Pedia 👶 Flashcards
Gyral pattern is established at what week?
38 weeks
Pattern of Myelination: True or False
Back to Front
Caudad to Cephalad
Central to Peripheral
True
Sequence of DEVELOPMENT of the corpus callosum:
Genu>body>isthmus>Splenium
True
Sequence if MYELINATION of the Corpus Callosum:
Genu> body> isthmus
FALSE
Splenium> genu
(Posterior to Anterior)
Pattern of vascularity in Preterm neonatal brain wherein the penetrating arteries supply the periventricular regions by extending INWARD from the surface of the brain
VentriculoPETAL
Pattern of vascularity where in the blood flow goes AWAY from the ventricles extending into the brain from the lateral ventricles; the intervascular border is moved peripherally to parasagittal region, hence affecting the subcortical white matter and parasagittal region in hypoxic injury
VentriFUGAL
Type of asphyxia with INTACT autoregulation, hence, there is redistribution of blodd flow to the hypermetabolically deep gray matter structures resulting to INJURY predominantly in the WATERSHED zones of the cerebrum
Mild to Moderate asphyxia
Type of asphyxia characterized by loss of autoregulation resulting to injury of the vulnerable regions such as the deep gray matter and early or active myelinating fibers.
Profound Asphyxia
Effects of hypoxic ischemic injury in premature infants (< 36 weeks)
- Geminal matrix hemorrhage
- Intraventricular hge
- Periventricular White Matter Injury
Cranial US - preferred modality for evaluation
Germinal matrix hemorrhage extending into and distending the ventricles.
Grade III
Grade I - Mild; confined to the GM notch
Grade II - Intraventricular extension with no associated distention of the ventricle.
Grade IV- Hemorrhagic venous infarct in the periventricular white matter.
This hypoxic brain injury is due to the selective vulnerability of the periventricular white matter secondary to the ventriculoPETAL pattern of vascularity in the pretem infant.
Periventricular Leukomalacia
US: Echogenic lesion in the white matter adjacent to the atria of the lateral ventricles.
Destructive lesions PRIOR to 28-30 weeks results in cavitation (PORENCEPHALY) True or False?
True
*capacity to develop gliosis does not occur until 28-30 weeks.
PVL Grading characterized by INCREASE periventricular echogenicityin deep WM into SUBCORTICAL cysts.
Grade IV
Grade I : Increase periventricular echogenicity WITHOUT cystic formation persistent for > 7 days.
Grade II: SMALL periventricular cyst.
Grade III: EXTENSIVE periventricular cyst in occipital and frontoparietal regions.
Perinatal Arterial Ischemic Stroke occurs between 20 wks AOG to 28 postnatal days, commonly affecting the MCA and is usually seen in TERM neonates. True or False?
True
Most common cause of small amounts of Subarachnoid, subdural and intraventricular hemorrhages in the TERM New Born
Normal Delivery
MC congenital heart disease?
Bicuspid aortic valve
Edema which may be accompanied by hemorrhage within the SUBCUTANEOUS tissues typically seen after vaginal delivery. It is NOT LIMITED by sutures and resolves within a few days without complication.
Caput Succedaneum
SUBPERIOSTEAL HEMORRHAGE CONFINED BY SUTURES which may ba ssociated with skull fractures and epidural hematomas. Increases in size after birth and may calcify.
