CNS Infections Flashcards Preview

Clin Med IV - Geriatrics & Neuro > CNS Infections > Flashcards

Flashcards in CNS Infections Deck (70):
1

Most common causes of meningitis

- Bacterial (acute bacterial meningitis)
- Viral (aseptic meningitis)

2

Most common pathogens of ABM

- Streptococcus pneumoniae
- Neisseria meningitidis
- Haeomphilus influenza type B
- Group B Streptococcus
- Listeria monocytogenes

3

Most common causes of viral meningitis

- ENTEROVIRUS**
- HSV
- Lymphocytic choriomeningitis virus
- VZV

4

Aseptic bacterial pathogens that cause meningitis

- M. tuberculosis
- Lyme*
- Trepenoma
- Ehrlichia

5

Drug-induced causes of non-infectious meningitis

- Bactrim
- Ciprofloxacin
- Flagyl
- Amoxicillin, penicillin
- Keflex
- NSAIDs
- Ranitidine
- Carbamazepine

6

2 broad categories of non-infectious causes of meningitis

- Drug-induced
- Systemic

7

Cardinal sx's of ABM (4)

- Fever**
- Headache
- Nuchal rigidity
- Altered mental status

2/4 found in almost all ABM cases

8

What special PE tests would support ABM dx?

Positive Brudzinski and Kernig's signs

9

33% ABM pts present with dysfunction in these CNs

III
VI
VII
VIII

10

How does aseptic meningitis differ from ABM?

More benign course, self-limited → symptomatic support

11

Risk factors for meningitis

- Age >50
- URI, otitis media, sinusitis, mastoiditis
- Head trauma, neurosurgery
- Crowded living conditions
- Immunocompromised
- Antivacciners

12

Labs for ABM
- WBCs
- Glucose
- Protein

- WBC's elevated w/ neutrophilic shift
- Decreased glucose
- Elevated protein

13

Labs for viral meningitis
- WBCs
- Glucose
- Protein

- WBC's elevated, lymphocytic
- Glucose normal
- Protein elevated

14

Labs for fungal meningitis
- WBCs
- Glucose
- Protein

- WBCs elevated, lymphocytic
- Glucose normal to decreased
- Protein elevated

15

Labs for tuberculosis meningitis
- WBCs
- Glucose
- Protein

- WBCs elevated, lymphocytic
- Glucose decreased
- Protein elevated

16

Lactate _____ is associated with mortality in meningitis

>4

17

When should blood cx be obtained for meningitis?

BEFORE abx

18

Definitive test for diagnosing meningitis

Lumbar puncture

19

CSF findings in LP for meningitis

- Elevated opening pressure (>20mmHg)
- WBC >500 more likely bacterial source, but some do have lymphocytic shift early on

20

When should head CT be performed when diagnosing meningitis?

Before LP, if concerned for increased ICP

21

Indications for obtaining head CT before performing LP for meningitis

- Abnormal mental status
- Seizure within 1 week of presentation
- Known CNS disease/lesion
- Focal neuro findings
- Papilledema
- Age >60

22

When should abx be given to treat meningitis?

BEFORE LP/CT if high suspicion for ABM (still got some time before the CSF becomes affected)

23

How long do you have to obtain LP after giving abx in suspected ABM?

Within 2-4 hours

24

Tx meningitis

- Abx (based on age, predisposing condition) if ABM suspicion
- Dexamethasone prior to or with abx**
- Antivirals if suspicious for viral etiology

25

How should you treat elevated ICP?

Mannitol, mild hyperventilation, neurosurgery consult. Consider hypertonic saline

26

What should you use to tx ABM in age 16-50?

Vanco + 3rd gen. ceph (e.g. ceftriaxone)

27

What should you use to tx ABM in age >50?

Vanco + 3rd gen. ceph. + ampicillin

28

What organisms would you suspect in ABM for age 16-50?

- N. meningitidis
- S. pneumoniae
- H. influenzae

29

What organisms would you suspect in ABM for age >50?

- N. meningitidis
- S. pneumoniae
- Listeria
- Aerobic G- bacilli

30

What should you use to tx ABM in immunocompromised pts?

Vanco + 3rd gen ceph. + ampicllin

31

What organisms would you suspect in ABM for immunocompromised?

- N. meningitidis
- S. pneumoniae
- Listeria
- Aerobic G- bacilli

32

What should you use to tx ABM in pts w/ neurosurgery or recent head/cerebrospinal trauma?

