Neuro Flashcards
Ddx intraaxial hemorrhage
HTN, tumor (primary or mets), vascular malformation (cavernoma, AVM), trauma, amyloid, venous infarct, transformation of ischemic stroke
gelatinous pseudocysts - who? describe? caused by?
HIV pts
perivascular spread of infection from
cryptococcus, toxo, TB, fungal, angiocentric lymphoma
Intraventricular mass in adult
glioma (astrocytoma, subependymoma, giant cell astrocytoma), meningioma, ependymoma, choroid plexus papilloma, metastasis, cystercosis, central neurocytoma (young adult)
intraventricular mass in child
choroid plexus papilloma, ependymoma, primitive neuroectodermal tumor (PNET), teratoma, and astrocytoma
Posterior dysmyelinating disease
Adrenoleukodystrophy (unless it’s a girl - very unlikely in this X-linked disease) - has a leading edge of enhancement
PRES (ask about HTN)
Anterior dysmyelinating disease
Alexander
Childhood onset Alexander disease is sporadic and typically presents with macrocephaly, rapid neuorological deterioration, seizures and spasticity, and retarded psychomotor development
Describe pattern of metachromatic leukodystrophy
Diffuse, sparing of subcortical U fibers, “tiger striping”
How do you grade an AVM?
Spetzler-Martin
Size of nidus (6cm)
location (eloquent?)
draining vein deep or superficial
What is a ganglioglioma
low grade, typically temporal lobe.
Solid or partially cystic mass.
Ddx temporal lobe mass with cystic component
Ganglioglioma PXA: pleomorphic xanthoastrocytoma hemangioblastoma (can have cystic component) pilocytic astrocytoma met (lung, breast, etc.) oligodendroglioma (look for calcs on CT) DNET (bubbly on T2) all cystic - neurocysticercosis
Name the CNS vascular malformations
capillary telangiectasia, AVM, cavernous hemangioma, developmental venous anomaly
periventricular cystic spaces in a child
periventricular leukomalacia from HIE (hypoxic ischemic encephalopathy) in former premie
hypothalamic/suprasellar masses - adult
craniopharyhgioma, pituitary adenoma (maybe with hemorrhage), teratoma, aneurysm, rathke cleft cyst, chordoma,
mets
Wernickes Encephalopathy - what is it? findings?
Thymine (B1) deficiency
symmetrical increased T2 signal in the thalami, mamillary bodies, tectal plate, and periaqueductal area
Ddx leptomeningeal enhancement
meningitis (bacterial, fungal, TB) leptomeningeal carcinomatosis (CNS) lymphoma/leukemia sarcoidosis (moya moya)
intracranial hypotension - what? findings?
CSF leak (usually in spine)
cerebellar tonsillar herniation
dural venous sinus distention
dural (pachymeningeal) enhancement
Ddx dural/pachymeningeal enhancement
infection: bacterial, fungal, TB intracranial hypotension post-op dural mets (breast and prostate) sarcoid lymphoma
What’s the difference between leptomeninges and dura/pachymeninges?
Lepto = pia and arachnoid (gyriform) Pachymeninges = dura (follows dural reflections)
Enlarged lateral and third ventricles, small 4th ventricle
aqueductal stenosis
Multiple hemosiderin deposits in brain (“black dot” differential)
DAI, mets, amyloid, cavernomas, neurocystercercosis (calcification internally)
ring-enhancing lesions in the CNS
GBM (thick rim) abscess (restricted diffusion) CNS lymphoma with immunocompromised host tumefactive MS (incomplete ring) sequestered subacute infarct resolving hematoma radiation necrosis Toxoplasmosis (neurocystercercosis - some enhance, some not)
lesion in 3rd ventricle
colloid cyst, aneurysm, neurocystercercosis, subependymoma
NF2 lesions
meningioma, schwannoma (esp 8th nerve), ependymoma
what is a phakomatosis? name some
neurocutaneous disorder characterised by involvement of structures that arise from the embryonic ectoderm (thus central nervous system, skin and eyes)
neurofibromatosis type 1 (NF1)
neurofribromatosis type 2 (NF2)
tuberous sclerosis
encephalotrigeminal angiomatosis: or Sturge-Weber syndrome
von Hippel-Lindau disease
ataxia telangiectasia (etc…)
lesions in Tuberous Sclerosis
cortical tubers subependymal nodules subependymal giant cell astrocytomas (SGCA) renal angiomyolipomas (AML) renal cysts cardiac rhabdomyoma(s) LAM (lungs)
lesions in NF1
neurofibromas, pheochromocytoma malignant peripheral nerve sheath tumour (MPNST) previously known as neurofibrosarcoma overal risk of developing a MPNST is ~10% *optic nerve glioma* Wilms tumour rhabdomyosarcoma renal angiomyolipoma glioma juvenile pilocytic astrocytoma diffuse brainstem glioma spinal astrocytoma and spinal pilocytic astrocytoma carcinoid tumour(s) ganglioglioma leukemia
Sturge-Weber syndrome in the brain: features?
