NEURO/SPINE Flashcards
Acute spinal cord ischaemia clinical
Anterior
- bilateral
- paralysis below level
- pain and temperature loss
- sparing of proprioception and vibration
- anterior horn; sensation preserved
- cervical/man in barrel; bilateral arms, normal face and legs
Posterior
- unilateral
- complete sensory loss at level
- proprioception and vibration loss below
- minimal motor sx
Acute spinal cord ischaemia imaging
MRI
- T2 in cord, pattern based on artery
- restricted diffusion
Spinal subarachnoid haemorrhage (usually due to avm) also known as
Coup de poignard of Michon (poignon = french for dagger)
Spinal epidural haemorrhage aetiology
spontaneous (most common)
trauma
iatrogenic
AVM
tumours
pregnancy
Spinal AVM clinical
25% spinal vascular malformations
Clinically variable;
- foix alajouanine syndrome (progressive myelopathy)
- coup de poignard of Michon (stab in back)
Spinal AVM imaging
T1
- signal voids
- dilated perimedullary vessels, indent/scallop cord
T2
- signal voids
- increased cord signal due to oedema or myelomalacia
Spinal AVM classification
Intramedullary or extramedullary
four angio subtypes
1: single coiled vessel
2: intramedullary glmus AVM
3: juvenile
4: intradural perimedullary
Spinal AVF clinical
70% of all spinal vascular malformations
Cause venous congestion, vague sx
- motor; gait disturb and reduced power
- paraesthesia
- radicular pain
- later; incontinence, ED
Spinal AVF imaging
MRI
- tortuous enlarged vessel flow voids
- spinal cord oedema; usually centromedullary and multisegmental
- low T2 rim and peripheral of oedema, deoxy blood product
DSA
Spinal AVF classification
1: dural AVF
2: intramedullary glomus AVM
3: intramedullary juvenile AVM
4; perimedullary AVF
5: extradural AVF
Spinal cord cavernoma clinical
peak during fourth decade
blood filled endothelial lined spaces lined by thickened hyalinsed walls that lack elastic fibres and smooth muscle
typically thoracic
variable clinical course
Spinal cord cavernoma imaging
CT occult
DSA occult
MRI
minimal cord expansion unless recent hamorrhage
heterogenous, popcorn
bloom on GE
minimal enhancement
Cerebrovascular malformations classification
High flow
- AVM
- DAVF
- proliferative angiopathy
- pial AVF
Low flow
- Cavernoma
- Capillary telengiectasia
- DVA
- venous varix
- sinus pericranii
- mixed
Cerebral cavernoma/cavernous venous malformation clinical/path
40-60
can be single or multiple (?familial ?radiation)
incidental or presenting with haemorrhage
path; mulberry like cluster of hyalinsed dilated thin walled capilllaries with surrounding haemosiderin. No normal intersecting brain. Occ assoc with a DVA
Cerebral cavernoma/cavernous venous malformation imaging
difficult on ct, do not enhance
can be hyperdense if large or speckle calc
MRI
popcorn, rim of signal loss
T1; variable, fluid fluid levels
T2; hypointense rim, FF lvels, variable signal
SWI; blooming
C+ no ehnacment
ddx
amyloid
hypertensice
dai
vasculitis
hamorrhagic mets
parry romberg
mets/primary
calcified lesions (neurocyterocosis)
Cerebral cavernoma/cavernous venous malformation classification
Zabramski
1; subacute harmorrhage
2; classic popcorn
3; chronic haemorrhage
4; multiple punctate microhaemorrhage
Parry Romberg syndrome
Progressive facial hemiatrophy. rare phakamatosis.
