Neuro: CNS infections Flashcards
3 most common bugs that cause bacterial meningitis.
- S. pneumoniae
- N. meningitidis
- H. influenza (vaccine is decreasing cases)
What is Cushing’s reflex?
Physiological nervous system response to increased intracranial pressure (ICP) that results in Cushing’s triad:
- widening pulse pressure
- irregular breathing
- reduction of the heart rate
A sign of meningitis
What are the 3 major signs of meningitis?
- Nuchal Rigidity (unless a patient is comatose)
- Fever
- Headache
What is a defining feature used to diagnose infantile meningitis?
Bulging fontanelles
What is latex agglutination?
An antigen binding test that can be diagnostic for meningitis. Usually used to identify Strep. pneumo.
Symptom of Meningococcal Meningitis that is immediately observed on physical exam.
Petechial or hemorrhagic skin rash
N. meningitidis can be spread through respiratory droplets. What prophylactic treatment is given to friends and family of a patient with meningococcal meningitis?
Rifampin and Cipro
Name 3 complications of meningococcal meningitis.
- Disseminated Intravascular Coagulation (DIC): intense coagulation response of the whole body that leads to blockage of small capillaries to organs and tissues leading to necrosis.
- Adrenal Hemorrhage (Waterhouse Friderichsen syndrome)
- Circulatory Collapse
What 3 things can lead to a Haemophilus meningitis?
- Skull fracture
- otitis media
- sinusitis
What 3 conditions are linked to pneumococcal meningitis?
- Alcoholism
- Sickle Cell Disease (causes necrosis of the spleen)
- Asplenia (no ability to opsonize)
What is the treatment for bacterial meningitis?
Once it is suspected, immediately start on antibiotics. DON’T wait for spinal tap.
What are the two most common bugs that cause meningitis in newborns?
- E. coli
2. Strep. agalactiae (Group B)
Unique characteristics that define polio.
Unilateral flaccid paralysis
What are the two vaccines used for polio?
Sabin - live attenuated
Salk - killed
Main symptom that differentiates meningitis from encephalitis.
Seizures
How does HSV cause encephalitis and what are the symptoms of Herpes encephalitis?
Gains entry to the brain thru the Trigeminal ganglion or olfactory bulb.
Symptoms include seizure, headache, meningeal signs.
If it gain entry thru olfactory bulb, can affect frontal lobe leading to hallucination and personality changes.
If it gains entry tru CN V ganglion can lead to speech problems.
With most encephalitis conditions there is no increase in RBCs in the CSF. With herpes encephalitis the RBC count in CSF increases due to what?
HSV causes a hemorrhagic reaction
Treatment for Herpes encephalitis.
Acyclovir