leptomeningeal hemangioma results in a vascular steal affecting the subjacent cortex and white matter producing localised ischemia. The majority of cases (~ 80%) have unihemispherical involvement
Look for port wine stain on face
later get calcification starting subcortically
Hemangioblastoma - where? who gets them?
posterior fossa, spine. ~young adults. Consider vHL (25% are vHL, so always raise this possibility).
posterior fossa mass in child
medulloblastoma, JPA, ependymoma
posterior fossa mass in adult
mets, hemangioblastoma, meningioma, astrocytoma, epidermoid
Findings in ADEM? what does it mean?
Acute Disseminated Encephalomyelitis
monophasic acute inflammation and demyelination of white matter typically following a recent (1 - 2 weeks prior) viral infection or vaccination. Grey matter, especially that of the basal ganglia, is also often involved, albeit to a lesser extent, as is the spinal cord
PML - what does it stand for? Look like?
Progressive multifocal leukoencephalopathy
Demyelinating disease which results from the JC virus. strongly associated with immunosuppressed states, esp AIDS but also transplant patients and leukemia.
Asymmetric focal zones of low attenuation involving the peri-ventricular and sub-cortical white matter (including U fibers). This is in distinction to the more symmetrical hypo-attenuation seen in HIV encephalopathy.
What’s subacute sclerosing panencephalitis? Who gets it? Caused by?
Sub acute sclerosing panencephalitis (SSPE) (also known as Dawson disease)
- rare chronic, progressive and fatal encephalitis
- children and young adults
- caused by persistent infection of immune resistant measles virus
Appearance of HIV encephalitis
diffuse, symmetric cerebral atrophy, out of keeping with age
symmetric periventricular and deep white matter hypoattenuation and T2 hyperintensity
confluent or patchy
no mass effect
no enhancement
infant with large cyst and nodule - Ddx
DIG - desmoplastic infantile ganglioglioma
Ddx - supratentorial ependymoma, PNET, pilocytic astrocytoma
PNET - stands for? Includes what tumors?
Primative neuroectodermal tumor
aggressive brain tumor in child
medulloblastoma : by far the most common
supratentorial PNET : 15% of all CNS PNET
pineoblastoma : most common supratentorial PNET
spinal PNET : rare
hemangiopericytoma - what is it? where does it occur?
Think aggressive variant of meningioma that metastasizes
Helpful features include :
lobulated contour
absence of calcification and hyperostosis
invasion of the skull (common)
multiple flow voids on MRI (need to distinguish from spoke-wheel appearance of meningioma)
corkscrew arteries
may have a narrow base of dural attachment
Ddx of skull-base extra-axial masses
Hemangiopericytoma meningioma lymphoma dural mets plasmacytoma
Leigh disease - what? who? looks like?
also known as sub acute necrotizing encephalomyelopathy). Progressive (mitochondrial) neurodegenerative disorder and invariably leads to death in childhood
High T2 in:
brainstem
periaqueductal gray matter
medulla
midbrain
putamen : characteristic but not always present
Ddx of high T1 in basal ganglia
*TPN (hyperalimentation)
hepatic encephalopathy
NF1
Ddx of high T2 in basal ganglia
hypoxic event CO (globus pallidus) NF1 CJD (also cortex) Leigh dz (more generalized) Wilson's dz (also more generalized)
Finding in CO poisoning:
low density / high T2 in globus pallidus
What is Dandy Walker malformation?
triad of:
hypoplasia of the vermis and cephalad rotation of the vermian remnant
cystic dilatation of the fourth ventricle extending posteriorly
enlarged posterior fossa with torcular-lambdoid inversion (torcular lying above the level of the lambdoid due to abnormally high tentorium)
It is at the severe end of the spectrum denoted by the term Dandy-Walker continuum.
