Brain infections

Question 1

3 feature symptom/mechanisms of brain inft. development

Answer 1

1. Increased pressure Intracranial/spinal spaces (headache, back pain, alt. mental status, visual disturbance)
2. Direct injury to nervous tissue (focal neuro deficits, seizures)
3. Inflammation (Fever, leukocytosis, neck stiffness, kernig’s sign/brudzinski’s sign)

Question 2

Don’t MISS Physical Exam Aspects

Answer 2

1. Meningeal irritation (nucal rigidity, kernig/brudzinski sign, Jolt accentuation)
2. Intracranial hypertension (Fundoscopic exam, bulging anterior fontanelle in infants)
3. Focal Neurologic signs (Check level of consciousnesss; alert, oriented, examine cranial nerves and motor/sensory of extremities)

Question 3

What is the single most important diagnostic test for meningitis?!!!!!11111

Answer 3

Lumbar Puncture!

- “Must DO” Dx process when meningitis or encephalitis is suspected

Question 4

When is Lumbar Puncture contraindicated?

Answer 4

1. Intracranial mass lesion
2. Intracranial hypertension
3. Severe thrombocytopenia; coagulopathy
4. Agitated patient

Question 5

What tests are (routinely) run on CSF?

Answer 5

Opening pressure
Cell count w/ differential
Glucose
Total Protein
Gram stain
Bacterial culture

Question 6

Based on Clinical Context, what tests are run on CSF?

Answer 6

AFB smear/culture
Fungal smear/culture
Cryptococcal antigen
Cytology
PCR of specific organism (HSV, TB, Enterovirus)

Question 7

When to obtain CT before Lumbar Puncture?

Answer 7

1. Possible Intracranial mass
2. Possible Elevated intracranial pressure
3. (both) altered mental status
   - Never delay anti-biotics when waiting for CT scan-

Question 8

Suspect bacterial meningitis? What is the #1 thing associated with survival?

Answer 8

Faster initiation of antibiotic therapy! (within 45 minutes of walking in)

Question 9

2 main diagnostic tools to use when suspecting meningitis or encephalitis for a final diagnosis?

Answer 9

1. If LP can’t start quickly START empiric therapy (antibiotics) IMMEDIATELY!
2. Don’t forget to culture blood

Question 10

Why is CT given over MRI when suspecting meningitis or encephalopathy?

Answer 10

CT is quicker and helps rule out strokes. “Time is money.”

Question 11

What indicates the “last resort” Brain/Meningeal biopsy for dx?

Answer 11

1. Microbiologic diagnosis of brain abscess
2. Need differentiation of chronic infection vs. tumor
3. Need Dx of chronic meningitis infectious vs. autoimmune

Question 12

WHAT IS A MEDICAL EMERGENCY?!!!!

he will punch you if you forget this

Answer 12

Bacterial Meningitis

Question 13

Triad symptoms of meningitis

Answer 13

1. Headache (80-95%)
2. Fever (80-95%)
3. Nuchal Rigidity (80-90%)
   * Also can have altered mental status (70-80%) and Vomiting (20-50%)
   * * 95% of patients have at least two of these

Question 14

Neonatal Meningitis just like what?

Answer 14

Indistinguishable from sepsis
Consider meningitis for all febrile newborns + get LP to diagnose
*Symptoms: altered body temp, Seizure, poor feeding, Bulging fontanelle, nuchal rigidity

Question 15

CSF Results
WBC count: 1000-5000
Primary cell (Neutrophils):
protein:

what kind of meningitis is this?

Answer 15

Bacterial

Question 16

CSF Results
WBC count: 50-1000
Primary cell (Mononuclear): >40
Protein: 50-200

What kind of meningitis is this?

Answer 16

Viral

Question 17

CSF Results
WBC count: 50-300
Primary cell (Mononuclear):

Answer 17

Tuberculosis

Question 18

CSF Results
WBC count: 20-500
Primary cell (Mononuclear): 50

What kind of meningitis is this?

Answer 18

Fungal

Question 19

What is the most specific test for HSV Encephalitis?

Answer 19

HSV PCR on CSF
Sensitivity (>95%); specific (90%)
*gold standard

Question 20

You suspect Encephalitis, what is the FIRST THING YOU DO?

Answer 20

Give Acyclovir!!!!

Suspect HSV encephalitis until proven otherwise