Neuro Infections 1- MJ Flashcards
Infectious agents can gain access to CNS through what 3 major pathways?
- Invasion of the blood stream
- Retrograde neuronal pathway
- Direct contiguous spread
Most CNS infections can be categorized into what 3 types?
- Meningitis
- Encephalitis (involving brain itself)
- Brain abscess
- What are the 3 contraindications for performing a lumbar puncture?
- If a contraindication is present, what test must you do before LP?
- Signs or symptoms of increased ICP (papilledema, decreased LOC, focal neuro sxs)
- Severe coagulopathy (or on anticoags)
- Mass lesion
*if contraindications present, MUST get CT prior to LP*
What is Cushing’s Triad (indication of increased ICP)?
- Respiratory depression
- Bradycardia
- HTN
CSF analysis:
- What would be the appearance of normal CSF? What does abnormal look like?
- Normal: crystal clear and colorless, viscosity is similar to water
- Abnormal: Cloudy, purulent or pigment-tinged
What are 4 possible causes of RBCs in CSF on a lumbar Puncture?
- Traumatic LP (CSF clears by the 3rd tube)
- Subarachnoid hemorrhage (redness the same in all tubes)
- Intracerebral hemorrhage
- Cerebral infarct
What should you be concerned for if the CSF is cloudy?
Bacterial Meningitis
CSF analysis:
Bacterial infections are usually associated w/ a predominance of what type of cells?
PMN leukocytes
(neutrophils)
LP w/ CSF analysis:
What are the 4 possible causes of WBS on a CSF analysis?
- Bacterial infection
- Vasculitis
- Lekemic infiltration
- “Traumatic tap”
What is encephalitis?
Acute inflammation of the brain parenchyma causing abnormalities in brain function
Which of the following describes primary encephalitis vs post-infectious encephalitis?
- _______= Virus present and can be cultured/identified; (+) neuronal involvement
- ________= Virus not present; demyelination occurs; (-) neuronal involvement–> this is a secondary inflammation in the brain
- \_Primary_\__= Virus present and can be cultured/identified; (+) neuronal involvement
- __Post-infectious__= Virus not present; demyelination occurs; (-) neuronal involvement
What is the most common etiology of encephalitis?
Viruses (70%)
What puts a person at high risk for encephalitis? (4)
- Outdoors (forestry workers, campers, hunters)
- Travel to endemic areas
- Compromised immunity
- Lack of vaccines
Which virus is associated wtih post-infectious encephalitis?
Measles
The following are possible viral etiologies of what condition?
- HSV
- Arthropod-borne viruses (West Nile, Colorado tick fever, etc)
- Rabies
- HIV
- Enteroviruses (coxsackie, polio)- common
- Measles (assoc w/ post-infectious encephalitis)
- Influenza, mumps, adenovirus
Encephalitis
(basically any virus can cause this)
The following are possible bacterial causes of what condition?
- Borrellia burgdorferi (Lyme)
- M. tuberculosis
- Treponema pallidum (syphilis)
- Listeria spp.
- Leptospirosis
- Bartonella henselae (cat-scratch disease)
- Streptococcus spp.
- Klebsiella spp.
- Staphylococcus spp.
- Neisseria meningitides
- Rickettsia spp. (Rocky Mountain spotted fever)
Encephalitis