Path - Intro to Neuro Flashcards
what is central chromatolysis
nissl removed from the center of the cell to the periphery
- seen in the axonal reaction
intranuclear inclusions should make you think of what conditions
herpes or CMV
intracytoplasmic inclusions should make you think of what conditions
- rabies
- alzheimer’s
- parkinson
- CJD (Creutzfeldt–Jakob disease)
intracytoplasmic neurofibrillary tangles indicate _____
alzheimer’s
intracytoplasmic negri bodies indicate _____
rabies
in what conditions are Alzheimer’s type 2 astrocytes seen
not associated with Alzheimer’s just the same doc named them
- hyperammononemia (chronic liver dz)
- wilson dz
- hereditary metabolic disorder of the urea cycle
what is astrogliosis
an abnormal increase in the number of astrocytes due to the destruction of nearby neurons
- a reaction to craniopharyngioma (tumor from rathke pouch)
histologic hallmark of astrogliosis
Rosenthal fibers
in what conditions are Rosenthal fibers seen
- reaction to craniopharyngioma (tumor)
- long standing gliosis (pilocytic astrocytoma)
- Alexander disease
describe morphology of Rosenthal fibers
thick, elongated, brightly eosinophilic, irregular structures occurring within astrocyte processes
PAS+ stain should indicate ____
corpora amylacea
what is corpora amylacea
aging process of cells
- increase with age
- represents degenerative change
concentrically laminated, layered onion-looking histological marker indicates ____
corpora amylacea
CR3 and CD68 markers indicate what cells
microglia (macrophages of the CNS)
what is neuronophagia
the destruction of nerve cells by phagocytes
what is progressive multifocal leukoencephalopathy
a progressive demyelinating and usually fatal disease caused by the JC virus that destroys oligodendrocytes in the brain
what is multiple system atrophy
a fatal neurodegenerative disorder characterized by the abnormal accumulation of toxic forms of the synaptic protein alpha-synuclein (α-syn) within oligodendrocytes and neurons
compare vasogenic and cytotoxic edema
vasogenic: increase in EXTRAcellular fluid
cytotoxic: increase in INTRAcellular fluid
what are the pathological causes of hydrocephalus
- increased production of CSF
- obstruction
- decreased absorption of CSF (outflow obstruction)
what occurs in response to increased CSF
- absorption
- dilation of frontal and temporal horns
- elevation of corpus callosum
- thinning of the cerebral mantle
- stretching/perforation of the septum pellucidum
- enlargement downward of third ventricle
- papilledema
what can cause increased CSF production?
choroid plexus papilloma
appearance of broccoli (thick fibrous core/stalk) on histo indicates ____
choroid plexus papilloma
describe pyogenic meningitis
suppurative exudate covering the brainstem and cerebellum –> obstructive hydrocephalus
causes of acquired hydrocephalus
- infections (meningitis)
- mass lesions (neoplasms)
- inflammation
- post-hemorrhage
- choroid plexus papilloma
- sagittal sinus thrombosus
- hypervitaminosis A
too much vitamin A can lead to what brain condition
acquired hydrocephalus
why is the CSF normal in hydrocephalus ex-vacuo?
because it is a slow process - has time to normalize
the clinical triad of urinary incontinence, gait disturbance, and dementia, indicate what dz process?