Holoprosencephaly - describe the types:
Incomplete separation of the two hemispheres
Alobar: single midline monoventricle, absent midline structures
Semilobar: fused thalami, absence of septum pellucidum
monoventricle with partially developed occipital and temporal horns
rudimentary falx
Lobar: fusion of the frontal horns of lateral ventricles
wide communication of this fused segment with the third ventricle
fusion of the fornicies
absence of septum pellucidum
agenesis or hypoplasia of the corpus callosum
(Septo-optic dysplasia is in the ddx for lobar)
Schizencephaly - what do you have to have? Two types:
grey matter-lined cleft extending from the ependyma to the pia mater
Open lip: CSF seen between
Closed lip: cleft walls touch
rhombencephalosynapsis
absent or small cerebellar vermis and fused cerebellar hemispheres
abnormally shaped 4th ventricle
what does herpes encephalitis look like? What do you need to do?
T2 hyper, maybe enhancement, of medial temporal lobes, insular cortex and inferolateral frontal lobes (cingulate gyrus). The basal ganglia are typically spared
Call the clinician for immediate treatment!
Vein of Galen malformation: appearance? consequences? Rx?
AV fistula of the median prosencephalic vein (MPV) (a precursor of the vein of Galen) occurring at 6-11 weeks gestation. The MPV fails to regress and becomes aneurysmal.
Can cause high-output heart failure, hydrocephalus/aqueductal stenosis, ischemia
Rx: embolization
Signs of carotid-cavernous fistula
proptosis enlarged superior ophthalmic veins extra ocular muscles may be enlarged orbital edema may show SAH / ICH from ruptured cortical vein
fat going through dorsal spinal defect
lipomyelocele (no meningocele in the case shown)
Ddx intramedullary spinal cord lesion
astrocytoma (extensive, kids more)
ependymoma (bleeding and cysts, adults more)
hemangioblastoma (often cystic)
lymphoma
sarcoidosis
ADEM (expanding, continuous lesions affecting multiple levels)
MS
transverse myelitis - what is it? appearance
Inflammatory condition affecting BOTH HALVES of the spinal cord and associated with rapidly progressive dysfunction
Cause: idiopathic or e.g. MS, ADEM (post viral/vaccine), SLE
Usually thoracic
Usually 3-4 segments of cord, usually 2/3 of cross sectional area of cord
Nonenhancing cyst in conus
Ventriculus terminalis (normal structure)
CSF lesion displacing spinal cord
arachnoid cyst (rx fenestration)
What is a snake-eye or owl-eye appearance in the spinal cord?
compressive myelopathy from compression and venous infarction - means pt won’t totally recover after surgery
Spine: dorsal columns are involved, demonstrating high signal on T2 - what is it? cause?
Subacute combined degeneration (B12 deficiency)
or Tabes Dorsalis from tertiary Syphilis
name for enhancing lesion in or around conus
myxopapillary ependymoma
Name for spinal defect containing CSF? Containing neural elements as well?
Meningocele contains meninges
myelomeningocele contains neural elements
named for direction (dorsal, ventral, lateral) and location (thoracic, sacral, etc.)
widened neural foramen
Peripheral nerve sheath tumor (schwannoma), neurofibromas (NF1), synovial cyst, arachnoid cyst
Ddx ivory vertebral body - child
lymphoma
osteosarcoma
osteoblastoma
metastatic disease (eg neuroblastoma)
Ddx ivory vertebra - adult
osteoblastic mets (prostate, breast)
lymphoma
Paget disease of bone
What’s the Currarino triad?
Hereditary: anorectal malfomation or congenital anorectal stenosis sacrococcygeal osseous defect pre sacral mass e.g anterior sacral meningocoele
describe a hangman’s fracture. is it stable?
involves both pars interarticularis of C2, and is as a result of hyperextension and distraction
unstable
what’s os odontoideum
tip of dens is separate, not an acute fracture
Fracture in pt with ankylosing spondylitis
Anderson fracture
Defect and scelrosis at anterio-superior corner of a vertebral body
Limbus vertebra
Caused by herniation of a portion of the nucleus pulposus underneath the ring apophysis before its fusion to the body
More central is a Schmorl’s node
epidural spinal mass
epidural metastasis lymphoma epidural abscess herniated disk epidural hematoma meningioma
retrobulbar mass that changes in size with valsalva
orbital varix
Brain lesion with an outer ring of restricted diffusion
CNS lymphoma
Lesion: intraaxial cyst with enhancing nodule in adult
hemangioblastoma (often associated with vHL, so look for other lesions)
What’s the pattern of areas involved in DAI?
