L7: Neuro emergencies pt 1 Flashcards
Inflammatory disease of leptomeninges
bacterial meningitis
Bacteria access the CNS by…
- Bloodstream
- Contiguous spread
→ Inflammation damages the blood-brain barrier causing ↑ permeability→ alterations in protein and glucose transport→ Progressive cerebral edema with ↑ ICP and ↓ cerebral perfusion→ neurologic damage
Possible complications of bacterial meningitis
septic shock
DIC
acute respiratory distress syndrome
long term neuro: AMS
impaired cognition
sensorineural hearing loss
Labs for Bacterial meningitis
Positive Blood cultures X2 (before antibiotics) CBC with differential CMP, ESR, CRP Serum glucose→ compare to CSF glucose \+/- coag studie LP
Gold standard for diagnosing bacterial meningitis
LP with CSF analysis
G+ diplococci on gram stain is
pneumococcal
G- diplococci on gram stain is
meningococcal
G+ rods and coccobacilli on gram stain is
L monocytogenes
G- cooccobacilli on gram stain is
H influenzae
Bacterial meningitis presentation
Progressively→ days or following a febrile illness
Acutely→ signs and symptoms of sepsis, rapid over several hours, cerebral edema
HA (severe and generalized), Photophobia, N/V/A
Focal neurologic deficits
Weakness, cranial nerve palsies. Seizures
Altered mental status, Nuchal rigidity
Papilledema associated with ↑ ICP→ grade 1 to 4
Classic triad → Fever + nuchal rigidity + Altered mental status
N meningitis bacterial meningitis appears
Petechial rash and palpable purpura
(+) Kernig’s sign, Brudzinski’s sign
(+) Jolt accentuation test
Kernig’s sign
Inability/reluctance to allow full extension of knee when hop is flexed at 90 degrees
Brudzinksi’s sign
Spontaneous flexion of hops during attempted passive flexion of neck
Jolt accentuation test
Patient rotates head horizontally at a frequency of two times per second
(+) → exacerbation of an existing headache
Predictive of adverse outcomes in bacterial meningitis
altered mental status, seizures, and/or hypotension
Mainstay of treatment for bacterial meningitis
Dexamethasone .15mg/kg q 6 hours x 4 days
+
empiric IV antibiotics
immediately after blood cultures and LP
Dexamethasone helps bacterial meningitis by and if….
Decrease rate of hearing loss. neurologic sequelae ,morbidity and mortality
Benefit only in pneumococcal meningitis
Only continue if gram stain or blood cultures (+) for S. pneumoniae
+/- add Rifampin if steroid continued
Initiated shortly before/same time as antibiotic therapy (or it does not improve outcome)
2 types of injury most likely to have bacterial meningitis contiguous strep
Basilar skull fracture
Penetrating trauma/post-neurosurgery
Who gets blood cultures (without LP) stat instead of blood cultures + LP STAT when there’s suspicion for bacterial meningitis
Immunocompromised History of CNS disease New onset seizure Papilledema Altered consciousness Focal neuro deficit
These ppl get a CT next, then an LP if no CI
Bacterial meningitis types that we vaccinate against
S. pneumoniae
N. meningitidis
H. influenza
Post-Exposure prophylaxis for bacterial meningitis
Cipro
Rifampin
Ceftriaxone* (pregnant patients)
Your patient has pneumococcal meningitis as shown by gram stain/blood cultures
Continue the dexamethasone
Add rifampin
Targeted abx
Your patient has non-pneumococcal meningitis as shown by gram stain/blood cultures
Discontinue dexamethasone
Targeted abx
The gram stain or culture cam back negative but other CSF findings consistent with bacterial meningitis
Continue empiric antibiotic therapy + dexamethasone
Aseptic meningitis aka
“Viral meningitis” but it isn’t always viral
Clinical evidence of meningeal inflammation but bacterial cultures are negative
Aseptic meningitis
