CM II - 11 Infection

what is the normal color of CSF?

clear and colorness

what is xanthrochromia?

yellow-ish color due to breakdown of RBCs after 2-4 hrs

what are the cells in normal CSF?

0 RBC’s and < 5 WBCs/HPF

what would it mean if you see RBC in CSF?

hemorrhage or traumatic tap

what does it mean if you see more than 5 WBCs in CSF?

infection, inflammation

what is the typical chemistry of CSF?

protein (23-38 mg/dl) and glucose (60% serum)

conus medullaris is where?

L1/L2

where should you insert a LP?

L3/L4 interspace, insert needle parallel to floor, ideally you wouldn’t encounter cauda equina if you’re right in the midline and you won’t hit the peridermal veins

widest vertebral space!

what are the ABSOLUTE contraindications of LP?*

• infection of skin or dermopathy over puncture site

• trauma/mass of adjacent lumbar vertebrae

→ change site/level

what are the relative contraindications for LP?*

• bleeding diathesis

• coagulopathy

what is mandatory to do before performing LP in certain situations?*

noncontrast head computer tomography (CT) → r/o cerebral edema or midline shift

otherwise if you go straight in, you can cause a herniation

what are situations where you want to do CT scan BEFORE LP?*

1. high ICP

2. altered mental status

3. focal neuro deficits

4. papilledema

5. immunocompromised

6. seizures

what is most feared complication of LP?

brain herniation (d/t sudden dec in pressure in CSF from removal)

what is most common complication of LP?

post lumbar puncture headache “spinal headache” (d/t continued CSF leakage at site of puncture)

what does poliomyelitis present with?

painless muscle weakness with normal sensation, ascending DISTAL to proximal

• high fever, stiffness in neck/back, HA< asymmetric weakness, sensitivity to touch, difficulty swallowing, loss of reflexes, paresthesia, constipation, difficulty urinating

if you have poliomyelitis, what would you see if CSF?

elevated WBC + protein

poliomyelitis is primarily an infection where?

spinal cord → spreads to brain stem, cerebellum, motor → paralytic polio (spinal/bulbar/bulbospinal)

what kind of virus is the poliomyelitis?

enterovirus (GI tract), so the vaccine is ORAL

what is the primarily spread for poliomyelitis?

• fecal-oral mode of spread

• virus multiples in throat and GI

what causes botulism and tetanus?

BACTERIA infection (clostridium botulinum and clostridium tetani)

how do you acquire botulism?

ingestion of preformed botulin neurotoxin (BoNT) in food

how do you acquire tetanus?

wound contamination with c. tetani (soil)

what is the characterization of botulism?

descending, flaccid paralysis → respiratory arrest leads to death

why does botulism toxin cause flaccid paralysis?

inhibit acetylcholine release at NMJ (like myasthenia gravis)

what is the presentation of tetanus?

spastic paralysis (descending?) → respiratory arrest leads to death

why does TeNT cause spastic paralysis?

unbridled Ach d/t TeNT inhibiting glycine and GABA exocytosis

what level is diaphragm?

C3,4,5

what are the proteins involved in BoNT and TeNT?

SNARE proteins, the BoNT and TeNT blocks NTs because they cleave SNARE

what are SNARE proteins?

proteins involved in neuroexocytosis

what is the most potent toxin out of botulism and tetanus?

BoNT/A (type A)

what differentiates encephalitis and meningitis?

presence or absence of normal brain function

normal = meningitis

what is involved in encephalitis?

parenchyma → altered mental status, m/s deficits, alt behavior, sz

what are the classic sx of meningitis?*

1. fever

2. nuchal rigidity

3. photophobia/phonophobia

4. HA

5. cognition ok → altered mental status

what is the infectious agent of meningitis: neonates

Group B Strep, e. coli, coliform (gram -), listeria (from vaginal birth)

non-specific sx (not usual viral)

what is the infectious agent of meningitis: > 1 mo-3y

GBS, e. coli/other Coliform, coliform bacteria, haemophilus, neisseria (Meningitidis), s. pneumoniae (CHiMP)

fever, meningeal signs

what is the infectious agent of meningitis: 3-10y

s. pneumoniae, n. menigitidis, viral

what is the infectious agent of meningitis: 10-19 y

n. meningitidis (neisseria), viral

what is the infectious agent of meningitis: adults

viral is most common

GBS, s. pneumoniae, N. meningitidis, h. influenzae, listeria

what should you initiate immediately for bacterial meningitis?

abx therapy and dexamethasone TOGETHER (if the delay isn’t too bad, you can get LP and blood cultures)

do NOT give dexamethasone without the abx (vanco), otherwise → death

what 3rd generation cephalosporin have good CNS penetration?