Diffuse axonal injury
can be deceptive/absent on CT
grey white matter junction, in the corpus callosum or the brain stem/pons
extra-axial lesion with restricted diffusion
epidermoid
Mass in middle ear - two most likely lesions, how do you tell the difference? What are some things to check for?
Acquired cholesteatoma (pearly white), glomus tympanicum (red) Check for ossicular erosion, bony covering of lateral semicircular canal, covering of carotid and jugular
Parotid lesions: cystic and bilateral. Ddx:
lymphoepithelial cysts in HIV, Sjogren’s, warthin’s tumors, (sialocele)
“kissing spinous process(es)”
Baastrup disease - pain from friction
What does a “dense cerebellum” imply
Anoxic injury, the supratentorial brain is edematous and low attenuation
describe mesial temporal sclerosis
Decreased volume of one or both medial temporal lobes/hipocampi, usually related to intractable seizures. Rx surgery.
Thickened cerebellar folds/folia in a tiger-striped pattern
Lhermitte-Duclos - (probably) hamartoma of cerebellum (is benign)
Can be seen in Cowden syndrome:
-multiple hamartomas
-breast cancer
hypothalamic/ suprasellar masses - child
craniopharyngioma gliomas: chiasmatic/hypothalamic low-grade, optic chiasm glioma pituitary adenoma LCH Ewing sarcoma rathke cleft cyst hypothalamic hamartoma mets (neuroblastoma)
Abnormal signal in putamen
Methanol
Name the small round blue cell tumors
Ewing sarcoma neuroblastoma embryonal rhabdomyosarcoma pineoblastoma Wilms tumour retinoblastoma hepatoblastoma CNS primitive neuroectodermal tumour (CNS-PNET) (more)
Ddx for lesion in quadrigeminal plate cistern
aka tectal plate glioma dermoid teratoma lipoma (pineal region lesions)
Pineal region ddx
pineal parenchymal tumours (pineocytoma, pineoblastoma (aka PNET)) germ cell tumours (pineal germinoma (most common; ~ 50% of all tumours), others pineal teratoma astrocytoma of pineal gland pineal metastasis pineal cyst meningioma near pineal region other rare entities cavernoma in pineal region aneurysm in pineal region
PRES: what is it? appearance? causes?
2/2 inability of posterior circulation to auto-regulate in response to acute changes in BP. Hyperperfusion with resultant disruption of the BBB results in
appearance: vasogenic edema, but no infarction in the parieto-occipital regions.
causes: severe hypertension (post partum, eclampsia)
haemolytic uraemic syndrome (HUS)
thrombocytopaenic thromboic purpura (TTP)
systemic lupus erythromatosis (SLE)
drug toxicity
Pontine myelinolysis - how does it look different from ADEM?
Myelinolysis cortical spinal tracts of brainstem are spared
Risk factors for venous infarct:
dehydration, cancer, sickle cell, hypercoag. states (Prot. S), mastoiditis
What does DNET stand for? Where is found?
Dysembrioplastic Neuroepithelial tumor
benign (WHO I) lesion arising in cortical or deep grey matter, young patients. Does not enhance.
80% are associated with cortical dysplasia
60% in temporal lobe and assoc with SEIZURES
Oligodendroglioma - who what and where?
middle-aged adults presenting with seizure
involve white matter and overlying cortex
usually in frontal lobes (or temporal)
Commonly CALCIFY!!
Septo-optic dysplasia - describe
what’s it similar to?
What’s associated?
Pts have hypotelorism, severe visual problems, and short stature or other pituitary symptoms. Primary imaging findings include optic nerve hypoplasia and absent septum pellucidum.
Septo-optic dysplasia somewhat resembles lobar holoprosencephaly (septo-optic dysplasia is more common)
Septo-optic is assoc. with schizencephaly
but not assoc with agen of CC
Ddx gyriform enhancement
encephalitis, stroke
What’s a paranasal sinus mucocele?
result of obstruction of the ostium of a sinus with resultant accumulation of mucus and eventual expansion (bony remodeling) of the sinus
associated with non-invasive chronic fungal sinusitis
small middle ear mass at cochlear promontory
Glomus tympanicum (no bone erosion) must distinguish from aberrant carotid
What space does a JNA expand?