Aseptic meningitis presentation
Similar presentation to bacterial meningitis Symptoms less severe→ supportive care Complete recovery with no sequela Generally non-specific Headache, Fever, N/V \+/-Photophobia \+/- Nuchal rigidity
Labs for aseptic meningitis
Follow same diagnostic approach as bacterial meningitis Blood cultures X2 (before antibiotics) \+/-CT? (same criteria as bacterial) CBC with differential, CMP, ESR, CRP \+/-Other (clinical suspicion)
Most common cause of viral aseptic meningitis
Enterovirus
Viral causes of aseptic meningitis
Enterovirus (most common)→ Coxsackie, echovirus
(summer and autumn)
HSV-2, VZV, mumps,
HIV, West Nile virus,, EBV, CMV
Causes of infectious non-viral meningitis
Rare
Mycobacteria
Fungi→ Cryptococcus, coccidioidomycosis
Spirochetes→ Treponema pallidum, Borrelia burgdorferi
Malignancy as a cause of aseptic meningitis
Direct invasion of the meninges (uncommon)
Leukemia, lymphoma, melanoma, breast, lung, GI cancers
Drug induced aseptic meningitis can be caused by
Rare
Delayed hypersensitivity reaction vs. direct meningeal irritation
NSAIDs, TMP-SMX, chemotherapy,
phenazopyridine (pyridium)
Aseptic meningitis + travel
TB
Aseptic meningitis + ticks exposure
Borrelia burgdorferia
Aseptic meningitis + sexual activity
HSV-2
syphilis
HIV
Aseptic meningitis or encephalitis + unvaccinated + parotitis
Mumps
Aseptic meningitis + diffuse, maculopapular exanthema in mildly ill patient
Enteroviral infection
Primary HIV
Syphilis
Aseptic meningitis + oropharyngeal thrush + cervical LAD
Primary HIV
Aseptic meningitis or encephalitis + Asymmetric flaccid paralysis
West nile virus
If you’ve got aseptic meningitis and bacterial meningitis has been ruled out (aka CSF)
Discontinue empiric antibiotics
Viral Aseptic meningitis treatment
self limiting supportive analgesia antipyretics severe/immunocompromised get acyclovir
Drug induced Aseptic meningitis treatment
Discontinue meds and it’ll resolve in a few days
Meningitis vs encephalitis
Meningitis→ preservation of cerebral function. Fever,headache, and meningismus more common.
Encephalitis→ abnormalities in brain function more common: AMS, seizures, motor or sensory deficits personality changes, speech or movement disorders
Meningoencephalitis→ unclear which→ +/- photophobia, nuchal rigidity
Arboviruses (2)
Can cause encephalitis
West Nile Virus
St. Louis encephalitis
Transmitted by mosquitos so more common in summer
Most common cause of fatal encephalitis
HSV-1
causes epilepsy
Other causes of encephalitis
Influenza Lyme disease Rocky Mountain spotted fever syphilis Uncommon→ VZV, EBV, HIV, mumps, measles, rubella, rabies
West nile virus is found in
Africa
Asia
Europe
US
St. Louis virus is found in
Midwest/Southwest US
Lyme disease is found in
Wooded areas and Colorado
Primary infection in encephalitis
Due to direct viral invasion of CNS
Cultured from brain tissue
Neuronal involvement
Post-infectious encephalitis
Acute disseminated encephalomyelitis (ADEM)
No virus detected
Neurons are spared
Perivascular inflammation/demyelination
Typically occurs as initial infection is resolving
Encephalitis presentation
Headache, Fever
Altered mental status (subtle to unresponsive)
Confused, agitated, obtunded
Seizures (common)
Focal neurologic deficits
Hemiparesis, CN palsies, ↑ DTRs
Photophobia and nuchal rigidity (rare, may be seen in meningoencephalitis)
Encephalitis + tongue/lip/eye tremors
St. Louis virus
Encephalitis + hydrophobia, hyperactivity, pharyngeal spasms
Rabies
CSF findings indicative of HSV-1 as a cause of encephalitis
RBC
Decreased CSF/blood glucose
(also: temporal lobe changes on MRI)
MRI with contrast of encephalitis will show
+/- abnormalities acutely
