulomas, small and multiple with neutrophils

Question 17

Cryptococcus

Answer 17

Budding yeast w/ thick mucopolysaccharide wall. Bird excrement. IMMUNOCOMPROMISED, M>F, pulmonary entry.
Leptomeningitis, gelatinous “bubbly” exudate, macs, perivascular extension giving a grossly HONEYCOMB look, granulomas, abscess. PAS, mucicarmine +

Question 18

Candidiasis

Answer 18

Budding cells, branching pseudohyphae, Skin/GI entry, CNS dx 2/2 systemic or endocarditis. Chronic granulomas, microabscesses, GMS and PAS +

Question 19

Aspergillis

Answer 19

Dichotomously branching septate hyphae. Airborn lung infxn followed by hematogneous spread. Immunocompromised. A. fumigatus and A. flavus most common.
Granulomas with basal meningitis, septic infarcts, focal cerebritis, especially white matter

Question 20

Mucormycosis

Answer 20

Broad branching, non-septate. Entry from sinus or aspiration into lung. Rhinocerebral dx associated with DM and ketoacidosis. Hematogenous dx assoc w/ immunocompromised or IV drug use.
Acute meningeal inflammation, hemorrhagic coagulative necrosis of the brain (ventral), vascular lumen and mural invasion.

Question 21

Coccidiodes immitis

Answer 21

South America and Southwest US. Double contoured refractile capsules with endospores. Very rarely involves CNS. Basilar meningitis w/ neutrophils and fibrinous exudate later becomes granulomas and fibrosis; cranial osteomyelitis; parenchymal granulomas rare. Largest.

Question 22

Blastomyces dermatitidis

Answer 22

M>F, agricultural workers. Southwestern US, contaminated soil. Broad-based budding. Abscess

Question 23

Histoplasma capsulatum

Answer 23

Central and eastern states (Ohio and Mississippi river valleys). Inhalation of dust or soil contaminated by spores. Small ovoid and budding bodies, PAS and GMS+. Rarely involves CNS, Immunocompromised. Necrosis with macs containing organisms, lymphs and plasma cells

Question 24

Cowdry A inclusions

Answer 24

Intranuclear, spherical, halo. CMV, HSV, PML

Question 25

Cowdry B inclusions

Answer 25

Small, multiple, no nucleolar displacement. Polio

Question 26

Polio

Answer 26

Enterovirus. Fecal-oral transmission, rare vaccine reversion. Acute febrile dx, asymmetical paralysis (legs >arms >trunk). 5% mortality. Loss of large motor neurons w/ neuronophagia (ant. horn cells, motor neurons of cranial nerves); Neurogenic atrophy of skeletal muscle; lymphocytic perivascular inflammation, gliosis.
Post-polio: 30-40 yrs after acute illness, progressive weakness w/ decreased muscle bulk and pain

Question 27

Arbovirus

Answer 27

RNA virus, mosquito borne, Alpha-, flavi-, Buny-, and Reoviruses. Hematogenous spread, dx w/ serology. St. Louis, California, and Eastern and Western Equine.
Most infxns are subclinical. Widespread gray matter involvement, neuronal degen, neuronophagia, microglial nodules and perivascular and meningeal chronic inflammation.
Most severe changes w. eastern equine; West Nile preferentially involves brain stem and spinal cord.

Question 28

Aseptic meningitis

Answer 28

Culture negative meningitis. Coxsackie and echovirus are most common, but caused by many viruses. Meningeal and choroid plexus lymphs. low mortality

Question 29

Measles

Answer 29

Usually age <10, low fatality. Perivascular inflammation, demyelination, multinucleated giant cells, intranuclear and intracytoplasmic inclusions.

Question 30

Influenza

Answer 30

Abnormal behaviour, disorientation, seizures, and coma. Neuronal degen and inflammation

Question 31

Subacute sclerosing panencephalitis (SSPE)

Answer 31

Fatal, measles. age <12, M>F. Months-few years course. Progressive dementia, myoclonus, seizures, ataxia, and dystonia. Gray matter subacute encephalitis. Eosinophilic nuclear and cytoplasmic inclusions, neuronal loss, microglial proliferation, perivascular inflammation, demyelination, oligodendroglial inclusions, reactive astrocytosis, may see NFTs

Question 32

Mumps

Answer 32

2-10 days after onset. PERIVENOUS DEMYELINATION, low mortality, 10-20% aseptic meningitis

Question 33

Rabies

Answer 33

Variable incubation (1-3 months), death in 2-7 days. Anxiety, psychomotor  sensitivity, hydrophobia, dysphagia, and seizures. 
Encephalomyelitis (especially brain stem) w/ neuronophagia, microglial nodules, negri bodies (hippocampus and cerebellum), Lyssa bodies (lack inner formation)