Neuro: Brain Flashcards
what is massa intermedia?
gray + white matter struct –> thru 3rd vent –> connect bilat thalami
brain edema –> 3 types?
- cytotoxic edema
- vasogenic edema
- interstitial edema
cytotoxic edema –> MOA?
cell death –> damage Na-K ATPase pumps –> water ions trapped inside swollen cells
vasogenic edema –> MOA?
inc capillary permeability –> interstitial edema
cytotoxic edema –> MCC?
infarct
vasogenic edema –> MCC? (3)
- neoplasm
- infx
- infarct
interstitial edema –> MOA? MCC?
imbalance in CSF flow
obstructive hydrocephalus
interstitial edema –> imaging appearance?
periventricular fluid (transependymal flow of CSF)
subfalcine herniation –> comp? (1)
compress ACA
uncal herniation –> comp? (4)
- CN III paresis
- compress PCA
- Duret hemorrhage
- compress contralat cerebral peduncle
tonsillar herniation –> comp? (1)
compress medulla
CN III paresis –> clinical presentation? (2)
- pupil dilate
- eye –> down & out
upward transtentorial herniation –> comp? (1)
compress aqueduct –> hydrocephalus
what is communicating hydrocephalus?
no obstructing lesion –> venticles enlrg
communicating hydrocephalus –> 2 causes?
- subarachnoid hemorrhage
- normal pressure hydrocephalus
subarachnoid hemorrhage –> communicating hydrocephalus –> MOA?
impede arachnoid granulation from resorb CSF
what is T1? T2?
- T1: longitudinal recovery/relaxation
- T2: transverse relaxation
T1 shortening vs prolongation –> hypo or hyper-intense?
- T1 short –> hyper
- T1 prolong –> hypo
T2 shortening vs prolongation –> hypo or hyper-intense?
- T2 short –> hypo
- T2 prolong –> hyper
what is optic neuritis?
optic N –> inflamm –> non-neoplastic
optic neuritis –> clinical presentation? (3)
- pain
- subacute vision loss
- reduce color perception
optic neuritis –> MC etiology? less common etiologies? (4)
- # 1 mult sclerosis
- viral
- sarcoid
- vasculitis
- toxin
optic neuritis + spinal demyelination –> dx?
Devic synd
MRI orbit –> optic neuritis –> next step?
MRI brain & spine –> look for intracranial plaques
optic neuritis –> MR appearance? T2 signal? enhance?
- enlrg optic N
- T2 hyper
- active dz –> enhance
globe –> MC 1ary malig?
retinoblastoma
retinoblastoma –> epidemiology?
<5yo
retinoblastoma –> classic CT appearance?
normal size globe –> retinal mass –> hyperdense –> enhance –> calc
what is trilateral retinoblastoma?
- bilat retinoblastoma
- pineal gland –> pineoblastoma
what is quadrilateral retinoblastoma?
- bilat retinoblastoma
- pineal gland –> pineoblastoma
- suprasellar retinoblastoma
what is Coat dz?
retina –> vascular dz –> lipoproteinaceous subretinal exudate –> retina detach
Coat dz –> epidemiology?
slightly older than retinoblastoma –> M
Coat dz –> imaging appearance?
normal size globe –> subretinal soft tissue –> not enhance
premature infant –> prolong O2 therapy –> comp? (1)
retinopathy of prematurity
retinopathy of prematurity –> findings? (4)
- bilat microphthalmia
- abnormal vascular developmt
- hemorrhage –> high attenuation & calc
- retina detach
retinopathy of prematurity –> natural progression?
phthisis bulbi
full term infant –> retina detach, hemorrhage –> loss of vision –> dx?
persistent hyperplastic primary vitreous (PHPV)
what is persistent hyperplastic primary vitreous (PHPV)?
vitreous –> persistent embryonic vasculature –> hemorrhage, cataract, retina detach –> vision loss
persistent hyperplastic primary vitreous (PHPV) –> imaging features? (3)
- microphthalmia
- vitreous –> hyperdense
- no calc
most brain lesion –> T1 signal? T2?
- T1 hypo
- T2 hyper
T1 short (hyper) –> cause? (8)
- gad contrast
- fat
- protein
- blood –> paramagnetic stage –> metHb –> intra & extra-cell
- melanin
- mineral (copper, iron, mangenese)
- slow flow blood
- rare –> calcium
T2 short (hypo) –> cause? (6)
- blood –> most paramag stages –> except hyperacute blood & extracell metHb
- calc
- fibrous lesion
- high cellular tumor: high nucleus:cytoplasm ratio –> low water content –> ie. lymphoma, medulloblastoma
- vasc flow void
- mucin –> dessicated
what is fluid attenuation inversion recovery (FLAIR)?
T2 –> water suppressed (based on T2 charact)
brain –> white vs gray matter –> T1 signal?
- white matter: bright
- gray: darker
brain –> white vs gray matter –> FLAIR signal?
- white matter: darker
- gray: bright
MRI seq with highest signal to noise ratio?
proton density (PD)
proton density (PD) –> useful for eval of what condition?
mult sclerosis
diffusion MRI –> DWI & ADC –> based on what characteristic?
water proton –> Brownian motion
diffusion MRI –> DWI & ADC –> CSF vs pathologic process –> signal attenuation?
