CNS pathology Flashcards
1
Q
the wall of the neural tube forms ____
the hollow lumen forms ___
neural crests forms ____
A
CNS;
ventricles + spinal cord canal;
PNS;
2
Q
neural tube defects can be avoided by administering ____
A
high folate BEFORE conception
3
Q
Neural tube defects are dx prenatally by
A
↑AFP in amniotic fluid + maternal blood
4
Q
Pregnant pt tests positive for maternal polyhydroaminos and ultrasound of fetus presents with frog-like appearance (prominent eyes). Dx?
A
Anencephaly
hint: polyhyrdoaminos dt ↓swallowing (absent brain fx); frog-like appearance dt øskull/brain + prominent eyes
5
Q
when the posterior vertebral arch fails to close during fetal development; this is known as
A
spina bifida (vertebral defect)
6
Q
___ presents as dimple or hair patch over vertebral defect
A
spina bifida occulta
7
Q
____ is a protrusion of meninges only
A
spina bifida meningocele
8
Q
_____ is a protrusion of meninges + spinal cord
A
spina bifida meningomyelocele
9
Q
the most common cause of hydrocephalus + suture closure failure in newborns
A
cerebral aqueduct stenosis
hint: obstruction –> ↑ CSF –> ventricle swelling + ↑ head circumf
10
Q
What produces CSF in the ventricles
A
choroid plexus (lining ventricles)
11
Q
Name that channel:
- lateral –> ____ –> 3rd ventricle
- 3rd ventricle –> ____ –> 4th ventricle
- 4th ventricles –> ____ –> subarachnoid space
A
- foramen of Monro
- cerebral aqueduct
- Magendia (medial) and Luschka (lateral)
12
Q
MRI reveals massively dilated posterior fossa; newborn presents with hydrocephalus. Dx?
A
Dandy-Walker Malformation (øcerebella vermis dev + dilated 4th ventricle)
13
Q
MRI reveals cerebellar vermis + tonsil displacement thru foramen magnum.
A
Type II Arnold-Chiari Malformation
hint: Type I is asympto
14
Q
Arnold-Chiari Malformation (II) is often associated with what 2 sx?
A
hydrocephalus (CSF obstruction)
meningomyelocele (±)
15
Q
cystic degeneration of the spinal cord is known as _____ as usually dt what 2 causes
A
Syringomyelia (C8-T1);
Trauma or Type I Arnold-Chiari Malformation
16
Q
Describe the distribution of Syringomyelia
A
C8-T1: øpain/temp in upper extremity (UE)
hint: “cape-like distribution”
17
Q
What is responsible for the capelike distribution of pain and temp sensation loss in syringomyelia?
A
ant white commissure involvement (spinothalamic tract)
hint: dorsal column is spared –> fine touch + pos’n spared
18
Q
Syrinx expansion in syringomyelia involves what two tracts? Explain sx of each.
A
Anterior horn (LMN) + Lateral horn (hypothalamospinal tract);
- Ant horn = Muscle atrophy ↓muscle tone + reflexes (∆LMN)
- Lateral horn = Horner’s (ptosis, miosis, anhidrosis)
hint: HTS tract supplies sympathetics to the face
19
Q
After a recent viral infection, pt presents with flaccid paralysis, muscle atrophy + fasciculations, weakness w/ ↓muscle tone + reflexes; but Babinski is ⊖. Dx?
A
Poliomyelitis (poliovirus inftn –> LMN sign)
20
Q
Newborn pt presents as “floppy baby”; with no other pertinent positives (no recent honey intake, exposure)? Most likely dx?
A
Werdnig-Hoffman Dz (autosomal recessive)
hint: death a few years after birth
21
Q
what is the mechanism and inheritance pattern of Werdnig-Hoffman dz?
A
deg’n of ant motor horn;
autosomal rec
22
Q
Degeneration of upper AND lower motors neurons of the corticospinal tract is classified as
A
ALS (Amyotrophic Lateral Sclerosis)
23
Q
45 year old pt complains of atrophy and weakness in hands. Sensation to pain, temperature, and touch are in tact. What should you check for?
