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346 final > Meningitis Encephalitis > Flashcards

Meningitis Encephalitis Flashcards

1
Q

Anatomy

A 
LAYERS where
 = meninges
• Scalp • Subgaleal space • Skull • Epidural space • Dura mater • Subdural space • Arachnoid • Subarachnoid space
– filled with CSF
•
Pia mater
• Cerebral cortex
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2
Q

Morbidity and mortality
☺ Definitely good to know:
Acute complications

A 
Altered mental status, coma
Increased intracranial pressure (ICP)
Seizures
Subdural effusions, abscess
Intracerebral abscess
Shock
Respiratory distress/failure/arrest, apnea
Disseminated intravascular coagulation
Death
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3
Q

Morbidity and mortality
☺ Definitely good to know:
Sequelae

A

Focal neurologic deficits: deafness/sensorineural
hearing loss, blindness, paralysis, paresis

CNS structural sequelae/complications:
hydrocephalus, brain abscess, epidural abscess,
subdural abscess/effusion/empyema, cerebral
thrombosis, vasculitis

Seizure disorder
Personality changes
Gait disturbances
Impaired intellectual functioning, cognition

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4
Q

Signs & symptoms - varies with age
Fever
Irritability
Confusion

A 
“Classic” triad:
• Fever
• Headache (vs *altered mental status)
• Neck stiffness
Other symptoms could be:
• Nausea/vomiting
• Photophobia
• Rash
• Seizures
*altered mental status: confusion, irritability,
delirium, drowsiness, coma

Characteristic “petechial rash” is usually
located on the trunk and legs and may
rapidly evolve into “purpura

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5
Q

Meningitis symptoms

pearls

A 
• Could be rapid progression (over hours) vs
even dayssss
• Earlier symptoms?
• Fever, headache, irritability, N/V or altered
feeding
• Later symptoms?
• Drowsiness, aches & pain
• Even beyond that?
• Cold hands and feet
• Neck pain or stiffness
• Rash
• Confusion, delirium
• Difficult to wake → coma
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6
Q

pysical sign

A

spinal cord movement will make some activity urt

KErnig sign
Drudzinski sign

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7
Q

Final words on signs and symptoms?

A

Remember, in meningitis….
• One large review of 10 critically appraised studies on fever, stiff neck, mental status change
• 99-100% with have 1 of these findings
• 95% will have 2 of these findings
• <50% will have all 3 findings
• In the absence of all 3, many clinicians will rule out meningitis
• Up to 50% of patients will NOT have Brudzinski’s and Kernig’s sign
• NOT all meningitis will have “classic rash”
• You are likely to see this in N. meningitidis
• Not all petechiae or purpuric rash = meningitis

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8
Q

Diagnosis:

Investigations that helps

A

• Bloodwork
• Regular admission bloodwork
hold abx before getting a culture (at min, get a culture)

• Microbiological
• At minimum, when meningitis is suspected, pre-antibiotic blood culture
• Lumbar puncture for CSF if possible & not contraindicated → culture, fluid
analysis, PCR, (check opening pressure)
• (Full septic work up if applicable)

  • Imaging?
  • CT head vs MRI brain
  • vs ultrasound may be adequate in neonates/infants
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9
Q

Differential

diagnosis

A

• acute meningitis syndrome may be caused by
a wide variety of infectious agents & may also
be a manifestation of non-infectious diseases

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10
Q

Lumbar puncture

A

younger pt need sedation

coafulopathy

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11
Q

CSF analysis

see slide 21

A

k

• Before abx, ↑ WBC with >90% polymorphonuclear leukocytes
• Reduced % of PMNs if received abx prior to LP
• ↓ glucose as transport is impaired
• hypoglycorrachia
• ↑ protein as inflammatory damage to blood vessels within the
meninges → serum leaks into the CSF
• Gram stain – super useful clue for bacterial meningitis
• CSF culture, in the absence of prior abx, remains the most sensitive
test for diagnosis
read

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12
Q

which are common pathogens

A

see slide 23

no kid dose on exam

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13
Q

Local guideline, if Bugs & Drugs → Adults

> 50 years old, or
immunocompromised,
alcohol abuse,
debilitating illness,
pregnancy
A

