CNS Flashcards
What are sx of meningitis?
Cns infection sx (fever, nausea, vomiting, seizures, headache) + stiff neck, meningismus, photophobia
Your patient presents with confusion plus cns sx
Encephalitis
Encephalitis presents with which sx?
Nausea, vomiting, headache, fever + confusion
Your patient presents with cns sx and focal neurological findings
Brain abscess
Meninges are separated in 3 layers
Pia, arachnoid, dura
Meningitis is an infection of
Arachnoid or pia
Most common cause of bacterial meningitis?
Strep pmeumo
Most common etiology of neonatal meningitis
Group B Strep
Most common etiologies of bacterial meningitis
S. Pneumo GBS H.influenza N.meningitis Listeria, in immunocompromised (add ampicillin!) Staph (if recent surg)
Meningitis can give you focal abnormalities in which percentage of pts?
30%
If there is confusion you should…
Do a CT and an LP
What are specificities of cryptococcal meningitis?
Slow, goes on several weeks
Pt with stiff neck, photophobia, AIDS with
Cryptococcus
Stiff neck, photophobia, joint pain, target like rash, camper, facial palsy, most likely dx is
Lyme
Cryptococcus meningitis presents most likely in a patient with?
AIDS CD4>100
Lyme meningitis presents more often in a patient with?
Rash, joint pain, facial palsy, camper, hiker, tick remembered in 20 %
Patient is a hiker, has a rash that moved from arms and legs to trunk and stiff neck and photophobia
Rocky mountain spotted fever (Rickettsia)
Patient that has stiff neck and photophobia and TB?
Tuberculosis
Stiff neck and photophobia but nothing else :/
Viral meningitis
Stiff neck, photophobia, adolescent with petechial rash
Neisseria
Best initial test in meningitis?
LP
CSF evaluation in meningitis
Neutrophils: 1000s in bacterial, 10s-100s in crypto, lyme, rickettsia, TB and viral
Proteins: elevated in bacterial, crypto, lyme, rickettsia and specially TB, normal in viral
Glucose: decreased in all except viral
Gram stain and culture: positive in bact
In meningitis when is head CT the best initial test?
Papilledema
Seizures
Focal neurological abnormalities
Confusion (you cant do an accurate neuro exam in a confused pt)
If there is a contraindication to immediate LP, what is the best first step in management?
Antibiotics: ceftriaxone, vancomycin
Steroids
When is bacterial agglutination test indicated?
Those who received antibiotics prior to LP, cause culture may be falsely negative
Careful, if negative not sufficient to exclude bacterial meningitis
What is the most accurate test for TB?
Acid fast stain and culture on 3 high volume LPs
Centrifuge to concentrate organisms
TB has high CSF protein
Uncentrifuged sample of CSF is 10% sensitive
What is the most accurate dx for lyme and rickettsia?
Specific serologic testing, ELISA, western blot, PCR
What is the most accurate dx test for cryptococcus?
India ink is 60-70% sensitive
Crypto antigen is 95% sensitive and specific
What is the best dx test for viral meningitis?
None, it is a dx of exclusion
Best initial tx for bacterial meningitis?
You should base your tx answer on which test?
Ceftriaxone, vancomycin and steroids
Cell count
Your patient has sx of meningitis, on PL has 1000s of neutrophils and is immunocompromised what tx should you start?
Ceftriaxone, vancomycin and steroids, add ampicillin because immunocompromised to cover listeria
Listeria monocytogenes is resistant to?
Sensitive to?
Resistant to all forms of cephalosporins
Sensitive to penicillins : add ampicillin to tx
Risks factors for listeria monocytogenes infection
Elderly Neonates Steroid use AIDS/HIV immunocompromised (alcoholism) Pregnant Bone marrow transplant, leukemia, lymphoma etc.
Patients with neisseria meningititis, who should benefit from prophylaxis?
Their close contacts: major respiratory fluid contacts, household contacts, kissing, sharing cigarettes or eating utensils.
Close contacts should be treated with rifampin or cipro
Your patient has neisseria meningitis, when do you qualify as a “close contact”?
Intubated the patient
Performed suction
Have contact with resp secretions
Man comes to ER with fever, severe headache, stiff neck and photophobia. He has weakness in his left arm and leg, what is the best next step in management?
Ceftriaxone, vancomycin and steroids BEFORE head CT
What is the most common deficit of untreated bacterial meningitis?
VIII CN deficit or deafness
What is the most common cause of encephalitis?
Herpes simplex
What are specific sx of encephalitis?
Fever and confusion
What is the best initial test to do if encephalitis is suspected (cns infection signs plus confusion)
Head CT
What is the most accurate test of herpes encephalitis?
PCR of CSF
What is e best initial therapy for herpes encephalitis?
Acyclovir IV
In which situation would you use foscarnet?
In there is acyclovir resistant herpes encephalitis
A woman with herpes encephalitis confirmed by PCR gets 4 days of acyclovir. Her creatinine level rises. What is the most appropriate next step in management?
Reduce the dose of acyclovir and hydrate, you cannot stop acyclovir even if she has renal insufficiency
What is the problem (SE) with acyclovir?
Renal insufficiency,
Even worse with foscarnet
Your patient presents with stiff neck, photophobia and meningismus, the most likely dx is
Meningitis