- CSF –> most signal attenuation –> most signal loss
- path process –> less Brownian motion –> less diffusivity –> less signal loss –> DWI hyperintense
what is T2 shinethru?
DWI is T2 weighted –> T2 hyper lesion –> hyper on DWI, even if not restricted diffusion
restricted diffusion –> ddx? (6)
- acute stroke
- bacterial abscess
- cellular tumor –> ie lymphoma, medulloblastoma
- epidermoid cyst
- herpes encephalitis
- Creutzfeldt-Jakob dz
gradient recall echo (GRE) –> what creates blooming artifact? (2)
- hemosiderin
- Ca
GRE –> mult dark spots –> ddx? (5)
- HTN microbleed
- cerebral amyloid angiopathy
- familial cerebral cavernous malformation
- axonal shear injury
- mult hemorrhagic mets
cerebral amyloid angiopathy –> GRE –> mult dark spots –> location?
subcortical white matter –> usu parietal & occipital lobes
glioblastoma vs mets –> how differentiate on MR spectroscopy?
- glioblastoma –> infiltrative –> gradual transition from abnormal to normal spectroscopy
- mets –> more abrupt transition
what is N-acetylaspartate (NAA)?
normal marker of neuronal viability –> dec in most abnormalities
most tumor –> N-acetylaspartate (NAA) inc/dec? choline (cho)?
- NAA dec
- choline inc
NAA elevated –> ddx? (1)
Canavan dz –> dysmyelinating disorder
lactate “doublet” –> ddx? (1)
high grade tumor –> anaerobic metabolism
MRI brain –> parenchymal enhance –> MOA? cause? (5)
blood brain barrier disrupt:
- infx
- inflamm
- neoplasm
- trauma
- vascular
MRI brain –> regions w no BBB –> normally enhance? (5)
- choroid plexus
- pituitary gland
- pineal gland
- tuber cinereum –> inf hypothalamus
- area postrema –> inf 4th ventricle
MRI brain –> periventricular enhance –> ddx? (4)
- primary CNS lymphoma
- infx ependymitis
- primary glial tumor
- mult sclerosis
primary CNS vs systemic lymphoma –> leptomeningeal involvemt?
- primary CNS –> rarely involve meninges
- systemic lymphoma –> brain mets –> commonly involve leptomeninges
infx ependymitis –> MC org?
CMV
infx ependymitis –> imaging appearance?
ventricle margins –> thin linear enhance
gyrus enhance –> ddx? (5)
- herpes encephalitis
- meningitis
- subacute infarct
- post reversible encephalopathy synd (PRES)
- SMART synd
herpes encephalitis –> which locations affected 1st? (2)
- medial temporal lobe
- cingulate gyrus
what is SMART synd?
stroke like migraine attacks after rtx
ring enhance –> ddx? (7)
MAGIC DR:
- mets
- abscess
- glioma
- infarct –> subacute basal ganglia
- contusion –> subacute-chronic
- demyelination
- radiation
dura enhance –> ddx? (5)
- intracranial hypotension
- postop
- post lumbar puncture
- meningeal neoplasm
- hypertrophic pachymeningitis
hypertrophic pachymeningitis –> etiology? (4)
- infx –> TB/fungal, syphilis
- inflamm –> RA, granulomatosis w polyangiitis
- sarcoid
- idiopathic
what is pachymeninges? leptomeninges?
- pachy –> dura
- lepto –> pia & arachnoid
leptomeningeal enhance –> ddx? (4)
- meningitis
- viral encephalitis
- leptomeningeal mets
- inflamm amyloid
subarachnoid space –> FLAIR hyper –> ddx? (7)
- meningitis
- leptomeningeal mets
- subarachnoid hemorrhage
- slow vascular flow
- O2 tx
- propofol tx
internal carotid A –> segments? (4)
- cervical
- petrous
- cavernous
- supraclinoid
A1 segmt –> br?
recurrent A of Heubner
what is A of Percheron?
variant: P1 PCA –> dominant thalamic perforator –> supply b/l ventromedial thalami
what is fetal PCA?
normal variant: ICA –> enlrged P-comm –> no PCA
what is azygos ACA?
normal variant: –> b/l ACA converge into 1
azygos ACA –> assoc anomaly? (3)
- holoprosencephaly
- neuronal migration anomaly
- aneurysm formation
recurrent A of Heubner –> supplies what struct? (2)
- caudate head
- internal capsule –> ant limb
MC persistent carotid-basilar connection?
persistent trigeminal A
persistent trigeminal A –> assoc comp? (1)
aneurysm
persistent trigeminal A –> sign?
angio –> lat view –> “tau” sign
acute stroke –> perfusion imaging –> what is cerebral blood vol (CBV)?
blood vol per unit brain tissue
acute stroke –> perfusion imaging –> what is cerebral blood flow (CBF)?
vol of blood flowing per unit of brain tissue
acute stroke –> perfusion imaging –> what is mean transit time (MTT)?
avg time for contrast bolus to transverse a voxel
acute stroke –> perfusion imaging –> what is time to maximum (Tmax)/time to peak (TTP)?
time from scan start to max contrast bolus in voxel
acute stroke –> perfusion imaging –> how are CBF, CBV, and MTT related?
central volume eqn:
CBF = CBV/MTT
acute stroke –> perfusion imaging –> infarct core –> finding?
marked dec CBF –> matched dec CBV
acute stroke –> perfusion imaging –> ischemic penumbra –> finding? (2)
- mild dec CBF –> mismatch inc/normal CBV
- inc MTT & Tmax
stroke –> dating?