“wet, wacky, and wobbly)
normal pressure hydrocephalus
effects of tonsillar herniation
respiratory and cardiac center compression
describe kernohan’s notch phenomena
compressor of the cerebellar peduncle against the tentorium cerebella due to a transtentorial herniation
–> canes ipsilateral hemiparesis or hemiplegia on the side of the herniation
produces a visible “notch” in cerebellar peduncle
compare hypoxia and ischemia
hypoxia: low partial pressure of O2
ischemia: impairment of blood’s oxygen carrying capacity, or inhibition of O2 usage
what signs does the Sommer sector of the hippocampus show in hypoxia
shows decreased number of cells
what areas of the brain are first to show signs of hypoxia
purkinje of the cerebellum
pyramidal cells of the Sommer’s sector of the hippocampus (areas CA1 and CA2)
what signs does the purkinje of the cerebellum show in hypoxia
shrunken, eosinophilic, pyknotic cells
“dead red guys”
compare liquefactive and coagulative necrosis
liquefactive: no architectural remnants
coagulative: there are architecture remnants
histological hallmark of cerebral infarction
missing neuropil, appears pale, decreased number of cells
what is a hygroma
separation of arachnoid from the dura due to contraction of underlying brain parenchyma s/p infarct
describe myelomeningocele
extension of the CNS tissue through a defect in the vertebral column (most often lumbosacral)
describe meningocele
protrusion of the meninges through a defect in the vertebral column
describe encephalocele
disorganized brain tissue extending through defect in cranium (usually posterior fossa)
describe anencephaly
absence of most of the brain and calvarium, but still have cerebellum and brainstem
in what trimester do encephaloceles and ancecenphaly occur
first trimester
in what trimester do lissencephalia and microgyria occur
second semester
fetal alcohol syndrome, HIV-1, and Zika virus can cause what forebrain anomalies
microcephaly
describe lissencephaly
decreased number of gyro with a smooth or “cobblestone” surface
describe polymicrogyria
small, unusually numerous, irregularly formed convulsions of the gyri
describe neuronal heterotopias
what condition are they associated with
collections of neurons in inappropriate places along the pathway of migration
associated with epilepsy
describe holoprosencephaly and how it presents clinically
incomplete separation of the cerebral hemispheres across the midline
clinical: cyclopia, arrhinenceophaly
what is arrhinenceophaly
absence of olfactory cranial nerves
describe dandy walker malformation
enlarged posterior fossa with expanded, roofless fourth ventricle
- cerebellar vermis is absent and replaced by a cyst
describe Joubert syndrome
hypoplasia of the vermis, elongation of cerebellar peduncles and altered brainstem shape
“molar tooth sign”
molar tooth sign is indicative of _____
jobbery syndrome
describe syringomyelia and its sx
a fluid filled cleft-like cavity in the inner portion of the spinal cord
sx: isolated loss of pain and temp sensation of upper extremities bilaterally
describe hydromyelia
expansion of the ependymal-lined central canal of the cord
where are intraparenchymal hemorrhages seen
in germinal matrix
chalky yellow plaques are indicative of what dz process
periventricular leukomalacia
compare where skull fractures usually occur in an awake patient and in an LOC patient
awake: usually fall backward –> occipital fx
LOC: usually fall forward –> frontal impact
sx of basal skull fracture
otorrhea/rhinorrhea from CSF drainage from ear or nose
describe a TBI/CTE
some level of damage to the brain from an external mechanical force
- associated diminished or altered state of consciousness
- brain function temporarily or permanently impaired
when can CTE (chronic traumatic encephalopathy) be diagnosed?
only when examining brains after death
morphology of CTE (chronic traumatic encephalopathy)
progressive loss of normal brain matter and an abnormal buildup of the protein tau
hyperphosphorylated tau protein as neurofibrillary tangles, astrocytic tangled, and neuritis in striking clusters around small blood vessels of the cortex indicates what dz process
chronic traumatic encephalopathy (CTE)
general features of CTE
- neurofibrillary tangles/amyloid and tau deposition
- depigmentation of substantia nigra
- cerebral atrophy/enlarged ventricles
- micro-hemorrhages/DAD
what would cause a contrecoup parenchymal in jury of the brain
sudden deceleration –> head going forward, so brain hits the skull on the back
the brain contacts the skull on the side opposite from where impact occurs
yellowish brown patches involving the crests of the gyro indicate what
plaque jaune
- old trauma lesions
what is diffuse axonal injury
axonal swelling and/or focal hemorrhagic lesions that appear within hours
morphology of diffuse axonal injury
increased number of microglial areas and degeneration of involved tracts
axonal spheroids indicate what dz process
diffuse axonal injury
what microscopic test should be performed to diagnose shaken impact syndrome
microscopic iron to identify old bleeding
- use a Prussian blue stain
trauma in the epidermal space occurs how, what sx, and what type of blood is involved
how: skull fracture
sx: rapidly evolving neurologic sx
blood: arterial
trauma in the subdural space occurs how, what sx, and what type of blood is involved
how: mild trauma
sx: slowly evolving neurologic sx
blood: venous