Pterygopalatine fossa and pterygomaxillary fissure
Ddx petrous apex lesion
Cholesterol granuloma (bright T1 and T2) mucocele cholesteotoma/epidermoid petrous apicitis bone stuff: chondrosarcoma/osteosarcoma, lymphoma, plasmacytoma, mets
Small globe with enhancing cone-shaped posterior density, no calcification
PHPV: persistent hyperplastic primary vitreous
Calcified mass in the globe: what is it? What should you look for now?
Retinoblastoma
Look for contralateral, pineal, and suprasellar retinoblastomas
Ddx paranasal sinus mass
mucocele encephalocele esthesioneuroblastoma sinonasal carcinoma inverted papilloma (middle meatus, looks cerebriform) antrochoanal polyp (benign, snare it) (JNA in teenager) sinonasal polyposis (bilateral, atopia, ciliary) bone: fibrous dysplasia, osteoma
Parotid glands are missing
Chronic phase of sjrogen’s disease
Ddx optic nerve sheath enlargement
Fluid: hematoma, papilledema
Inflammation: optic neuritis, sarcoid, pseudotumor
Tumor: optic nerve glioma, nerve sheet meningioma, leukemia/lymphoma/mets
Who’s at risk for optic glioma?
NF1
Name the paragangliomas in and around the carotid space:
Glomus jugulare, vagale (9-12), tympanicum, carotid body tumor (splays)
ddx cystic mass in lateral neck
branchial cleft cyst necrotic lymph node abscess thrombosed IJ vein lymphangioma cystic nerve sheeth tumor (plexiform neurofibroma) plunging ranula
Difference b/t ranula and plunging/diving ranula:
Extension through the myelohyoid m. or posteriorly around it (requires a different surgical approach)
Ddx clivus lesion
Mets/myeloma, lymphoma chordoma (bright on T2) chondrosarcoma fibrous dysplasia osteomyelitis
describe presentation of acquired cholesteatoma
pars flaccida of TM
Prussak’s space with erosion of scutum
destruction of ossicles
Masticator space mass:
- odontogenic abscess
- osteomyelitis
- direct spread of squamous cell carcinoma
- lymphoma
- minor salivary gland tumours
- muscle sarcoma
- bone sarcoma
Parotid space lesions:
- salivary gland tumours (pleiomorphic adenoma, warthin, mucoepidermoid, adenoid cystic)
- metastatic adenopathy
- lymphoma
- parotid cysts
Describe orbital pseudotumor
idiopathic inflammatory condition that usually involves the extraocular muscles although, in some cases there is inflammatory change involving the uvea, sclera, lacrimal gland and retrobulbar soft tissues
- lacrimal pseudotumour
- anterior pseudotumour: immediately behind the globe
- posterior pseudotumour: distinguished from Tolosa-Hunt syndrome in that the cavernous sinus is spared
- diffuse pseudotumour
- myositic pseudotumour: predominantly involve the EOMs and therefore mimic thyroid associated orbitopathy (TAO)
Tolosa Hunt
idiopathic inflammatory condition that involves the cavernous sinus and orbital apex
Ddx for absent septum pellucidum
Septo-optic dysplasia, Lobar holoprosencephaly, isolated
Fluid-filled cyst in the sella ddx
Epidermoid, rathke cleft cyst, cystic adenoma
Increased periaqueductal T2 signal ddx:
MS, Wernicke enceph. (B1 deficiency)
T1 bright lesion in pituitary stalk
Ectopic pituitary, lipoma
Ddx cavernous sinus lesion
Adenoma (invasive), perineural spread of nasopharyngeal ca, clival lesion, lymphoma, meningioma, CC fistula
Which is more common - NF1 or NF2?
NF 1 is 9x more common than NF2
remember: NF2 gets “central” tumors
NF1 gets extradural/peripheral lesions
What’s the medical Rx for prolactinoma, and what’s the complication?
Bromocriptine, hemorrhage (apoplexy)
Cystic lesion in the 3rd ventricle
colloid cyst, aneurysm, dermoid/epidermoid
Ddx etiology of vertebral artery dissection
Trauma, connective tissue disease, spontaneous, arteriopathy
What’s Chiari III?
