Pediatrics Neuro Flashcards
Baby brain signal differences
Opposite adult pattern because myelin high water content (adult=cholesterol, glycolipids). T1 at age 1, T2 at age 2.
Most idea signal to assess myelination in kids?
T1 before age 1, T2 after.
Order and timing of brain myelination
- brainstem, pst limb internal capsule myelinated at birth.
- Back to front, inf to sup (OC at 12 mo –> FL at 18mo)
- subcortical FTP at 40 mo
Changes in signal of pituitary, globes pallidus, and bone marrow
- Pit = T1 & T2 bright (ant –> iso at 2 mo, pst T2 hypo)
- GP=darker (Fe incr)
- Bmarr (active T1 Hypo –> fatty T1 hyper)
order of sinus development
- MESF, complete by 15 yrs
- ME present at birth, visible by 5mo/1yr (respectively)
- FS (~5 yrs on CT)
*I (ME) can Smell Finally!
colpocephaly-what is it, ass?
asymmetric dilation of occipital horns
- Colpocephaly is a congenital brain abnormality in which the occipital horns - the posterior or rear portion of the lateral ventricles (cavities) of the brain – are larger than normal because white matter in the posterior cerebrum has failed to develop or thicken.
- cc genesis, colocephaly, pericallosal lipoma
order of corpus callous formation
Front to back –> rostrum
CC parts (Good Bodies In utero Start Right)
Rostrum under. Genu, body, isthmus, splenium.
Probst bundles
WM tracts destined to cross the CC
Probst bundles or longitudinal callosal fascicles denote white matter fibers normally destined to cross the corpus callosum that instead parallel the interhemispheric fissure in patients with agenesis of the corpus callosum. These lead to widely spaced lateral ventricles forming the characteristic racing car sign.
CC agenesis findings
- abscent cc
- widely spaced lateral ventricles (steer horn, vertical ventricles)
- many other associations (MC anomaly seen with other cos malformation?), MC= lipoma.
MC locs intracranial lipomas ass with cc agenesis
inter hemispheric (50%), quad cistern (25%)
Iniencephaly
- deficient occipital bone with defect in the cervical region. (Inien=back of head/neck)
- star gazing
Inien
Back of head/neck
True or false-hindbrain preserved in anencephaly
True
what’s the most common location encephalocele and most classic association
occipital. Chiari III
Rhombencephalosynapsis-what is it, features, classic imaging, associations
- Absent Vermis –> abN fusion cerebellum.
- Rounded fastigial point, absent primary fissure, small 4th Vt, aqueduct stenosis–> hydrocephalus
- classic image: transversely oriented/continuity of single-lobed cerebellum
- association=holoprosencephaly, aqueductal stenosis
Joubert Syndrome-path, features, classic imaging, associations
- AR ciliopathy –> hindbrain malformation –> dysgen rotated vermis/small cerebellum –> MOLAR TOOTH
- large 4th vt, absent fastigial point and primary fissure, absent pyramidal decussation
- Ass- retinal dysplasia (50%), MCDK (30%), liver fibrosis (COACH)
molar tooth
dysgenesis of bs isthmus –> elongation pontomesencephalic junction –> deepening of interpeduncular fossa –> thick, straight, Long superior cerebellar peduncles
3 consistent findings of “Classic Dandy Walker”
Triad:
1) Vermis hypoplasia (usually inf pt). Cerebellar hemispheres displaced anterolateral (shape/volume maintained). Vermis upward rotation
2) torcular lamboid inversion (2/2 elevated tentorium.)
3) dilated 4th Vt
buzzword “torcular lamboid inversion”
what is the lambdoid and torcula?
Classic DW
- torcula-confluence of sinuses
- lamboid- BL sutures connecting parietal and occipital bones
What defines and comprises the Dandy-Walker continuum?
- Group of pst fossa malformations. In order of severity:
1) classic DWM
2) Vermian hypoplasia (VH)
3) Blake pouch (BP) remnant/cyst
4) Mega Cisterna magna (MCM)
manifestation classic DW
- OB screen
- intracranial P, macrocephaly (1mo)
classic DW associations
- hydrocephalus (90%)
- CNS malformations (~40%)- cc agen, encephalocele, heterotopia, polymicrogyria, etc.
vermis hypoplasia/variant DWM
- small/hypoplastic vermis with dilation of 4th Vt.
- vermis superiorly rotated, no torcular lamboid inversion
- Hydro (+) (25%)