CNS Emergencies I Flashcards
When do you want to think about a possible CNS infection?
Fever, HA and neurologic signs/sxs
What might be seen in survivors of bacterial meningitis?
Neurologic sequela
How can bacteria get into CNS?
Bloodstream or contiguous spread (ex sinus infection)
Pathogenesis of bacterial meningitis
Inflammation damages BBB causing increased per so alterations in protein and glucose transport–progressive cerebral edema with increased ICP and decreased cerebral perfusion leads to neurologic damage
Etiology of bacterial meningitis from exposure during delivery (up to 4 wks old)
E coli, Group B strep
Etiology of bacterial meningitis from colonization from nasopharynx
Sinusitis, otitis media, mastoiditis–strep pneumo
Etiology of bacterial meningitis from crowded conditions
Military, college–N meningitides
Etiology of bacterial meningitis from head trauma
Staph species
Etiology of bacterial meningitis from post-neurosurgical procedures
Staph species, gram (-)
2 most common organisms of bacterial meningitis
N meningitides and s pneumoniae
Risk factors for s pneumoniae infection
Cochlear implants, fractures of face/skull
Who is listeria monocytogenes meningitis seen in?
Elderly and neonates
What meningitis do you worry about with breaks in the skin?
Coag neg staph or s. aureus
Which meningitis do you worry about with unvaccinated children and adults?
H. influenzae
How might bacterial meningitis present?
Progressively over a couple days or after febrile illness
Acutely with signs and sxs of sepsis (rapid progression over several hrs and cerebra edema)
Manifestations of bacterial meningitis
HA, photophobia, n/v/anorexia, focal neurologic deficits (weakness, cranial nerve palsies), seizures, AMS, nuchal rigidity, papilledema and increased ICP
Classic triad of bacterial meningitis
Fever
Nuchal rigidity
AMS
What organism produces a petechial rash and palpable purpura?
N meningitides
Tests for bacterial meningitis
Kernigs sign: won’t extend knee with hip flexed
Brudzinskis: flexion of hips with passive flexion of neck
Joint accentuation test: pt rotates his or her head 2 times per second and positive test is exacerbation of existing HA
Diagnostics for bacterial meningitis
Blood cultures x 2!!! (before abx)
Maybe CT
LP for CSF analysis
CBC with diff, CMP, ESR, CRP, serum and CSF glucose
Gold standard for bacterial meningitis diagnosis
CSF culture
CSF findings for bacterial meningitis
Increased WBC (>1000 with mostly neutrophils) Decreased glucose (<40) Increased protein (100-500) \+ gram stain and culture Increased opening pressure CSF/blood glucose
Recommendation to get a CT before LP
With 1+ of following factors: Immunocompromised History of CNS disease New onset seizure Papilledema Abnormal LOC Focal neurological deficit
What might happen if there is increased ICP during an LP?
Mass lesion present can result in cerebral herniation
What do gram positive diplococci suggest?
Pneumococcal infection
What do gram negative diplococci suggest?
Meningococcal infection
What do gram negative coccobacilli suggest?
H influenzae infection
What do gram positive rods and coccobacilli suggest?
L monocytogenes infection
What is predictive of worse outcomes with bacterial meningitis?
AMS, seizures or hypotension
What is started immediately after blood cultures and LP
Empiric IV abx and dexamethasone (glucocorticoid) at same time or shortly before
(if waiting for LP til after CT, still start the abx after cultures)
Empiric tx for newborn meningitis and the causative organism
Ampicillin + cefotaxime OR gentamycin
(Group B strep, E coli, L monocytogenes)
**do not use Vanco when 4 wks and younger
Empiric tx for meningitis at 1-23 mos and the causative organism
Vanco + ceftriaxone OR cefotaxime + dexamethasone
Strep pneum, H flu, E coli, N meningitides
Empiric tx for meningitis at 2-20 yrs and the causative organism
Vanco + ceftriaxone OR cefotaxime + dexamethasone
S pneum or N meningitides
Empiric tx for meningitis when >50 YO and the causative organism
Ampicillin + Vanco + ceftriaxone OR cefotaxime + Dexamethasone
(Strep pneum, L monocytogenes, gram - bacilli, N meningitides)
Empiric tx for meningitis when immunocompromised and the causative organism
Ampicillin + Vanco + Cefepime OR meropenem + Dexamethasone
Strep pneum, L monocytogenes, gram - bacilli, N meningitides
What should be switched if there is a penicillin allergy?
