Meningitis & Encephalitis Flashcards
Meningitis
inflammation of which spaces
- pia mater
- arachnoid
- CSF filled subarachnoid space
Meningitis
which age has majority of cases? why?
- adults
- vaccination
Meningitis
common bacterial organisms causing meningitis
5
- strep pneumoniae
- neisseria meningitidis
- Group B strep
- H. flu
- Listeria
Meningitis
sx in Bacterial Meningitis
6
- Fever
- HA
- Nuchal Rigidity
- AMS (altered mental status, confusion, lethargy)
- photophobia
- n/v
Meningitis
PE Findings
7
- Fever
- pos Kernig and Brudzinski
- Nuchal Rigidity
- Seizures
- Focal Neuro Deficits (CN VI, III, IV, VIII)
- Papilledema (rare)
- skin rashes
Meningitis
describe Kernig Sign
- flexing knee causes pain
Meningitis
describe Brudzinski sign
lifting head causes knee flexion w/ pain
Meningitis
describe CN III palsy
lateral, downward deviation
w/ ptosis
Meningitis
describe CN IV Palsy
upward deviation
Meningitis
CN VI palsy
medial deviation
Meningitis
essentials of dx
5 components
- fever, HA, v, delirium, seizures
- rash on skin/mucous membranes
- neck/back stiffness
- pos Kernig, Brudzinski
- purulent spinal fluid
Meningitis
dx
- Head CT before LP
- culture of cerebrospinal fluid
Meningitis
bacterial vs viral meningitis
bacterial more probable if:
* glucose < 34
* protein > 220
* WBC > 2000
* Neutrophil > 1180
Meningitis
what would gram positive diplococci in CSF suggest?
pneumococcal
Meningitis
what would gram negative diplococci in CSF suggest?
meningococceal
Meningitis
what would gram negative coccobacilli in CSF suggest?
H. flu
Meningitis
what do gram pos rods suggest?
listeria
Meningitis
what do gram pos cocci in pairs and short chains in CSF suggest?
GBS
Meningitis
Labs for Dx bacterial meningitis
7
- CMP
- CBC
- PT/PTT
- Lactic Acid
- STI Panel (HIV/Syphilis included)
- Blood Cultures
- UA
Meningitis
imaging to dx bacterial meningitis
CXR
Meningitis
Bacterial Meningitis Tx
- emperic: cephalosporin w/ vanco
- steroids: dexamethasone
- ceftriaxone to clear NP carrying
Meningitis
what to add to tx if suspecting…
* listeria
* HSV
* Rocky Mountain Spotted Fever
- ampicillin
- acyclovir
- doxy
Meningitis
describe aseptic meningitis
- clinical and lab evidence for meningeal inflammation w/ mononuclear pleocytosis w/ negative gram stain, neg bacterial cultures
Meningitis
causes of aseptic meningitis
6
- viral
- bacterial
- fungal
- medications
- malignancies
- autoimmunity
Meningitis
what is viral meningitis likely caused by?
7
- enterovirus
- HSV
- HIV
- WNV
- VZV
- Mumps
- CMV
Meningitis
describe enterovirus meningitis
3 components
- most common cause
- rash, sore throat, diarrhea, joint ache, HA
- CSF: PMNs predominate early, repeat LP will show evolution to lymphocytic predominance
Meningitis
describe HSV meningitis
4 components
- high CSF RBC count
- HA, photophobia, stiff neck, neurologic complications
- Tx: acyclovir IV
- high mortality rate
Meningitis
predisposing factors for cryptococcosis meningitis
- chemo
- Hodgkin lymphoma
- corticosteroid therapy
- structural lung diseases
- transplant recipients
- TNF alpha inhibitor therapies
- AIDS
Meningitis
sx of cryptococcosis meningitis
- HA
- AMS
- meningismus
Meningitis
cryptococcosis meningitis CSF findings
demonstration of capsular polysaccharide antigen or pos culture
Meningitis
non-infectious causes of asepctic meningitis
4 categories
- malignancies
- systemic processes
- inflammatory
- drug hypersensitivity
Meningitis
drug induced meningitis likely due to
5
- NSAIDs
- Abx
- IV immune globulin
- chemo drugs
- anti-epileptics
Meningitis
pathophys
- delayed hypersensitivity rxn or direct meningeal irritation
Meningitis
PE findings Aseptic Meningitis
5
- maculopapular exanthem (HIV/Syph)
- parotitis (mumps)
- vesicular and ulcerative gential lesions (HSV)
- Oropharyngeal thrush/cervical LAD (HIV)
- asymmetric flaccid paralysis (WNV)
Meningitis
aseptic meningitis CSF findings
- high lymphocytes
- high protein
- normal glucose, neg gram stain
Meningitis
prevention
- vaccination
- PEP
differentiate encephalitis vs meningitis
- Encephalitis: abnormalities in brain function, AMS, motor/sensory deficits, altered behavioral/personality changes, speech, movement disorders
- Meningitis: uncomfortable, lethargic, distracted by HA, cerebral function remains normal
Encephalitis
etiology (viral)
9
- HSV
- VZV
- EBV
- measles
- mumps
- rubella
- rabies
- CMV
- arboviruses
Encephalitis
presentation
- viral prodrome (fever, malaise, myalgia, HA, etc)
- signs/sx of causative agent
- AMS from subtle deficits to complete unresponsiveness
- seizures common
- papilledema rare
- focal neurologic abnormalities (hemiparesis, aphasia, CN palsies)
Encephalitis
imaging
- MRI sensitive for demyelination, edema, necrosis, inflammation
- Head CT w/ or w/out contrast if suspecting space occupying lesions, brain abscesses
Encephalitis
what does temporal lobe involvement suggest
HSV encephalitis
Encephalitis
LP findings
6
- PCR pos for viral cause
- RBCs suggest HSV-1
- normal glucose
- increased WBCs
- elevated protein
- elevated opening pressure
Encephalitis
Tx
- causative agent rarely identified, but tx of underlying cause if found
- important to r/o HSV (if suspected, ASAP acyclovir)
- corticosteroids
