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Clin Med B 2 > (Enochs + some)Lecture 4: CNS Infections > Flashcards

(Enochs + some)Lecture 4: CNS Infections Flashcards

1
Q

What are the types of CNS infections?

A
  • Meningitis - inflammatory of meningies
  • Encephalitis - inflamm of brain itself
  • Meningoencephalitis - inflamm of both
  • Brain Abscess - collection of purulent material within brian tissue
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2
Q

What are the meningeal signs?

A
  • Nuchal rigidity
  • Brudzinski’s (neck)
  • Kernig’s (knee)
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3
Q

What physical manifestation is seen in increased ICP in infants?

A

Bulging fontanelle

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4
Q

What are the S/S of increased ICP?

A
  • Papilledema
  • Poorly reactive pupils
  • Abducens palsy (horizontal diplopia)
  • N/V
  • Bulging fontanelle in infants
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5
Q

describe each of the following:
- dura mater
- arachnoid mater
- subarachnoid space
- pia mater

A
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6
Q

What layers of the meninges does meningitis typically affect?

A
  • Arachnoid mater
  • Pia mater
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7
Q

What are the typical colonization areas for pathogens that cause meningitis?

A
  • Nasopharynx
  • Respiratory tract
  • Skin
  • GI/GU tracts
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8
Q

What are the two ways pathogens spread to the CNS?

A
  • Hematogenous (MC)
  • Direct contiguous spread via face sinuses (sinusitis, OM, trauma, neurosurgical)
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9
Q

How can newbornes get bacterial meningitis

A
  • pathogens colonized from the maternal intestinal or genital tract
  • transmitted from nursery personnel or caregivers at home
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10
Q

What is the #1 community acquired bacteria to cause meningitis?

What are the other 4 bacterial causes?

A

Strep pneumo (MC in adults > 20)

Group B strep
N. meningitiditis (causes SEVERE meningitis)
H flu type B
Listeria monocytogenes

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11
Q

What are the most common healthcare acquired bacterial meningitis pathogens and when does it occur?

A
  • Staph aureus and coagulase-negative staph (normal skin flora)
  • MC after neurosurgical procedures
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12
Q

What is the MC bacteria that causes meningitis in neonates?

A
  1. GBS
  2. E. coli
  3. gram neg bacilli
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13
Q

What is the MC bacteria that causes meningitis in children > 1 month?

A
  1. Strep pneumo
  2. N. meningitiditis
  3. H flu (unvaccinated)
  4. GBS
  5. Gram neg bacilli
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14
Q

What is the classic triad of bacterial meningitis?

A
  1. Headache (MC)
  2. Fever (2nd MC)
  3. Nuchal rigidity/meningeal signs
  4. ALOC/AMS (sometimes)

First 3 occur 50% of all cases

2 out of 4 are present in almost all cases

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15
Q

What additional S/S are seen in bacterial meningitis for adults?

A
  • N/V
  • Photophobia
  • Increased ICP (papilledema, CN palsy)
  • Meningococcal rash (petechiae or purpura)

Presence of meningococal rash suggests N. meningitiditis, which is more severe.

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16
Q

what symptom is associated with septic N meningitidis

A

maculopapular rash that become petechial and/or purpuric involving the trunk, LE, mucosal membranes, conjunctiva

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17
Q

How might an pediatrics present in bacterial meningitis?

A
  • Restlessness
  • V/D
  • Poor feeding
  • Respiratory distress
  • Seizures
  • Jaundice
  • Bulging fontanelle (infants)
  • fever/hypothermia

Kernig and brud is NOT reliable in younger children

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18
Q

What are the historical red flags for bacterial meningitis?

A
  • Recent exposure
  • Recent illness/abx tx (sinusitis, otitis, pna, ect)
  • Recent travel to endemic areas (sub-saharan africa)
  • Penetrating head trauma
  • CSF otorrhea or CSF rhinorrhea (hx skull fx)
  • Cochlear implants
  • Recent neurosurgery (esp. VP shunts)
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19
Q

What is the absolute #1 treatment for bacterial meningitis?

A

Starting Empiric ABX

Goal is 60 minutes to starting abx!

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20
Q

What two things are of upmost importance in diagnosing bacterial meningitis?

A
  • Blood cultures x2
  • LP
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21
Q

What would prompt us to order a CT scan prior to performing an LP?