A
Sporadic ALS
hint: earliest sign is atrophy + weakness in hands
24
Q
How can you differentiate ALS from Syringomyelia?
A
- ALS: intact sensation
- syringo: ant horn involvement from C8-T1 (cape distr) + øP/T sensation
25
Difference bwn UMN and LMN lesions (4 each)? What structures/tracts are involved in each?
UMN (lateral corticopinal tract): spastic paralysis; hyperreflexia; ↑muscle tone; ⊕Babinski
LMN (ant horn): flaccid paralysis; atrophy + fasciculations; ↓reflexes + tone; ⊖Babinski
hint: things go up for UMN lesions; things go down in LMN lesions
26
What is a common association in familial ALS
SOD1 mut (zinc-copper superoxide dismutase) --> free radical injury to neurons
27
What structures are degenerated in Friedreich Ataxia? What are the subsequent sx?
Cerebellum + spinal cord
```
Cerebellum: ataxia
spinal cord (mult tracts): LE muscle weakness, ø DTRs; ø vibration + proprioception sense
```
28
What is the mechanism and pattern of inheritance of Friedrich Ataxia?
unstable trinucleotide repeat (GAA) in frataxin gene (mt Fe reg'n);
autosomal rec
29
What results with frataxin mutation (trinuc expansion)
ø mitochondrial iron regulation --> free radical dmg (via Fenton rxn)
30
4 yo pt presents with LE muscle weakness, absent DTRs, neuro exam confirms ataxia with little to no vibratory + proprioception sense; CXR reveals enlarged heart. Family is requesting wheelchair provision. Dx?
Friedrich Ataxia
hint: presents in early child; hypertrophic cardiomyopahty is common
31
leptomeninges include the ___ layers (2)
Arachnoid and Pia menginges
32
what 3 infectious agents commonly affect neonates
Group B strept (3rd trimester prophx)
E.coli
Listeria monocytogenes
33
what infectious agent commonly affect children AND teenagers
N. meningitidis
34
what infectious agent commonly affect adults and elderly
S. pneumoniae
35
what infectious agent commonly affect nonvax'd infants
H. flu
36
what MOST COMMON infectious agent affects children
Coxsackievirus
hint: fecal oral tranmission
37
what infectious agent commonly affect immunocompromised pts
fungi
38
Pt presents with headache, nuchal rigidity and fever, what other symptoms might also be present? Describe how to sample CSF?
Meningitis (class triad: headache, nuchal rigidity and fever);
± nausea, vomiting, confusion (AMS)
lumbar puncture bwn L4 and L5 (iliact crest)
39
why is lumbar puncture done at L4 and L5?
spinal cord ends at L2
| subarachnoid space + cauda equina end at S2
40
describe CSF findings for Bacterial; viral; fungal meningitis
Bacterial: neutros + ↓CSF glucose
Viral: Lympho + normal CSF glu
Fungal: lymphos + ↓CSF
hint: viruses dont need food (ø glucose consumption observed)
41
Explain the complications of bacterial meningitis (2 pathways)
1. cerebral edema --> herniation --> death
| 2. fibrosis --> hydrocephalus (CSF obstr) + hearing loss (nerve damage) + seizures (cerebral scarring)
42
Cerebral Vasc Dz (CVD) is 85% dt ____ and 15% dt ___
85% ischemia (↓Q)
| 15% dt hemorrhage (bleed)
43
what are the 4 major etiologies of global cerebral ischemia?
1. low perfusion
2. acute ↓Q (cardiogenic shock)
3. chronic hypoxia (anemia)
4. ↑ hypoglycemia episodes (insulinoma)
44
Explain why glucose would result in ischemia
neurons need glucose for energy (necrosis within 3-5 min)
45
Transient confusion w/prompt recovery. Ischemia severity?
mild global ischemia
46
infarcts in watershed areas and vulnerable regions. Ischemia severity?
moderate global ischemia
47
diffuse necrosis; death or vegetative state with survival. Ischemia severity?
severe global ischemia
48
Pyramidal neurons of _____ leads to laminar necrosis
cerebral cortex 3-5-6 (moderate global ischemia)
49
long term memory disfunction in moderate global ischemia is assc w/ dmg to what structure?
pyramidal neurons of hippocampus (temporal lobe)
50
Damage (dt moderate global ischemia) to what layer of the cerebellum would interfere with sensory perception + motor control
Purkinje Layer
51
focal ischemia <24 hrs is considered ___
TIA (transient ischemic attack)
52
focal ischemia >24 hrs
stroke
53
3 subtypes of stroke?
thrombotic
embolic
lacunar
54
describe etiology and sx of:
- thrombotic stroke
- embolic stroke
- lacunar stroke
thrombotic: artherosclerotic plaque* at branch pts (IC + MCA) --> pale infarct in peripheral cortex
embolic: afib --> emboli from L heart to MCA --> hemorr* infarct in peripheral cortex
lacunar: htn --> hyaline arteriolosclerosis in LS vessels --> small cystic infarctions
55
explain why thrombotic stroke is pale and embolic stroke is hemorrhaged?
thrombotic: presence of athero plaque --> thrombus reforms --> pale infarct sustained
embolic: embolism lysed --> re-perfusion --> hemorrhage
56
Lacunar stroke of internal capsule results in
pure motor stroke
57
Lacunar stroke of thalamus results in
pure sensory stroke
58
ischemic stroke results in ___
liquef necrosis
59
List the changes (cell popn's) assc with necrosis bwn 1 day; 1 week; 1 month of ischemic infarct
```
red neurons (eosinophilic∆) - 12 hrs p/infarct
necrosis - 24 hrs ""
Nø - 1-3 days ""
Mø - 4-7 days ""
granulation/gliosis - 2-3wks ""
gliotic cysts - end stage
```
60
Intracerebral hemorrhage is usually dt _____
htn --> rupture of Charcot-Bouchard microaneurysm of LS vessels
61
most common site of intracerbreal hemorrh?
basal ganglia
62
Severe headach, naseua, vomiting, eventual coma is characteristic of (intracerebral/subarachnoid)
intracerebral hemorrhage
63
Pt with sudden onset of "worst headach of life" w/ nuchal rigidity most likely is suffering from?
subarachnoid hemorrhage
64
with subarachnoid hemorrhage, blood is most likely to pool where?
on the bottom of the brain
65
What layer is missing in berry aneurysms? What s the most frequent location for BAs?
ø media layer at branch points;
| Anterior Communicating Artery in (ant circle of Willis)
66
what 2 dz's is subarachnoid hemorrhage assc with?
Marfan Syndrome + Auto dom polycystic kidney dz
67
Oligodendrocytes myelinate the______. Scwhann cells myelinate the ______
CNS;
| PNS
68
How are demyelinating disorders characterized
destruction of myelin or oligodendrocytes (CNS) w/ axonal sparing
hint: axons are spared, but impulse is damaged
69
Luekodystrophies are characterized by what process? 3 types of leukodystrophies are?
enzymatic mutations lead to ∆myelin storage/synth;
1. Metachromatic leukodystrophy
2. Krabbe Dz
3. Adrenoleukodystrophy
70
Metachromatic Leukodystrophy is due to a deficiency of what enzyme and affects pathway?
arylsulfate defc; leads to sulfatide acc'm in oligodendrocytes
hint: metachromatic leukodyst is a lysosomal storage dz)
71
Krabbe Dz is due to a deficiency of what enzyme and affects pathway?
galactocerebrosidase; leads to galactocerebroside acc'm in mø
72
Adrenoleukodystrophy is due to a deficiency of what enzyme and affects pathway?
impaired coA addition to FAs; leads to FA acc'm --> dmg to adrenal glands and brain white matter
73
The inheritance patter of Metachromatic Leukodystrophy and Krabbe Dz is _____; while Adrenoleukodystrophy is ____
autosomal recessive; X-linked
74
Autoimmune destruction of CNS myelin + oligodendrocytes is known as ____-
Multiple Sclerosis (MS)
75
25 yo female pt, who appears drunk, presents with blurred vision in R eye, weakness and ↓sensation in lower extremities and intermittent episodes of hemiparesis/paresthesia. MRI shows plaques in white matter. Lumbar puncture is done and shows ↑lymphocytes; high res electrophoresis is done, and shows ↑Igs, oligoclonal IgG bands, myelin basic protein.
Dx? Tx (acute and longterm)?
MS (autoimmune);
acute tx: high dose steroid
long term: IFN-β (↓progression)
76
What 2 tools confirm MS dx?
MRI + lumbar puncture
77
Neuro deficits of MS occur in periods of _____. Name the structure involved in each following clinical features?
1. blurred vision in one eye
2. Vertigo + scanning speech (~drunkenness)
3. Internuclear opthalmoplegia
4. Hemiparesis/unilateral sensation loss
5. LE weakness and sensation loss
6. Bowel, bladder, and sexual dysfx
remission;
1. optic nerve
2. brainstem
3. medial longitudinal fasciculus (mlf)
4. (periventricular*) cerebral white matter
5. spinal cord
6. autonomic nervous system
78
Name the genetic predisposition and env trigger for MS
HLA-DR2 (gene) + regions far from equator (env)
79
Common popn for chronic MS?
young adult (20-30); ↑in women
hint: MS is the most common chronic CNS dz of young adults
80
epidural hematoma is bwn what two layers/structures
dura + skull
hint: temporal skill fracture + middle meningeal bleed
81
A lens shaped lesion on CT and lucid interval point to what dx?
epidural hematoma
hint: herniation = lethal complication
82
where does blood collect during a subdural hematoma
under dura (covers the surface of the brain)
83
With trauma, tearing of what structures (bwn dura and arachnoid) leads to subdural hematoma
bridging veins
84
A crescent shaped lesion on CT with progressive neurologic deficits points to what dx?
subdural hematoma
hint: herniation = lethal complication
85
What ↑ occurrence subdural hematoma in elderly pts?
cerebral atrophy --> stretched bridging veins
86
Displacement of brain tissue is also known as _____. What 2 mechanisms lead to displacement of brain tissue
Herniation
1. mass effect (MVA)
2. ↑intracranial P
87
Herniation type that involves cerebellar tonsils into foramen magnum ± cardiopulmonary arrest.
Tonsillar herniation
hint: CP arrest dt compression of brain stem
88
Herniation type that involves cingulate gyrus displacement under falx cerebri. Compression of what artery leads to infarction?
subfalcine herniation;
| Anterior Cerebral Artery (ACA) leads to infarction
89
Pt presents with the following
1. "down and out eye" and dilated pupil (name lesion)
2. contralateral homonymous hemianopsia (name lesion)
3. Duret (brainstem) hemorrhage (name lesion)
Dx?
1. CN III compression
2. post cerebral artrey compression --> occipital lobe infarct
3. paramedian artery rupture
Dx Uncal Herniation
90
Uncal Herniation involves displacement of what structure?
temporal lobe uncus under tentorium cerebelli
91
progressive/debilitating encephalitis dt to persistent measles virus inftn of the brain. Characterized by viral inclusion in gray and white matter
Subacute sclerosing panencephalitis
hint: infections in infancy --> neuro defects in childhood
92
rapidly progressive neuro signs (ø vision, weakness, dementia) dt JC virus iftn of oligoDCs (white matter)
Progressive Multifocal Leukoencephalopathy
hint: leads to death
93
Why is progressive multifocal leukoencephalopathy typically seen in AIDS or leukemia pts?
immunosuppression reactivates latent JC virus
94
What dz is chrz'd by pontine demyelination and presents as acute bilateral paralysis (locked in syndrome)?
central pontine myelinolysis
95
What clinical action usually results in central pontine myelinolysis?
rapid IV correction of hyponatremia
hint: esp if pt is severely malnourished (alcoholic/liver dz)
96
dementia is chrz'd by what process?
acc'm of protein --> ↓ neurons in cortical*** gray matter
97
deg'n of what structured leads to movement disorders (2)
brainstem + basal Ganglia (BG)
98
80 yo pt presents with slow-onset memory loss --> progressive disorientation; loss of motor skill and language; behavioral changes; and family members say he has recently gone mute and spends most of time in bed? Dx?