“ax”

cefotaxime and ceftriaxone

what are the sequelae of bacterial meningitis for children?

neuro ie intellectual/behavioral deficits, neuro (CP), sensorineural (cochlear/CN VIII)

what is different about the sequelae of bacterial meningitis for adults vs. children?

adults have arthritis (and the rest is the same)

what is the fulminant course of meningococcal meningitis (12-24 hrs)?*

1. petechial rash → pupura fulminans*

2. waterhouse-friderichsen syndrome (adrenal infarction)* (you lose your adrenal hormones)

3. disseminated intravascular coagulation* (→ use of lots of CFs and plts → hemorrhage AKA clotting → bleeding)

4. general malaise, flu, fever, meningeal signs

5. hypotension, shock

what is the tx for meningococcal meningitis?

Pen G IV

generally, what do you ask if baby has a fever?

“does baby have a rash?” if yes → ER

what is lyme meningitis?

BACTERIAL infection caused by borellia burgdorferi

(lyme dz → meningitis)

what is a big lab finding of lyme meningitis?

LOTS of lymphocytes in CSF

what is the tx for lyme meningitis?

ceftriaxone

what causes syphilis?

bacterium treponema pallidum

what is syphilis?

bacteria infects CNS in primary, secondary, or tertiary stages → neurosyphilis

h pylori is a member of what?

spirochetes

what is the early stage of neurosyphilis?

contemporaneous (same time) w/ primary and secondary syphilis, usually more clear

what is late stage of neurosyphilis?

contemporaneous (same time) w/ tertiary syphilis

what are findings suggestive of neurosyphilis?

elevated CSF protein and WBC (pleocytosis)

also seen in HIV+ pts

what is pleocytosis?

elevated WBC in the CSF

what is the tx for neursyphilis?

penicillin

what is the manifestation of early neurosyphilis?

1. lymphocytic meningitis

2. meningovascular disease

3. stroke

4. hearing loss (sensorineural)

5. visual effects, ie uveitis, iridocyclitis, cranial nerve palsies, optic neuritis

what is the manifestation of late neurosyphilis (tertiary stage)?*

1. generalized paresis

2. incontinence

3. personality changes

4. dementia

5. tabes dorsalis

6. argyll-robertson pupil

what is tabes dorsalis involved in?

posterior columns of spinal cord and dorsal roots → ataxia (you need normal proprioception or you won’t walk well), absent LE reflexes, paroxysmal lancinating pain

what is argyll-robertson pupil?

small pupil that contracts normal when accommodating but does not react to light (by constricting), painful stimuli (dilating), mydriatics by dilating completely

prostitute pupil because it accommodates but does not react

what is viral meningitis presentation?

nonspecific (fever, HA, N/V, photophobia, stiff neck)

AKA as aseptic meningitis b/c no bacteria, will get better

acute bacterial meningitis CSF findings*

• increased pressure

• LOTS of cells, polys

• LOTS of proteins

• LOW glucose

acute viral meningitis CSF findings*

• slight inc in pressure

• mostly lymphocytes

• slight inc in protein

• glucose = normal

what are the most common causes of viral meningitis and encephalitis?

• enterovirus (peak in late summer/fall, ie polioviruses, echoviruses)

• herpes simplex virus type 2

• HIV

• arboviruses (mosquito) borne (ie west nile)

what causes herpes simplex meningitis?

HSV-2

what is the presentation of herpes simplex meningitis?

meningeal involvement (HA, photophobia, meningismus) w/ primary genital herpes

genital lesions appear a week before meningitis sx start

tx for herpes simplex meningitis?

IV acyclovir

what is HIV meningitis presentation?

mononucleosis-like syndrome, fever, malaise, lymphadenopathy, rash, pharyngitis → can turn into meningitis or meningoencephalitis

sx resolves spontaneously

what lab levels may you see in HIV meningitis?

pleocytosis and elevated protein levels

what are the sequelae of viral encephaltiis?

neuro dysfunction

• motor difficulties

• mental status changes

• global neuro deficits

• visual and hearing issues

what causes herpes simplex encephalitis if pt is OLDER than 3 months?

HSV-1 (it likes temporal and frontal lobe)

what causes herpes simplex encephalitis if pt is YOUNGER than 3 months?

HSV-2, acquired at delivery (remember HSV-2 related to genital herpes)

brain involvement is generalized

what is arbovirus an acronym for?

arthropod-borne virus

what is eastern equine encephalitis?

1. once neuro sx begin, 90% progress rapidly to coma

2. 30% mortality

3. no definitive tx

what is west nile virus?

• pts with maculopapular rash less likely to develop neuro infection

• 2% mortality w/ meningitis, 12% w/ encephalitis

• tx: ribavirin, interferon alpha-2b, ivig

what is dengue fever?

1. “break bone fever” (muscle and joint pain)

2. hemorrhagic fever, sometimes encephalitis

3. mortality of regular dengue is low, but high if encephalitis develops

what is the zika virus?

• can spread through the placenta → microcephaly and birth defects

• can cause GBS