A
  • Immunocompromised state
  • Increased ICP S/S
  • History of CNS disease
  • New onset seizures
  • Papilledema
  • ALOC
  • Focal neurologic deficit

DO NOT DELAY EMPIRIC ABX THERAPY FOR LP OR CT

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22
Q

What are the landmarks and location for LPs?

A
  1. Iliac crest/PSIS
  2. L2-L3, L3-L4 or L4-L5 intervertebral spaces
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23
Q

What does high flow of CSF from a LP suggest?

A

Increased ICP

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24
Q

What are the 4 tubes for CSF analysis?

A
  1. Cell count and diff
  2. Glucose and protein
  3. Gram stain, C&S
  4. Cell count and diff (repeat) or special studies
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25
On a CSF analysis suggestive of bacteria, what would I see?
1. Increased pressure 200-300 2. Cloudy, purulent appearance 3. Many PMNs >80% 4. Low glucose <40 5. High Protein >100 6. Elevated lactate (>= 31.53) (additional study) 7. Decreased CSF:serum glucose ratio < 0.4 (additional study) | Bacteria eat glucose so glucose is low, and then they poop out protein.
26
On a CSF analysis suggestive of viral infection what would i see
27
what lab studies do we order to work up bacterial meningitis
* CBC - PMN leukocytosis (left shift) * CMP - assess liver/kidney fxn for abx * coag panel to differentiate who needs FFP or platelets after LP
28
What kind of illness can be negative on CSF fluid?
Tick-borne diseases (Lyme and Ehrlichiosis)
29
What could MRI show in terms of differentials for meningitis?
* Brain Abscess * SAH
30
When is ABX given in terms of LP?
After the LP UNLESS the LP is delayed.
31
What is step 1 of empiric therapy for bacterial meningitis? what is the purpose of this step?
* Dexamethasone given to ALL pts 0-20 min prior to ABX * prevents release of inflammatory cytokines initiated by antibiotics when they act on bacterial cell wall
32
For a healthy patient that is less than 50 yo, what is the empiric ABX for bacterial meningitis?
* Rocephin (can use cefotaxime or cefepime)+ * Vanco+ * Acyclovir+ (given to cover HSV encephalitis) * additional empiric therapy if indicated | Do all 3 until a CSF analysis returns. ## Footnote * Rocephin can be subbed for ceftazidime or meropenem for neurosurg patients to cover p. aeruginosa. Roc the van cycle
33
What is the alternative to rocephin in neonates?
Cefotaxime + ampicillin ## Footnote Rocephin causes hyperbilirubinemia amplified taxes
34
When is ampicillin indicated as additional therapy for bacterial meningitis?
* Cover listeria * indicated in < 1 month old or > 50 yo * also in Immunocompromised patients (includes preggo)
35
When is doxycycline indicated as additional therapy for bacterial meningitis?
During tick season
36
When is metronidazole indicated as additional therapy for bacterial meningitis?
G- anaerobes from sinusitis, otitis, or mastoiditis
37
What should we do to manage increased ICP?
* Elevation of the patient's head to 30deg * Intubation with hyperventilation * Mannitol (osmotic diuretic to reduce fluid)
38
What bacteria requires the longest duration of ABX therapy in bacterial meningitis?
Listeria (21 days)
39
When is repeat CSF analysis indicated in bacterial meningitis?
* No improvement after 48 hrs of appropriate therapy * Microorganisms resistant (2-3 days after initiation of therapy) * Persistent fever > 8 days (without any other known cause)
40
If CSF cultures are positive on repeat, what should we do with our ABX?
Adminster them intrathecally or intraventricularly. | A repeat culture should be sterile ideally.
41
How does mortality vary in bacterial meningitis?
* Highest < 1 year * Low in midlife * Increases in old age
42
What is the PPE isolation for bacterial meningitis?
Droplet | gotta wear mask, eye prot, gown and gloves
43
When do we do prophylaxis for bacterial meningitis and what is the treatment?
* Close exposure to H flu meningitis * Rifampin 4 days | if allergic to rifampin contact ID
44
What is considered contact for H flu meningitis?
Contact for 5/7 days for 4 hours for an index patient. * Anyone exposed to someone < 2yo * Anyone exposed to someone < 4yo and lives with them * Anyone exposed to someone that is not vaccinated against Hib
45
What is chemoprophylaxis for N. menigitiditis? | who is included in phrophylactic treatment?