Cephalhematoma
Most common cause of neonatal brain abscess
- Citrobacter
- Serratia
- Proteus
Most common form of pediatric CNS infection
Bacterial Meningitis
Neonate: GBS, E. coli
>1 yo: HiB, S. pneumonia, E. coli and N. meningitides
Typical imaging findings of CNS VIRAL INFECTION
US: Echogenic
CT: HYPOdense
MR: T2/FLAIR HYPERintense
Earliest sign og VIRAL encephalitis on MRI
Restricted diffusion in DWI
Often caused by REACTIVATION of previous OROFACIAL INFECTION with the following imaging findings:
MR: unilateral/bilateral T2/FLAIR HYPERintense signals in the MIDDLE TEMPORAL lobe
CT: HYPOdensities in the TEMPORAL lobe and INSULAR CORTEX
Herpes Simplex Virus 1 encephalitis
-leptomeningeal and cortical enhancement and focal calcification and hemorrhage may also be present
ATROPHY and resultant ventricular and SAS prominence associated with SUBCORTICAL and BASAL GANGLIA CALCIFICATIONS
HIV encephalitis
Focal or multifocal PERIVASCULAR INFLAMMATORY and DEMYELINATING disorder presenting as T2 HYPERintense signals with corresponding T1 HYPO- to ISOintense signal abnormalities with variable pattern of enhancement (solid, ring-like, or none), affecting both gray and white matter. History of RECENT VIRAL illness or VACCINATION is key in diagnosis
Acute Demyelinating EncephaloMyelitis (ADEM)
Caused by REACTIVATION of MEASLES virus years after infection presenting as T2/FLAIR HYPERintense signals in the cortex and basal ganglia
Subacute Sclerosing Panencephalitis
Cause of intractable epilepsy in children, presenting @ 1-15 yo. Imaging shows
1. HEMISPHERIC atrophy
- T2/FLAIR hyperintense signals in the FRONTAL and TEMPORAL lobes (predominantly WM regions) and in the BASAL GANGLIA
RASMUSSEN’S encephalitis
Bacterial and Viral infections are most commonly transmitted intrapartum and post-natally. True or False
False. Bacterial and FUNGAL
Infections most commonly transmitted in utero
- Syphilis
- Rubella
- CMV
- Toxoplasma
Infections acquired during the 1st trimester cause severe congenital malformations, while that acquired during the 3rd trimester cause destructive lesions. Tue or False
True
Most common serious viral infection in the New Born associated with polyMICROGYRA, especially in the Sylvian Fissure
Cytomegalovirus (CMV)
Congenital viral infection characterized by the following imaging findings:
- Periventricular/subependymal calci or hge.
- Ventricular or Sulcal prominence
- Periventricular and subcortical white matter changes
Cytomegalovirus (CMV)
Splenium should be as thick as the genu at what age?
1 yo
The lateral ventricles have parallel orientation, with posterior dilation (Colpocephaly), upturned anterior horns, and interhemispheric sulci extending up to the 3rd ventriclular margin with associated underrotation of the hippocampi
Complete Agenesis of Corpus Callosum
Seen as truncation of the anterior-posterior dimension of the corpus callosum
Partial Agenesis/ hypogenesis of the Corpus Callosum
Texas Longhorn appearance of the lateral ventricle is seen in this condition
Complete Agenesis of the Corpus Callosum
Partial agenesis of the Corpus Callosum is frequently associated with these interhemispheric lesions
Interhemispheric Cyst or Lipoma
Optic Nerve dysplasia is most reliably diagnosed on
Ophthalmologic Examination
Malformation caused by abnormalities in differentiation and midline cleavage of the prosencephalon on 5th week AOG. Hallmark: abnormal communication of the gray and/or white matter across the midline. There is facial dysmorphism (80%) (hypotelorism, cyclopia, cleft lip/palate)
HOLOPROSENCEPHALY
Gene mutation involving ciliary proteins characterized by vermian hypoplasia, thickening and elongation of the superior cerebellar peduncle (MOLAR sign) clinically manifesting as “panting” or “laughing” respiration with occulomotor apraxia in infancy
Joubert Syndrome
Characteristic enlargement of the ventricular atria
Colpocephaly
Complete absence of cleavage with anterior displacement of the cerebral tissue into “PANCAKE” configuration, large MONOVENTRICLE expanding posteriorly into a dorsal cyst.
Alobar Holoprosencephaly
Lack of separation of the posterior frontal and parietal regions with separation of the anterior frontal and the occipital lobes
SYNtelencephaly
Triad of enlarged posterior fossa, cystic dilation of 4th ventricle and vermian hypoplasia/agenesis.
Dandy-Walker Malformation
Majority of the Neuronal MIGRATION MALFORMATION occurs at what gestational week?
Between 12-24 weeks
A severe in utero brain injury which is attributed to bilateral internal carotid artery occlusion that often result to fetal demise?
Hydranencephaly
Absence of all brain parenchyma supplied by carotid arteries, with preservation of the posterior fossa structures and medial temporal lobes.
Treatment: CSF DIVERSION WITH VENTRICULAR SHUNT
Hydranencephaly
Distinct pattern of WHITE MATTER INJURY in utero (bet 24-34 weeks GA) caused by damage of OLIGODENDROCYTE PRECURSOR CELLS due to HYPOXIA
Periventricular Leukomalacia
This PATTERN WHITE MATTER INJURY shows a symmetric loss of periventricular white matter surrounding the TRIGONES of the lateral ventricles and shows a characteristic ANGULAR morphology of adjacent lateral VENTRICLES
Periventricular Leukomalacia
Also known as WHITE MATTER INJURY OF PREMATURITY
US: hyperechoic in the WM bordering the bodies of the lateral ventricles
MR: Punctate foci of abnormal hyperintensity on T1WI
Periventricular Leukomalacia
Characterized by Hemicerebral ATROPHY, IPSILATERAL compensatory osseous HYPERtrophy, and Enlargement of the FRONTAL SINUS
Dyke-Davidoff-Masson Syndrome
Characterized by Hemicerebral ENLARGEMENT, Ipsilateral osseous hypertrophy and paradoxical ENLARGEMENT of the LATERAL VENTRICLE, and thickened and ill-defined cortical ribbon?
