Sos: development of CNS Flashcards
brain to gut; the ultimate survival machine
autonomic NS
areas that close last along neural tube where congenital malformations happen
cranial and sacral region
neural plate to neural _____ to neural ____
plate to crest cells to tube
sensory and regulated by TGF-beta and BMPs (bone morphogenic proteins)
Alar plate (dorsal)
motor and induced by SHH
basal plate (ventral)
neural tube has same ____ as spinal cord
orientation
neural migration:
ventricular region to pia mater using radial glial cells and hormones
telencephalon and diencephalon
forebrain
mesencephalon
midbrain
pons and cerebellum
metencephalon
medulla oblongata
myelencephalon
metencephalon and myelencephalon
hindbrain
cerebrum, thalamus, hypothalamus
forebrain
brain stem
midbrain and hindbrain
comes from neural crest tissue and from mutation in C-MYC gene
neuroblastoma
causes of neuronal migration defects
failure of neurons to migrate
scattered neuron arrangement
late stage neuronal migration
abnormal migration of neurons causes abnormal ____ pattern
gyral
well studied gene associated with neuronal migration defects
RELN/Lis
With _____ mutation, actin and microtubules don’t form properly and they don’t migrate; don’t migrate to final resting place=cant be fully functional
RELN/Lis
neuronal migration defects lead to a 4 layer cortex instead of a ____ layer cortex
6
stain to look at cell bodies
Nissl stain
Smooth cortex without gyri and thick cortex with four cell layers
Lissencephaly
Lissencephaly
smooth cortex
microcephaly
mental delay/seizures
Lissencephaly
Lissencephaly
Lissencephaly
cortex has irregular grooves forming a cobblestone pattern; total disarray of cortex
cobblestone cortex
no cortical layers
irregular grooves
neurons migrate past cortex
cobblestone cortex
Broad gyri and thick cortex with few layers
tissue not compatible with learning and development
Pachygyria
broad gyri
Pachygyria
broad gyri and thick cortex
Pachygyria
Surface of the cortex appears to form microgyri
Polymicrogyria
Often found in vascular territories or watershed areas suggesting a hypoxic/ischemic event; microgyri
Polymicrogyria
normal neurons/glia found in the wrong place
heterotopia
Collections of neurons found under the ependyma of the lateral ventricles
Unilateral variants are silent and incidental findings during imaging studies
(neurons found in wrong place)
Periventricular (subependymal) Heterotopia
Periventricular (subependymal) heterotopia
neurons in wrong place (didnt migrate out)
periventricular (subependymal) heterotopia
Collections of neurons in the cerebral white matter diffusely scattered, clustered into nodules, bands or grouped in large masses
Subcortical neuronal (band) heterotopia
associated with seizures
subcortical neuronal (band) hetertopia
used to stain myelin
Luxol fast blue (LFB)
not termed precancerous when talking about the brain
cortical dysplasia
(grey matter) improperly forming
Most common form is focal ____
cortical dysplasia
most common cause of epilepsy (often gray matter found in temporal lobe)
cortical dysplasia
cortical dysplasia
top
bottom
top: normal
bottom: cortical dysplasia
Infected in utero; skull in vault doesn’t form and brain and cortex don’t form
(microcephaly)
Zika virus
autism, muscle spasms, mental delay
Due to disrupted neuronal migration along with an abnormal neuronoglial differentiation
tuberous sclerosis syndrome
organs involved in tuberous sclerosis syndrome
brain, heart, kidneys, skin
Neocortical tubers
Subependymal nodules
Subependymal giant cell astrocytomas (SEGAs)
brain involvement of tuberous sclerosis syndrome
rhabdomyomas— heart
angiomyolipomas (hamartomas)– kidney
angiofibromas —-skin
Tuberous sclerosis syndrome
tubers
(tuberous sclerosis sydnrome)
heart mass in children
tuberous sclerosis syndrome
heart rhabdomyoma
kidney angiomyolipoma (hamartoma)
tuberous sclerosis syndrome
A single telencephalic ventricle with continuity of the cerebral hemisphere across the midline
Holoprosencephaly
forebrain aka
prosencephalon
Associated craniofacial abnormalities, most severe being cyclopia
holoprosencephaly
holoprosencephalies
alobar holoprosencephalies
most common congenital malformation disorders
neural tube defects
increased AFP in amniotic fluid
neural tube defects
poorly controlled DM
valproic acid
folic acid and vitamin B12 deficiency
neural tube defects
open brain and lack of skull vault
Anencephaly
herniation of meninges and midbrain
Encephalocele
some of vertebrae are not completely closed; asymptomatic (can sometimes feel tuff of hair there)
Spina bifida occulta
protrusion of meninges and CSF
through defect in skull or spine
Meningocele
open spinal cord w/ a meningeal cyst (spinal cord and meninges pushed out)
Myelomeningocele
meningocele
skull defect
involves meninges and CSF
meningocele
skull defect involves brain parenchyma, meninges, and CSF
Encephalocele
80% of cephaloceles happen in what region
occipital region
myeloencephalocele or encephalocele
midline of cerebellum
vermis
hindbrain aka
posterior fossa
condition in which brain extends through the foramen magnum
Chiari malformations
minimal brain tissue extends downwards
cerebellar tonsils are displaced and
Syrinx formation
Type I Chiari malformation
greater amounts of brain tissue extends downward and a myelomeningocele and hydrocephalus 90% of time
type II chiari malformation
kinking of medulla and hydrocephalus
type II chiari malformation
most severe and rare, includes cerebellum and brainstem extending downward
type III chiari malformation
cerebellum pushed up
enlarged ventricles
hydrocephalus
Dandy-Walker syndrome
cerebellum pushed up
Dandy-Walker syndrome
can’t find vermis
(vermal aplasia)
Dandy-Walker syndrome
Most likely due to decreased or lack of blood flow and brain development
brain still intact
almost complete loss of cortical tissue though
Hydranencephaly
hydranencephaly
Brain parenchyma compressed to where it is almost nonexistent/nonfunctioning
Hydranencephaly
MCA stroked and all lateral part of brain necrosed
cavitary necrosis of the cerebrum, extending to the surface of the brain
Porencephaly
Porencephaly
all tissue looks like lissencephaly
a cleft of the cerebrum without ventricular communication
Schizencephaly
blood into ventricles of fetus and causes clot and cardiac arrhythmia and death
germinal matrix bleeds
Immature vessels w/o stroma
Hypoxic stress
Ischemic endothelial cells
germinal matrix bleeds
germinal matrix bleed
Neurological disorders that appear in infancy or early childhood and permanently affects body movement and muscle coordination but doesn’t worsen over time
cerebral palsy
muscle tone that is either too stiff or too relaxed and appears before child reaches 3
ataxia
Cerebral palsy
