DSA 30 CNS Infections (Vuitch)

Question 1

what pathogen causes acute pyogenic (bacterial) meningitis in neonates?

Answer 1

e.coli and group B strep

Question 2

what pathogen causes acute pyogenic (bacterial) meningitis in infants/children?

Answer 2

s. pneumoniae

Question 3

what pathogen causes acute pyogenic (bacterial) meningitis in adolescents/young adults?

Answer 3

neisseria meningitidis (aka meningococcal disease)

Question 4

what pathogen causes acute pyogenic (bacterial) meningitis in the elderly?

Answer 4

s. pneumoniae and listeria monocytogenes

Question 5

what is the clinical presentation of acute pyogenic (bacterial) meningitis?

Answer 5

fever, headache, photophobia, clouded sensorium, neck stiffness

Question 6

what are the characteristics of CSF in acute bacterial meningitis?

Answer 6

purulent, neutrophils and organisms, increased protein, decreased glucose

Question 7

what is the expected protein and glucose level in the CSF of patient with viral meningitis?

Answer 7

moderate increase in protein, normal glucose

Question 8

what is the most common etiology of viral meningitis?

Answer 8

enteroviruses

Question 9

what are the principal organisms involved in brain abscess?

Answer 9

streptococcus and staphylococcus

Question 10

what is clinical presentation of brain abscess?

Answer 10

focal neurologic deficits and signs of increased ICP

Question 11

what would be seen with an older brain abscess?

Answer 11

fibrous capsule surrounded by reactive gliosis and marked vasogenic edema (results from disruption of BBB)

Question 12

what are characteristics of CSF in brain abscess?

Answer 12

high WBC count, increased protein, normal glucose

Question 13

with prompt diagnosis and treatment, what is the residuum of subdural empyema?

Answer 13

thickened dura

Question 14

what causes subdural empyema?

Answer 14

bacterial/fungal infection of skull bones or air sinuses spreads to subdural space

Question 15

what can result from untreated subdural empyema?

Answer 15

focal neurologic signs, lethargy, and coma

Question 16

what is the clinical presentation for tuberculous meningitis?

Answer 16

headache, malaise, mental confusion, and vomiting

Question 17

what are characteristics of CSF in tuberculous meningitis?

Answer 17

pleocytosis of mononuclear cells or mix of neutrophils and mononuclear cells, increased protein, moderately decreased or normal glucose

Question 18

what are complications of chronic tuberculous meningitis?

Answer 18

arachnoid fibrosis → hydrocephalus. obliterative endarteritis → arterial occlusion and infarction.

Question 19

what is meningovascular neurosyphilis?

Answer 19

chronic meningitis involving the base of the brain, more variably cerebral convexities and spinal leptomeninges

Question 20

what is paretic neurosyphilis?

Answer 20

caused by invasion of brain by t. pallidum

Question 21

what is the clinical manifestation of paretic neurosyphilis?

Answer 21

insidious but progressive cognitive impairment associated with mood alterations that terminate in severe dementia. parenchymal damage of cerebral cortex in frontal lobe.

Question 22

identify: these lesions are characterized by loss of neurons, proliferation of microglia, gliosis, and iron deposits

Answer 22

paretic neurosyphilis

Question 23

what causes tabes dorsalis?

Answer 23

damage to the sensory axons in the dorsal roots → impaired joint position sense and ataxia, loss of pain sensation (Charcot joints), lightning pains, no DTRs.

Question 24

identify: symptoms include aseptic meningitis, facial nerve palsies, other polyneuropathies, and encephalopathy.

Answer 24

neuroborreliosis (Lyme disease)

Question 25

what is Waterhouse-Friderichsen syndrome?

Answer 25

results from mengitis-associated septicemia with hemorrhagic infarction of adrenal glands and _cutaneous petechiae_

Question 26

what is the clinical presentation of arthropod-borne viral encephalitis?

Answer 26

generalized neurologic deficits: seizures, confusion, delirium, stupor, coma. focal signs: ocular palsy, reflex asymmetry.

Question 27

identify: CSF is colorless with slightly elevated pressure, increased protein, normal glucose, neutrophilic pleocytosis → lymphocytosis.

Answer 27

arthropod-borne viral encephalitis

Question 28

what are the symptoms of meningoencephalitis caused by HSV-1?

Answer 28

alterations in mood, memory, and behavior

Question 29

in which demographic do you predominantly see meningoencephalitis caused by HSV-1?

Answer 29

children and young adults

Question 30

what areas of the brain are affected by meningoencephalitis caused by HSV-1?

Answer 30

inferior and medial regions of the temporal lobes; orbital gyri of the frontal lobes

Question 31

what can HSV-2 cause in patients with active HIV infection?

