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My Pathoma Unit 3 > Chapter 17 CNS > Flashcards

Chapter 17 CNS Flashcards

1
Q

Invagination of the neural plate early in gestation forms what?

A

The neural tube

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2
Q

What do the following structures eventually form?Wall of the neural tubeHollow lumenneural crest

A

Wall of the neural tube forms CNS tissueHollow lumen forms ventricles and spinal cord canalNeural crest forms the PNS

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3
Q

What nutritional deficiency is associated with NTD?

A

Folate PRIOR to conception

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4
Q

What marker in maternal blood and amniotic fluid is used to test for neural tube defects?

A

elevated AFP levels in amniotic fluid and maternal blood

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5
Q

What maternal complication does does anencephaly lead to?

A

polyhydramnios since fetal swallowing of amniotic fluid is impaired

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6
Q

How does spina bifida and spina bifida occulta present?

A

Spina bifida presents as with cystic protrusion of the underlying tissue through the vertebral defectspina bifida occulta presents as a dimple or patch of hair overlying the vertebral defect

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7
Q

What is the difference between a miningocele and a meningomyelocele?

A

Meningocele - protrusion of meningesMeningomyelocele - protrusion of meninges and spinal cord

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8
Q

What is the cerebral aqueduct?

A

channel that drains CSF from the 3rd to the 4th ventricle

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9
Q

What does cerebral aqueduct stenosis lead to?

A

hydrocephalus

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10
Q

How does CSF move from lateral to third ventricle?

A

interventricular Foramen of monro

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11
Q

How does CSF flow from the 4th ventricle into the subarachnoid space?

A

Via the foramina magendie and luschka

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12
Q

How does congenital cerebral aqueduct stenosis present in newborns?

A

Presents with enlarging head circumference due to dilation of the ventricles (Cranial suture lines are not fused)

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13
Q

Where is CSF produced?

A

Choriod plexus

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14
Q

What is the Dandy-Walker Malformation, and how does it present?

A

Congenital failure of the cerebellar vermis to develop. Presents as a massively dilated 4th ventricle (posterior fossa) with an absent cerebellum; often accompanied by hydrocephalus

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15
Q

What is the Arnold-Chiari Malformation Type I and II?

A

Type I is usually asymptomatic Type II is congenital downward displacement of the cerebellar vermis and tonsils though the foramen magnum

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16
Q

What does an Arnold-Chiari type II malformation lead to?

A

Commonly results in hydrocephalus due to obstruction of CSF flow. It is often associated with meningomyelocele and syringomyelia

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17
Q

What is syringomyelia?

A

Cystic degeneration of the spinal cord

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18
Q

How does syringomyelia commonly arise?

A

With trauma or in association with a type 1 arnold-chiari malformation

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19
Q

At what spinal level does syringomyelia generally occur?

A

C8-T1

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20
Q

How does syringomyelia present?

A

Sensory loss of pain and temp with sparing of fine touch and position sense in the upper extremities (“cape like” distribution)

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21
Q

What spinal cord structure is involved in syringomyelia?

A

anterior white commisure of the spinothalamic tract with sparing of the dorsal column

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22
Q

What addition symptoms can occur in syringomyelia is the syrinx expands into other spinal structures?

A

Muscle atrophy and weakness with decreased muscle tone and impaired reflexes- due to damage to lower motor neurons of the anterior hornHorner syndrom with ptosis, miosis, and anhydrosis due to disruption of the lateral horn of the hypothalamospinal tract

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23
Q

Where does polio initially infect? how does it spread to CNS?

A

Initially infects small bowel and oropharynx giving you constitutional symptoms then eventually spreads to CNS by the blood and infects anterior horn

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24
Q

What spinal cord structure is damages in poliomyelitis?

A

damage to the anterior motor horn due to poliovirus infection

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25
Q

How does poliomyelitis present?

A

with lower motor neuron signs- flaccid paralysis with muscle atrophy, fasciculations. weakness with decreased muscle tone, impaired reflexes, and negative babinski sign (downgoing toes)

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26
Q

What is Werding-Hoffman Disease and how does it present?