IPSILATERAL: leptomeningeal enhancement, paracnchymal atrophy, microhaemorrhage, clacifications, aneurysms
Perimesencephalic haemorrhage is
SAH around midbrain cisterns. 95% cause not found ?venous SAH. Better outcomes than if aneurysm, AVM AVF or trauma
Hypertensive microangiopathy is
sustained elevated blood pressure leading to lipohyalinosis and charcot boiuchard aneurysms prone to rupture
Hypertensive microangiopathy imaging
microhaemorrhages affecting the basal ganglia, pons and cerebellar hemispheres
Hypertensive microangiopathy ddx
cerebral amyloid (more peripheral)
multiple familial cavernous malformation syndrome
neurocystericosis
calcified treated mets
Cerebral AVM is
intracranial high flow vascular malformation composed of enlarged feeding arteries, nidus closely associated with parenchyma and draining veins
Cerebral AVM syndromes
typically single but when multiple ?syndromes;
Osler weber rendu HHT
Wyburn mason syndrome CAMS
Cerebral AVM imaging
CTA bag of worms
DSA
MRI
Cerebral AVM grading
Perioperative morbidity. Spetzler Martin
Size: <3, 3-6, >6
Eloquence of brain
Veins: superficial or deep
Cerebrofacial arteriovenous metameric syndrome encompasses
Sturge Weber and Wyburn Mason syndrome. Intracranial and maxillofacial components required.
Three types based on location
1: medial prosencephalic - nose and hypothalamus
2: lateral prosencephalic - occipital, chiasm, optic tract, thalamus, retina, maxiall
3: rhombencephalic = cerebrallum, pons, mandible
Wyburn Mason syndrome is
rare, non hereditary neurocutaneous disorder. Unilateral vascular malformations incolving the brain, orbits and facial structures.
Features:
facial vascular naevus
visual pathway/orbital ACM
intracranial AVM, commonly midbrain
Dural AVFs are
high flow vascular malformations that share AV shunting from dural vessels.
Dural AVF imaging
CTA: abnormal enlarged cortical veins, enlarged transosseous vessels, abnormal dural venous sinuses
MRI: same. watch out forsuperiorly flowing venous blood as arterialised in the left jugular.
DSA
Dural AVF classification
Borden or Cognard. Single most important feature is presence of retrograde leptomeningeal venous drainage.
Borden
1: drain into meningeal veins, spinal epidural veins or dural venous sinus. normal antegrade flow.
- cognard 1 and 2a
2: drain into meningeal veins, epidural veins or dural venous sinus. Retrograde flow into subarachnoid veins.
- cognard 2b and 2a+b
3: direct drainage to subarachnoid veins or isolated segment of venous sinus
- cognard 3, 4, 5
Capillary telangiectasia are
small low flow vascular lesions of the brain. dilated capillaries interspersed with normal brain parenchyma.
Capillary telangiectasia imaging
commonly in hte brainstem, especially the pons. usually solitary. can be assoc with OWR syndrome. usually only seen on MR
T2 subtle high signal
FLAIR subtle high signal
SWI low signal
C+ faint stippled enhancement
Developmental venous anomalies are
congenital malformations of veins which drian normal brain. Characterised by a caput medusae sign of veins draining into a single larger collecting vein (palm tree).
DVA imaging
commonly frontoparietal, cerebellar
usually solitary except in blue rubber bleb naevus syndrome
assoc with cavernomas
CT; curvilinear enhancing structure. can have dystropic calcification.
DSA caput medusae appearance
MRI; postcon t1 and SWI
Cerebral varix is
an uncommon vascular malfomation, usually found in combination with another vascular malformation. Focal dilation of a single vein with no neural tissue or vessel anomalies
Sinus pericranii is
a cranial venous anomaly where there is abnormal communication between intracranial dural sinuses and extracranial venous structures usually via an emissary transosseous vein
Caroticocavernous fistulas are
abnormal communications between the carotid circulation and cavernous sinus. Can be direct or indirect.
Caroticocavernous fistula classification
Barrow classification
A: direct
B: indirect with ICA branches
C: indirect with ECA branches
D: B+C
Caroticocavernous fistula causes
Direct
- trauma
- aneurysm
- CTD
Indirect
- probably secondary to cavernous thrombosis with revascularisation.