Vanco + Moxifloxacin + Bactrim replace Ampicillin in >50YO and immunocompromised
Empiric tx for meningitis due to contiguous spread from basilar skull fracture and the causative organism
Ampicillin + cefotaxime OR gentamycin
Group A beta hemolytic strep, strep pneum or H flu
Empiric tx for meningitis due to contiguous spread from penetrating trauma and post-neurosurgery and the causative organism
Vanco + ceftazidime OR cefepime OR meropenem
s aureus, pseudomons, coag neg staph
What is the benefit of adding dexamethasone?
Decreased rate of hearing loss and neurologic sequelae and decreases morbidity and mortality in PNEUMOCOCCAL meningitis only
What must be added to the steroid if cultures are positive for S pneumoniae?
Rifampin (better CNS coverage)
Meningitis management algorithm for pt meeting criteria for CT before LP
Blood cultures STAT
Dexamethasone + empiric abx
CT of head
(if contraindication for LP like increased ICP then continue med regimen)
Perform LP if not contraindicated
CSF for gram stain, cultures, cell count, glucose, protein
Meningitis management algorithm for pt not meeting criteria for LP before CT
Blood cultures LP Empiric abx + dexamethasone CSF sent for gram stain, cultures, cell count, protein, glucose Tailor tx based on results
Meningitis management algorithm for CSF gram stain positive
If gram positive diplococci, target abx therapy to strep pneum and continue dexamethasone and rifampin
All other bacteria, target abx and d/c dexamethasone
Meningitis management algorithm for gram stain neg but other CSF findings consistent with meningitis
Continue empiric tx and dexamethasone
Complications of bacterial meningitis
Septic shock
DIC
Acute respiratory distress syndrome
Possible neurologic long term complications (impaired mental status or cognition, sensorineural hearing loss)
Important vaccines to prevent bacterial meningitis
S pneum, N meningities, h flu
What is used for post exposure prophlyaxis for bacterial meningitis?
Cipro, rifampin or ceftriaxone (in pregnant pts)
What is aseptic meningitis?
Evidence of meningeal inflammation but bacterial cultures are neg–sometimes called viral meningitis
Presentation of aseptic meningitis
Similar to bacterial but usually less severe sxs so just supportive care
Most common cause of aseptic meningitis
Enterovirus (think with diarrhea too)
Other viral causes are coxsackie and echovirus (summer and autumn), HSV-2, VZV, mumps, HIV, west nile etc
Other infectious causes of aseptic meningitis
Mycobacteria
Fungi (crypto, cocci)
Spirochetes (treponema or borrelia)
Malignancy causing aseptic meningitis?
Uncommon but may see due to direct invasion of mets into meninges
Leukemia, lymphoma, melanoma, breast, lung or GI CA
Drug induced aseptic meningitis?
Uncommon but exclude other diagnoses
Must tell if delayed hypersensitivity rxn or direct irritation
NSAIDs! also abx like bactrim, chemo or pyridium
Clinical manifestations of aseptic meningitis
HA, fever, n/v, maybe photophobia or nuchal rigidity
What history clues are necessary for aseptic meningitis?
Travel and expsoure hx Sexual activity (HSV-2, syph, HIV)--look for genital lesions for HSV-2
PE clue suggesting mumps as etiology of aseptic meningitis
Unvaccinated pt with parotitis
PE clue suggesting HSV-2 as etiology of aseptic meningitis
Severe vesicular genital lesions
PE clue suggesting enteroviral infection, HIV or syph as etiology of aseptic meningitis
Diffuse macpap exanthema in mildly ill pt
PE clue suggesting primary HIV as etiology of aseptic meningitis
Oropharyngeal thrush and cervical LAD
PE clue suggesting west nile virus as etiology of aseptic meningitis
Asymmetric flaccid paralysis
Diagnostis for aseptic meningitis
Blood cultures x2 before abx CT (same criteria) LP for CSF analysis CBC with dif, CMP, ESR, CRP Others based on suspicion
CSF findings for aseptic meningitis
WBC<500 and >50% lymphocytes if viral Normal glucose (40-80) Normal or mildly increased protein - gram stain and culture PCR (HSV, MMR, CMV, epstein barr) Cultures
Management for viral aseptic meningitis
Start empiric abx at presentation but d/c when r/o bacterial
Self limiting so just supportive (analgesics, antipyretics or acyclovir if severe or immunocompromised)
Management for malignancy induced aseptic managment
Malignant cells within CSF
Oncology
Management for drug induced aseptic meningitis
d/c offending med and then sxs resolver
Management for uncommon causes of aseptic meningitis
Treat accordingly
Require ID and neuro involvement
What distinguishes meningitis and encephalitis?
Presence of absence of normal brain function
Meningitis: preserve cerebral function and more common to have fever, HA, meningismus
Encephalitis: abnorm brain function due to inflammation of brain (AMS, seizures, motor/sensory deficits, personality changes, speech )
What is the primary infection of encephalitis?
