Transcript CNS Infections - Georgia Regents University

CNS Infections
J. Ned Pruitt II
Associate Professor of Neurology
Medical College of Georgia
Case 1
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A 35 yo man is brought to the ER after 5 days of
fever and chills. His wife relates that he has been
very confused today and she called 911 after a
seizure.
PMHx is unremarkable except for a splenectomy
at age 14 after a traumatic injury.
Meds – prn tylenol in the last week.
NKDA
Vaccinations are up to date.
Case 1
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Exam – Ill appearing man. Temp 39 C.
Lethargic and can answer simple questions
but can give no meaningful history. Neck is
stiff to flexion and extension. A fine
petechial rash is on his chest and upper
arms.
Case 1 – What next?
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More examination or history?
 Labs?
 Radiology?
 Medications?
CNS Infections
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Meningitis
– Bacterial, viral, fungal, chemical,
carcinomatous
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Encephalitis
– Bacterial, viral
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Meningoencephalitis
 Abscess
– Parenchymal, subdural, epidural
CNS Infections
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Signs and symptoms
– Fever
– Headache
– Altered mental status -lethargy to coma
– Neck stiffness – meningismus – flex/ext
– Increased intracranial pressure – papilledema,
nausea/vomiting, abducens palsies, bulging
fontanelle in infants
Exam in suspected CNS
Infection
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Mental Status
 Cranial nerve and fundiscopic exam
 Meningeal Signs
 General exam – rashes, lymphadenpathy
 Labs – CBCD, BMP, PT/PTT, bHCG, blood
cultures, UA C&S
 Radiology – CT head - uncontrasted if no
focal signs, contrast if mass suspected
LP
Increased intracranial pressure is expected –
but LP contraindicated if a mass is present
or if epidural spinal abscess is suspected
Left lateral decubitus position
L3-L4 interspace or L4-L5 interspace
Think about your studies before the LP
LP
Tube #1 – glucose and protein
 Tube #2 – cell count and differential
 Tube #3 – gram stain and rountine culture,
cyrptococcal antigen, AFB stain and culture
 Tube #4 – VDRL, or viral studies (PCR)
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CSF Characteristics
Bacterial
Viral
Fungal
TB
Opening
Pressure
Elevated
Slightly Normal Ususally
elevated or High high
Glc
Low
Normal Low
Low
Pro
Very high Normal High
High
Rbcs
Few
None
None
None
Wbcs
(c/mm3)
>200
<200
<50
20-30
Diff
PMNs
Mono
Mono
Mono
Key CSF Features
CSF is not liquid gold – get enough to get your answer
 CSF Glucose is 2/3 of serum glucose
– Important in diabetic patients
 Traumatic LPs –
– CSF pro increases by 1 for every 1000 rbcs
– Tube #1 and Tube#4 for rbcs when SAH is in the
differential not as a routine
 Very high CSF Protein levels will make CSF yellow
 Send a full tube of CSF for cytology not just a few cc’s
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Case 1
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CT of head negative.
 LP - OP (opening pressure) 250mm,
glucose 17, protein 92, Rbcs 3, Wbcs 280
with 89% pmns, 11% lymphocytes
 Gram stain - + for Gram neg organisms
Bacterial Meningitis
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Streptococcus pneumoniae
 Hemophilus influenzae
 Listeria moncytogenes
 Group B streptococcus
 Niesseria meningitidis
Bacterial Menigitis
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Age less than 3 months– Group B strep
– L. Monocytogenes
– E. coli
– Strep pneumoniae
Bacterial Meningitis
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3 Months to 18 years –
– N. meningitidis
– S. pneumoniae
– H. influenzae
Bacterial Meningitis
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Age 18 to 50 years
– S. pneumoniae
– N. meningitidis
– H. influenzae
Bacterial Meningitis
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Over age 50 years
– S. pnemoniae
– L. monocytogenes
– Gram (-) bacilli
Treatment of Bacterial
Meningitis
PCN G or 3rd generation cephalosporin and
consult ID
 Steroids – Dexamethasone IV q6 for 4 days
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Viral Meningitis
Very common
Often caused by enteroviruses
Treatment is supportive
Viral Encephalitis
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Encephalitis (Meningoencephalitis)
– Altered mental status and seizures
– Herpes Simplex virus – medial temporal lobe
 Acyclovir
 Management of seizures
 Very high morbidity and mortality
 PCR diagnosis of CSF
– West Nile, St Lousi E, EEE, CMV
Chronic Meningitis
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Immunocompromised patients
– Cryptococcus neoformans
– HIV
– M. tuberculosis
– M. avium
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Carcinomatous meningitis
– Lung, breast
Case 1
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Meningitis caused by N. Meningitidis
– Treatment with 3rd generation cephalosporin for
10 days
– Dexamethasone
– Prophlaxis with Rifampin for contacts