A. Rassmussen Encephalitis
B. Dyke-Davidoff-Masson Sundrome
C. Hemimegalencephaly
D. HIV encephalitis
HEMIMEGALENCEHALY
Characterized by HEMICEREBRAL ATROPHY, T2/FLAIR HYPERintense signals in he FRONTAL and TEMPORAL lobes, as well as in the BASAL GANGLIA?
A. Rassmussen Encephalitis
B. Dyke-Davidoff-Masson Sundrome
C. Hemimegalencephaly
D. HIV encephalitis
RASMUSSEN Encephalitis
complete failure of division of the promesencephalic vesicle. A monoventricle is identified with “kissing choroid” by ultrasound. The thalami and basal ganglia are fused. The falx, corpus callosum, and interhemispheric fissure are absent
Alobar Holoprosencephaly
Fetal vermis is not completely developed until how many weeks gestation?
18 weeks AOG
It is characterized by fluid collection posterior inferior to the vermis and COMMUNICATES with the 4th ventricle. The vermis is typically intact. The tentorium is ELEVATED. No connection with the subarachnoid space is noted.
a. Dandy-walker
b. mega cisterna magna
c. Chiari Malformation
d. Arachnoid Cyst
Blake’s Pouch Cyst
Retrocerebellar cyst that COMMUNICATES with the 4th ventricle. The POSTERIOR FOSSA is ENLARGED, with an elevated tentorium. The vermis is INCOMPLETE, elevated, and rotated (>180 deg):
a. Dandy-walker
b. mega cisterna magna
c. Chiari Malformation
d. Arachnoid Cyst
Dandy-Walker Malformation
Cystic lesion taht amy develop in the posterior fossa, causing mass effect in the otherwise NORMAL VERMIS. It does NOT COMMUNICATE with the 4th ventricle and the tentorium MAY BE elevated.
a. Dandy-walker
b. mega cisterna magna
c. Chiari Malformation
d. Arachnoid Cyst
Arachnoid Cyst
*MC locaion: MIDDLE cranial fossa (50-60%)
other common location:
Retrocerebellar
Galassi classification of middle cranial fossa arachnoid cysts characterized by small, spindle-shaped, limited to the anterior portion of the middle cranial fossa, below the sphenoid ridge, and FREELY COMMUNICATING with the subarachnoid space. This type of represents the most common type of arachnoid cyst.
A. Type I
B. Type II
C. Type III
D. Type IV
Type I
Type II: extends to the Sylvian Cistern, displaces the temporal lobe with slow communication to subarachnoid space
Type III: LARGE, fills the whole middle cranial fossa, w/ midline shift, little communication with subarachnoid space
Results from arrest of migration of neuroblasts with abnormal cortical lamination and failure of sulcation
Agyra/ Pachygyra
This results from excessive folding of the cerebral cortical cells layers w/ fusiosn of the gyral surface. It is common after CMV infection in the 2nd trimester. It appears as mulitple SMALL, IRREGLAR SULCI.
Polymicrogyra
This is the leading infectious cause of sensorineural hearing loss. It is cahracterized by periventricular and subependymal calcifications. Ct may demonstrate Mondini malformation.
CMV infection
*Mondini Malformation
- absent interscalar septum
- large vestibule
- enlarged vestibular aqueduct
Maternal infection with toxoplasmosis after 20 weeks AOG has LESSER rate of transmission to fetus with less severe sequela such as blindness, epilepsy, and mental retardation.
FALSE; much HIGHER rate of transmission
The following are imaging findings of congenital TOXOLASMOSIS except:
a. Non-shadowing cerebral and hepatic calcifications
b. intracranial calcifications mau be periventricular or random distribution.
c. Subependymal cysts
d. “Candle stick” sign
e. None of the above.