2 days of rifampin for any close exposures. ## Footnote * prolonged >8hr.exposure in <3ft proximity * direct exposure to oral secretions * exposure 7 days prior to onset of symptoms up through 24 hrs after initiation of abx
46
What is the chemoprophylaxis for GBS meningitis?
* Vaginal/anal swab at 35-37 weeks gestation * IV PCN during vag delivery to treat * preop neurosurgical prophylaxis is also indicated!!!
47
What is the #1 way to prevent meningitis?
* Pneumococcal vaccine * MenB and MenACWY * Hib
48
What is the MCC of viral/aseptic meningitis?
Enteroviruses
49
What are the risk factors for viral meningitis?
* Infants < 1 mo * Immunodeficient patients * Exposure * Travel to endemic west nile, lyme, or other ticks * Sexual exposure (HSVs, HIV, syphilis)
50
How does viral meningitis typically present?
* Less severe version of bacterial * SHOULD NOT SEE focal neuro deficits | sHA, nuchal rigid, photophbia, pain w EOM, constutional, diminished LOC
51
What specific findings are related to certain viruses for viral meningitis?
* Diffuse maculopapular exanthem: entero, HIV, syphilis * Parotitis/orchitis: mumps in unvaccinated * Genital/oral lesions: HSV or syphilis * Thrush: HIV * Asymmetric flaccid paralysis: West Nile
52
What additional study should be ordered in viral meningitis suspicion?
PCR tests for **every individual virus** | Usually start with enterovirus
53
How does WBC count vary in viral meningitis?
Elevated but not as high as bacterial because it is predominantly lymphocytes.
54
What lab test may be elevated specifically in mumps?
Amylase (due to parotitis)
55
What viruses should NOT be tested serologically?
* HSV * VZV * CMV * EBV | Everyone has exposure to these usually. ## Footnote reminder: viral serology tests for IgM
56
When is imaging indicated for viral meningitis?
* altered LOC * Seizures * Focal neurologic s/s * atypical CSF profile
57
Who do we treat empirically for suspected viral meningitis?
* Elderly * Immunocompromised * Strong early suspicion of bacterial meningitis (err on the side of caution)
58
If we have a patient that we suspect viral meningitis but their CSF is indeterminate after analysis, what can we do?
* Administer empiric ABX after getting cultures * Observe for 24 hrs without giving ABX and repeat CSF in 6-24 hours. | either or
59
What are the two viruses that require acyclovir for viral meningitis?
* HSV * VZV | Newborns require the longest duration of antivirals
60
What vaccines help prevent viral meningitis?
* IPV * MMR * Varicella Zoster
61
what is encephalitis? what is it called if meninges are involved? What is it called if spinal cord/nerve roots are involved?
* encephalitis - inflammation of brain parenchyma * meningioencephalitis - meningial involvement * encephalomyelitis/encephalomyeloradiculitis - spinal cord/nerve root involvement
62
What is the MC etiology for encephalitis?
Viral (HSV, VZV, EBV)
63
What environmental factor might suggest amebic encephalitis?
Warm, freshwater area
64
What environmental factor might suggest toxoplasmosis induced encephalitis?
Cat litter
65
What is the primary difference between encephalitis and meningitis?
Encephalitis has more neurologic symptoms, but varies depending on the area inflammed.
66
what is the clinical presentation of encephalitis?
ones i think stand out: * fever * seizures * psychotic s/s (hallucination, personality/behavioral changes) * focal neurologic signs (speech/hearing probs, mem loss, paralysis) * Involvement of HPA axis ( hypothermia, diabetes Insip, SIADH) | no stand out: HA, NV, altered LOC
67
what is the clinical presentation of neonatal or young infants with encephalitis
* fever * poor feeding * irritablity * seizure * decreased perfusion
68
What S/S suggest poor perfusion?
* Slow cap refill * Cool extremities * Decreased urine output * Decreased level of altertness
69
What findings would suggest a neonate has a HSV infection?
* Herpetic lesions (face) * Keratoconjunctivitis * Oropharyngeal lesions
70
What is the primary diagnostic test for encephalitis?
CSF PCR tests for individual viruses | CSF analysis should be same as viral meningitis.
71
What CT/MRI findings suggest HSV etiology?
Focal findings on CT/MRI | 90% of HSV encephalitis have focal findings.
72
What do EEG abnormalities suggest for encephalitis etiology?
HSV | >75% of HSV encephalitis shows EEG abnormalities
73
When is a brain biopsy indicated?
All of the 3: 1. Focal abnormality on MRI 2. Negative CSF/PCR 3. Deterioration despite acyclovir and standard therapy.
74
when would you order these additional labs and what would they show in encephalitis - electrolyes - glucose - BUN/Cr - LFT - PT/PTT
- electrolyes for abnormalities if dehydrated or SIADH - glucose to compare CSF glucose or r/o hypoglycemia - BUN/Cr to assess hydration status, end organ damage and renal function for med dose adjustments - LFT to assess for end organ damage or med adjustment - PT/PTT assess need for platelet or FFP transfusion
75
What CSF finding is characteristic of amebic infection?
Motile trophozoites seen in wet mount of fresh, warm CSF.
76
what will be seen in the CSF of autoimmune encephalitis?
specific autoantibodies
77
What is the primary anticonvulsant for encephalitis?
Lorazepam | For acute treatment
78
What is secondary prevention of seizures in encephalitis accomplished with?
Phenytoin or Fosphenytoin | Prevention only.
79
What are the neuro checks?
* LOC * A/O * pupil check * facial symmetry * tongue midline * speech clarity * sensation * grasp strength * strength and ROM of UE and LE
80
What is empiric antiviral therapy for encephalitis?
IV acyclovir for 21 days | Within 30 minutes
81
When is definitive antiviral therapy indicated for encephalitis?
* HSV * Severe VZV/EBV
82
When should CSF be repeated for encephalitis?
* Repeat if they were PCR +. * If repeat is positive, then remain on therapy
83
What is a brain abscess?
Uncommon, focal, suppurative infection within brain parenchyma and surrounded by a capsule. ## Footnote Non-encapsulated is cerebritis
84
What are the common etiologies for brain abscess?
1. Direct spread (otitis media and mastoiditis are MC) 2. Hematogenous (25%) 3. Trauma/Surgery (30%)
85
What is the MC symptom in brain abscess?
Gradual HA | >75% of pts. gradual over 10 days
86
What are the 3 common abscess locations that produce focal neurological deficits?
* Frontal lobe: Hemiparesis * Temporal lobe: Aphasia/dysphasia * Cerebellar: nystagmus/ataxia | present in >60% pts
87
What are the common S/S of a brain abscess?
1. HA 75% 2. Focal neurologic deficits 60% 3. Fever 50% 4. New onset seizure 5. S/S of increased ICP (papilledema, change in LOC, confusion)
88
What imaging is used to workup a brain abscess?
CT or MRI WITH contrast | MRI preferred but not typically as readily available ## Footnote CT shows area of hypodensity surrounded by ring enhancement and edema MRI shows hypodense center surrounded by edema
89
what are the following labs used for in brain abscess CBC CMP Blood cultures
CBC - elevated WBC CMP - assessing renal and liver fxn for med doses blood cultures - x2 prior to abx to cater tx
90
How are ABX of brain abscess given?
CT/MRI guided stereotactic needle aspiration | must get C&S of the abscess aspirate to guide ABX therapy
91
Lack of what sign may suggest brain tumor over brain abscess?
Fever | More likely to be a solid mass
92
What is the empiric treatment for community acquired brain abscess?
* IV Rocephin + metronidazole * Drain abscess
93
What is the empiric treatment for head trauma or neurosurgery related brain abscess?
* Ceftazidime + Vanco * Meropenem + Vanco * Drain abscess
94
When are steroids indicated for brain abscess?
Significant peri-abscess edema with associated mass effect and increased ICP | Steroids prevent encapsulation.
95
What are the indications to NOT drain a brain abscess?
* Inaccessible abscess * Small < 3cm or non-encapsulated * Unstable condition
96
When is it indicated to completely excise an abscess?
Multiloculated or aspiration
97
What is the overall treatment for a brain abscess?
* Prophylaxis for seizures * Empiric parenteral ABX therapy * Drain abscess
98
What is the clinical course of a brain abscess?
* 6-8 weeks of parenteral ABX * Serial MRI or CT monthly or 2x monthly * Prophylactic anticonvulsant for 3 months minimum (until EEG is normal)
99
What suggests poor prognosis for brain abscess?
* Rapid progression of infection prior to admission * Severe mental status changes on admission * Stupor or coma (Extremely bad) * Rupture into ventricle (Extremely bad)
100
How common are sequelae in brain abscess survivors?
20% of survivors

Clin Med B 2 (44 decks)

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