What is the inheritance pattern?

A

Inherited degeneration of the anterior motor horn: autosomal recessive. Presents as a “floppy baby”; death occurs within a few years after birth

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27
Q

What types of neurons are affected in Amyotrophic lateral sclerosis?

A

Upper and lower motor neurons of the corticospinal tract

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28
Q

What does anterior horn degeneration in ALS lead to?

A

leads to lower motor neuron signs - flaccid paralysis with muscle atrophy, fasciculations, weakness with decreased muscle tone, impaired reflexes, and negative babinski sign.

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29
Q

What does lateral corticospinal tract degeneration lead to in ALS?

A

Leads to upper motor neuron signs - spastic paralysis with hyperreflexia, increased muscle tone, and positive babinski sign

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30
Q

What is an early sign in ALS?

A

atrophy and weakness of hands

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31
Q

What distinguishes ALS from syringomyelia?

A

Lack of sensory impairment

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32
Q

Are most cases of ALS sporadic or inherited?

A

sporadic occurring in middle aged adults

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33
Q

What mutation is implicated in familial ALS?

A

Zinc-copper superoxide dismutase (SOD1) leads to free radical injury (O2 –> H2O2)

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34
Q

What structures are involved in Friedreich Ataxia?

A

Degeneration of the Cerebellum and spinal cord

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35
Q

What does degeneration of the cerebellum lead to in friedreichs astaxia?

A

ataxia

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36
Q

What does degeneration of multiple spinal cord tracts lead to in friedreichs ataxia?

A

loss of vibratory sense and proprioception, muscle weakness in the lower extremities, and loss of deep tendon reflexes

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37
Q

How is Friedreichs ataxia inherited and what is the defect?

A

AR, due to expansion of an unstable trinucleotide repeat GAA in the frataxin gene

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38
Q

What is frataxin and what does loss result in?

A

Frataxin is essential for mitochondrial iron regulation; loss results in iron buildup with free radical damage

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39
Q

When does Friedreichs ataxia present?

A

in early childhood; patients are wheelchair bound within a few years

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40
Q

What complication is friedreichs ataxia associated with?

A

hypertrophic cardiomyopathy

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41
Q

What are the leptomeninges?

A

The pia and the arachnoid?

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42
Q

What layers are inflammed in meningitis?

A

the leptomeninges

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43
Q

What are the 3 most common infectious agents leading to meningitis in neonates?

A

Group B strepE coliListeria Monocytogenes

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44
Q

What is the most common viral cause of meningitis in children?

A

Cocksackievirus (fecal-oral transmission)

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45
Q

What is the most common bacterial cause of meningitis in children and teens?

A

N Meningitidis

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46
Q

What is the most common bacterial cause of meningitis in adults and elderly?

A

Steptococcus Pneumoniae

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47
Q

What is the most common bacterial cause of meningitis in nonvaccinated infants?

A

H. Influenza

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48
Q

What is the most common cause of meningitis in immunocompromised patients?

A

Fungi

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49
Q

What is the classic presenting triad of meningitis and what are some other associated symptoms?

A

Classic triad - headache, nuchal rigidity, and fever Other associated - photophobia, vomiting and altered mental status

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50
Q

How is diagnosis of meningitis confirmed?

A

Lumbar puncture

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51
Q

What spinal level is an LP performed at and what space is samples?

A

between L4 and L5 (level of iliac crest) and samples subarachnoid space

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52
Q

Where does the spinal cord end?

A

L2

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53
Q

What are the CSF findings in bacterial meningitis?

A

neutrophils and decreased glucose (bacteria consume it)gram stain and culture often identify the causative organism

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54
Q

What are the CSF findings in viral meningitis?

A

lymphocytes with NORMAL CSF glucose

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55
Q

What are the CSF findings in fungal meningitis?

A

lymphocytes with decreased CSF glucose

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56
Q

What is a normal level of CSF glucose?

A

~2/3 of serum glucose

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57
Q

What percentage of cerebrovascular disease is due to ischemia and what percent is due to hemorrhage?

