review Flashcards
LUCKENSCHADEL skull?
also known as lacunar skull
Seen almost exclusively with Chiari II malformations
The inner table is more affected than the outer, with regions of apparent thinning (corresponding to nonossified fibrous bone) of the skull vault.
beaten brass skull?
The appearance of copper beaten skull is associated with raised intracranial pressure in children. Convolutional markings may be normal, but are usually confined to the posterior part of the skull’s inner table.
Pacchionian granulation?
aka Arachnoid granulation
most frequently occurs in a parasagittal location and can cause an osteolytic, sharply circumscribed lucency on a skull x-rays, or a filling defect in dural venous sinuses, which can be mistaken for dural venous thrombosis. They increase in size with age and are seen in approximately two-thirds of patients.
HYPEROSTOSIS FRONTALIS INTERNA, who gets it?
Older females (>35 yoa)
90% female
DDx for wormian bones?
P—pyknodysostosis O—osteogenesis imperfecta R—rickets healing K—kinky hair syndrome (menkes) C—cleidocranial dysplasia H—hypothyroidism/hypophosphatasia O—otopalatodigital syndrome P—primary acro-osteolysis (Hajdu-cheney)/pachydermoperiostosis S—syndrome of down
persistent metopic suture seen in what 3 conditions?
Can be seen in cleidocranial dysostosis, pyknodysostosis and downs syndrome
Chamberalin’s and McGregor’s measurements?
3mm, 4.5mm (yochum says 7mm for McG, he is wrong, even by his own reference)
2 most common syndromes associated with craniosynostosis are?
Aperts and Crouzons
what synostosis is seen in apert’s?
coronal synostotis with an malformed and short cranial base resulting in a short and high skull (brachyturricephaly)
3 metabolic conditions associated with premature suture fusion?
hyperthyroidism, hypercalcemia, hypophosphatasia
MICROCEPHALY?
premature fusion of all sutures
Can get cloverleaf skull
MCC: defective development of brain which doesn’t require the skull to enlarge
SCAPHOCEPHALY?
aka DOLICHOCEPHALY
Elongated head A-P due to premature closure of sagittal suture
TRIGONOCEPHALY?
premature fusion of metopic suture, small pointed forehea
BRACHYCEPHALY
Short AP diameter, wide transverse diameter
Bilateral coronal suture closer
TURRICEPHALY?
Bilateral coronal and/or lambdoid synostosis, skull is shortened with upward growth (i.e. increased vertical diameter)
PLAGIOCEPHALY?
Unilateral premature fusion of coronal or lambdoid suture (M/C synostosis)
DYKE-DAVIDOFF-MASSON SYNDROME?
(1) Decrease size of ½ of cranium due to hypoplasia/atrophy of a cerebral hemisphere
(2) Mental retardation, Atrophy of body side opposite lesion
(3) Skull may be thickened to accommodate for small brain size
defects in sphenoid bone and absent posteriosuperior orbital wall -> pulsating exopthalmos due to temporal meningocele/herniation
NEUROFIBROMATOSIS
ddx for floating teeth?
EG, periodontitis, ameloblastoma, F/D, desmoplastic fibroma, HPT, Giant Cell reparative granuloma, odontogenic cyst (gorlins), Infection (actinomycosis)
Battle’s sign?
ecchymosis over mastoids, indicates temporal bone fx
Temportal bone fractures are longitudinal how often?
70-90% of temporal bone Fx’s
M/C Fx of facial bones?
Tripod Fx
due to blow over malar eminence, primarily involves zygoma
affects zygomatic arch, orbital process, and maxillary process
Dorsal induction abnormalities?
Anencephaly, Cephalocele, meningocele, encephalocystomeningocele
Ventral induction abnormalities?
Holoprosencephaly, Dandy-Walker malformation, Cerebellar agenesis, Septo-optic dysplasia, Arhinencephaly
What and when is dorsal induction?
When neural plate appears and forms rudimentary components of CNS
Primary neurulation, 1st 3-4 wks
Secondary neurulation, 4-5th wks
What and when is ventral induction?
5-10th wks
Anatomic components of brain formed (pros, tele, di, my and rhombencephalon, etc)
Prosencephalon divides into what?
Tele and diencephalon
Teleencephalon is cortex, basal ganglia, etc
Diencephalon is thalamus, etc
Mesencephalon includes what?
Tectum, Cerebral peduncle, Pretectum, cerebral aqueduct
Rhombencephalon divides into what?
Met and myelencephalon
Metencephalon: Pons, Cerebellum
myelencephalon: Medulla Oblongata
Neuronal proliferation abnormalities?
Neuronal proliferation occurs in the 2nd-4th months
The phacomatoses are examples
Migration abnormalities?
Occurs in the 2nd-5th months
Examples include: Lissencephaly (agyria), Pachygyria, Polymicrogyria, Schizencephaly, Heterotopias
Common associated finding with septo-optic dysplasia?
