CNS Pathoma Flashcards
What vitamin is necessary to prevent neural tube defects?
Folate, levels must be high enough prior to coneception
What is a common characteristic seen during pregnancy due to anencephaly?
polyhydramnios
What is the most common cause of hydrocephalus in newborns?
cerebral aqueduct stenosis
What clinical finding is seen in children with cerebral aqueduct stenosis?
enlarging head cirumference due to dilation of the ventricles
What is degenerated in syringlomyelia?
C8-T1 degeneration of the anterior white commissure, sometimes with involvement of the anterior horns
What sxs are seen in syringomyelia?
loss of pain and temp in upper extremities, sensation intact. If involves anterior horn, then LMN signs.
What sxs will present if syringomyelia spreads to invole the lateral horn?
Horner syndrome, loss of hypothalamospinal tract which carries sympathetics to the face
Poliomyelitis spreads to CNS via what manner?
spreads through the blood
What is damaged in poliomyelitis? sxs?
anterior motor horn– LMN signs (flaccid paralysis, myscle atrophy, fasiculations, weakness with dec muscle tone, impaired reflexes, negative babinski downward toes)
What is Wednig-Hoffman Disease?
inherited degeneration of anterior motor horn, presents as a “floppy baby”, death in a few years
What gives rise to the LMN lesions in ALS?
degernation of anterio motor horn
What gives rise to UMN lesions in ALS?
degeneration of lateral corticospinal tract
How can you differentatie between syringomyelia and ALS?
ALS is only motor loss, sensation intact. Syringomyelia is loss of sensation (pain and temp)
What mutated enzyme can lead to ALS?
zinc-copper superoxide dismutase mutation– leads to free radical injury in neurons.
What is the frataxin gene in friedreich ataxia involved in?
mitochondrial iron regulation–loss or mutation of this gene results in iron buildup and free radical damage (fenton reaction)
What heart condition is associated with Friedrich’s Ataxia?
hypertrophic cardiomyopathy
How does N. meningitidis spread to the brain?
enters through the nasopharynx and enters the blood to access the meninges
Where do you place the needle for a lumbar puncture?
@ L4-L5 (level of iliac crest). Spinal cord ends at L2, but subarachnoid space and cauda equina continue to S2
What layers are transversed during a lumbar puncture?
skin, ligaments, epidural space, dura and arachnoid. Do not pierce the pia!
What two major classes of cerebrovascular disease exist?
Can be ischemic or hemorrhagic.
What two classes of ischemic cerebrovascular disease exist?
Focal and global
What are the common causes of global cerebral ischemia?
Low perfusion (atherosclerosis), acute decrease in blood flow (cardiogenic shock), chronic hypoxia (anemia), and repeated episodes of hypoglycemia (insulinoma)
What areas of the brain are most suspetible to moderate global ischemia?
Watershed areas, pyramidal neurons (layers 3, 5, 6) and purkinje layer of the cerebellum
What type of necrosis can damage to the purkinje layers lead to?
laminar necrosis, creates a line of necrosis
Definition of transient ischemic attack?
if symptoms of stoke last less than 24 hours
What causes a thombotic stroke?
Atherosclerosis, which usually develops at branching points (MCA and internal carotid bifurcation in circle of wilils)
What does a thrombotic stroke look like?
pale infarct in the periphery of the cortex
What causes an embolic stroke?
a fib, clot from left heart that lodges in the MCA
What will an embolic stroke look like grossly?
hemorrhagic infarct (thrombus lysed allowing reperfusion of the cortex)
What causes a lacunar stroke?
hyaline arteriolosclerosis– due to benign HTN, diabetes. Infarction of lenticulostriate vessels resulting in small cystic areas of the brain
What causes a pure motor stroke?
infarction of internal capsule
What causes a pure sensory stroke?
infarction of the thalamus
What is the first sign of liquefactive necrosis in the brain
Red neurons, see at 12 hours
What is the end result of a lacunar stroke after healing?
fluid filled cystic space that is surrounded by gliosis
What is a common cause of a intracerebral hemorrhage?
Charcot-Bouchard microaneurysm of lenticulostriate vessels due to hypertention and hyaline arteriolosclerosis which weaksens the vessel wall
What is the most common site of a intracerebral hemorrhage?
basal ganglia
Why is the lumbar puncture yellow in subarachnoid hemorrhage?
xanthochromia–yellow hue due to bilirubin breakdown
Where will a berry aneurysm most likely occur?
branch points of ACA in circle of willis, due to the lack of a media layer at branching points
What is a complication of tonsillar herniation?
cardiopulmonary arrest–cerebellar tonsils into the foramen magnum
Complication of uncal herniation?
Compress CNIII (down and out eye), compress PCA (contralateral homonymous hemianopsia), rupture of paramedian artery (brainstem hemorrhage)
What causes progressive multifocal leukoencepharlopathy?
JC Virus of oligodendrocytes, in immunosuppressed patients
What brain matter is affected in MS?
autoimmune destruction of myelin and oligodendrocytes.
What eye issue is commonly associated with MS?
internuclear ophthalmoplegia- damage to the MLF
What gene is associated with increased risk and decreased risk of Alzheimer’s disease?
increased risk- ApoE4
decreased risk- ApoE2
(4>2=inc risk in 4)
What gene is associated with early onset alzheimers?
presenilin 1
On what chromosome is APP located on, and what population is at increased risk for developing Alzheimer’s because of this?
Chr 21– Downs
What is cerebral amyloid angiopathy?
Amyloid can also deposit around the vessels increasing the risk of hemorrhage
What are neurofibrillary tangles made of?
hyperphosphorylated tau–Alzheimers
What neurotransmitter is dec in Alzheimers and where is it normally located?
loss of ACh from the nucleus of meynert
What are the histological findings of Alzheimers?
neurofibrillary tangles (tau) and neuritic plaques (extracellular AB amyloid with entangled neuritic processes)
What part of the brain is affected by Pick’s disease?
frontal and temporal lobe
What is the histological finding in Pick’s disease?
Pick bodies–round saggregates of tau protine in neurons of the cortex
What disease is due to a loss of dopaminergic neurons in substantia nigra of basal ganglia?
Parkinson Disease
What drug contaminant has been linked to Parkinson Disease?
MPTP contaiminant in illicit drugs
What are the hisotlogical findings of Parkinson Disease?
eosinophilic inclusion of alpha-synuclein Lewy bodies found in the substantia nigra
What disease is associated with degeneration of GABAergic neurons in the caudate nucleus?
Huntington Disease
When are the extra trinucleotide repeats gained in Huntington Disease?
during spermatogenesis, leads to anticipation