A

ischemia 85%Hemorrhage 15%

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58
Q

How fast to neurons undergo necrosis due to ischemia?

A

3-5 min

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59
Q

Which cause of meningitis is usually associated with complication and why?

A

bacterial meningitis due immune reaction creating massive amounts of exudate and pus

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60
Q

What complications seen with bacterial meningitis?

A

Death - herniation secondary to cerebral edema hydrocephalus, hearing loss, and seizures are all related to fibrosis caused by the healing process

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61
Q

Name four causes of global ischemia to the brain

A

1 Low perfusion (atherosclerosis)
2 Acute decrease in blood flow (Cardiogenic shock)
3 Chronic Hypoxia (anemia)
4 Repeated episodes of hypoglycemia (insulinoma)

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62
Q

What do the clinical features of global ischemia depend on?

A

duration and magnitude of the insult

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63
Q

What does mild global ischemia result in and what is the classic example?

A

transient confusion with prompt recovery. Classic example is insulinoma

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64
Q

What does severe global ischemia lead to?

A

results in diffuse necrosis which most dont survive. those who do survive are left in a vegetative state

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65
Q

What does moderate global ischemia lead to?

A

infarcts in watershed areas between the anterior and middle cerebral arteries and damage to highly vulnerable regions

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66
Q

Name 3 highly vulnerable locations for moderate global ischemia

A

1 pyramidal neurons of the cerebral cortex (layers 3,5,6) leads to laminar necrosis - known as cortical laminar necrosis
2 Pyramidal neurons of the hippocampus (temporal lobe)- important in long term memory
3 Purkinje layer of the cerebellum - integrates sensory perception with motor control

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67
Q

What is an ischemic stroke and how does it differ from a transient ischemic event (TIA)?

A

regional ischemia to the brain that results in focal neurologic deficits lasting > 24 hours. If symptoms last < 24 hours the event is termed a TIA

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68
Q

What are the 3 subtypes of ischemic strokes?

A

thrombotic, embolic, and lacunar

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69
Q

What are thrombotic strokes due to?

A

rupture of an atherosclerotic plaque

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70
Q

Where does atherosclerosis tend to develop?

A

at branch points ( eg bifurcation of internal carotid and middle cerebral artery in the circle of willis)

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71
Q

What type of infarct does a thrombotic stroke cause?

A

Pale. The body with try and lyse this but since the plaque is ruptured the thrombosis with continue to reform

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72
Q

What is the most common source of emboli in an embolic stroke?

A

left side of the heart (eg atrial fibrillation)

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73
Q

What artery is usually involved in a hemorrhagic stroke?

A

middle cerebral

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74
Q

What type of infarct does an embolic stroke result in?

A

hemorrhagic infarct at the periphery of the cortex. Thrombus eventually gets lysed and blood goes back in

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75
Q

What do lacunar strokes occur secondarily to?

A

hyaline arteriosclerosis; a complication of HTN (benign HTN or diabetes)

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76
Q

What vessels are usually involved in lacunar strokes? and what is the result?

A

SMALL vessels, most commonly the lenticulostriate vessels (Branches of the MCA) resulting in small cystic areas of infarction

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77
Q

What two major areas of the brain are involved in lacunar strokes and what are the consequences?

A

Internal capsule involvement leads to a pure motor strokeThalamus involvment leads to pure sensory stroke

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78
Q

What type of necrosis do ischemic strokes lead to?

A

liquefactive

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79
Q

What is an early microscopic finding in ischemic strokes?

A

Eosinophillic change in the cytoplasm of neurons (RED NEURONS) occurs after about 12 hours

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80
Q

What cells cause necrosis in ischemic strokes?

A

Neutrophils then microglial cells

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81
Q

What is gliosis and when does it occur after an infarct?

A

Gliosis is reactive astrocytes that will line the cystic space with gliotic connective tissue similar to granulation tissue

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82
Q

How long does it take to form a fluid filled cyst after an ischemic stroke?

A

about 1 month

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83
Q

What is an intracerebral hemorrhage?

