Neuropathology

Front 1

Astrocyte characteristics
(6)

Back 1

1. Envelope basement membranes of endothelial cells in capillaries, neurons, synapses
2. Maintain BBB
3. Metabolism of some NTs
4. Buffer K+ concentration in the ECM
5. Proliferate in injury (gliosis)
6. Contain GFAP, used in immunostaining

Front 2

Oligodendrocyte characteristics
(2)

Back 2

1. CNS myelin formation
2. Myelenate 30-50 axons each

Front 3

Ependymal cell characteristics
(4)

Back 3

1. Ciliated cells
2. Line the ventricles
3. Forms barrier between CSF and brain
3. Choroid plexus is an extension of these cells - makes CSF

Front 4

Microglia characteristics
(4)

Back 4

1. Part of the macrophage system
2. Small rod-shaped nuclei
3. Convert into macrophages during CNS infection (mainly in viral)
4. Involved in CNS lymphoma

Front 5

Brain vs Body differences
(7)

Back 5

1. Gliosis vs scarring
2. Brain has autoregulation of blood flow
3. Little regeneration of cells in brain injury
4. Brain has no lymphatics
5. Brain has limited immune surveillance
6. Brain is in an enclosed rigid space
7. Brain floats in CSF

Front 6

Blood Brain Barrier characteristics

Back 6

Made of tight endothelial junctions that may become leaky in inflammation.
Prevent drugs/blood cells from entering CSF

Front 7

Hydrocephalous

Back 7

Accumulation of CSF in the brain due to problems with drainage, poor CSF absorption at the arachnoid villi, or an overproduction of CSF

Front 8

Communicating hydrocephalous

Back 8

Blockage is extraventricular, so all of the ventricles are equally effected and enlarged

Front 9

Non-communicating hydrocephalous

Back 9

Due to CSF obstruction within the ventricular system so one or more the ventricles becomes enlarged

Front 10

Ex vacuo hydrocephalous

Back 10

Overproduction of CSF in brain atrophy to fill the space
Seen in Alzheimer's, non-pathogenic

Front 11

Vasogenic cerebral edema

Back 11

Leaking of fluid from blood vessels into the extracellular space
Associated with BBB breakdown
Mainly effects white matter

Front 12

Cytotoxic cerebral edema

Back 12

Swelling and leaking of cells into the extracellular space
Due to increased intracellular Na and K
Mainly effects gray matter

Front 13

Interstitial cerebral edema

Back 13

CSF enters the extracellular space of the periventricular white matter
Clinically rare

Front 14

Increased intracranial pressure

Back 14

Monroe-Kellie hypothesis: bony calvarium limits intracranial capacity - as volume increases, pressure increases.
When any of the 3 (paranchyma, blood, CSF) increase in volume it is at the cost of the other 2.

Front 15

CPP = MAP - IAP

Back 15

Cerebral perfusion pressure (blood to the brain) =
mean arterial pressure - intracranial pressure
**if intracranial pressure is too high, blood can not get to the brain

Front 16

Herniation

Back 16

Intracranial pressure increases and the brain will herniate around the dural structures, foramen magnum, or skull defects

Front 17

Subfalcial herniation

Back 17

Herniation across the falx cerebri - compression of the ACA

Front 18

Transtentorial herniation

Back 18

Medial temporal lobe herniates over the tentorium and compresses the ipsilateral occulomotor nerve and cerebral peduncle and PCA

Front 19

Tonsillar herniation

Back 19

Brain protrudes through foramen magnum compressing the cranial nerves and brainstem

Front 20

Upward herniation

Back 20

Cerebellum herniates upward over the tentorium

Front 21

Transcalvarial herniation

Back 21

Brain protrudes through a skull defect

Front 22

Treatment of intracranial pressure

Back 22

1. Raise the head 30 degrees
2. Intubate and hyperventilate to increase O2 and decrease perfusion
3. Hyperosmotic agents to draw fluid out of the brain
4. Drain the ventricles manually
5. Barbiturate induced coma

Front 23

Subdural hematoma

Back 23

Tearing of bridging veins that go to the sagittal sinus
Increased risk with brain atrophy
Acute subdural hematoma associated with contusions
Shape is uneven and non-lens-like

Front 24

Epidural hematoma

Back 24

Tearing of meningeal arteries in a skull fracture
Disects the dura away from the skull
Creates a lens-shaped collection of blood

Front 25

Brain contusion locations

Back 25

Typically at the inferior frontal lobe and the temporal poles where the brain hits either the fossa or the sphenoid ridge