brain hypoxia, cerebral venous anatomy, hydrocephalus

Question 1

What areas of the brain are most vulnerable to hypoxia?

Answer 1

hippocampus, neocortex, cerebellum, and watershed areas

Question 2

What should I know about stroke imaging on CT and MRI? What about timing? How might this influence medical management?

Answer 2

bright on diffusion weighted MRI within 3-30 minutes.
Dark abnormality on non-contrast CT within 12-24 hrs. Absence of bright areas on CT is great at excluding hemorrhage, which is very important before TPA administration

Question 3

Describe timeline of histo features for ischemic stroke

Answer 3

12-24 hrs: red dead neurons
24-48 hrs: necrosis and neutrophils
3-5 days: macrophages
1-2 wks: reactive gliosis and vascular prolif
>2 wks: glial scar

Question 4

Causes of hemorrhagic stroke. What is the most common site for hemorrhagic stroke?

Answer 4

HTN, anticoagulation, cancer (abnormal vessels). May be secondary to ischemic stroke followed by reperfusion, since vessels will be fragile.
most common site is the basal ganglia

Question 5

What are the guidelines for giving tPA?

Answer 5

good for ischemic stroke if within 3-4.5 hrs and no hemorrhage/risk of hemorrhage.

Question 6

How do you reduce ischemic stroke risk?

Answer 6

aspirin, clopidogrel; control BP, sugars, and lipids, treat AFib

Question 7

What is the purpose of the venous sinuses? Where do they drain?

Answer 7

to drain blood and CSF from arachnoid granulations. They empty into the internal jugular vein.

Question 8

draw dural venous sinues

Answer 8

see pg 463

Question 9

draw ventricular system of the brain

Answer 9

see pg 464

Question 10

What makes CSF (include cell type and structure)? What reabsorbs CSF? Where does it drain?

Answer 10

ependymal cells of the choroid plexus
reabsorbed by the arachnoid granulations
drains to the dural venous sinues

Question 11

Non-obstructive hydrocephalus: subtypes. For each subtype, explain cause and clinical manifestations

Answer 11

No blockage of CSF.

1. “communicating”: Decr. CSF absorption by arachnoid granulations causes increased intracranial pressure. See papilledem and possible herniation. May occur after arachnoid granulation scarring post-meningitis
2. Normal pressure hydrocephalus: no increase in the subarachnoid space volume, but increased ventricle size distorts the corona radiata. urinary incontinence, ataxia, cognitive dysfunction (wet, wobbly, wild)
3. Ex-vacuo: incr. CSF to fill up empty space left by brain atrophy. Intracranial pressure is normal.

Question 12

Numbers of spinal nerves

Answer 12

31 total

8 cervical, 12 thoracic, 5 lumbar, 5 saccral, 1 coccygeal

Question 13

Describe the anatomy of exiting spinal nerves as they relate to vertebra.

Answer 13

C1-C7 exit above the corresponding vertebra. all other nerves exit below.

Question 14

What is the anatomical process that occurs during a disc herniation?

Answer 14

nucleus pulposus herniates through the annulus fibrosis. typically occurs posterolaterrally at L4-L5 or L5-S1. may want to draw a picture: