Neurology I- VI Flashcards
Anencephaly
Encephalocele
myelomeningocele
Arnold-chiari malformation
Myeloschisis
These conditions have problem with what neural developmental process?
Primary neurulation (dorsal induction)
3-4 weeks
FYI: myeloschisis is a flat neural tube defect without a layer of skin covering the opening in the spine. (the spinal cord and the surrounding nerve tissue are also exposed to the amniotic fluid. similar risks and symptoms as myelomeningocele)
what does each of the following Prefix/Suffix mean?
An- or a -
encephalo-
myelo-
meingo -
holo -
- cele -
pros -
An- or a - : “not”, “without”
encephalo- : “brain”
myelo- : “spinal cord”
meningo - : “membrane” , “meinges, coverings of the brain and spinal cord”
holo - : “entire”, “complete” (i.e. no cleavage)
- cele : “hernia”, “swelling”
pros - : “before”, “forward”
tethered cord, lipoma, teratoma spinal cysts, myelocystocele, meningocele-lipomeningocele
These conditions have problem with what neural developmental process?
Secondary neurulation (dorsal induction)
4-7 weeks
These are are spinal cord and lower sacral segment
aprosencephaly
holoprosencepahly
Midline development defect:
agenesis of corpus callosum,
agenesis or absence of septum pellucidum,
septo-optic dysplasia
These conditions have problem with what neural developmental process?
Prosencephalic development (ventral induction)
(ventral induction)
2-3 months
Micrencephaly
Macrencephaly
These conditions have problem with what neural developmental process?
Neural and glial proliferation
3-4 months
Micrencephaly: abnormal smallness and underdevelopment of brain
Macrencephaly: hypertrophy of the brain
Schizencephaly
Lissencephaly
Pachygyria
Polymicrogyria
These conditions have problem with what neural developmental process?
Neuronal migration
3-5 months
Schizencephaly: abnormal clefs of the brain
Lissencephaly: underdevelopment of gyri, smooth brain
Pachygyria: broad, abnormally large gyri, lead to less sulci
Polymicrogyria: numerous small convolutions
Mental deficiency, Trisomy 21, Fragile X, Autism, Angelman, Prematurity
has issue in what neural development process.
Neuronal organization
(axonal outgrowth and proliferation, dendritic and synapse, synaptic rearrangements
what is the last pathway to myelinate
association bundle (prefrontal cortex with temporal and parital lobe): complete at 32 yrs of age.
myelination normally happens birth to years.
Corticospinal tract myelinate 38 wk GA to 2 year.
Anecephaly is due to failure of __ closure. (It happens within __day of gestation)
Encephalocele is due to failure of __ closure.
Myelomeningocele is due to failure of ___ closure
Anecephaly - anterior tube closure (within 26 days)
Encephalocele - rostral neural tube closure
Myelomeningocele - posterior neural tube closure
All are Primary neurulation defect
How are Anecephaly and Aprosencephaly different?
Anecephaly: primary neurulation defect. failure of anterior tube closure. Degeneration of forebrain (no skull, scalp, large amount of brain tissue).
female > male
hispanic women, increase risk with maternal hyperthermia, maternal folate, copper, zinc defieincy.
^ recurrent risk 2-6%.
association with other abnormalities
Aprosencephaly: abnormal development in prosencephalic stage in formation. There is abscence of telencephalon and diencephalon with porencephalic remnant. minimal brain volume. Has intact skull, hair, and dermal coverings.
cyclopia or no eye. associated external genitalia and limb abnormalities.
autosomal recessive
For anecephaly, during prenatal testing, what level is elevated in maternal serum
maternal alpha-fetoprotein.
Encephalocele is associated with what syndrome?
Does encephalocele has a genetic cause?
Meckel-Gruber syndrome.
Genetic cause of encephalocele is suggested. risk higher in families with history of NTD.
Maternal alpha-fetoprotein level in encephalocele is __ ? (higher, lower, norrmal)
normal
where is the most common location of defect in encaphlocele? which locations has better prognosis.