Colpocephaly, agenesis of CC, tonsilar ectopia, occipital encephalocele
What’s associated with agenesis of the corpus callosum?
MANY things, among them:
Chiari II, III, trisomy 13 & 18, holoprocencephaly, Dandy-Walker
3 most common sites for encephaloceles:
- Occipital (75%)
- fronto-ethmoidal encephalocoele / nasal encephalocoele : ~ 15% of cases
- sphenoethmoidal (is this separate?)
Ddx lesion of mandible
periapical cyst dentigerous cyst (around crown of unerrupted tooth) ameloblastoma (aka adamantinoma) odontogenic keratocyst (around root) brown tumor ABC bisphosphonates, radiation, mets, infection Child: LCH (floating teeth)
Complications of sinusitis
cavernous sinus thrombosis
intracranial spread with subdural empyema, meningitis, encephalitis, brain abscess, mastoiditis
subcutaneous spread
Chronic: mucocele
carotid space mass ddx
schwannoma neurofibroma paraganglioma (various) metastatic adenopathy lymphoma cellulitis/abscess meningioma cystic: 2nd branchial cleft or necrotic lymph node
Limbic encephalitis - what is it? Looks like? Caused by?
paraneoplastic syndrome caused by non-CNS primary tumors resulting in functional and imaging changes in the limbic system
High T2 medial temporal lobe(s) - looks like herpes
*small cell carcinoma of the lung (classic cause)
also testicular, thymic, breast, ovarian carcinoma
Ddx lesion in pituitary stalk/infundibulum:
*hypothalamic glioma, *lymphoma, *LCH (in child), *sarcoid, TB, lymphocytic hypophysitis (related to pseudotumor), teratoma / germinoma,
Sclerosis of cochlea is probably what? What causes it?
Labyrinthitis ossificans, mostly meningitis (could be tumor or trauma)
Ddx high T2 signal in corpus callosum
Tumor: GBM, lymphoma
Demyelination: MS, ADEM
Infarct, incl. venous (check thalami)
Trauma: DAI
What’s the normal myelination pattern in a young child?
Bottom to top
back to front
central to peripheral
@9 months, the splenium of the CC is myelinated
Ddx diffuse low T1 signal in bones (esp spine)
Marrow infiltrating process:
lymphoma/leukemia
prostate mets, myeloma
myelofibrosis
One side of brain is larger than the other - no significant flow voids. What’s it called? Causes?
Hemimegalencephaly (rare congenital disorder of cortical formation with hamartomatous overgrowth of part of all of a cerebral hemisphere)
Klippel-Trenaunay Syndrome
McCune-Albright syndrome
Proteus syndrome
(Ddx is Sturge-Weber, should be pial angioma)
What’s the hockey stick sign?
hyperintense signal involving the pulvinar and dorsomedial thalamic nuclei bilaterally on FLAIR, in cases of variant Creutzfeldt-Jakob disease (vCJD), which has the shape of a hockey stick.
Ddx for high T2 signal in the pons
Tumor (pontine glioma - may not enhance)
ADEM or osmotic demyelination
Midline lipoma can be normal but is associated with:
agenesis of the corpus callosum
ddx white matter disease in a young to middle aged woman
MS, CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy), Susac syndrome (vasculitis), MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes)
Ddx high T2 signal in thalamus / thalami
HIE, ADEM, myelinolysis, venous infarct (artery of Percheron), (bilateral) thalamic glioma, wernicke encephalopathy (B1 defic), Fabry dz, Fahr dz, Wilson dz, Leigh dz
DDx for dislocated lens
trauma, Marfan’s, Ehlers-Danlos
What CNS tumor has a predilection for the periventricular area?
Lymphoma
Ddx diffusely irregular/indented inner table of skull
- Infant/very young child: Luckenschadel skull: dysplasia of the membranous skull vault and is associated with Chiari II malformations - NOT from hydrocephalus
- Older child - Copper beaten skull from increased intracranial pressure
Ddx for moya moya appearance
RAINS Radiation arteritis/atherosclerosis Idiopathic (actual dz) NF1 Sickle Cell
Ddx enlarged, enhancing cauda equina nerve roots
arachnoiditis
lymphoma, mets
Guillan-Barre
What is an esthesioneuroblastoma? Who gets it?
olfactory neuroblastoma - ethmoids and invading into the anterior cranial fossa and/or orbit
bimodal age distribution~ 2nd decade) and another peak in the 5th to 6th decades
Why are dural AV fistulas treated?
