Neurologic Infections

Question 1

Which neurologic infection is most likely to be fatal?

Answer 1

Bacterial Meningitis (fatal in 15-20%, ~25% of survivors have serious long-term health problems or disability)

Question 2

What organisms most commonly cause bacterial meningitis?

Answer 2

S. pneumoniae and N. meningitidis

Question 3

What factors place a patient at increased risk for bacterial meningitis?

Answer 3

Crowded living conditions
Being immunocompromised
Recent neurosurgery or skull fracture

Question 4

What causes increased ICP in bacterial meningitis and what are the consequences of increased ICP?

Answer 4

Brain parenchyma becomes edematous from both inflammatory response and alteration in permeability of the BBB
Elevated ICP can then cause decreased cerebral perfusion causing further cell death, even after bacteria are killed by abx

Question 5

What are the symptoms of bacterial meningitis?

Answer 5

Rapidly developing fever
Stiff neck
Headache
Altered mental status
Seizures
Photophobia
Purpural rash of meningococcemia (rare)

Question 6

What are the signs of bacterial meningitis?

Answer 6

Febrile
Tachycardic
+/- Septic by SIRS (systemic inflammatory response) criteria
Confused
Stiff neck (+Kernig’s and/or Brudzinski’s sign)
Meningococcemia (late sign)

Question 7

If you suspect bacterial meningitis, what are your steps of action?

Answer 7

Immediately get blood cultures and ideally have another nurse starting IV antibiotics at the same time. Send for CT while abx are running. If rule out bleed, then move forward with LP. LP results should be valid for up to 2 hours past time of starting abx due to abx taking time to cross BBB. Also can obtain CMP, Heme 8, Coags and other tests as necessary to rule out other etiologies.

Question 8

What findings on LP indicate bacterial meningitis?

Answer 8

Glucose down, Protein up, WBC up

Question 9

What is the appropriate treatment of bacterial meningitis?

Answer 9

IV antibiotics, usually ceftriaxone and vancomycin.
Add Ampicillin in patients over 65 yo to cover Listeria
IV steroids (dexamethasone) for prevention of hearing loss, in developed world ONLY. Not for use in areas with high prevalence of TB or HIV

Question 10

What viruses are associated with viral meningitis?

Answer 10

Herpes simplex
Enteric viruses
Coxsackie viruses

Question 11

What are the symptoms and signs of viral meningitis?

Answer 11

Confusion (in children)
Several days of headache
Neck stiffness
Fatigue without high fever
\+/- Diarrhea, pharyngitis, adenopathy, rash

Question 12

Why may CT be used in evaluation of patient with viral meningitis?

Answer 12

Rule out subarachnoid hemorrhage

Question 13

How would you treat viral meningitis?

Answer 13

Treat for HSV with acyclovir if suspicious

Consider hospital admission for serial exams to ensure no progression

Question 14

How would you work up a patient presenting with headache x 3 days, neck stiffness and low grade fever?

Answer 14

Suspect viral meningitis…
CT for rule out mass/bleed
LP to rule out bacterial meningitis
Neuro exam likely non-focal

Question 15

If my neighbor in Ross 227 gets fungal meningitis can I get it from them? =0 Why or why not?

Answer 15

No, there is no person to person transmission.

Common fungi are inhaled and then spread hematogenously from lungs to CSF.

Question 16

Which organisms are most likely to cause fungal meningitis?

Answer 16

Cryptococcus
Histoplasma
Blastomyces
Coccidioides

Question 17

Who is most likely to obtain fungal meningitis?

Answer 17

Immunocompromised patients:
HIV + with low CD 4+ counts
Organ transplant recipients
Cancer pts being treated with chemo
Autoimmune dz pts being treated with immunosuppressive therapy
Pts with genetic immunodeficiency syndromes

Question 18

How do symptoms and signs of fungal meningitis differ from those of bacterial or viral?

Answer 18

More indolent due to BBB blocking fungal infection from immune system
Symptoms can wax and wane
Less common to have altered mental status
May not have fever d/t immunocompromised state
Nuchal rigidity less likely
Chronically unwell, late-stage signs of immunosuppression

Question 19

How can you test for fungal meningitis?

Answer 19

LP (including opening pressure which would be elevated), India ink stain for Cryptococcus
Serum Cryptococcus antigen
MRI

Question 20

What is the treatment for fungal meningitis and what are your concerns during/after?

Answer 20

Anti-fungals, typically started IV
Need life-time prophylaxis (fluconazole) after tx
If elevated ICP, consult neurosurgery for shunt

Concerns: Hepatotoxicity of drugs; Mortality up to 10% even with therapy

Question 21

55 year old patient presents with ataxia, memory loss, speaking nonsense and lack of sensation. What is the neurologic infection on top of your DDx and what is the treatment?

Answer 21

Creutzfeldt-Jakob Disease
Abnormalities in almost every area of neuro system should raise flag for CJD
No treatment, symptomatic, supportive and psychological care for pt and family

Question 22

What causes Creutzfeldt-Jakob disease?

Answer 22

Typically unknown but associated with travel to places where food was not well cooked (even decades prior). CJD is a rare, progressive, fatal cause of dementia due to a prion infection. “Mad cow disease”

Question 23

What organisms cause chronic meningitis?

Answer 23

M. tuberculosis - worldwide (high prev TB areas)
Brucella - South and Central America (raw milk)
B. burgdorferi - US (lyme disease)
C. neoformans - worldwide