Path- 1: Neuro/cytology

Question 1

What happens to the Schwann cells in segmental demyelination?

Answer 1

They have either a disfxn (in hereditary motor or sensory neuropathy) or damage (like in Guillian Barre)

Question 2

What happens to the axons in segmental demyelination?

Answer 2

NOTHING

Question 3

What do you see on a microscope with chronic de- and remyelination?

Answer 3

Onion bulbs

“Pissed off shrek in plastic wrap.”

Question 4

Which cells are absolutely ESSENTIAL for the regeneration of the injured PNS?

Answer 4

Schwann cells

Question 5

What is the pattern of demyelinatiopn in multifocal motor neuropathy?

Answer 5

Segmental demyelination of a motor axon

Question 6

In axonal degeneration and muscle atrophy, what happens first and second?

Answer 6

There is primary destruction of the axon and a secondary loss of the myelin sheath.

Question 7

Define: This is a bundle of muscle fibers that lose innervation from a nerve, so they become small and angular.

Answer 7

Grouped atrophy

Question 8

What is the process called when there is axonal injury due to transection?

Answer 8

Wallerian dgeneration

Question 9

What happens in wallerian degeneration at the distal portion of the nerve?

Answer 9

axon breaks down within a day –> Schwann cells begin to destroy myelin and engulf axon fragements –> macrophages FEAST

Question 10

What happens in wallerian degeneration at the proximal portion of the nerve?

Answer 10

there is degeneration for only 2 or 3 distal internodes, undergoes regenerative activity

Question 11

What happens to the muscle in axonal transections?

Answer 11

Atrophy

Question 12

What forms on the nerve “stump” as far as the reinervation process?

Answer 12

It forms clusters of small axons with thin myelin

Question 13

Define: this is a benign, encapsulated neoplasm that has neoplastic proliferation in the endoneurium with the perineurium forming the capsule. Typically forms around VIII.

Answer 13

Schwannoma

Question 14

What are the clinical Sx of Guillian Barre?

Answer 14

Can cause resp arrest, ascending paralysis, segmental demyelination of the spinal and peripheral nerves (primary lesion)

it’s like when Neo sticks his hand in that mirror and that mirror shit climbs up his body and then down his troat. Crazayyyy

Question 15

What causes Guillian Barre?

Answer 15

immune mediated response due to infection of Capylobacter jejune, CMV, mycoplasma pneumo or vaccines.

Question 16

Is nerve conduction velocity increased or decreased in Guillian Barre?

Answer 16

Decreased

Question 17

Is CSF protein increased or decreased in Guillian Barre?

Answer 17

increased

Question 18

What causes HMSN’s?

Answer 18

mutations in genes involved in peripheral nerve function

Question 19

What is the most femousestestest type I HMSN?

Answer 19

Charcot Marie Tooth

Question 20

Who does CMT affect?

Answer 20

KIDS or young adults

Question 21

What is the inheritance of CMT?

Answer 21

AD

Question 22

What is the clinical presentation of CMT?

Answer 22

Progressive paralysis below knee (peronial muscular atrophy), sensorimotor deficit with orthopedic deficit such as pes cavus, notmal life span

Question 23

What type of HMSN of Dejerine Sottas?

Answer 23

HMSN tpye III

Question 24

Where in the doby does Dejerine Sottas affect?

Answer 24

both the trunk and the limb muscles

Question 25

What is the inheritance of Dejerine Sottas?

Answer 25

AR

Question 26

What is the clinical presentation of Dejerine Sottas?

Answer 26

infintile onset (1-12mo), large peripheral nerves, demyelination w/onion (skrek) bulbing, more severe than CMT

Question 27

What are the suspected causes of peripheral neuopathies in diabetes tpye 2?

Answer 27

Polyol pathway and non-enzymatic glycosylation

Question 28

What is the clinical presentation of peripheral neuopathy in DM type 2?

Answer 28

most common symmetiric neuropathy involving both sensory and motor nerves, decreased sensation in the distal extremtiies, decreased paiin --> ulcers, ANS dysfxn (including NO BONERS OH NOOOOOOOOOOOOOOOOOO)

Question 29

Tumors usually cause what types of dysfxns with nerves?

Answer 29

Compression

Question 30

What process is Lambert-Eaton syndrome assocaited with?

Answer 30

paraneoplastic process, 60% of the time it's small cell CA of the lung

Question 31

What are the Sx of LES?

Answer 31

proximal muscle weakness w/autonomic dysfxn

Question 32

Does LES pt's repsond to anti-AchE's? Why?

Answer 32

NO. this is an autoimmunity to Ca++ channels, not to the Ach channels (like in MG).