Alzheimer's dz
hint:
- ø focal deficits
- presumptive dx after excluding other ddx; confirmed at autopsy (histo)
99
What % of Alz is seen in the eldery and is mostly sporadic?
95%
hint: risk doubles every 5 yrs after 60
100
which allele of APOE is assc with high risk/low risk (ℇ4/ℇ2)
ℇ4 - high risk;
| ℇ2 - low risk
101
early onset AD is seen in (2)
1. familial cases (presenilin1* + 2)
2. Down Syndrome (t21 w/ extra APP gene)
hint: onset by 40 yo in DS
102
cerebral atrophy (hydrocephalus exvacuole); neuritic Aβ plaques w/entangled processes; hyperPO4'd tau + neurofibrilary tangles - are all morpho features of what dz?
AD
103
when amyloid deposits around bvs in AD, the pt is at risk for?
cerebral angioid neuropathy --> hemorrhage
104
how is Aβ amyloid formed?
APP (chrom 21) undergoes β cleavage (non degradable) --> acc'm
105
What is tau?
microtubule assc protein
106
Multifocal infarction dt htn, atherosclerosis, or vasculitis is chr-istic of what dz?
vascular dementia
hint: 2nd most common cause of dementia
107
Degeneration of frontal and temporal cortex leading to early behavorial and language sx (resepctively) followed by dementia is what dz?
Pick Disease
108
on histo, round aggregates of tau protein are observed in cortical neurons. What are these structures? Dx?
Pick bodies; Pick Dz
109
damage to and loss of dopaminergic neurons in the substantia nigra of BG is chr of what dz?
Parkinsons's
110
nigrostriatal pathway of BG is responsible for what action?
movement initiation (via dopamine) - important for PD
111
Name the Clinical features of PD (5)?
```
hint: TRAPS
T remor
R igidity (cogwheel)
A kinesia/bradykinesia (expressionless)
P ostural instability
S huffling gait
```
112
on histo, round eosinophilic inclusions of 𝛂-synuclein are seen. What are these structures? Dx?
Lewy bodies; PD
hint: ø pigemented neurons in SN seen
113
What is the difference bwn PD and Lewy body dementia
- PD - late-onset of dementia
| - LBD - early-onset dementia + cortical* Lewy bodies + hallucinations (parksonian features)
114
Degeneration of GABAergic neurons in the caudate nucleus (BG) as a results of CAG trinuc expansion is what dz?
Huntington's Dz
hint: autosomal dominant (chrom 4)
115
in HD further expansion of repeats during _____ leads to anticipation
spermatogenesis
116
45 yo pt presents with chorea, progressive dementia, and depression. Pt admits to suicidal ideation? dx?
Huntington Dz
117
Describe the tremor commonly seen in PD
pill rolling tremor at rest***
| disappears with movement
118
Pt presents with urinary incontinence; gait instability, and dementia subsequent to hydrocephalus (∆reabs in vneous sinus --> inc csf --> ventricles). Dx? Tx?
Normal Pressure Hydrocephalus;
tx: lumbar puncture for relief; ventriculoperitoneal shunting (VP shunting)
hint: triad = wet, wobbly, wacky
119
conversion and cycling of PrPc --> PrPsc (non degradable) leading to intracellular vacuoles is chr of what dz?
spongiform encephalopathy
120
This most common* type of Spongiform encephalopathy is usually sporadic but can be transmitted via corneal/GH transplant*?