3-4 days for changes:
Hydrocephalus→ bacterial, fungal, parasitic etiology
Temporal lobe changes (MRI) → HSV
Do serology for encephalitis if…
not improving or no pathogen identified→ IgM antibody serum and CSF testing for West Nile, mumps, EBV
Do a brain biopsy of encephalitis if…
Last resort
etiology still unknown
Encephalitis prognosis
Initial diffuse cerebral edema or intractable seizures→ poor neurologic recovery, increased mortality
Elevated initial ICP → prognostic for bad outcome
Serial ICP→ document to show improvement
HSV most important to identify and treat→ fatal, causes epilepsy
Encephalitis management
Empiric→ Acyclovir 10 mg/kg IV q8 hours
Seizure prophylaxis/control
Increased ICP→ diuretics→ mannitol, furosemide
Encephalitis management
Empiric→ Acyclovir 10 mg/kg IV q8 hours
Seizure prophylaxis/control
Increased ICP→ diuretics→ mannitol, furosemide
Common viral causes of meningitis
Coxsackie HSV-2 HIV Mumps Measles
but all can still cause encephalitis
Common viral causes of encephalitis
West Nile Virus
HSV-1
CMV
Influenza
but can still cause meningitis
Focal area of infection with a collection of pus resulting from infection, trauma, or surgery in the brain
Cerebral abscess
3 ways you could get a cerebral abscess
- Direct spread→ typically a single abscess. Otitis media, mastoiditis, meningitis, head/facial trauma, sinusitis, dental infection, post neurosurgical or spinal procedure.
- Hematogenous spread→ multiple abscesses and bacteremia. Infections: chronic pulmonary, skin, pelvic, intraabdominal, bacterial endocarditis. Following esophageal dilatation.
- No site/underlying condition→ 20-40%
Cerebral abscess in inferior temporal lobe and cerebellum from direct spread is caused by
subacute or chronic otitis media, mastoiditis
Cerebral abscess in frontal lobes from direct spread is caused by
frontal or ethmoid sinuses, dental infection
Hematogenous spread causes abscesses in the _____
MULTIPLE ABSCESSES
so everywhere
Cerebral abscess presentation
Nonspecific→ diagnostic delay
Unilateral headache
(unless multiple abscesses)
→ Sudden or gradual onset
→ Severe pain, not relieved with OTC pain medications
Fever (45-50%)
Nuchal rigidity (15%) → More common in occipital lobe abscess
Altered mental status→ severe cerebral edema→ bad sign
Increased intracranial pressure→ Vomiting
Focal neurologic deficits (50%)
Seizures (25%)
Papilledema (25%) → Late finding
An immigrant from Mexico might have a cerebral abscess caused by
Cysticercosis→ Taenia solium, pork tapeworm larvae→ Common in immigrants from Mexico
An immunocompromised patient could get a cerebral abscess caused by
Toxoplasma gondii
Listeria monocytogenes
Nocardia asteroides
Fungal cerebral abscesses…
Multiple abscesses
Poor outcomes
Cryptococcus
Coccidioides
Aspergillus
Candida
Diagnostic workup for cerebral abscess
Blood cultures X2 (before antibiotics)
CBC with diff, CMP
MRI without contrast→ 1st choice
CT-guided aspiration or surgical excision for cultures
CT with contrast
What does a cerebral abscess look like on MRI without contrast?
Ring-enhancing lesion
Early (1-2 weeks) → lesion poorly demarcated, localized edema, acute inflammation, no tissue necrosis
Late (>2 weeks) → necrosis and liquefaction, lesion surrounded by fibrotic capsule
Managing a cerebral abscess
CT-guided aspiration or surgical excision
Neurosurgery involvement
IV Antibiotics empirically→ based on suspected origin, gram stain→ culture results→ 4-8 weeks
oral don’t penetrate
MRI→ Track regression/progression
With a cerebral abscess, it’s necessary to use _____ because _____
IV Antibiotics empirically
Oral abx don’t penetrate
What’s an intracranial abscess? How do you get one?