A

Bleeding into the brain parenchyma

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84
Q

What are the classic cause of intracerebral hemorrhage?

A

rupture of Charcot-Brouchard microaneurysms of the lenticulostriate vessels

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85
Q

What is intracerebral hemorrhage a complication of and what structures are most commonly affected?

A

Complication of hypertension; treatment of hypertension reduces the incidence by halfBasal ganglia is the most common site

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86
Q

How do intracerebral hemorrhage present?

A

severe headache, nausea, vomiting, and eventual coma

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87
Q

How does a subarachnoid hemorrhage present?

A

presents as a sudden headache (“worst of my life”) with nuchal rigidity

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88
Q

What does lumbar puncture show in subarachnoid hemorrhage?

A

xanthochromia (yellow hue due to bilirubin breakdown)

89
Q

What is the most frequent cause of subarachnoid hemorrhage and what are two other causes?

A

Most frequently (85%) due to rupture of a berry aneurysm; other causes include AV malformations and an anticoagulated state.

90
Q

Describe a berry aneurysm and the most frequent location

A

Berry aneurysms are thin walled saccular outpouching that lack a media layer, increasing the risk for ruptureMost frequently located in the anterior circle of willis at branch points of the anterior communicating artery

91
Q

What conditions are associated with berry aneurysm and subarachnoid hemorrhages?

A

Marfan syndrome and autosomal dominant polycystic kidney disease

92
Q

Where does blood collect in an epidural hematoma?

A

Collection of blood between the dura and the skull

93
Q

What is the classic cause of an epidural hematoma?

A

fracture of the temporal bone with rupture of the middle meningeal artery; bleeding separates the dura from the skull.

94
Q

What is seen on CT with an epidural hematoma?

A

a lens shaped lesion

95
Q

Why is an epidural hematoma called the talk and die syndrome?

A

Because a lucid period may precede neurological deficits

96
Q

What is a lethal complication from epidural hematoma?

A

herniation

97
Q

Where does blood collect in a subdural hematoma?

A

blood underneath the dura; blood covers the surface of the brain

98
Q

What are subdural hematomas due to?

A

tearing of bridging veins that lie between the dura and arachnoid; usually arises with trauma

99
Q

What is seen on CT with a subdural hematoma?

A

A crescent shaped lesion. also is the only type where you will see a bleed on the bottom of the brain

100
Q

How does a subdural hematoma present?

A

presents with progressive neurological signs as blood builds up.

101
Q

Which population has an increased rate of subdural hematomas and why?

A

increased rate of occurrence in the elderly due to age related cerebral atrophy which stretches the veins

102
Q

What is the lethal complication of subdural hematomas?

A

herniation

103
Q

What does tonsillar herniation involve? what does it cause?

A

the displacement of the cerebellar tonsils into the foramen magnum which causes compression of the brain stem and leads to cardiopulmonary arrest

104
Q

What does subfalcine herniation involve? what does it cause?

A

displacement of the cingulate gyrus under the falx cerebri which causes compression of the anterior cerebral artery which leads to infarction.

105
Q

What does uncal herniation involve? what does it cause?

A

displacement of the temporal lobe uncus under the tentorium cerebelli which leads to
1 compression of CN III leading to the eye moving down and out and a dilated pupil (first)
2 Compression of posterior cerebral artery leads to infarction of occipital lobe (contralateral homonymous hemianopsia)
3 Rupture of the paramedian artery leads to duret (brainstem) hemorrhage

106
Q

What cells myelinate neurons in the CNS? PNS?

A

CNS - oligodendrocytesPNS - Schwann Cell

107
Q

Are axons preserved in demyelinating disease?

A

Yes, however the conduction of the impulse is impaired

108
Q

In general terms, what are leukodystrophies?

A

Problems with white matter

109
Q

Inherited leukodystrophies involve enzymes with what types of functions?

A

production and maintenance of myelin

110
Q

What enzyme is deficient in metachromic leukodystrophy and what does this lead to? What is the inheritance pattern? What cells are involved?

