L40- Nervous System and Special Senses Infections III Flashcards

1
Q

Encephalitis:

  • (1) definition
  • (2) are the most common causes of primary form
  • (3) = secondary cause
A

1- inflammation of brain parenchyma

2- Viral: HSV-1/2, Arbovirus, Enterovirus

3- ADEM (acute disseminated encephalomyelitis) occurs post-infection and results from an autoimmune attack on myelin

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2
Q

Encephalitis:

  • (1) is the major criterion for Dx
  • (2) are the other minor criterion
A

1- Altered Mental Status: impairment of consciousness, memory, mental status

2:

  • fever w/in 72hrs of presentation
  • seizure
  • CSF w/ pleocytosis
  • imaging with evidence of parenchymal inflammation
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3
Q

name the associated pathogen with the following unique sign seen in each encephalitis:

  • (1) grouped vesicles in dermatomal pattern on skin
  • (2) parotitis
  • (3) flaccid paralysis
  • (4) hydrophobia, aerophobia, pharyngeal spasms, hyperactivity
  • (5) tremors in eyelids, tongue, lips, extremities
A
1- VZV
2- mumps
3- WNV
4- rabies
5- WNV, SLV (st. louis)
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4
Q

Meningitis, indicate if present or absent:

  • (1) fever
  • (2) HA, lethargy, n/v
  • (3) photophobia, neck stiffness
  • (4) seizures
  • (5) CN palsies
  • (6) altered mental status
A
1- yes
2- yes
3- yes
4- minimal
5- no
6- minimal
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5
Q

Encephalitis, indicate if present or absent:

  • (1) fever
  • (2) HA, lethargy, n/v
  • (3) photophobia, neck stiffness
  • (4) seizures
  • (5) CN palsies
  • (6) altered mental status
A
1- yes
2- yes
3- no
4- yes
5- yes
6- yes
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6
Q

name the associated pathogen with the following imaging seen in each encephalitis:

  • hydrocephalus suggest encephalitis caused by (1)
  • (2) involvement of temporal lobe
  • (3) involvement of basal ganglia
A

1- non-viral cause (bacteria, fungal, parasite)

2- HSV

3- respiratory virus infection, Creutzfeldt-Jakob disease, arbovirus, Tb

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7
Q

(1) is the most common cause of encephalitis, ~10% of all cases:
- (2) describe mortality
- commonly affects (3) age group

A

1- HSV: 1 > 2
2- >50% if untreated
3- any age

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8
Q

describe the clinical presentation of HSV encephalitis- include affected brain regions

A

-HA, fever for up to 5 days

  • personality / behavioral changes –> frontal lobe damage
  • memory, speech problems –> temporal lobe damage

-seizures, hallucinations, altered levels of conciousness

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9
Q

Powassan encephalitis:

  • (1) describe microbe
  • (2) incubation period
  • (3) Sxs
A

1- (rare- US, Canada) Arbovirus transmitted via ticks

2- 7-10 days after bite

3- HA, fever, nausea, confusion, partial paralysis, coma, seizures

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10
Q

describe the progression of infections that cause Brain Abscess — include affected area of brain parenchyma

A

Hematogenous Seeding

Contiguous Spread:

  • subacute/chronic otitis media –> inferior temporal lobe, cerebellum
  • frontal / ethmoid sinuses –> frontal lobe
  • dental infections –> frontal lobe

Note- most are polymicrobial

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11
Q

brain abscess Sxs

A
  • HA, 90%
  • mental status changes, 67%
  • hemiparesis, 61%
  • fever, 57%
  • papilledema, 56%
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12
Q

describe brain abscess Dx (importantly indicate what procedure is contraindicated) and Tx

A

Dx: CT / MRI
NO LUMBAR PUNCTURE => herniation

Tx: drainage

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13
Q

______ is the most common cause of acute viral myelitis

A
  • Enterovirus: poliovirus
  • Flavivirus
  • some others
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14
Q

Poliovirus: family, genus, genome, structure

A

picornaviridae- enterovirus

  • (+)ssRNA
  • non-enveloped
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15
Q

list the different diseases caused by Poliovirus

A

1) abortive poliomyelitis: non-specific Sxs: fever, HA, sore throat, anorexia, vomiting, abdominal pain
2) non-paralytic poliomyelitis – aseptic meningitis
3) paralytic poliomyelitis (abortive –> paralysis), <2% of cases

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16
Q

describe progression of paralytic poliomyelitis

A

<2% cases, Biphasic:

1) Minor Illness / Abortive Poliomyelitis: (non-specific Sxs)
- fever, HA, sore throat
- anorexia, vomiting, abdominal pain

2) Major Illness:
- Meningitis –> Myalgia –> weakness and asymmetric flaccid paralysis
- some groups more involved than others
- respiratory compromise is primary complication

17
Q

describe Polio prevention

A

1) inactivated polio vaccine / Salk vaccine:
- IPV given IM, in countries w/o WT-virus

2) live oral attenuated polio vaccine / Sabin vaccine
- OPV is live virus
- given orally –> replicates in GI –> Ab production –> virus is evacuated in BM
- **small risk of associated paralytic disease — VAPP = vaccine associated paralytic polio (WT reversion)