50-67% have diabetes insipidus
schizencephaly ~50%
septo-optic dysplasia AKA?
de Morsier syndrome
Lisch nodules?
small hamartomas/low grade malignancies on anterior iris, seen in 90% of those with NF
Ventral induction abnormalities?
Holoprosencephaly, Dandy-Walker, other cerebellar dysplasias, septo-optic dysplasia, arhinencephaly
% of NF’s that malignantly degenerate?
5-15(or up to 30)% (neurofibrosarcoma)
In NF, 5. Multifocal high signal lesions on T2 in globus pallidus, brainstem, cerebellum, thalamus, internal capsule are probably what?
M/C low grade benign astrocytomas or hamartomas
intramedullary tumors in NF 2?
ependymomas
Sturge-Weber syndrome AKA?
encephalotrigeminal angiomatosis
30% of SW pts have what ipsilateral to facial nevus?
scleral angiomatosis
Tuberous sclerosis aka?
Bourneville’s
Locations of hamartomas in TS?
brain & retina, skin, Heart, Kidney
e Subependymal nodules?
Tuberous Sclerosis
90% of pts on CT, iso to grey matter, 88% have calcification on CT, 31% have ring enhancement on MR
Subependymal giant cell astrocytoma - who, what, where, what do they look like?
benign tumour, seen almost exclusively in tuberous sclerosis (but <10% have them)
M/C at foramen of Monro (subependymal), homogeneous enhancement, can obstruct foramen
90% have partial calcification, iso to parenchyma on T1, hyper T2
Clinical findings in VHL?
increased intracranial pressure, cerebellar dysfunction, subarachnoid hemorrhage, polycythemia
associated findings/malignancies with VHL?
Renal cell carcinoma (25-40%), pheochromocytomas (10%), cystic disease of Kidney/pancreas/Liver (50-70%)
types of schizencephally?
Type I – closed-lip – cleft walls are in apposition
Type II – open-lip – walls are separated, M/C
Major ddx for schiz?
porencephalic cyst – due to insult to normally developing brain, line with white matter, not grey
% of low grad astrocytomas that progress?
50% of surgically Tx’d lesions evolve into anaplastic astrocytomas or GBMs (M/C/C of death = degeneration into a higher-grade tumor)
Oligodendroglioma’s are MC found where?
MC frontal lobes, occasionally parietal. 85% supratentorial
40% of all pineal region neoplasms?
Germinomas
possible lab finding in germinoma, teratoma & Choriocarcinoma?
May produce beta-HCG in CSF, serum
15% of pineal masses?
teratomas (MC male, up to 8:1)
only pineal region tumor to undergo spontaneous hemorrhage?
Choriocarcinoma
2nd M/C tumor in pineal region?
Glial neoplasms, M/C astrocytoma
size cutoff for micro vs macroadenomas?
10mm
ddx for craniopharyngioma?
Rathke’s cleft cyst, necrotic pituitary adenoma, thrombosed aneurysm, cystic hypothalamic or opticochiasmatic glioma
ependymoma found where in kids and adults
More common in 4th ventricle in kids
More common in supratentorial parenchyma in adults, ventricular lesions in adults occur in body or trigone of lateral ventricle
M/C brain tumor in kids <2 yoa, 86% occur before 5yoa?
Chroid plexus papilloma
Chroid plexus papilloma location in kids vs adults?
4th ventricle is M/C in adults, 2nd M/C kids (40%)
lateral ventricles are 2nd M/C in adults but M/C in kids (50%)
Hemangioblastoma may secrete what and do what to the blood?
polycythemia due to erythropoietic factor within neoplasm
If AVM is in the temporal lobe, greater risk for what?
8% of pts >20 yoa with and AVM develop epilepsy, 37% if the AVM is in the temporal lobe
CSF signal mass that displaces vessels?
Arachnoid cyst. Main DDx is epidermoid tumor which encases arteries and nerves
3 MC cerebellopontine angle masses?
- Schwannoma
- Meningioma
- Epidermoid cyst
MC location for intracranial lipoma?
80% are supratentorial, 50% of which occur near the splenium of the corpus callosum
term for region surrounding infarcted tissue?
penumbra
Lacunar infarcts – 15-25% of all strokes, occur where? are usually associated with what?
Small, deep cerebral infarcts, M/C located in basal ganglia, internal capsule, and thalamus, M/C multiple, usually associated with HTN
Infarction of what area results in expressive aphasia?
Broca’s
how often are berry aneurysms multiple?
15-20% are multiple, with 75% have 2 aneurysms, 15% have 3, 10% >3
Female more likely to have multiple
MC location for aneurysm?
90% occur in circle of Willis, 40% of which are at anterior communicating artery
hemorrhagic infarct usually due to what?
M/C due to reperfusion after ischemia
MC location for DAI to occur?
Grey/white junction (66%), CC 20%
most lethal head injury?
SDH, up to 30% of fatal injuries
period between traumatic event and onset of coma/neuro deterioration in EDH?
lucid interval
85-95% of EDH are due to a fx that lacerates what artery?
middle meningeal artery