17_CNS Flashcards
Most common cause(s) of Meningitis in neonates?
- Group B Strep
- E. coli
- L. monocytogenes
Most common cause(s) of Meningitis in children & teenagers?
N. meningitidis
enters through nasopharynx → blood → meninges
Most common cause(s) of Meningitis in adults & the elderly?
Strep pneumonia
Most common cause(s) of Meningitis in non-vaccinated infants?
H. influenza
Most common cause(s) of Meningitis in immunocompromised patients?
Fungi
Most common viral cause of Meningitis?
Coxsackie virus
fecal-oral transmission
Classic Triad of Meningitis?
Headache, Neck Stiffness, & Fever
Photophobia, vomiting, & altered mental status are other possible Sx
Which meningeal layers are pierced by the needle on Lumbar Puncture?
Dura & Arachnoid space
does NOT pierce the pia
LP fluid results in viral vs. fungal cause?
Viral = Lymphocytes w/ normal glucose
Fungal = Lymphocytes w/ low glucose
Complications such as Herniation & Death are typically only seen w/ what type of meningitis?
Bacterial meningitis b/c of exudate & pus inflammation where there’s no room for it
Pyramidal neurons represent highly vulnerable areas to ischemic infarction. In which layers of the cortex are they seen?
Layers 3, 5, & 6
(results in cortical laminar necrosis)
(pyramidal neurons of the hippocampus are another vulnerable area)
What are typically the most highly vulnerable areas of the brain to moderate global ischemia?
- Watershed regions: very end of ACA or MCA
- Pyramidal neurons of Cortex (layers 3, 5, & 6)
- Pyramidal neurons of Hippocampus
- Purkinje layer of Cerebellum
Ischemic stroke of the brain leads to liquefactive necrosis. What is the earliest change seen on histology during this process?
Presence of Red Neurons
after ~ 12 hours
Intracerebral Hemorrhage:
a) Classically due to rupture of ______
b) Complication of _____
c) _____ is the most common site
d) Presents as _____
a) Charcot-Bouchard microaneurysms
b) HTN
c) Basal ganglia
d) Headache, nausea, vomiting, & eventual coma
Subarachnoid Hemorrhage:
a) Presentation?
b) Findings on LP?
a) Headache w/ nuchal rigidity (“worst headache of my life”)
b) Xanthochromia (yellow CSF due to bilirubin breakdown products)