18
Q

Clostridium botulism microbial features, sources, toxin MOA

A

anaerobic **spore-forming Gram+ rod, β-hemolytic

Sources:

  • Food: poorly canned vegetables OR contaminated honey given <1y/o
  • wound contamination
  • infection from organism / toxin

Botulinum –> binds presynaptically in NMJ –> prevent ACh release => flaccid paralysis

19
Q

Clostridium botulism clinical presentation, Tx, and laboratory studies

A

(ingestion of toxin) —> flaccid paralysis OR death –> Tx with anti-toxin + supportive care

  • isolation via wound, stool // toxin detection in blood, stool, food
  • Note- may not seen as infection travels fast
  • β-hemolytic
20
Q

Clostridium tetani microbial features

A

anerobic Gram+ rod
motile, spore forming
catalase-

21
Q

describe pathogenesis and MOA of C. tetani toxin

A

1) C. tetani acquired via injury with infected device (eg. rusty nail)
2) anaerobic environment => spore germination
3) Tetanospasmin (neurotoxin is released)
4) binds presynaptic membrane in NMJ
5) internalized –> transported to spinal cord
6) blocks release of glycine / GABA => no inhibition of NMJ
7) spastic / rigid paralysis

22
Q

list the forms of Prion disease and indicate most common diseases

A

Sporadic:

  • **sporadic Creutzfeldt-Jakob disease (sCJD, *85-95% of all cases)
  • sporadic familial insomnia (sFI)

Familial:

  • **familial CJD (*5-15% of all cases)
  • fatal familial insomnia (fFI)

Acquired: eg. Kuru

23
Q

list the common neuropathological features of TSEs

A
  • neural loss
  • proliferation of glial cells
  • absence of an inflammatory response
  • presence of small vacuoles w/in neuropil => spongiform appearance
24
Q

describe the protein changes in TSEs

A

PrP(Sc) scrapie prion protein — originally PrP(c)

-α-helix –> β-sheets, indigestible

25
Q

______ is the hallmark microscopic sign of TSEs

A

Spongiform lesions: vacuoles in cortex, cerebellum

26
Q

JC virus:

  • (1) family, genome, structure
  • causes (2), mostly in (3) population
A

1- Polyomaviridae: non-enveloped dsDNA

2- PML, progressive multifocal leukoencephalopathy
3- immuno-compromised (rare in immuno-competent)

27
Q

PML:

  • (1) disease process
  • (2) Dx
A

(progressive multifocal leukoencephalopathy)
1:
-demyelinating disease => high morbidity, high mortality

  • *Kidney transplant recipients: nephropathy, uretal stenosis
  • *Hematopoietic cell transplant recipients: hemorrhagic cystitis

2: PCR, urine cytology, serology, histopathology

28
Q

OE infections:

  • (1) most affected age group
  • (2) infection location
  • (3) risk factors
  • (4) two most common causes
  • (5) signs, Sxs
A

1- 5-14 y/o
2- external auditory canal or auricle
3- swimming, foreign devices (Q-tip), trauma (Q-tip)
4- P. aerugiosa, S. aureus
5- fever, pain, pruritis, discharge, hearing loss, lymphadenopathy

29
Q

OM infections:

  • (1) most affected age group
  • (2) infection location
  • (3) risk factors
  • (4) distribution of causes
  • (5) signs, Sxs
A
1- 6-24 mo/o
2- TM
3- viral URI, daycare
4- bacteria and viruses
5- fever, irritability, apathy, trouble sleeping, vomiting, inflammation, edema
30
Q

labyrinthitis / vestibular neuritis:

  • (1) most affected age group
  • (2) infection location
  • (3) risk factors
  • (4) common causes
  • (5) signs, Sxs
A

1- all ages
2- vestibular portion of CN-8
3- cold, flu, URI
4- bacteria and viruses —- or from OM/URI extension
5- purulent discharge, vertigo, n/v, gait impairment, tinnitus, hearing loss`

31
Q

Mastoiditis- infection of mastoid bone:

  • mainly stems from (1) in (2) population
  • (3) signs and Sxs
A

1- otitis media
2- children

3:

  • fever, HA
  • hearing loss, ear drainage, redness/tenderness behind ear
  • **bulging and drooping of ear
32
Q

what is the indication for culture in OM/OE

A
  • severe or chronic forms

- immuno-compromised patients

33
Q

Acathameoba infection:

  • (1) clinical presentation
  • (2) risk factors
A

(free-living protozoa)
1- conjunctival hyperemia, tearing, foreign body, pain, photophobia

2- immuno-deficiencies, long-term contact lens use

34
Q

Trachoma = (1):

  • (2) is the cause, include microbial features and serotypes
  • main cause of (3) in the world, spreads via (4) routes
A

1- chronic keratoconjunctivitis
2- Chlamydia trachomatis: small obligate intracellular gram- /// serotypes A, B, C

3- preventable blindness
4- eye, nose, throat secretions; flies; fomites

35
Q

describe clinical presentation of Trachoma

A

Phase 1: young children
-self-limiting conjunctivitis

Phase 2: adults

  • chronic infection –> inflammation and scarring of eyelid
  • ingrown eyelashes –> edema, ulceration, scarring
  • *eventually blindness