1/10 of epidural abscess
Localized lesion with central collection of pus surrounded by wall of inflammatory tissue +/- calcified
Tight attachment of dura at foramen magnum→ Rapidly spreads caudally
Complication of neurosurgery
Fetal monitoring probes→ osteomyelitis of skull→ spread
Less common: sinusitis, otitis, mastoiditis
Intracranial abscess presentation
Signs and symptoms from infection and expanding abscess
Fever, headache, lethargy, N/V
Secondary to sinusitis→ +/- purulent drainage from nose or ear
Can compress the brain→ Increased ICP, papilledema, +/- focal neurologic changes
Can mimic intracranial mass lesions: metastatic tumors, hematomas, brain abscess, meningioma
Intracranial abscess diagnostics
CBC with diff, ESR – can be variable
MRI w/contrast (1st choice), CT with contrast
CT guided aspiration or open drainage→ stains and cultures
Intracranial abscess management
Neurosurgery→ burr holes, craniotomy
Empiric antibiotics once abscess sample obtained (1-2 days max), sooner if immunocompromised or concerning
→ Contiguous spread→ Metronidazole + ceftriaxone/cefotaxime
→ Other→ Vancomycin + Metronidazole + Ceftriaxone/Cefotaxime/Ceftazidime
Repeat MRI 4-6 weeks→ monitor. Good prognosis with tx
Spinal epidural abscess presentation and progression
Initial manifestations may be non-specific
Classic triad→ fever, spinal pain, neurologic deficits
+/- Fever absent→ delay in diagnosis
Progression of symptoms:
Back pain, focal and severe
Nerve root pain (shooting, “electrical” pain)
Motor weakness, sensory changes, bowel/bladder dysfunction
Paralysis→ quickly becomes irreversible (24-36 hrs)
fever \+ spinal pain \+ neurologic deficits
Spinal epidural abscess “classic triad”
Diagnostics for spinal epidural abscess
CBC with diff
ESR →elevated or normal
MRI w/contrast entire spine ASAP→ first line
→ Positive early in course of infection
→ “skip lesions” down spine
→ Differentiates epidural soft tissue edema from abscess
CT with contrast→ 2nd line
CT guided extraction of pus from abscess for culture
Skip lesions on MRI with contrast of entire spine
Epidural abscess
Epidural abscess prognosis
Death due to sepsis or complications – 5%
Irreversible paraplegia – up to 22%
Some degree of neurologic damage related to duration of deficit
Epidural abscess treatment
Blood cultures x2
Empiric antibiotics ASAP once diagnosis is suspected (after blood cultures!)
→ Vancomycin + cefotaxime/ceftriaxone/cefepime/ceftazidime
x 4-8 weeks
Early surgical decompression and drainage
MRI in 4-6 weeks→ follow up
At risk of spinal epidural abscess
Immunocompromised→ HIV, DM, alcoholism
Direct Inoculation→ Epidural catheter, paraspinal injection, trauma
Hematogenous→ tattooing, acupuncture, bacteremia, IVDU, hemodialysis
Spinal epidural abscess pathophysiology
Bacteria gain access→ Hematogenous spread, Direct extension (osteomyelitis), Direct inoculation into spinal canal (epidural catheter)
Longitudinal extension
Acutely, granulation tissue +/- pus
More common in thoracolumbar area
Damages spinal cord→ direct compression, thrombosis of vessels, bacterial toxins/inflammation, interrupt arterial blood supply
Most common cause of spinal epidural abscess
S aureus
Other causes of spinal epidural abscess
G- bacilli > Streptococci > Coag neg staph (more common after spinal manipulation)