A

deficiency in arylsulfatasesulfatides cannot be degraded and accumulate in the lysosomes of oligodendrocytes (lysosomal storage disease)Autosomal Recessive inheritance

111
Q

What enzyme is deficient in Krabbe disease, what does this lead to and what is the inheritance pattern? What cells are involved?

A

deficiency in galactocerebrosidase
galactocerebrosides accumulate in macrophages
Autosomal recessive inheritance

112
Q

What function is impaired in adrenoleukodystrophy? what is the inheritance pattern?

A

impaired addition of coenzyme A to long-chain fatty acids.

Accumulation of fatty acids damages adrenal glands and white matter of the brainX-linked

113
Q

What happens in multiple sclerosis? (type of disease, what is damaged…not symptoms)

A

Autoimmune destruction of CNS myelin and oligodenrocytes. Leukodystrophy

114
Q

MS more common in men or women?

A

women

115
Q

What genetic marker is associated with MS?

A

HLA-DR2

116
Q

In what regions is MS most common?

A

Away from the equator (Environmental trigger)

117
Q

How does MS present (general terms not specific symptoms)

A

relapsing neurologic deficits with periods of remission (multiple lesions in time and space)

118
Q

What are 6 clinical features of MS

A

1 blurred vision in one eye (optic nerve).
2 Vertigo and scanning speech mimicking alcohol intoxication (Brainstem).
3 internuclear opthalmoplegia (MLF).
4 Hemiparesis or unilateral loss of sensation (cerebral white matter, usually periventricular).
5 Lower extremity loss of sensation or weakness (spinal cord).
6 Bowel, bladder, and sexual dysfunction (autonomics)

119
Q

How is diagnosis of MS made? what are the findings?

A

MRI reveals plaques (areas of white matter demyelination)
LP shows increase lymphocytes, increase immunoglobulins with oligoclonal IgG bands on high resolution electrophoresis, and myelin basic protein

120
Q

What does gross examination show in MS?

A

Shows gray-appearing plaques in the white matter

121
Q

How are acute MS attacks treated? what does long term treatment involve?

A

Acute attacks are treated with high does steroids

long-term treatment with interferon beta slows progression

122
Q

What is subacute sclerosing panencephalitis and what causes it?

A

It is a progressive, debilitating encephalitis leading to death due to slowly progressing, persistent infection of the brain by measles virus

123
Q

When does infection occur in sclerosing panencephalitis and when doe neurological signs arise?

A

infection occurs in infancy and neurologic signs arise years later (during childhood)

124
Q

What is subacute sclerosis panencephalitis characterized microscopically?

A

viral inclusions within neurons (gray matter) and oligodendrocytes (white matter)

125
Q

What is Progressive multifocal leukoencephalopathy? What cells does it affect?

A

JC virus infection of oligodendrocytes (White matter)

126
Q

What can cause Progressive multifocal leukoencephalopathy?

A

Immunosuppression (AIDS or Leukemia) leads to reactivation of the latent virus

127
Q

How does Progressive multifocal leukoencephalopathy present?

A

with rapidly progressive neurologic signs (visual loss, weakness, dementia) leading to death.

128
Q

What is central pontine myelinolysis?

A

Focal demyelination of the pons (anterior brain stem)

129
Q

What causes central pontine myelinolysis?

A

rapid IV correction of hyponatremia

130
Q

Who does central pontine myelinolysis occur in typically?

A

severely malnourished patients (alcoholics and patients with liver disease)

131
Q

How does central pontine myelinolysis classically present?

A

as acute bilateral paralysis in which voluntary movement from head to toe is paralyzed except for eyes (“locked in” syndrome)

132
Q

What are dementia and degenerative orders characterized by?

A

Loss of neurons within the gray matter; often due to accumulation of protein which damages neurons

133
Q

Degeneration of which structures correlate with dementia and movement disorders?

A

cortex - dementia.

brainstem and basal ganglia - movement disorders

134
Q

What is degenerated in Alzheimer Disease?

A

cortex - most common cause of dementia

135
Q

What are 4 clinical features of alzheimer disease?