- maybe pregnancy, surgery, sinusitis
Caroticocavernous fistula imaging
orbital congestion
- proptosis and exopthalmos
- retrobulbar fat stranding
- enlarged EO muscles
venous engorgement
- enlarged SOV
- bulging cavernous sinus
- asymmetric enhancement
Dehiscent ICA - snowman
haemorrhage
Reversible cerebral vasoconstriction syndrome is
a group of conditions characterised by thunderclap headache and reversible vasoconstriction of the cerebral arteries
Reversible cerebral vasoconstriction syndrome associated conditions/risk factors
Pregnancy
Drugs (lots)
migraines
hypercalc
phaeos
carcinoid bronchial
idiopathic
Reversible cerebral vasoconstriction syndrome imaging
vascular narrowings and/or
- convexity SAH
- lobar hamorrhage
- watershed infarct
- vasogenic oedema
smooth tapered narrowings invovling large to medium sized arteries followed by abnormally dilated segments. beaded or sausage shaped.
Reversible cerebral vasoconstriction syndrome differentials
SAH with vasospasm
Vasculitis
Arterial dissection
untreated fungal/bacterial meningitis
Central nervous system vasculitis are
a heterogenous group of inflammatory diseases affecting the walls of blood vessels in the brain, cord and meninges. Can be primary or secondary
Primary - confined to the CNS, primary angiitis
Secondary - in the context of a systemic process
Central nervous system vasculitis imaging
variable and non specific. infarctions are most common, 53%.
focal or multifocal segmental narrowing
T2 FLAIR high intensity white matter (non spec). meningeal enhancement and ICH can be seen.
Cerebral amyloid angiopathy is
a disorder caused by the accumulation of cerebral amyloid in the tunica media and adventitia of leptomeningeal and cortical vessels causing fragility.
Cerebral amyloid angiopathy forms
Sproadic
- incidental, prominent in autopsy of elderly and alzheimers patients
- not assoc with systemic amyloidoses
Familial
- rare
- usually autosomal dominant
- lots of types includ; AB peptide with precursor protein APP, ACys peptide with precursor protein cystatin c
Assoc; alzheimers, downs, chronic traumatic encephalopathy
Cerebral amyloid angiopathy presentation
Cortical vessels
- lobar/cerebellar haemorrhage
- cognitive impairment
Leptomeningeal vessel involvement
- convexity SAH
Other
- inflammatory type; rapid cognitive decline
- amyloidoma
Cerebral amyloid angiopathy imaging
Haemorrhage
- ICH; corticosubcortical, lobar. tends to spare BG and pons
- microhaemorrhage; tends to spare BG and pons
- convexity SAH
- superficial siderosis
Ischaemia
- ischaemic leukoencephalopathy
- microinfarcts and lobar lacunes
Others
- dilated perivascular spaces of the centrum semiovale
- cortical atrophy
Cerebral amyloid angiopathy ddx
Hypertensive microangiopathy
Multiple cavernoma
Haemorrhage mets
DAI
Neurocystericosis
Fat embolism syndrome
Radiation induced vasculopathy
Cerebral amyloidoma is
a rare manifestation of cerebral amyloid deposition, appearing as a solid enhancing mass.
Cerebral amyloidoma imaging
Nodular solid masses with vivid contrast enhancement centred within the white matter and often abutting the ventricles. Mantle of vasogenic oedema.
CT: hyperattenuating typically. enhancing.
MR
T1 and T2 variable
Vivid enhnacement, can have peripheral radial enhancement
microhaemorrhages
Sturge Weber syndrome is
a phakomatosis characterised by facial port wine stains and pial angiomas
Sturge Weber syndrome path
sporadic, no hereditary component. associated gene GNAQ 9q21.
leptomeningeal haemangioma results in a vascular steal affecting the cortex and white matter producing ischaemia
Sturge Weber syndrome imaging
XR - gyral calcification
CT - subcortical and cortical calc (tram track). calvarial and regional sinus enlargement. dyke davidoff masson appearance. orbital choroidal haemangiomas. ipsilateral cavernous and choroidal enlargement.
