Infections Of The CNS Flashcards
Difference in clinical presentation between meningitis and encephalitis
Meningitis = fever, stiff neck, headache, nausea/vomiting, lethargy, NORMAL CEREBRAL FUNCTION
Encephalitis = fever, seizures, neuro defects, DECREASED CEREBRAL FUNCTION
Most common causes of developing meningitis
Via hematogenous and/or septic spreading
Common areas to start are ear,sinuses, nose, cribiform plate
Top 3 etiologies angents for meningitis in patients above 2 yrs old
S. Pneumonia
N. Meningitids
L. Monocytogenes
Top 3 etiologies angents for meningitis in patients younger than 1 month
S. Agalactia
E. Coli
L. Monocytogenes
Antibiotic therapy for meningitis in most 1 month olds or younger
Ampicillin and 3rd gen cephalosporin (cefotaxime) OR Aminoglycosides
* not both*
Antibiotic therapy for meningitis in most people greater than 1 month old
Vancomycin + 3rd gen cephalosporin
for old people (>50 yrs) add ampicillin to cover listeria
Major risk factors for meningitis
Age (really young and really old)
Otitis media infections
Immunosupression
Diabetes
Sepsis
Trauma to head/neck
Unvaccinated patients (especially measles)
What two nerves do viruses use to travel to the CNS
Trigeminal and olfactory nerves
Classic symptoms of bacterial meningitis
Top 4:
- fever
- stiff neck
- altered mental status
- headache
Others:
- photophobia
- systemic petechiae (specific to meningococcal)
- phonophobia
- vomiting
Complications to meningitis
Cerebral edema
Poor CSF drainage
-hydrocephalus
Hemorrhages
Herniation of the Brain
What groups of patients need a head CT before conducting an LP
Age over 60
History of CNS disease
Immunosuppressive patients
History of seizures (especially within 1 wk of admittance)
Recent head trauma
Patients that show depresses consciousness or papilledema on physical examination
In what specific case of meningitis is dexamethasone indicated for treatment?
In patients that are confirmed top have pneumococcal meningitis and have a GSC of 8-10 or lower
must be given in conjunction with definitive antibiotic therapy
** also if use vancomycin, DONT. Instead give rifampin since vancomycin cant pierce BBB w/ dexamethasone usage**
What is the most common viral etiology for viral (aseptic) meningitis?
Enterovirus family
Encephalitis
Predominantly is viral and most common is HSV-1
Symptoms
- fever
- headaches
- marked personality and behavioral changes
- hallucinations
- speech issues
- seizures
Brain damage in the frontal and temporal lobes are the most common locations in encephalitis (due to the skull anatomy being sharper around these areas),
Treated with IV acyclovir
What is the 2nd most common viral causes of encephalitis?
Flavaviruses