A

1 slow onset memory loss (Begins with short-term memory loss and pregresses to long-term memory loss) and progressive disorientation
2 Loss of learned motor skills and language
3 changes in behavior and personality
4 patients become mute and bedridden

136
Q

What is a common cause of death is AD?

A

infection

137
Q

Do focal neurologic deficits occur early or late in AD?

A

LATE!!!

138
Q

Are most cases of AD sporadic or inherited and what demographic are they seen in?

A

most are sporadic(95%) seen in the elderly

139
Q

What are two risk factors for sporadic AD?

A

Age
e4 allele of apolipoprotein increases risk
e2 allele decreases risk

140
Q

What are the two scenarios where early onset AD is seen and what causes it?

A

familial - associated with presenilin 1 and presenilin 2 mutations
Down Syndrome - occurs by age 40 and is due to APP being on Cr 21

141
Q

What can be seen grossly in AD?

A

Diffuse cerebral atrophy with narrowing of the gyri, widening of the sulci, and dilation of the venticles (hydrocephalus ex vacuo)

142
Q

Describe the structure of neuritic plaques in AD?

A

extracellular core comprised of AB amyloid with entangled neuritic processes

143
Q

Where is AB amyloid derived from, whats its normal processing and what processing leads to amyloid?

A

derived from amyloid precursor protein which is coded on Cr21. APP normally undergoes alpha cleavage; beta cleavage results in AB amyoid

144
Q

What enzymes are involved in breaking down APP?

A

normally alpha secretase, however can be beta secretase which leads to amyloidosis

145
Q

What is the definition of dementia?

A

memory loss and cognitive dysfunction without any loss of consciousness

146
Q

Describe cerebral amyloid angiopathy

A

AB protein can also deposit around blood vessels causing amyloid angiopathy which weakens the wall of blood vessels which increases the risk for hemmorrhage

147
Q

What are neuofibrillary tangles and what protein is involved?

A

intracellular aggregates of fibers composed of hyperphosphorylated tau protein. tau is a microtubule associated protein

148
Q

Where is there a loss of cholinergic neurons in AD?

A

basalis of meynert

149
Q

How is diagnosis of AD made?

A

by clinical and pathological correlationpresumptive diagnosis is made clinically after excluding other causes and is confirmed only by histology at autopsy

150
Q

What is vascular dementia a consequence of?

A

moderate global cerebral ischemia

151
Q

What type of injury is vascular dementia and what is it due to?

A

Multifocal infarction and injury due to hypertension, atherosclerosis, or vasculitis2nd most common cause of dementia

152
Q

What areas are most vulnerable to vascular dementia?

A

layers 3,5,6 of cortex and pyramidals of hippocampus

153
Q

What is Pick Disease?

A

Degenerative disease of the frontal and temporal cortex; spares the parietal and occipital lobes

154
Q

What is Pick Disease characterized by histologically?

A

ROUND aggregates of tau protein (pick bodies) in neurons of the cortex

155
Q

Describe the symptomatic progression of pick disease

A

Behavioral (Frontal) and language (Temporal) symptoms arise early; eventually progresses to dementia

156
Q

What happens in parkinsons disease (not symptoms)

A

Degenerative loss of DA neurons in the substantia niagra of the basal ganglia. nigrostriatal pathway of basal ganglia uses DA to initiate movement

157
Q

What are the clinical features of parkinsons disease?

A

‘TRAP’
Tremor - pill rolling tremor at rest; disappears with movement
Rigidity - cogwheel rigidity in the extremities
Akinesia/bradykinesia - slowing of voluntary movement ; expressionless face
Postural instability and shuffling gate

158
Q

What dopamine receptors stimulate and what inhibit the cortex

A

D1 increases stimulation D2 Decreases inhibition

159
Q

What does histology reveal in parkinsons?

A

loss of pigmented neurons in the substantia nigra and round, eosinophillic inclusions of alpha-synuclein (lewy bodies) in affected neurons

160
Q

Is dementia a feature of early or late disease in parkinsons? what does the other suggest?