- DWI bright, ADC dark –> 10days
- T1 dark –> 16hr
- T2 bright –> 8hr
- FLAIR bright –> 6hr
subacute infarct –> what is 2-2-2 rule?
enhance:
- begin at 2 days
- peak at 2wk
- resolve by 2mo
subarachnoid hemorrhage –> comp? (3) which is MC?
- # 1 vasospasm –> delayed ischemia
- hydrocephalus
- superficial siderosis
aneurysm –> subarachnoid hemorrhage –> hemorrhage location –> indicates aneurysm of what vessel?
- ant interhemispheric fissure
- suprasellar cistern
- Sylvian fissure
- perimesencephalic cistern
- ant interhemispheric fissure –> A-comm
- suprasellar cistern –> P-comm
- Sylvian fissure –> MCA
- perimesencephalic cistern –> basilar tip
what is perimesencephalic subarachnoid hemorrhage?
pattern of nontraumatic SAH –> likely venous origin –> benign prognosis
what is reversible cerebral vasoconstriction synd (RCVS)?
nontraumatic, nonaneurysmal –> SAH & ischemia
MC cranial N palsy from giant aneurysm?
P-comm aneurysm –> CN III palsy
isolated intraventricular hemorrhage in 4th ventricle –> ddx? (1)
PICA aneurysm rupture
mycotic aneurysm –> etiology?
septic emboli
what is oncotic aneurysm?
aneurysm caused by neoplasm
what is AVM?
congenital –> high flow vasc malformation –> directly connecting A & V –> no intervening capillary
what is dural AVF (dAVF)?
high flow vasc malformation –> meningeal arterioles & dural venules –> AV shunt
dural AVF (dAVF) –> #1 prognostic factor?
presence & degree of cortical venous drainage
dural AVF (dAVF) –> what is a subtype of dAVF?
carotid-cavernous fistula (CCF)
what is V of Galen malformation?
high flow vasc malformation –> thalmoperf br & deep venous system –> AVF –> enlrg median prosencephalic V
CNS –> vasc malformation –> high flow (2) vs low flow (3) –> ddx?
high flow:
- AVM
- dural AVF
low flow:
- cavernous malformation (cavernoma)
- developmental venous anomaly (venous angioma)
- capillary telangiectasia
cavernous malformation (cavernoma) –> comp? (2)
- hemorrhage –> small risk
- sz
cavernous malformation (cavernoma) –> assoc anomaly?
developmental venous anomaly (venous angioma)
mult cavernous malformation (cavernoma) –> ddx? (1)
familial cerebral cavernous malformation synd
what is cavernous malformation (cavernoma)?
vasc hamartoma
cavernous malformation (cavernoma) –> assoc RF? (1)
brain rtx
cavernous malformation (cavernoma) –> CT appearance?
well-circumscribed rounded hyperdense lesion
cavernous malformation (cavernoma) –> usu diagnostic on CTA –> T/F?
F
usu occult on vasc imaging
cavernous malformation (cavernoma) –> MRI appearance? T1/T2? enhance?
- T1/T2 mixed “popcorn-like” signal –> blood of varying ages
- dark rim of hemosiderin
- no enhance
what is developmental venous anomaly (venous angioma)?
abnormal V –> provide functional drainage to normal brain
developmental venous anomaly (venous angioma) –> usu only seen on contrast-enhanced or susceptibility weighted imaging –> T/F?
T
developmental venous anomaly (venous angioma) –> imaging appearance?
radially oriented V –> caput medusa appearance
cavernous malformation (cavernoma) –> Do Not Touch lesion –> T/F?
F
developmental venous anomaly (venous angioma) –> Do Not Touch lesion –> T/F?
T
capillary telangiectasia –> Do Not Touch lesion –> T/F?
T
what is capillary telangiectasia?
low flow vasc malformation –> dilated capillaries w interspersed normal brain –> asx
capillary telangiectasia –> usu diagnostic on CTA –> T/F?
F
occult on vasc imaging
developmental venous anomaly (venous angioma) –> usu diagnostic on CTA –> T/F?
T
capillary telangiectasia –> MRI appearance? T2? GRE? enhance?
- occult on T2/FLAIR
- GRE –> blooming artifact
- contrast –> “brush stroke”-like lesion
capillary telangiectasia –> MC location?
brainstem
what is venous angle?
intersect of septal V & thalmostriate V –> angio landmark for foramen of Monro
deep venous sinus or cortical V –> thrombosis –> RF? (5)
- preg/OCP
- thrombophilia
- malig
- infx