MR
T1: volume loss
C+: leptomeningeal enhancement
T2: low signal white matter subjacent
SWI: calcification
Spectro: decreased NAA
Sturge Weber syndrome ddx
AVM
Torch infections
neurocystericosis
PHACE syndrome
health cortical infarct
radiotherapy
gobbi syndrome
PHACE syndrome
aka cutaneous hamangioma vascular complex syndrome
phakamatosis
comprised of:
P: posterior fossa malformation
H: haemangiomas
A: arterial anomalies
C: coaractation of the aorta/cardiac anomalies
E: eye anomalies
Gobbi syndrome aka CEC syndrome
coliac, epilepsy, cerebral calcifications
bilateral occipital calc. no atrophy.
Superficial siderosis is
a rare condition which results from deposition of haemosiderin along the leptomeninges with eventual neurological dysfunction.
classically presents with gradual bilateral sensorineural hearing loss, cerebellar dysfx and pyraimydal signs
Superficial siderosis imaging
MR
pial and ependymal surfaces coated with low signal haemosiderin, particularly brainstem and cerebllum
should image whole axis to look for causative lesion, if presnet
CADASIL is
cerebral autosomal dominant arteriopathy with subcortical infarcts and lekuencephalopathy
AD microvasculopathy characterised by recurrent lacunar and subcortical white matter ischaemic strokes and vascular dementia in young and middle aged patients without known vascular risk factors.
CADASIL path
chromosome 19p13.12
NOTCH 3 gene
small vessel and arteriole stenosis secondary to fibrotic thickneing of the basement membrane.
CADASIL imaging
CT non spec wm hypoattenuation
MR
confluent white matter hyperintensities
lesions can be seen in pons, BG, thalami
initial course anterior temporal lobe and external capsule. can be diffuse subcortical
sparing occipital, orbitofrontal white matter, cortex and subcortical U fibres
CADASIL ddx
hypercoaguable state
MELAS
subcortical arteriosclerotic encephalopathy SAE
Susac syndrome
CNS vasculitis
CARASIL
Susac syndrome quick hitter
retinocochleocerebral vasculopathy. middle aged women. triad of subacute encephalopathy, bilateral sensorineural hearing loss, branch retinal arterial occlusion.
imaging
- small rounded T2 hyperintense snowball lesion, with one in the CC.
- CC predilection; central fibres of the body and splenium without abutting the callosal undersurface
- leptomeningeal enhancement
- punched out T1 holes when chronic
retinal/vestibulocochlear involvement clinically
Remote cerebellar haemorrhage is
benign complication of craniotomy, spinal surgery, LP and shunt insertion. may be secondary to post surgical CSF hypovolaemia, tends to be self limiting.
layering of blood over the superior folia - Zebra sign
Brain abscess imaging features
CT
- outer hypo inner hyperdense rime (double rim)
- uniform hyperdense ring
- central low attenuation
- vasogenic oedema
- ventriculitis
- obstructive hydro
MRI
T1
- low intensity centrally and peripherally
- ring enhancement
T2/FLAIR
- central high intensity
- peripheral high intensity vasogenic
- capsule may have intermediate to low thin irm
DWI
- high DWI centrally
SWI
- low intensity rim; typically smooth and complete
- dual rim sign
Perfusion
- CBV reduced in surrounding oedema
Spectro
- elevated peaks corresponding to lipids/lactate, succinate, acetate, amino acids
Brain abscess differentials
Mets or GBM
- abscesses have smooth wall, satellite lesions,low intensity capsule, reduced perfusion, restriction
Subacute iunfarct, haemorrhage, contusion
Demyelinating lesion
Radiation necrosis
Ventriculitis is
inflammation/infection of the ependymal lining of the ventricles. most often due to meningitis
Ventriculitis imaging
US
- periventricular echogenicity and irregularity of the surface
- choroid plexus irregularity
- intraventricular debris
CT
- hyperdense layering material
- hydrocephalus
- periventricular low density
- thin uniform ependymal enhancement post con
MR
- debris layering
- intensely restricuted diffusion of the debris
- periventricular oedema
- ependymal enhancement
Subdural empyema is
intracranial infection with a suppurative collection b/w the dura and the arachnoid. Commonly seen as a complication of sinusitis, otitis, mastoiditis or surgical intervention.