A

Dementia is common feature of LATE parkinsonsEarly onset dementia is suggestive of Lewy Body dementia

161
Q

What Lewy body dementia characterized by?

A

characterized by dementia, hallucinations and parkinsonian features: histology reveals cortical Lewy Bodies

162
Q

What happens in Huntingtons disease? (be specific)

A

degeneration of GABAergic neurons in the caudates nucleus of the basal ganglia

163
Q

How is Huntingtons disease inherited what is the defect?and what expression property does it display?

A

Autosomal dominant inheritance, characterized by expanded trinucleotide repeats (CAG) in the huntingtin gene on chromosome 4 Further expansion of repeats during spermatogenesis leads to anticipation (future generations get earlier onset)

164
Q

How does huntingtons present and progress?

A

presents with chorea that can progress to dementia and depression; average age at presentation is 40 yearscan also get aphetosis which is slow snake-like movements of the fingers

165
Q

What is a common cause of death in Huntington’s?

A

suicide

166
Q

How does normal pressure hydrocephalus present?

A

urinary incontinence, gait instability, and dementia (“wet, wobbly, and wacky”)

167
Q

What can relieve symptoms in normal pressure hydrocephalus and what is a long term treatment?

A

lumbar puncture relieves symptoms and treatment involves a ventriculoperitoneal shunt

168
Q

What is spongiform encephalopathy due to?

A

degenerative disease due to prion protein

169
Q

What are the two forms of prion protein?

A

Prion protein is normally expressed in CNS neurons in an alpha helical configuration (PrPc)Disease arises with conversion to a beta pleated conformation (PrPsc)

170
Q

What are the three modes of conversion in spongiform encephalopathy?

A

sporadic
inherited
transmitted

171
Q

What is cellular damage characterized by in spongiform encephalopathy? What type of cells are affected?

A

Damage to neurons and glial cells is characterized by intracellular vacuoles

172
Q

What causes increased CSF in normal pressure hydrocephalus?

A

loss of function of arachnoid granulations

173
Q

How does creutzfeld-jakob disease usually arise?

A

Most cases are sporadic; rarely can arise due to exposure to prion infected human tissue (human growth hormone or corneal transplant)

174
Q

How does CJD present?

A

presents as rapidly progressive dementia associated with ataxia (cerebellar involvement) and startle myoclonus periodic sharp waves (spikes) are seen on EEGResults in death usually in less than a year

175
Q

What is variant CJD?

A

a special form of the disease related to exposure to bovine spongiform encephalopathy (mad cow disease)

176
Q

What is familial fatal insomnia?

A

an inherited form of prion disease characterized by severe insomnia and an exaggerated startle response.

177
Q

What is Amyloid Precursor Protein?

A

A membrane receptor with unknown function

178
Q

What percentage of CNS tumors are metastatic vs primary?

A

50:50

179
Q

In general terms describe the locational trends of adult vs child tumors

A

Tumors in adults usually occur above the tentorium and child CNS tumors generally occur below.

180
Q

How doe metastatic CNS tumors present and what are 3 common sources?

A

present as multiple, well circumscribed lesions at the gray-white junction
Lung
Breast
Kidney

181
Q

What are the most abundant glial cell?

A

astrocytes

182
Q

Primary CNS tumors are classified according to cell type of origin, what are the five major cell types?

A 
astrocytes (form BBB)
meningothelial
ependymal
oligodendrocytes
neuroectoderm
183
Q

Do primary CNS tumors tend to metastasize?

A

they are locally destructive but rarely metastasize

184
Q

What are the most common (3) CNS tumors in adults?

A

Glioblastoma multiforme
meningioma
schwannoma

185
Q

What percentage of CNS cells are neurons vs glial?

A

50/50

186
Q

What are the most common (3) CNS tumors in children?

A

pilocytic astrocytoma
ependymoma
medulloblastoma

187
Q

What cell type is involved in Glioblastoma multiforme? what is the grade and malignant/benign? prognosis?

A

Malignant, high-grade tumor of astrocytespoor prognosis

188
Q

What is the most common primary malignant CNS tumor in adults?