Due to direct viral invasion of CNS and can be cultured from brain tissue (neuronal involvement)
What is post infectious encephalitis (acute disseminated encephalomyelitis ADEM)?
No virus is detected and neurons are spared but there is perivascular inflammation and demyelination
Occurs as initial infection is resolving
Most common cause of encephalitis is US
West nile (arbovirus)
Other causes of encephalitis
Influenza, Lyme, RMSF, syph, VZV/EBV/HIV/MMR (immunocompromised mostly)
Most common cause of fatal encephalitis
HSV-1
More common in meningitis or encephalitis: coxsackie
Meningitis
More common in meningitis or encephalitis: west nile
Encephalitis
More common in meningitis or encephalitis: HSV-1
Encephalitis
More common in meningitis or encephalitis: HSV-2
Meningitis
More common in meningitis or encephalitis: varicella
infrequent in both
More common in meningitis or encephalitis: CMV
Encephalitis
More common in meningitis or encephalitis: EBV
Infrequent in both
More common in meningitis or encephalitis: HIV
Meningitis
More common in meningitis or encephalitis: Influenza
Encephalitis
More common in meningitis or encephalitis: mumps
Meningitis
More common in meningitis or encephalitis: measles
Meningitis
Manifestations of encephalitis
HA, fever, AMS, seizures, focal neuro deficits (hemiparesis, CN palsies, increased DTRs)
What is rare in encephalitis?
Photophobia and nuchal rigidity (but can be seen in meningoencephalitis)
Clues for HSV-1 on encephalitis PE
Ulcers or vesicles
Clues for WNV on encephalitis PE
Flaccid paralysis and rash
Clues for rabies on encephalitis PE
Hydrophobia, hyperactivity, pharyngeal spasms
Clues for St louis virus on encephalitis PE
Tremors of tongue, lips, eyelids
Diagnostics for encephalitis
Blood cultures x 2 CBC with diff, CMP PCR of CSF for HSV, enteroviruses, HBV CSF tests (unless C/I) Cultures
What can indicated HSV-1 infection in CSF?
RBCs
CSF analysis in viral encephalitis
WBC<250 Glucose 40-80 (decreased in HSV tho!) CSF/blood glucose .6 Protein elevated <150 Gram stain - Increased lymphocytes
Study of choice for encephalitis
MRI with contrast (might take a couple days to see the changes)
Other diagnostics for encephalitis
CT with contrast if no MRI
Maybe EEG
What suggests HSV on MRI?
Temporal lobe changes (illuminating contrast)
What suggests bacterial/fungal/parasitic etiology of encephalitis on MRI?
Hydrocephalus
When is serology ordered with encephalitis?
If pt not improving or no diagnosis based on CSF, culture or PCR
IgM testing for WNV, mumps, EBV
Brain biopsy for encephalitis
Only if etiology unknown
Last resort!!
Management for encephalitis
Acyclovir 10mg/kg IV Q8hrs–empiric ASAP
Seizure prophylaxis and control (carbazepime)
Diuretics if increased ICP (Mannitol or furosemide)
Prognosis of encephalitis
Poor neuro recovery and increased mortality if inital diffuse cerebral edema or intractable seizures
Elevated initial ICP is not good
Monitor serial ICPs
Causes of direct spread cerebral abscess
Usually single abscess
Otitis media, mastoiditis, meningitis, head/facial trauma, sinusitis, dental infection or S/P neurosurgical or spinal procedure
How to determine etiology of cerebral abscess
Location of the abscess on MRI to determine direct spread
What does inferior temporal lobe or cerebellum abscess suggest?
Subacute and chronic otitis media
Mastoiditis
What do frontal lobe abscessed suggest?
Frontal or ethmoid sinusitis
Dental infection
Causes of hematogenous spread cerebral abscesses
Usually multiple and has bacteremia
Chronic pulm infection, skin infection, pelvic infection, intraabd infection, bacterial endocarditis or after esophageal dilatation
Most common cause of cerebral abscess
Bacterial:
Paranasal: strep or haemophilus
Odontogenic: strep or bacteriodes
Otogenic: strep, enterobacter, pseudomonas
Penetrating head trauma: staph, enterobacter
Neurosurgery: strep, staph, pseudomonas
Most common cause of cerebral abscess when there is an immigrant from mexico
Parasite (cysticercosis due to taenia solium/pork tapeworm)
Immunocompromised pathogens causing cerebral abscess
Toxoplasma, listeria moncytogenes or nocardia asteroides
Fungal pathogens causing multiple abscesses and poor outcomes
Crypto, cocci, aspergillus, candida
Manifestations of cerebral abscess
Unilateral HA (unless multiple) Sudden or gradual onset Severe pain not relieved with OTC pain meds Maybe fever or nuchal rigidity (more common in occipital lobe abscess) AMS (severe cerebral edema) Vomiting (increased ICP) Focal neuro deficits Seizures Papilledema (late)
Diagnostics for cerebral abscess
Blood cultures x2
CBC with diff, CMP
MRI (study of choice!!!)