S. pneumoniae, L. monocytogenes, N. meningitidis,
Enterobacteriaceae ☺

Ceftriaxone 2g IV q12h plus
Vancomycin 15 mg/kg IV q8-12h plus
Ampicillin 2G IV q4h

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14
Q

Local guideline, if Bugs & Drugs → Adults

Age 18 - 50 years old

A

Ceftriaxone 2g IV q12h plus

Vancomycin 15 mg/kg IV q8-12h

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15
Q

Duration of therapy

A

☺ If no organism cultured: 10 - 14 days

Streptococcus pneumoniae 10 – 14 
Streptococcus agalactiae 14 – 21 
Enterococcus spp 14 
Listeria monocytogenes 14 – 21 (ped)
≥ 21 (adult)
Neisseria meningitides 7 (ped)
5 - 7 (adult)
Haemophilus influenzae 7 (ped) – 10 (adult) 
Enterobacteriacae 21
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16
Q

You may also see acyclovir added to the above

regimen

A

• Not that many VIRAL causes that we can treat → fever, headache,
photophobia, stiff neck and altered mental status
• Acyclovir age appropriate dosing, IV q8h sometimes given for HSV 2
meningitis x 10-14 days
• Because HSV is the most common cause of sporadic fatal encephalitis and is
one of the few treatable cause → ppl may be reluctant to stop
• Using encephalitis dose for HSV 1 encephalitis:
• ≤ 12 yo 60 mg/kg/day IV div q8h
• > 12 yo 30 mg/kg/day IV div q8h
• ≥ 18 yo 10 mg/kg (based on IBW or actual BW, whichever is less) IV q8h x 14-
21 days ☺

17
Q

☺ The role of acyclovir ….

A

• Remember, current suggestions:
• HSV 2&raquo_space;» HSV 1 for Meningitis
• Do not be surprised about step down from IV Acyclovir to PO valacyclovir 1G TID (adjust
for renal function) to complete total of 7 – 14 days
• The need to and benefit of treating HSV or VZV meningitis remains uncertain
• HSV 1&raquo_space;» HSV 2 for Encephalitis – most will complete IV therapy x 14 - 21
days
• VZV meningitis – 15 mg/kg IV q8h x 10 -14 days
• But more importantly, we are fearful of HSV encephalitis
• The use of ACV supported by RCT to decrease mortality

18
Q

SteroidsB

What does steroids do? IN BRIEF

A 
• Inhibits synthesis of interleukin 1 (IL-1)
and tumor necrosis factor (TNF) at mRNA level
• Decreases CSF outflow resistance →
brain edema
• Stabilizing the blood brain barrier →
decreases entrance of more
leukocytes
Once macrophages/neutrophils are
activated and TNF production has
been induced = ↓ effect
19
Q

The conclusion Brouwer 2015?

A

• Non-significant ↓ mortality – 17.8 vs 19.9 %
• *Significant ↓ rates of hearing loss
• Severe 6.9 vs 9.3 %
• Any 13.8 vs 19%
• *Significant ↓ rates of neurological sequelae
• Pathogen specific (as subgroup analysis, not powered)
• ↓ mortality in Streptococcus pneumoniae – 29 vs 36% with no effect in
Haemophilus influenzae, Neisseria meningitidis
• In children with H. influenzae - ↓ rate of hearing loss 4 vs 12%
* = effect only seen in high-income countries

20
Q

Can we use any steroids in meningitis, and any

countries??

A
  • Dexamethasone has been investigated most extensively
  • Experimental studies
  • Methylprednisolone demonstrated lower CNS concentration
  • Studies exists where dexamethasone vs PLACEBO
  • Most trials use dexamethasone
  • Trials in Pediatric & Adult both used dexamethasone
  • No beneficial effect in low-income countries
21
Q

Do we use steroids for every child?

read

A

• Controversial, except in Hib meningitis → ↓ severe hearing loss in Hib
meningitis

• = Local guideline (B&D): If S pneumoniae or H influenzae or no pathogen
identified, continue dexamethasone for 4 days

22
Q

Do we use steroids for every adult?