Cause cord ischemia (often symptoms are LE weakness)
Lytic skull lesions
LCH, mets (neuroblastoma in child), leptomeningeal cyst (aka growing fracture), myeloma, lymphoma, hemangioma, epidermoid, Paget’s
Name the hemorrhagic brain mets
renal, thyroid, choreocarcinoma, breast, lung
What do you look for with mastoid air cell opacification?
could be from eustachian tube obstruction from nasopharyngeal mass - carcinoma or lymphoma
Also: otitis media, temporal bone lesion
Low T2 signal along the brain surfaces
Superficial hemosiderosis
Look for a source - angiography (CT, MR, etc.)
Ask about Sx deafness (8th nerve is sensitive to hemorrhage)
What’s the significance of air in one laryngeal ventricle?
Laryngeal ventricle is just above the true cord
Means unilateral vocal cord paralysis (look for medial deviation of the arytenoid cartilage)
This means lesion somewhere along the vagus/recurrent laryngeal nerve.
Top locations for intracranial aneurysms:
What happens a week after subarachnoid hemorrhage?
Anterior communicating a.
Posterior communicating a.
MCA
~7 days out: vasospasm
jugular foramen “smudged” or obviously eroded:
Glomus jugulare
Describe the three bones of the inner ear
Malleus (hammer) ice cream, incus between malleus and stapes, stapes has two foot platse (could be a staple) on the oval window
tumor near aqueduct, mastoid, IAC:
What sydrome might the patient have?
Endolymphatic sac tumor
VHL
Ddx tumor involving lacrimal gland:
sarcoid, Sjogren’s, lymphoma, pseudotumor (if fat stranding & pain)
Ddx for calcified neck lymph nodes
Papillary thyroid ca (also characteristic are cystic changes of the lymph nodes), TB, treated lymphoma
Lesions of VHL
CNS: cerebellar, spinal, and retinal hemangioblastomas Pheochromocytomas endolymphatic sac tumors Renal: RCC, cysts, (AMLs) Pancreas: cysts, islet cell tumors Liver cysts
Intradural, extramedullary spine lesions:
schwannoma, meningioma, neurofibroma, myxopapillary ependymoma, mets, lipoma, cysts (dermoid, epidermoid, arachnoid)
Origin and territory of the PICA
What happens when it’s occluded?
Posterior inferior cerebellar artery - arises directly from ipsilateral vertebral artery, supplies the inferior cerebellum
Occlusion = Wallenberg (lateral medullary) syndrome of deficit in ipsi cranial nerves and face, contra trunk
MR spect peaks & basic significance:
Choline, Lactate, NAA
Choline - CHO - cell membrane and turnover marker
Lactate - necrosis
NAA - brain tissue
Intraaxial masses with restricted diffusion:
(abscess - cystic) lymphoma medulloblastoma CJD (basal ganglia and cortex) meningioma
Sphenoid wing is absent on one side
Sphenoid wing dysplasia - make sure edges are smooth, no evidence of mass
50% are NF1 (rest sporadic)
Ddx midline spinal (sacral) mass:
chordoma, teratoma, GCT, chondroblastoma
then regular bone stuff - Ewings, myeloma, etc.
Corpus callosum demyelination and atrophy
Machiafava-Bignami (chronic alcoholics, other malnutrition)
Ddx basal ganglia calcification
aging Fahr dz (also cerebellum and cerebrum) toxic (CO, Pb, rad, chemo) infxn (TORCH, TB, neurocyster) metabolic (hyperpara)
Ddx for enopthalmos (orbit retraction)
scirrous breast cancer, radiation
Ddx neck lymphadenopathy
Infection (Mono, cat scratch) Lymphoma mets (esp H&N, thyroid) Castleman's TB
Ddx hyperdense CNS lesion on CT
aneurysm/hematoma, meningioma, lymphoma, melanoma
Temporal lobe atrophy, more than just mesial temporal sclerosis:
Rasmussen’s encephalitis (uncertain etiology)
usually children under 10y
Order of extraocular muscle involvement with thyroid orbitopathy
IMSLO
ddx for extraorbital muscle enlargement
thyroid orbitopathy, pseudotumor (painful), CC fistula, lymphoma, cellulitis or myositis (sinusitis), mets, hematoma
