EXAM #1: CNS INFECTIONS Flashcards
What is the first thing to ask yourself with a patient that has a suspected CNS infection?
Duration
What is the second thing to ask yourself with a patient that has a suspected CNS infection?
Etiology
What is the third thing to ask yourself with a patient that has a suspected CNS infection?
Work-up
What is the fourth thing to ask yourself with a patient that has a suspected CNS infection?
Treatment
What are the four main types of infections that affect the brain?
1) Acute meningitis
2) Chronic meningitis
3) Brain abscess
4) Ecephalitis
What are the non-infectious etiologies of presentations similar to a CNS infection?
1) Neoplasia
2) Collagen Vascular Disorder
3) Medications
What are the routine tests done on a lumbar puncture?
1) WBC w/diff
2) RBC
3) Glucose
4) Protein
5) Gram stain
6) Bacterial culture
7) Opening pressure
What infectious etiology is associated with an elevated opening pressure?
Cryptococcal meningitis
What is xanthochromia?
Yellow supernantant of CSF from RBC lysis
What are the expected CSF findings in bacterial meningitis?
- 1000-5000 WBC
- 100-500 Protein
- Less than 40 glucose
- Neutrophils
What CSF findings are associated with tuberculous meningitis?
- 50-300 WBC
- Mononuclear
- Less than 45 glucose
- 50-300 Protein
What CSF findings are associated with viral meningitis?
- 50-1000 WBC
- Mononuclear
- Greater than 45 glucose
- Less than 200 protein
What are the CSF findings associated with Cryptococcal meningitis?
- 20-500 WBC
- Mononuclear
- Less than 40 glucose
- Greater than 45 protein
What imaging study is preferred for neuroimaging in the setting of CNS infection?
MRI
When is imaging warranted?
1) Persistent or prolonged fever
2) Focal neuro findings
3) Increased ICP
4) New/ recurrent seizure
5) Persistent dysfunction
6) Persistently abnormal CSF parameters
*An enlarging head circumference in a neonate
What are the characteristics of the antibiotic you want to give for acute bacterial meningitis?
1) Needs to CROSS the BBB
2) Must be BACTERIOCIDAL
What are the two most common causes acute bacterial meningitis?
1) Streptococcus pneumonaie
2) Neisseria meningititdis
What viruses are most viral meningitis?
1) Enterovirus
2) Herpes virus
What three pathogens are associated with subacute/ chronic meningitis?
1) M. tuberculosis
2) T. pallidum
3) Borrelia burgdorferi
What is the intracellular pathogen that can cause meningitis in the very young and old?
L. monocytogenes
How do you start off treating a patient with acute bacterial meningitis?
1) IV Vancomycin
2) Ceftriaxone
If a patient is very young or old and you’re considering L. monocytogenes, what drug should you add?
Ampicillin
In a patient that has had neurosurgery, what pathogens should come to mind?
1) Coagulase negative S. species
2) Pseudomonas
*B/c this is part of the normal skin flora
What drug covers coagulase negative Staph species?
Vancomycin
What drug do you need to use to cover for Pseudomonas?
Ceftazidime (4th gen. cephalosporin, NOT 3rd)
What pathogen responds well to steroids?
S. pneumoniae
What is the vector for Lyme disease?
Ixodes tick
What is the first line drug for Lyme Disease?
Doxycycline
*Alternative is amoxicillin
What is the initial treatment for Cryptococcal meningitis?
1) Amphotericin B or fluconazole
2) Reduction ICP
What duration of symptoms is associated with chronic meningitis?
4 weeks
What is the most common cause of chronic meningitis?
Cryptococcus neoformans
What is a potential neurologic complication of chronic meningitis?
Hydrocephalus