Occipital more common
Frontal has better prognosis
what is cranial meningocele?
a type of encephalocele but does not have CNS tissue protruding through the lesion.
Difference between Meningocele and Myelomeningocele?
Meningocele: defect in spinal canal, meninges herniate through the defect.
Myelomeningocele: spinal cord, meninges herniat through the defect.
What maternal medications and what maternal medical conditions increase risk of NTD?
valprroate
carbamazepine
maternal diabetes
NTD might need VP shunt due to risk of hydrocephalus
level of lesions, segmental innervation, reflex present and ambulation potential
Do we need to know? (page 6)
What are the difference and similarities between Arnold-Chiari malformation and Dandy-Walker Malformation?
Name/describe two types of Arnold-chiari malformation.
What other CNS conditions are Dandy-Walker highly associated with?
Arnold-Chiari Malformation:
- primary neurulation defect.
- caudal displacement of cerebellar tonsils below foramen magnum.
*Type I: most common. caudal displacement of cerebellar tonsils below foramen magnum. 4th ventricle and brainstem in normal position.
associate with syringomyelai, hydromelia, skeletal anoamlies.
*Type II: in infants. more extensive elongation and caudal displacement of cerebrella tonsils, 4th ventricles, choroid plexus and brainstem, into the cervical spinal canal.
associated with hydrocephalus, myelomeingocele.
Dandy-Walker Malformation:
- occurring very early in neurological developmental phase.
- AGNESIS / Hypoplasia of the cerebellar vermis, cystic dilation of the 4th ventricle, enlargement of the posterior fossa.
- associated with hydrocephalus, risk of motor and cognitive delays.
holoprosencephaly’s epidemiology and association
increase risk in IDM. familiar reoccurences described.
30-50% w/ chromosomal anomalies (T13)
50% w/ extracranial abnormalities.
Holoprosencephaly happens in __ stage of neurodevelopment? It’s the primary defect in __?
prosencephalic stage
defect in cleavage.
4 types of holoprosencephaly
middle interhemispherice varient (MIHV)
Lobar
Semilobar
Alobar
Agenesis of Corpus Calllsum happens in __ stage of neurodevelopment? It’s the primary defect in __?
cause/inference
prosencephalic stage
defect in mideline development
some x-linked dominant and some autosomal recessive.
Fetal infection earlier in pregnancy or intrauterine alcohol exposure.
What is septum pellucidum?
Abesecence of septum pellucidum is associated with what?
double thin vertical membrane separating the anterior horns of the left and right lateral ventricles
(cavum septum pellucidum is the potential space in between the two double membranes)
learning disabilities, vision problems, seizures, behavioral issues, septo-optic dysplasia
Diagnosis of septo-optic dysplasia criteria
2 out of 3 features:
optic nerve hypoplasia
pituitary gland dysfunction
absence of septum pellucidum
Name the three main cerebral arteries and the area of they supply
Anterior Cerebral Artery:
from internal carotid
supply medial, frontal, parietal lobes, AND caudate
Middle:
from internal carotid
supply lateral hemispheres
Posterior:
from basilar artery, which from vertebral artery
supply midbrain, occipital lobes and inferior temporal lobes
cerebral perfusion pressure (CPP) equation
CPP = ?
CPP = MAP - ICP
ICP: intracranial cerebral pressure
MAP: mean arterial pressure
If given BP and not MAP, remember:
MAP = 2/3 DBP + 1/3 SBP
autoregulation with blood pressure change:
describe the curve in premature infant and curve in normal state
what’s x-axis and what’s y-axis
x-axis: BP
y-axis: cerebral blood
autoregulation: with increase BP, cerebral blood flow can remain stable for a period of time.
no regulation: BP and cerebral flow are directly correlated.
PaO2 and PaCO2 impact on CBF (cerebral blood flow)
Increased PaCO2 increases CBF (cerebral blood flow)
Decrease PO2 increases CBF.