Lecture 7 -- CNS Path: categories of injury

Question 1

what happens you cut an axon:

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

Answer 1

Site of the cut - swelling

Proximal – central chromatolysis

Distal – Wallerian Degeneration

Question 2

Astrocytes:

role –

Answer 2

Supportive, detoxifying role
Astrolytic proliferation to injury
accumuatlion of GFAP

Question 3

Astrocytic reactions:
- what protein accumulates with reactive astrocytes?

3 other reactions involving astrocytes

Answer 3

GFAP, Gemistocytic Astroycytes

Rosenthal Fibers

Corpora Amalacea

Alz Type 2 Astrocytosis

Question 4

Astrocytic reactions:

Answer 4

Rosenthal Fibers —

Corpora Amalacea — age related start accumulations

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

Question 5

Oligodendrocyte histopath

Answer 5

Inclusions – JC virus in PML

Synuclein positive oligodendroglia inclusion in multiple system atrophy

Question 6

two types of brain edema –

differences between the two

Answer 6

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;

Question 7

three types of brain herniations:

Answer 7

Transtentorial (Uncal) herniation

Cerebellar Tonsillar herniation

Subfalcine/Cingulate Herniation

Question 8

Transtentorial (Uncal) herniation

• what is it?
  physical findings -

Answer 8

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

Question 9

Cerebellar Tonsillar herniation

what is it?
consequences?

Answer 9

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

can quickly lead to cardiopulmonary arrest

Question 10

Subfalcine/Cingulate Herniation

what is it?

Answer 10

displacement of the cingulate gyrus under the falx cerebri.

Less Life threatening than previous two

may have LE weakness

Question 11

Head trauma – Parenchymal brain injury: contusions –

what is a contusion – manifesations?

difference between coup contusion and contra coup contussion

Answer 11

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

Question 12

Vascular brain Injury:

what are the two types of hematoma?

Answer 12

Epidural Hematoma

Subdural Hematoma

Question 13

Epidural Hematoma –

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

Answer 13

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

Question 14

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

Answer 14

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

Question 15

Subarachnoid Hemorrhage (SAH) —

where does it typically occur?
what type of aneurysm?

Clinical presentation?

Answer 15

Ruptured sacular aneurysm (branch points of circle of Willis)

Life threatening, thunderclap headache “worst of my life”

Question 16

Intra-Parenchymal Hemorrhage (Intracerebral hemorrhage)

– what type of aneurysm?

Answer 16

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

Charcot-Bouchard Micro aneurysm

Question 17

Acute Infarct –> Focal Ischemia

results in what type of necrosis?

Answer 17

Liquefactic necrosis

Question 18

Global cerebral ischemia

etiologies:
type of necrosis?

Answer 18

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

Pathological manifestation is laminar necrosis

Question 19

Lacunar Infarct

pathognominc for what type of vascular disease?

particularly with what vessels?

Answer 19

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)

Question 20

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

Answer 20

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

Pyramidal neurons of the hippocampus

Purkinje layer of the cerebellum –

Question 21

histopath appearance of:
acute ischemia

subacute ischemia

Remote ischemia

Answer 21

acute: red/dead neurons

Subacute: edema/foamy

Remote: cavitation