CT guided aspiration or surgical excision for cultures (contrast!!)
What will be seen on an MRI of a cerebral abscess?
Ring enhancing lesion
Early: lesion is poorly demarcated, localized edema, acute inflammation, no tissue necrosis
Late (>2 wks): necrosis and liquefaction, lesion surrounded by fibrotic capsule
Management of cerebral abscess
Empiric abx (based on gram stain) for 4-8 wks after find out pathogen on culture (IV) Track progression on MRI every 4-6 wks
Empiric tx of cerebral abscess due to oral, otogenic, sinus spread
Oral: Metro + Pen G
Otogenic or sinus: Metro + ceftriazone OR cefotaxime
Empiric tx of cerebral abscess due to hematogenous spread
Vanco + Metro
Empiric tx of cerebral abscess due to post op neurosurgery
Vanco + ceftazidime OR cefepime OR meropenem
Empiric tx of cerebral abscess due to penetrating trauma
Vanco + ceftriaxone OR cefotaxime
Empiric tx of cerebral abscess due to unknown source
Vanco + cetriaxone OR cefotazime + Metro
Most common reasons for intracranial epidural abscess
Usually complication of neurosurgery or can be spread from osteomyelitis of skull from fetal monitoring probe (infections!! sinusitis, otitis)
What is an intracranial epidural abscess?
Localized lesion with central collection of pus surrounded by wall of inflammatory tissue which may calcify (rarely spreads caudally due to tight attachment of dura at foramen magnum)
Manifestations of intracranial epidural abscess
Fever, HA, lethargy, n/v
If secondary to sinusitis: purulent drainage from nose or ear
Compressing brain: increased ICP, papilledema, focal neuro changes
Diagnostics of intracranial epidural abscess
CBC with diff, ESR
MRI with contrast
CT with contrast if can’t MRI
CT guided aspiration or open drainage for stains and cultures
Management for intracranial epidural abscess
Drainage and abx
Burr holes or craniotomy (neurosurgical)
MRI every 4-6 wks after initiation of tx
What to remember about abx with intracranial epidural abscess!!!
Empiric abx once sample of abscess fluid is obtained (so waiting 1-2 days before start!)
Can be earlier with immunocompromised pt or concerning findings
Management of intracranial epidural abscess due to contiguous spread
Metro+ceftriaxone OR cefotaxime
Abx for all other intracranial epidural abscesses
Vanco + Metro + ceftriaxone OR cefotaxime OR ceftazidime
How does spinal epidural abscess happen?
Bacteria get access by hematogenous spread, direct extension (osteomyeltis) or direct inoculation into spinal canal (epidural cath)
How does spinal epidural abscess spread?
Longitudinal extension so can go through whole spine! (more common in thoracolumbar area)
Why do sxs occur with spinal epidural abscess?
Direct compression on spinal cord
Thrombosis of nearby vessels
Bacterial toxins or inflammation
Arterial blood supply interruption
Major players in spinal epidural abscess
Staph aureus (mostly), gram - bacilli, streptococci, coag neg staph
Risk factors of spinal epidural abscess
Immunocompromised (DM, alcoholism, HIV)
Direct inoculation (epidural cath, paraspinal injection, trauma)
Hematogenous (tattooing, acupuncture, bacteremia, IV drug use, hemodialysis)
Classic triad of spinal epidural abscess
Fever, spinal pain and neurologic deficits (at or below abscess)
Manifestations of spinal epidural abscess
May be non-specific at first
Absent fever may be seen (present multiple times before diagnosed!!)
Back pain focal and severe
Nerve root pain (shooting or electrical)
Motor weakness, sensory changes, bowel or bladder dysfunction
Paralysis that quickly becomes irreversible
First line diagnostic for spinal epidural abscess
MRI with contrast ASAP (skip lesions on entire spine, want to see epidural soft tissue edema vs abscess)
Other diagnostics for spinal epidural abscess
CBC with diff with ESR
CT with contrast is 2nd line
Ct guided extraction of pus fro abscess for culture
Management of spinal epidural abscess
Blood cultures x2
Empiric abx after suspect (after cultures!!)–Vanco + cefotaxime OR ceftriaxone OR cefepime OR ceftazidime for 4-8 wks
Surgical decompression and drainage
Follow up MRI in 4-6 wks
Prognosis of spinal epidural abscess
Can have death due to sepsis or complications but rare
Irreversible paraplegia can happen
Degree of neuro recovery related to duration of deficit