A

Glioblastoma multiforme

189
Q

Describe the gross involvement of the brain in glioblastoma multiforme?

A

Usually arises in the cerebral hemisphere; characteristically crosses the corpus callosum “butterfly lesion”

190
Q

Describe the histology seen in Glioblastoma multiforme?

A

characterized by regions of necrosis surrounded by tumor cells (pseudopalisading) and endothelial cell proliferation; tumor cells are GFAP positive

191
Q

What is GFAP?

A

an intermediate filament in glial cells

192
Q

What cell type is involved in a meningioma, malignant/benign? who is it most commonly seen in?

A

Benign tumor of arachnoid cellsmore commonly seen in women; rare in children

193
Q

What hormone receptor are meningioma positive for?

A

Estrogen

194
Q

How doe meningiomas present?

A

may present as seizures; tumor compresses, but does not invade, the cortex

195
Q

What does imaging reveal in meningioma?

A

round mass attached to the dura

196
Q

What is the most common benign primary CNS tumor in adults?

A

meningioma

197
Q

What does histology show in meningioma?

A

whorled patter; psamomma bodies may be present

198
Q

What cell type is affected in schwannoma? malignant/benign?

A

benign tumor of schwann cells

199
Q

Describe the structural involvement of schwannoma?

A

Involves crainial or spinal nerves; within the cranium, most frequently involves CN VIII at the cerebellopontine angle (presents as loss of hearing and tinnitus)

200
Q

What cell marker are schwannomas positive for?

A

S-100

201
Q

what disease leads to bilateral schwannomas?

A

neurofibromatosis type 2

202
Q

what cell type is involved in oligodendroglioma? malignant/benign? kids/adults?

A

malignant tumor of oligodenrocytes

203
Q

What does imaging reveal in oligodendroglioma?

A

reveals a calcified tumor in the white matter, usually involving the frontal lobe; may present with seizures

204
Q

What is the classic appearance of cells on biopsy of oligodendroglioma?

A

Fried egg appearance

205
Q

What cell type is affected in pilocytic astrocytoma? malignant/benign? kids/adults? where?

A

benign tumor of astrocytes in children usually arises in the cerebellum

206
Q

What does imaging reveal in pilocytic astrocytoma?

A

cystic lesion with a mural nodule

207
Q

What does biopsy reveal in pilocytic astrocytoma?

A

Rosenthal fibers (thick eosinophilic processes of astrocyte) and eosinophilic granular bodies;

208
Q

What are tumor cells positive for in pulocytic astrocytoma?

A

GFAP

209
Q

What cell type is affected in medulloblastoma? malignant/benign? adults or kids?

A

Malignant tumor derived from the granular cells of the cerebellum (neuroectoderm) usually arises in children

210
Q

What does histology reveal in medulloblastoma?

A

reveals small, round blue cells; Homer-Wright rosettes may be present (small round blue cells wrap around pink areas of neuritic processes)

211
Q

What is the prognosis in medulloblastoma?

A

poor prognosis; tumor grows rapidly and spreads via CSF

212
Q

What is a metastasis to the cauda equina from the brain termed?

A

drop-metastasis

213
Q

What cell type is affected in ependymoma? malignant/benign? kids/adults?

A

Malignant tumor of ependymal cells usually seen in children

214
Q

Where do ependymomas commonly arise and what do they present with?

A

4th ventricle and may present with hydrocephalus

215
Q

What are a characteristic finding on biopsy in ependymoma?

A

perivascular pseudorosettes

216
Q

What are ependymal cells?

A

They line the ventricular spaces

217
Q

Where do craniopharyngiomas arise from? malignant/benign?

A

Arise from epithelial remnants of Rathke’s pouchIt is benign, but tends to recur after resection

218
Q

How does craniopharyngioma present?

A

supratentorial mass in a child or young adult; may compress the optic nerve chiasm leading to bitemporal hemianopsia

219
Q

What are commonly seen on imaging in craniopharyngioma?

A

calcifications (derived from “tooth-like” tissue)

My Pathoma Unit 3 (1 decks)

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