None of the Above
Findings of pituitary hypoplasia, absent septum pellucidum, and optic dysplasia:
A. Syntelencephaly
B. Septo-optic Dysplasia
C. Semilobar Holoprosencephaly
D. Lobar Holoprosencephaly
Septo-Optic Dysplasia
P-A-O
P ituitary hypoplasia
A bsent septum pellucidum
O ptic dysplasia
Refers to the dilation of the ventricular trigone and occipital lobes due to agenesis of the corpus callosum
Colpocephaly
Texas longhorn, Viking Helmet, Race Car appearance
Corpus Callosal Agenesis
Most severe form of malformation due to generalized ABNORMAL transmantle MIGRATION. The brain is smooth with hour glass shape due to mild infolding of the Sylvian fissure
Lissencephaly
It results from the DISRUPTION of the normal TERMINAL neuronal MIGRATION resulting in an increased in small gyri; associated thickened dysplatic overlaying of leptomeninges
Polymicrogyra (PMG)
- often BILATERAL
Most common location of Polymicrogyra
PeriSylvian Cortex
Abnormal Gray matter-lined cleft extending from the ventricular ependymal surface to the pial cortical surface. The cleft is lined by polymicrogyra, extending full length of the cleft.
SCHIZENCEPHALY
Open Lip - communicates w/ ventricle
Close Lip - cleft walls closely appose
Unilateral schizencephaly is often associated with contralateral periSylvian polymicrogyra (PMG). True or False
TRUE
*Porencephaly vs Schizencephaly
Porencephaly = lined by white matter
Schizencephaly = lined by PMG
Trapped nest of gray matter within the brain, which appear as variable sized nodules that are isointense to gray matter in all sequences.
Heterotopias
Does NOT enhance or CALCIFY
Results from early ARREST of MIGRATION. Double Cortex syndrome. Symmetric band of gray matter is separated from the overlying cortex by a thin band of white matter producing a three-layer cake appearance.
Band Heterotopia
*Lissen = smooth agyric, thick cortex
*Band heterotopia= thin cortex, multiple gyri, shallow sulci
Results from abnormal PROLIFERATION and DIFFERENTIATION of neurological precursors:
a. Band heterotopia
b. Focal cortical dysplasia
c. Schizencephaly
d. Lissencephaly/Pachygyra
Focal Cortical Dysplasia (FCD)
*Histo Hallmark:
Lack of normal cortical lamination
* Subcortical HYPERINTENSE T2 w/ adjacent subtly thickened cortex
FCD types
Type I = Alteration in cortical layering
Type II = Cortical dyslamination/ Dysmorphic neurons
Type III = Encephaloclastic lesion
True
*FCD present as intractable epilepsy
Radial extension of the balloon cells and ectopic neurons into the deep white matter seen in type I FCD
Transmantle Sign
Differential diagnosis for posterior fossa cyst
D andy walker Complex
A arachnoid cyst
M ega Cisterna Magna
B lake’s pouch cyst
Angle formed by 2 lines along the anterior surface of the vermis and the dorsal surface of the brainstem; Normal is <18 deg
Tegmento-Vermian Angle
Line drawn horizontally from the fastigium (dorsal point of the 4th ventricle) and most dorsal point of the vermis taken in sagittal view
Fastigium-Declive line
posterior fossa = enlarged
vermis = hypoplastic
T-V angle = >18
Classic Dandy-Walker Malformation
Posterior fossa = Normal
Vermis = hypoplastic
T-V angle = >18
Vermian Hypoplasia
Posterior fossa = Normal
Vermis = Normal
T-V angle = >18 deg
Blake Pouch Remnant
*Due to non-perforation o fthe foramen of Magendie
Posterior fossa = Normal
Vermis = Normal
T-V angle = Normal
Mega Cisterna Magna
*Normal size Cisterna Magna
2-10 mm
Largest of the subarachnoid cisterns
Cisterna Magna
a.k.a cerebellomedullary cistern
Midline fusion o fthe cerebellar hemispheres & absence of vermis; best seen in coronal view as cerebellar folia that is contiguous across the midline
Rhombencephalosynapsis
Failure of decussation of the superior cerebellar peduncles; superior cerebellar peduncles appear thickened Molar Tooth appearance
Joubert Syndrome
Increased/prominent inner table convolutions, sellar erosions, and enlargement.
Copper Beaten Skull
- seen in:
Craniosynostosis
Hydrocephalus
Hypophosphatamia
Closing of fontanelles:
Posterior Fontanelle
Anterior Fontanelle
Metopic Suture
2- 3 months - post fontanelle
18 months - ant fontanelle
1 yo - metopic suture
Closed suture: Sagittal
Head shape: Long, narrow
Scaphocephaly/ Dolicocephaly