Creutzfeldt-Jakob dz (CJD)
121
Contraction is related to bovine spongiform encephalopathy (mad cow) and is typically seen in young pt? (Variant CJD/Familial Fatal Insomnia)
Variant CJD
122
Contraction is related to inherited prion and chrzd by exaggerated startle response and severe insomnia? (Variant CJD/Familial Fatal Insomnia)
Familial Fatal Insomnia
123
Pt presents with rapidly progressive dementia , ataxia, and startle myoclonus. Periodic sharp waves are seen n EEG. Dx? Px?
CJD Spongiform Encephalopathy;
death <1 year
hint: startle myoclonus = invol movt w/min stimulus
124
Forms of Spongiform Enceph conversion (3)?
1. sporadic
2. inherited
3. transmitted
125
_____ tumors are multiple, well circumscribed lesion at the gray white junction (metastatic/primary)
Metastatic
hint: usually arise from lung breast, kidney
126
_____ tumors are classified acc to cell type of origin (metastatic/primary)
Primary
hint: locally destructive; rarely metastisize
127
Where are primary tumors located in adults/kids?
adults - supratentorial
| kids - infratentorial
128
gliobastoma multiform, meningioma, and scwhannoma are typical found in what popn?
adults
129
pilocytic astrocytomas, ependymoma, and medulloblastoma are most common in what popn?
kids
130
Pseudopalisading necrosis, endothelial cell prolifn, and GFAP+ tumors are assc with what dz>
glioblastoma multiforme (GBM)
131
40 yo pt dx'd a with malignant, astrocytic tumor; butterfly lesion is seen on autopsy. Dx?
GBM
hint: poor prognosis
132
50 yo female pat presents with seizures. round masses attached to the dura are seen on imaging. Histo reveals whorled patterning + psammoma bodies. Dx (meningioma/oligodendroglioma)? Is this tumor benign/malignant?
meningioma;
benign tumor of arachnoid cells
hint: more common in women (± estrogen related); seizures dt cortical compression (ø cortical invasion)
133
Pt presents with hearing loss and tinnitus; on imaging, tumor involves CN VIII and CPA (cerebellopontine angle). on IHS tumor cells are s-100+ . Dx?
Scwannoma
134
in Neurofibromatosis type 2 (Schwannoma), what is typical lesion is observed?
bilateral tumors
135
Pt presents with seizures on biopsy cells have a 'fried-egg' appearance; imaging reveals calcified tumor with white matter of forntal lobe*. Dx meningioma/oligodendroglioma)? Is this tumor benign/malignant?
oligodendroglioma;
malignant tumor of oligodendrocytes
hint: 1p/q19 mut
136
A cystic lesion with a mural nodule is detected in the cerebellum of a 6yo pt? Dx? Is this tumor benign/malignant?
pilocytic astrocytoma;
benign tumor of astrocytes
hint: most common CNS tumor in kids
137
What diagnosis is consistent with eosinophilic Rosenthal fibers + granular bodies, and GFAP⊕ tumor cells?
pilocytic astrocytoma
138
What diagnosis is consistent with small round blue cells and Homer-Wright rosettes? What is drop metastasis?
medulloblastoma;
| metastasis to cauda equina
139
Is medulloblastoma benign/malignant
malignant tumor of cerebellar granular cells (neuroectoderm)
hint: common in kids (cerebellar)
140
What diagnosis is consistent with hydrocephalus and perivascular pseudorosettes (ependymoma/craniopharyngioma)? Is this tumor benign/malignant?
ependymoma;
malignant tumor of ependymal cells
hint: 4th ventricle involvement --> CSF obstruction --> hydroceph
141
What diagnosis is consistent withbitemporal hemianopsia calcifications on imaging; and recurrence after resection (ependymoma/craniopharyngioma)? Is this tumor benign/malignant?
craniopharyngioma;
| benign tumor of epith remnants of Rathke's pouch
142
in neurofibillary tangles, assc with AD what protein is hyperphosphorylated?
tau
143
Loss of cholinergic neurons in AD occurs where? (basal ganglia/nucleus basalis)
Nucleus basalis of Meynert
