Flashcards in 3. Neuropathology Deck (58)
Primary brain vesicles
Forebrain (prosencephalon) - tele and dien
Midbrain (mesencephalon) - mesen
Hindbrain (rhombencephalon) - meten and myelen
Secondary brain vesicles
Formation of neural plate (day 18-19)
Neural folds (20-21)
Closure of neural tube (22)
Rostral then caudal
Development of neural tube (day 28)
What spinal level does spinal cord end during prenatal life at 12 week, 15 week and 24 week?
C5, S3, S1
What spinal level does spinal cord end at newborn and adult life?
L3, L1-2 (end of dura/arachnoid sac at S2)
Tissue repair in fetus vs adult brain
Macrophages cause phagocytosis (without gliosis) -> pseudoprimary malformation
(hydranencephaly or porencephalic cyst before or at early 2nd trimester)
Subependymal germinal matrix hemorrhage occur in which population?
Prematurely born (<1500 kg) within 3 days after delivery
Pathogenesis of germinal matrix hemorrhage?
Periventricular area with fragile microcirculation stroma
Hypoxic stress -> autoregulation fails and excessive perfusion ruptures GM microcirculation
Grades of GM hemorrhage
I confined in GM
II filling lateral ventricles
III with distention
Usual location of GM hemorrhage
Head of caudate > thalamus > behind foramen of monro
Where do contusions occur most frequently?
Frontal and temporal lobes
Traumatic epidural hematoma source of bleeding?
Middle meningeal artery
Less common: laceration of venous sinus (transverse sinus from occipital fracture)
Delayed upper brainstem hemorrhage from rapidly evolving descending transtentorial herniation
Pathophysiology of Duret hemorrhage
Stretching/laceration of pontine perforating branches of basilar artery
Diffuse axonal injury?
parasagittal white matter, corpus callosum, internal capsule, cerebellar peduncles
Duret hemorrhage vs brainstem small tissue-tear hemorrhages in DAI?
Both in upper brainstem, but Duret is delayed and in paramedian areas, whereas DAI located in dorsolateral brainstem
Microscopic timeline picture of DAI?
Axonal swellings (beta-amyloid precursor protein), then axonal disconnection, then microglial clusters around degenerating axons (5-10 days)
I: frontal/temporal, cerebellar and internal capsule
II: corpus callosum (splenium)
III: brainstem/cerebellar peduncles and corticospinal tracts
Biochemical changes in DAI
1h: neurofilament immunoreactivity
4-5: accum of bAPP
1d-2m: axonal swelling
2m-y: wallerian degeneration/demyelination
Which type of temporal bone fracture results in conductive hearing deficit?
Longitudinal temporal bone fracture
Transverse causes more direct nerve damage ith sensorineural hearing deficit (more forceful)
Most striking microscopic finding in lisencephaly type I?
Cortex made from 4 layers (molecular - external neuronal - cellular - internal nuronal)
Macroscopic and microscopic picture of mesial temporal lobe (hippocampal sclerosis)
Ammon's horn sclerosis
Macroscopic: hippocampus smaller than other side, enlarged temporal horns
Microscopic: neuronal loss in CA1, gliosis
Rare disorder in children
Progressive unilateral neurologic deficit + sudden onset epilepsy refractory to medical treatment.
Hemiplegia, hemianopsia, intellectual deterioration
Microscopic picture of Rasmussen syndrome
Like chronic viral encephalitis - lymphocyte cuffs around blood vessels, microglial nodules
What are rosenthal fibers
See in neoplasms (juvenile pilocytic astrocytomas), around craniopharyngiomas, multiple sclerosis plaques, Alexander disease
Classifications of astrocytomas
Grade 1 (juvenile pilocytic): GFAP staining, rosenthal fibers
Grade 1 (subependymal giant cell): assoc. with tuberous sclerosis
Grade 2 (diffuse): nuclear atypia but no mitosis, moderately increased cellularity
Grade 2 (pleomorphic xanthoastrocytoma): pleomorphic lipidized cells in bg of reticulin network)
Grade 3 (Anaplastic): nuclear atypia and mitosis
Grade 4 (GM): nuclear atypia, mitosis, microvascular proliferation and necrosis
Grade 4 (Gliomatosis cerebri): extensively diffuse at least 3 lobes, superficial and/or deep gray matter
Primary vs secondary glioblastoma
Primary (age>55, males) - EGFR overexpression, PTEN
Secondary (younger, women) - 2/3 TP53 mutations and no EGFR amplifications
Usually anterior 3rd ventricles
Glistening cysts with mucin - outer fibrous connective tissue capsule lined by ciliated pseudostratified epithelium, PAS+ mucin