Path: Vascular & Trauma

Question 1

What are the consequences of brain herniation?

Answer 1

infarcts due to vascular compression
CN compression
cardio-respiratory compromise (brainstem)
secondary brainstem (Duret) hemorrhages

Question 2

What is the relationships between ischemia/hypoxia and brain injury?

Answer 2

ischemia rather than hypoxia is major determinant of parenchymal necrosis
delivery of also nutrients (glucose) is impaired
ischemia –> stagnation –> accumulation of products like lactic acid

Question 3

What are the different patterns of brain injury?

Answer 3

selective neuronal necrosis or pan-cellular necrosis (neurons and glia)

Question 4

What does the severity and pattern of brain injury due to global ischemic injury depend on?

Answer 4

degree and duration of ischemia
presence of pre-existing vascular dz
other factors (temp, blood glucose, pH) - hypothermia better, hyperthermia worse

Question 5

What is the irony of early intervention with brain infarcts?

Answer 5

early intervention can preserve tissue, but reperfusion can also exacerbate damage (free radical production)

Question 6

What are the manifestations of an ICA infarct?

Answer 6

massive infarction of ipsilateral hemisphere, similar symptoms to MCA plus monocular blindness, smaller deficits than expected due to circle of willis

Question 7

What can cause intracranial hemorrhages and where do most occur?

Answer 7

primary (spontaneous) or secondary due to trauma or primary ischemic injury (hemorrhagic infarct)
mostly brain parenchyma and subarachnoid space

Question 8

What are primary brain parenchymal hemorrhages and what can cause them?

Answer 8

mid to late adulthood, rupture of intraprenchymal vessel

*HTN, AV malformations, vascular dz (amyloid angiopathy, vasculitis), inf in vessel walls, coagulopathies, neoplasms

Question 9

Where are common sites of hypertensive hemorrhage?

Answer 9

basal ganglia, thalamus, brainstem, cerebellum

Question 10

What is one feature seen in hemorrhagic infarcts but not primary intraparenchymal hemorrhages?

Answer 10

large areas of necrosis

Question 11

What are some causes of sporadic berry aneurysms?

Answer 11

smoking, HTN, PCKD, Marfans, coarctation of aorta, AV malformations
acquired from chronic injury to vessel wall, not congenital

Question 12

What can complicate an aneurysmal subarachnoid hemorrhage?

Answer 12

vasospasm and delayed (4-7 days post rupture) ischemic brain injury

Question 13

What are the three groups of traumatic brain injuries caused by blunt force?

Answer 13

parenchymal injuries
epidural hematomas
subdural hematomas

Question 14

What are the three types of parenchymal traumatic brain injuries?

Answer 14

diffuse axonal injury, contusions, chronic traumatic encephalopathy

Question 15

What is traumatic (diffuse) axonal injury?

Answer 15

caused by sudden acceleration/deceleration that stretches/tears axonal processes
cause of most cases of post traumatic vegetative state

Question 16

Where does DAI usually occur?

Answer 16

corpus callosum, internal capsules, dorsolateral aspect of brainstem

Question 17

What are the microscopic features of DAI?

Answer 17

axonal swellings = spheroids

Question 18

Where are the common sites of brain contusions and a possible consequence?

Answer 18

orbital-frontal regions, temporal lobes

can cause subarachnoid hemorrhage

Question 19

What is chronic traumatic encephalopathy?

Answer 19

progressive neurological dysfunction following repeated episodes of head trauma
sports trauma!
accumulation of abnormal tau - neurofibrillary tangles

Question 20

What are the manifestations of chronic traumatic encephalopathy?

Answer 20

mood disorders, motor abnormalities, cognitive impairments, frank dementia develops over time