A

In adults, ↓ mortality and hearing loss in S. pneumoniae meningitis
• meningitis due to S pneumoniae treated with corticosteroids had a lower death
rate (29.9% versus 36.0%)
• No benefit in any other pathogen → discontinue?
• ↑ mortality when steroid is used in Listeria monocytogenes (do not use with listeria)

• = Local guideline (B&D): If S pneumoniae or H influenzae or no pathogen
identified, continue dexamethasone for 4 days

23
Q

Encephalitis
☺ For this section: I recommend study in detail, all slides related to
HSV for exam.

Herpes simplex virus 1 & 2

A 
• Family:
Herpesviridae
• DNA virus
• Described over
2000 years ago.
Classified as a
virus in 1940s
Season or geographical
• Seasonality:
none
• Distribution:
worldwide
Vectors/Mode of transmission
• Transmission:
person to
person
• Prevention:
none
24
Q

Herpes simplex virus 1 & 2

Signs & symptoms

A 
• Acute onset fever, confusion,
focal neurologic symptoms
• Up to 2/3 have convulsive seizures
• Commonly temporal lobes →
HSE
• Associated with:
• meningitis
• encephalitis
• Most cases are caused by HSV 1 but
~10% are caused by HSV 2
25
Q

Diagnosis HSV

The typical lesions on the lips or face are
not usually seen, because reactivated
virus migrates up the Vth cranial nerve
toward the CNS rather than toward the
periphery.
Recall, typically:
HSV1 → orofacial disease
HSV2 → genital disease
A 
CSF analysis
• Lymphocytic pleocytosis
• Normal or low glucose
• Mild ↑ protein
• RBC may be present when hemorrhagic
lesions are present
• PCR → high specificity and sensitivity BUT
• May be falsely NEG until several days into the
illness with treatment
• Rpt CSF in 24-72 hours may be needed
• Imaging et al.
• CT scan or MRI: temporal lobe edema,
hemorrhage
• Can be normal acutely, but by 48 h, >90% will
have abnormalities
• EEG: activity in temporal lobe(s)
26
Q

Herpes simplex virus

A 
Treatment
• Acyclovir 10 mg/kg IV q8h for 14-
21 days
• Use actual or ideal body weight,
whichever is less
• MUST adjust for renal function
• Neurotoxicity
• Even if dosed appropriately, can
cause crystal nephropathy if
inadequate hydration
• Insufficient data to support the use
of adjunctive corticosteroids
Pearls:
• HSV 1 >>>> HSV 2 for encephalitis
• Could be from primary infection,
reactivation of latent infection, or
reinfection
• In encephalitis, acyclovir
treatment ↓mortality from ~70 to
25%
• ¾ dies vs ¼ dies
• Long term disability or neurologic
impairment occurs in >50% of
patients
27
Q

Enterovirus

A

Signs & symptoms
• 2
nd most common cause of viral encephalitis in
pediatric, after HSV1
• Incubation 3 - 6 days in most cases
• Mostly asymptomatic, have no “prodrome”
• But If symptomatic, usually:
• Fever, gastrointestinal tract symptoms, or respiratory
tract symptoms before
• Neurologic symptoms of meningitis:
• Headache, fever, stiff neck, irritability, malaise,
photophobia
• Enteroviruses causing meningitis, encephalitis: EVA71
• During some outbreaks of HFMD → severe
neurological complications

28
Q

Enterovirus

Why do we care?

A
  • Non-polio EV → significant and frequent illnesses in pediatric population
  • Non-specific febrile illness → septic work up
  • Resp: Coryza, pharyngitis, stomatitis, bronchiolitis, pneumonia
  • Derm: hand-foot-and-mouth disease, onchomadesis, nonspecific exanthems
  • Neuro: aseptic meningitis, encephalitis, acute flaccid paralysis
  • GI/GU: V/D abdominal pain, hepatitis, pancreatitis, orchitis
  • Eye: acute hemorrhagic conjunctivitis and uveitis
  • Heart: myopericarditis
  • Muscle: pleurodynia, other skeletal myositis

346 final (18 decks)

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