Answer 31

acute hemorrhagic and necrotizing encephalitis

Question 32

what two populations are affected by CMV infections in the nervous system?

Answer 32

fetuses and immunosuppressed

Question 33

how does CMV manifest in utero?

Answer 33

periventricular necrosis → severe brain destruction → microcephaly and periventricular calcification

Question 34

what are Negri bodies and what infection are they involved in?

Answer 34

cytoplasmic eosinophilic inclusions found in rabies infection

Question 35

where can Negri bodies be found?

Answer 35

pyramidal neurons in hippocampus and Purkinje cells in cerebellum

Question 36

what are the clinical features of rabies infection?

Answer 36

malaise, headache, fever, and _local paresthesias around the wound_ initially. progression to extraordinary CNS excitability, foaming at the mouth, hydrophobia, flaccid paralysis. alternating mania and stupor → coma → death from respiratory failure.

Question 37

what is HIV encephalitis?

Answer 37

chronic inflammatory reaction associated with widely distributed microglial nodules often containing multinucleated giant cells. foci of tissue necrosis and reactive gliosis

Question 38

what causes progressive multifocal leukoencephalopathy?

Answer 38

JC polyomavirus

Question 39

what cells are preferentially affected in PML and what is the result?

Answer 39

oligodendrocytes, demyelination

Question 40

identify: focal and progressive neurologic signs and symptoms. extensive lesions in hemispheric or cerebellar white matter

Answer 40

progressive multifocal leukoencephalopathy

Question 41

identify: this CNS infection occurs in children or young adults after an initial infection with measles.

Answer 41

subacute sclerosing panencephalitis

Question 42

identify: CNS infection chracterized by widespread gliosis and myelin degeneration, viral inclusions in nucleus of oligodendrocytes and neurons, inflammation of white and gray matter, and neurofibrillary tangles.

Answer 42

subacute sclerosing panencephalitis

Question 43

what is the clinical presentation of subacute sclerosing panencephalitis?

Answer 43

cognitive decline, spasticity of limbs, and seizures

Question 44

what organisms can cause fungal meningoencephalitis, specifically vasculitis?

Answer 44

mucor species and aspergillus; directly invade the blood vessels

Question 45

which fungal species can cause fungal meningoencephalitis, specifically parenchymal invasion?

Answer 45

candida and cryptococcus, often cause granulomas or abscesses

Question 46

cryptococcal meningitis is seen in what clinical setting?

Answer 46

it is common in AIDS patients

Question 47

identify: soap bubbles (small cysts within parenchyma) seen in basal ganglia.

Answer 47

chronic meningitis resulting from cryptococcal infection

Question 48

identify: abnormal forms of cellular protein that cause rapidly progressive neurodegenerative disorders that may be sporadic, familial, or transmitted.

Answer 48

prions

Question 49

what is the pathogenesis and molecular biology of prion diseases?

Answer 49

conformational change of normal neuronal protein PrP. resistant to protease digestion, induces more protein molecules to change conformation

Question 50

what is the clinical course of CJD?

Answer 50

rapid progression of dementia with gait abnormalities and myoclonus. spongiform change, neuronal loss, no inflammation.

Question 51

what pathologically characteristic of vCJD?

Answer 51

extensive cortical plaques surrounded by halo of spongiform change

Question 52

name 3 ways in which vCJD differs from CJD.

Answer 52

1. ) affects young adults 2. ) behavioral disorders in early stages 3. ) neurologic syndrome progresses more slowly

Question 53

idenfity: onset is linked to consumption of bovine spongiform encephalopathy agent in contaminated foods.

Answer 53

vCJD

Question 54

identify: cerebral gummas (plasma cell-rich mass lesions)

Answer 54

meningovascular neurosyphilis

Question 55

what is common pattern of meningeal involvement in pneumococcal meningitis?

Answer 55

outer surfaces of cerebral hemispheres (cerebral convexities)

Question 56

CSF findings in TB meningitis?

Answer 56

normal glucose, high protein, lymphocytes

Question 57

what are common complications of TB meningitis?

Answer 57

obliterative endarteritis, hydrocephalus, destruction of cranial nerves

Question 58

identify: this organism is most common CNS organism seen in AIDS patients. imaging shows ring-enhancing lesions. CSF has high protein, normal glucose, no organisms.

Answer 58

toxoplasma gondii

Question 59

how can you use CSF findings to differentiate between toxoplasma gondii and cryptococcus infection?

Answer 59

toxoplasma gondii organisms _will not_ be present in CSF while cryptococcus organisms _will_ be present in CSF

Question 60

identify: cell type with CD4 coreceptor and CCR5 or CXCR4 chemokine receptors

Answer 60

microglia