Neuropathology (Martin)

Question 1

Histology of acute neuronal injury

Answer 1

12-24 hr injury; “red neurons” ; loss of nissl substance w intense eosinophilia

Question 2

Histology of axonal reaction

Answer 2

“central chromatolysis” nissl removed from center of cell to periphery

Question 3

3 major pathologies associated with intracytoplasmic inclusions

Answer 3

1. rabies - negri bodies
2. alzheimer - neurofibrillary tangles
3. parkinson - lewy bodies

Question 4

the intracytoplasmic “wear & tear” pigment

Answer 4

lipofuscin; golden brown pigment that accumulates with age

Question 5

the major pathology associated with intranuclear inclusions

Answer 5

herpes - cowdry body

Question 6

the pathology that presents with both intracytoplasmic and intranuclear inclusions

Answer 6

CMV “owl eyes”

Question 7

What is the most important histopathological indicator of CNS injury?

Answer 7

gliosis AKA astrogliosis; hypertrophy and hyperplasia of astrocytes; dysfunction to BBB

Question 8

Gemistocytes

Answer 8

a state of astrocytes in response to injury (reactive); enlarged and becomes “bright pink”

Question 9

Rosenthal fibers

Answer 9

thick, elongated, worm-like or “corkscrew” eosinophilic bundle found in astrocytes; contains alpha/beta-crystalline, HSP27 and ubiquitin; commonly found in pilocytic astrocytomas - benign slow growing tumor

Question 10

pilocytic astrocytoma

Answer 10

slowing growing tumor that arises from astrocytes

Question 11

corpora amylacea

Answer 11

granular bodies generated by astrocytes; polyglucosan bodies PAS+; increases with age (degenerative process)

Question 12

chromatolysis

Answer 12

neuronal cell body reaction to injury; swollen cells body, eccentric displacement of nucleus and loss of nissl body

Question 13

cell markers of microglia

Answer 13

CR3 & CD68; macrophages of the CNS

Question 14

Where would you typically see microglial nodules?

Answer 14

aggregated around small foci of necrosis in the brain

Question 15

Where you typically see neurophagia?

Answer 15

microglia thats congregated around cell bodies of dying neurons; engulfing the dying neurons

Question 16

cerebral edema

Answer 16

accumulation of fluid in brain parenchyma; two types: vasogenic and cytotoxic

Question 17

vasogenic edema

Answer 17

increase EXTRAcellular fluid due to BBB dysfunction; often follows ischemic injury

Question 18

Cytotoxic edema

Answer 18

increase INTRAcellular fluid; can lead to herniation

Question 19

What is a major complication to hydrocephalus

Answer 19

papilledema; increase in intracranial pressure

Question 20

the 3 possible pathogenesis to hydrocephalus?

Answer 20

1. increased production - choroid plexus papilloma
2. obstruction - many causes
3. decreased absorption - outflow obstruction

Question 21

Choroid plexus papilloma

Answer 21

rare; increased production of CSF (max its absorption capacity) on histology will see a thick fibrous core/stalk

Question 22

What are 2 common infectious processes that can cause communication (non-obstructive) hydrocephalus?

Answer 22

TB and neurosyphilis; causes pyogenic meningitis covering the brainstem and cerebellum; no single point of obstruction (symmetrically dilated ventricles)

Question 23

What would you see on a brain MRI if cysticercosis was the cause of hydrocephalus?

Answer 23

many calcified cysts throughout the cerebral tissue

Question 24

Aqueductal stenosis causing which type of hydrocephalus?

Answer 24

obstructive (non-communicating)

Question 25

Hydrocephalus ex-vacuo

Answer 25

dilation of the ventricle due to atrophy of the brain; can be seen in chronic neurodegenerative disorders; CSF will be normal

Question 26

Normal pressure hydrocephalus (NPH)

Answer 26

symmetric hydrocephalus in older adults; drainage of CSF is blocked gradually; CSF is normal but the enlarged ventricles exert pressure on brain and patient may exhibit dementia-like symptoms; can be reversed but if often misdiagnosed doe Alzheimers to Parkinson's. Triad: "wet, wacky and wobbly" - urinary incontinence - gait disturbance - dementia

Question 27

Symptoms of "wet, wacky and wobbly"

Answer 27

Normal pressure hydrocephalus (NPH); Triad: of urinary incontinence, gait disturbance and dementia

Question 28

What is the symptomatic triad seen in Normal pressure hydrocephalus (NPH)?

Answer 28

urinary incontinence, gait disturbance and dementia

Question 29

Which cranial nerve will have the highest risk of injury in a transtentorial herniation?

Answer 29

CN3 - will see dilated pupil and impaired eye movement; Kernohan's notch phenomenon

Question 30

Why is a tonsillar herniation typically life threatening?

Answer 30

cerebellar tonsils displaced through foramen magnum and compressed the respiratory and cardiac centers of the brainstem

Question 31

Kernohan's notch phenomenon

Answer 31

compression of the cerebral peduncle against the tentorim cerebella due to a transtentorial herniation; IPSILATERAL hemiparesis or hemiplegia due to a false localizing sign; will also see CNIII compression with a blown pupil

Question 32

CNS infarct results in which type of necrosis?

Answer 32

liquefactive

Question 33

Hygroma

Answer 33

separation of arachnoid from dura due to contraction of underlying brain parenchyma and infarct

Question 34

When is neural tube closure typically complete in gestation?

Answer 34

Day 28

Question 35

Spina bifida occulta

Answer 35

asymptomatic bony defect; folate acid deficiency

Question 36

What is the most common lumbosacral NTD?

Answer 36

Myelomeningocele; CNS tissue through the defect in the vertebral column

Question 37

Fetal alcohol syndrome typically causes what forebrain anomaly in the newborn?

Answer 37

microcephaly; small head circumference

Question 38

Arnold-Chiari malformation

Answer 38

occurs in the small posterior fossa; type II - more severe with downward extension of cerebellar vermis through the foramen magnum

Question 39

Dandy-Walker malformation

Answer 39

enlarged posterior fossa - expanded floorLESS 4th ventricle; cerebellar vermis is ABSENT

Question 40

Syringomyelia (syrinx)

Answer 40

fluid-filled cleft-like cavity in the inner portion of the cord; isolated pain and temperature sensation of the upper extremities bilaterally

Question 41

Which spinal cord pathology will produce isolated pain and temperature sensation of the upper extremities b/l?

Answer 41

Syringomyelia (syrinx)

Question 42

Basilar skull fracture

Answer 42

orbital and/or mastoid hematomas; will see CSF drainage from ears or nose; hemotympanum (blood in ears); battle's sign behind ears and raccoon eyes

Question 43

Concussion

Answer 43

clinical syndrome with altered consciousness secondary to a head injury

Question 44

What is the most common location for contusions?

Answer 44

frontal lobes/orbital ridges and temporal lobes

Question 45

When does the baby typically pass from shaken baby?

Answer 45

don't die instantly; after hours of brain swelling; look for old bleeding - iron with Prussian blue stain

Question 46

Chronic traumatic encephalopathy (CTE)

Answer 46

repeated concussive injury associated with playing sports; deposition of tau proteins around small blood vessels of the cortex, typically at the sulcal depths; will see a decrease in the parenchymal overtime

Question 47

Which vessel is typically injured in an epidural hematoma?

Answer 47

artery - middle meningeal artery

Question 48

Which vessel is typically injured in a subdural hematoma?

Answer 48

veins - venous blood