Lecture 7 -- CNS Path: categories of injury Flashcards Preview

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Flashcards in Lecture 7 -- CNS Path: categories of injury Deck (21):
1

what happens you cut an axon:

- the site of the cut
- the cell body
- distal to the cut

Site of the cut - swelling

Proximal -- central chromatolysis

Distal -- Wallerian Degeneration

2

Astrocytes:
role --

Supportive, detoxifying role
Astrolytic proliferation to injury
accumuatlion of GFAP

3

Astrocytic reactions:
- what protein accumulates with reactive astrocytes?

3 other reactions involving astrocytes

GFAP, Gemistocytic Astroycytes

Rosenthal Fibers

Corpora Amalacea

Alz Type 2 Astrocytosis

4

Astrocytic reactions:

Rosenthal Fibers ---

Corpora Amalacea --- age related start accumulations

Alz Type 2 Astrocytosis -- due to increased ammonia in the blood;

5

Oligodendrocyte histopath

Inclusions -- JC virus in PML

Synuclein positive oligodendroglia inclusion in multiple system atrophy

6

two types of brain edema --

differences between the two

Cytotoxic Edema -- intracellular water; gray matter
cell death leading to incompetence of the cell membrane;



Vasogenic Edema -- Incompetence of the blood brain barrier; Extra-cellular water in gray matter.
The endothelial cell tight junctions of the BBB are broken down;

7

three types of brain herniations:

Transtentorial (Uncal) herniation

Cerebellar Tonsillar herniation

Subfalcine/Cingulate Herniation

8

Transtentorial (Uncal) herniation

- what is it?
physical findings -

isplacement of the medial temporal lobe over the free edge of the tentorum-cerebellar; compressing Cerebral Peduncles and CN III

CN III damage -- ipsilateral eye drops down and out; pupil blown

Cerebral Peduncle damage -- contralateral weakness

9

Cerebellar Tonsillar herniation

what is it?
consequences?

displacement of the cerebellar tonsils into the foramen magnum compressing the medullary cardiorespiratory centers of the brainstem

can quickly lead to cardiopulmonary arrest

10

Subfalcine/Cingulate Herniation

what is it?

displacement of the cingulate gyrus under the falx cerebri.

Less Life threatening than previous two

may have LE weakness

11

Head trauma -- Parenchymal brain injury: contusions --

what is a contusion -- manifesations?

difference between coup contusion and contra coup contussion

Contusion -- "Bruise on the brain"
A large contusion can clot and produce mass effect
May be residual seizure disorders


Coup Contusion -- "blow" contusion; contusion at the point of impact (usually blunt trauma to stationary head)


Contra-coup Contusion -- contusions opposite to point of impact -- usually due to rotational accerlation

12

Vascular brain Injury:

what are the two types of hematoma?

Epidural Hematoma

Subdural Hematoma

13

Epidural Hematoma --

where is the blood?
Charactersitcally associated with...?
Uni vs bilateral?
artery vs vein?
lethal?

Collection of arterial blood between the dura and skull

almost always associated with skull fracture, ((middle meningeal artery rupture))

almost always unilateral,


Patient can present as OK, but if Enough blood accumulation --> mass effect --> die

14

Subdural Hematoma --
where is the blood?
who is prone?
veins vs artery?
Progression?
what unqiue lesion is seen histologically?

Venous blood collection beneath the dura

Rupture of bridging veins

Older patients (slight brain atrophy which stretches bridging veins) who have head trauma

No skull fracture

Progressive neurologic signs -->mass effect --> Herniation --> Death


Fomation of the Neomembrane

15

Subarachnoid Hemorrhage (SAH) ---

where does it typically occur?
what type of aneurysm?

Clinical presentation?

Ruptured sacular aneurysm (branch points of circle of Willis)

Life threatening, thunderclap headache "worst of my life"



16

Intra-Parenchymal Hemorrhage (Intracerebral hemorrhage)

-- what type of aneurysm?

Deep hematoma which occurs spontaneously
Usually associated with long standing hypertensive cerebral vascular disease

Charcot-Bouchard Micro aneurysm

17

Acute Infarct --> Focal Ischemia

results in what type of necrosis?

Liquefactic necrosis

18

Global cerebral ischemia

etiologies:
type of necrosis?


Etiologies: Low perfusion (atherosclerosis), decreased blood flow (acute cardiogenic shock); Chronic hypoxia

Pathological manifestation is laminar necrosis

19

Lacunar Infarct

pathognominc for what type of vascular disease?

particularly with what vessels?

Pathognomic for HTNsive chronic cerebral vascular disease

small penetrating vessls of the circle of Willis that come off at 90 degress (vulnerable to turbulent flow)

20

which areas of the brain are particularly vulnerable in global ischemia ?

Pyramidal neurons of the cerebral cortex (layers 3, 5, 6)

Pyramidal neurons of the hippocampus

Purkinje layer of the cerebellum --

21

histopath appearance of:
acute ischemia

subacute ischemia

Remote ischemia

acute: red/dead neurons

Subacute: edema/foamy

Remote: cavitation