Vanco + 3rd gen ceph. + anti-pseudomonal
OR
Vanco + meropenem

33

Management for likely viral meningitis

- Admit and treat w/ IV abx while awaiting CSF cx (24 hrs)
- If confident and pt comfortable/reliable can discontinue with 24-48hr follow up +/- single dose abx

34

Most common etiologies of encephalitis

- Direct viral invasion
- Delayed hypersensitivity reaction to virus or other foreign protein several weeks s/p exposure

35

Most common viruses that cause encephalitis via direct viral invasion

- Enterovirus
- HSV

36

Most common viral cause of encephalitis worldwide

Measles

37

How would you diagnose encephalitis secondary to hypersensitivity reaction?

CSF has no viral proteins

38

Presentation of encephalitis

- Altered mental status**
- Fever
- Headache
- HPI of mild flu or febrile viral illness w/ possible evidence of meningeal involvement

39

Risk factors for encephalitis

- Age (young/old)
- Immunocompromised
- Geographic location
- Travel
- Outdoor activity
- Season
- Immunization

40

Dx encephalitis

Clear, cloudy, turbid, bloody CSF
- Opening pressure >20mmHg
- Slightly elevated protein
- Pleocytosis w/ lymphocytic predominance
- Normal glucose
- Negative gram stain, culture
- PCR*

41

Findings of HSV on head neuroimaging

Focal edema in orbitofrontal and temporal areas

42

Findings of WNV, EEE on head neuroimaging

Demyelination in basal ganglia and thalamic areas

43

Tx encephalitis

- Acyclovir (even before CSF results if suspected)
- Supportive tx → suppress fever, ICP monitoring, fluid restrict, SIADH/hypoNa+
- Benzos/anticonvulsants ppx for seizure
- If elevated ICP → mannitol or hypertonic saline, neurosurgery consult

44

Arbovirus method of transmission

Through vector (e.g. mosquito)

45

Where is West Nile Virus found?

All states in summer, early fall

46

Greatest risk for WNV is _____

Elderly

47

Most cases of WNV are mild and clinically unapparent with ____ days of sxs and ____ days of incubation

3-6 days sx
3-14 days incubation

48

Dx WNV

CSF or serum for WNV IgM 3-5 days s/p exposure → positive up to 3 months

May have to repeat if 1st sample negative

49

Epidemiology of fatal LaCross encephalitis

Age <16

50

Epidemiology of Eastern Equine encephalitis

Eastern/Central states (none in MA, VT)

51

Epidemiology of Japanese encephalitis

Travelers (ppx vaccine available)

52

How is rabies transmitted?

Infected vector to humans by saliva or brain/nervous tissue to mucous membranes, eyes, nose, mouth, open wound

53

Incubation period for rabies

2-8 weeks before sx's develop

54

Tx rabies exposure

Post-exposure ppx even in cases w/out direct contact
- Passive → rabies IG injection x1 around wound
- Active → HDCV IM days 0,3,7,14

No treatment if rabies develops → ~100% fatal

55

What animals might you specifically be concerned of contracting rabies from?

- Raccoon
- Fox
- Coyote
- Skunk
- Brown bats

56

Are small rodents able to transfer rabies to humans?

No

57

What should you do if you suspect a domestic animal has rabies?

10-day observation/quarantine → rabid demeanor reveals itself within this time

58

Should you be concerned your pet has rabies?

Not really... vaccines are pretty good here (not so much in other countries)

59

Tx paraneoplastic or autoimmune encephalitis

- IVIG
- Methylprednisolone
- Early tumor resection if applicable

60

90% epidural abscesses occur where? Why?

Spinal, esp. thoracolumbar region - dura is adherent to skull

61

Etiology of intracranial epidural abscess

- Sinusitis
- Orbital cellulitis
- Skull fracture
- Neurosurgery

62

Presentation of intracranial epidural abscess

- Fever
- Headache
- Malaise
- Lethargy
- N/V

63

Risk factors for epidural abscess

- DM
- ETOH
- Trauma/surgery
- IVDA
- CKD
- Immunosuppression
- Anesthesia/injections
- Pregnancy

64

Tx intracranial epidural abscess

- Craniotomy to dran abscess
- Vanco + 3rd/4th ceph +/- Flagyl

65

Common locations of spinal epidural abscess

Thoracic > Lumbar > Cervical

66

Etiologies of spinal epidural abscess

- Hematogenous spread**
- Direct extension

67

4 stages of spinal epidural abscess manifestations

- Fever + local back pain
- Radiculopathy d/t nerve root compression
- Spinal cord compression → cauda equina, motor/sensory deficits, saddle anesthesia, ecr. DTRs
- Paralysis

68

LP should be performed in spinal epidural abscess. T/F

No!

69

Diagnostic of choice for spinal epidural abscess

MRI (or CT)

NO LP

70

Tx spinal epidural abcess

- Consult neurosurgery, spine surgery, ID → early surgical decompression/drainage w/ laminectomy within 24 hrs
- May attempt CT-guided drainage if neuro deficits
- Vanco + 3rd/4th ceph. +/- Flagyl → taylor to cx results