Question 33

Is there an increase or decrease in nerve conduction with repetitive stimualtion?

Answer 33

Increase (you're allowing more Ca++ to enter the presynaptic terminal)

Question 34

What are traumatic neuromas?

Answer 34

They're misaligned or tangles segments that occur in a random fashion after attemped nerve REGENERATION post-truama

Question 35

Though neurons vary in size/shape/structure, what 4 things do all neurons have?

Answer 35

Microtubules, neurofilaments, golgi, and rER

Question 36

Do mature neurons divide?

Answer 36

No

Question 37

Since mature neurons dont divide, what does this mean clinically?

Answer 37

Lose neurons with age, neurons do not regenerate over long distances in the CNS, infarcts that transect the internal capsule --> permanent motor deficits

Question 38

What are Nissl bodies?

Answer 38

rER basophilic granules in the cytopasm of the neuron

Question 39

What is neuromelanin?

Answer 39

Some neurons of the substantia nigra, the locus ceruleus, dorsal motor nucleus of X, and median raphe nucleus contain dark pigment

Question 40

What are the 2 changes in chomatolysis in response to neuronal injury?

Answer 40

1. cytoplasm expands and Nissle substances disperse near the plasma membrane 2. Nucleus becomes eccentric (like oh shit oh shit oh shit)

Question 41

What happens in neuonophagia?

Answer 41

Injuries that kill neurons create debris and elicit phagocytosis by microglial cells Microglia are like small sharks feeding off a dying whale. This makes me sad. DYING WHALES IS HORRIBLE

Question 42

What are the signs of atrophied neurons (Creutzfeld-Jacob disease)?

Answer 42

Neurons shrivel and become hyperchomatic

Question 43

What bug causes intranuclear inclusions with prominent clear halos?

Answer 43

CMV

Question 44

Which bug causes cytoplasmic "negri bodies" which resemble RBC's?

Answer 44

Rabies

Question 45

Which pt's have Lewy bodies?

Answer 45

Parkinsons pts

Question 46

Which infections cause Cowdry bodies?

Answer 46

Herpes

Question 47

Astrocytes contain which important staining marker?

Answer 47

GFAP

Question 48

What is the response of astrocytes to trauma?

Answer 48

Proliferate locally (astrocytosis or reactive gliosis)

Question 49

Astrocytosis is the most important histopathologic indicator of what?

Answer 49

CNS injury

Question 50

What is the result of astrocytosis?

Answer 50

Glial scar

Question 51

What are the characteristics to astrocytosis?

Answer 51

hypertrophy, hyperplasia, cytoplasm stains bright pink (gemistocytic astrocytes).

Question 52

Long stanging gliosis associated with rosenthal fibers are associeted with what?

Answer 52

Cerebellar pilocytic astrocytoma

Question 53

What is it called when astrocytes undergo neoplastic transformation resulting ina tumor?

Answer 53

Astrocytosis/glioma

Question 54

What are corpora amylacea?

Answer 54

5-50 micrometer basophils and amorphous structes which accumulate with normal agins int eh subpial and subependymal regions, represent degenerative change in astrocytes

Question 55

Alzheimer type II astrocytes occur in which pts?

Answer 55

pts with long standing hyperammonia, wilsons or hereditary metabolic diseases of the urea cycle

Question 56

What are the fxns of glia/astrocytes?

Answer 56

act as BBB, metabolic buffers, repair and scar formation

Question 57

What are the fxns of oligodendrocytes?

Answer 57

myelination of multiple axons

Question 58

What is the fxn of ependymal cells?

Answer 58

Line CSF-filled spaces, regulate CSF transport

Question 59

Some viral infections target ependymal cells during gestation which may result in what condition?

Answer 59

Hydrocephalus

Question 60

Where are ependymomas?

Answer 60

tumors usually in the ventricles but can appear in spinal cord

Question 61

What is the main fxn of microglia?

Answer 61

macrophages of the CNS which proliferate after injury

Question 62

What types of injuries cause red neurons to ARISE?

Answer 62

Acute CNS hypoxia/ischemia think red neurons --> red blood

Question 63

What are the characteritics of red neurons?

Answer 63

cell body atrophy, pyknosis of the nucleus, loss of Nissl substance, and intense eosinophilia of the cytoplasm

Question 64

When are the subacute and chronic degeneration of neurons seen?

Answer 64

In necrosis/progressive disease, seen early as reactive gliosis, lasts 2 weeks and longer

Question 65

What are axonal reactions?

Answer 65

they're just the axonal regeneration, increased protein sysnthesis