Subdural empyema imaging
CT
- resemble subdural haematomas
- crescentic, although can seem biconvex
- enhancing surrounding membrane
MR
- same as CT but better
- better for complications like cerebritis, abscess and venous thrombosis.
Intracranial epidural abscess is
a pyogenic collection within the epidural space. sinusitis again most common. strep, h influ, staph.
Intracranial epidural abscess imaging
CT
- less good than MR
- similar to EDH
- peripheral enhancement post con
MR
- T1 hyper
- C+ peripheral enhancement
- T2/FLAIR iso to hyper
- PD same
- DWI restricted
Child/Adult HSV encephalitis is
most common cause of fatal sporadic fulminant necrotising viral encephalitis. Typically HSV1.
Child/Adult HSV encephalitis imaging
General
- typically bilateral, asymmetric
- limbic, medial temporal, indular cortices and inferolateral frontal
- BG spared
CT
- low density in thje anterior and medial temporal lobe and island of reil (insular cortex)
- enhancement rare in first week, then patchy
MR
T1: usually low, unless haemorrhage
C+: enhancement absent early, variable late (gyral, lepto, ring, diffuse)
T2: hyperintensity of white matter and cortex
DWI: restricted due to cytotoxic oedema, less than infarct
SWI: blooming in haemorrhagic
Child/Adult HSV encephalitis differentials
Limbic encephalitis
Gliomatosis
Status epilepticus
MCA infarct
Trauma
Ohter viral encephalitis.
- EBV
- HHV 6
- VZV
- Flu a
- Rabies
Neurosyphlis
Neurocysticercosis is
a CNS infection caused by the pork tapeworm taenia solium which is endemic in low income countries
Neurocysticercosis stages
Escobars pathological stages
- Vesicular - viable, no host reaction
- Colloidal vesicular - cyst fluid becomes turbid. l;eaky oedema.
- granular nodular - oedema decreases as cyst retracts, enhancement persists
- nodular calcified - calcified cyst
Neurocysticercosis locations
SAS - lack a scolex
Parenchyma, most common, GW junction
Basal cisterns “grape like” lack scolex
Ventricles, most common 4th
Spinal
Neurocysticercosis imaging
Vesicular
- cyst with a dot
- CSF density/intensity
- eccentric hyperintense scolex T1
- minimal enhancement/oedema
Colloidal vesicular
- cyst fluid turbid, T1 hyper, CT attenuating
- oedema
- peripheral enhancement
- scolex initially, shrinks down
Granular nodular
- oedema decreases
- retracts to small enhancing nodule
- less enhancement, but persits
Nodular calcified
- end stage quiescent calcified nodule
- no oedema or enhancement
- T2 and * signal dropout
Neurotoxoplasmosis is
an opportunistic infection caused by toxoplasma gondii. Typically in patients with HIVAIDS and most common cause of abscess in these
Neurotoxoplasmosis imaging
Multiple lesions with a predilection for the BG, thalami and CM junction.
CT
- multiple hypodense regions
- BG and CM junction
- variable size
- thin nodular or ring enhancement
- dot like calcification in treated
MR
T1: iso to hypo
T2:
- variable intensity. hyperintense necrotising, iso organising abscess
- concentric alternating zone of hypo hyper iso signal
- perilesional oedema
C+: ring or nodular enhancement
Spectro: incr lactate and lipids. Red cho/cr/naa
PET cold
Neurotoxoplasmosis vs CNS lymphoma
Lymphoma
- subependymal
- solitary
- solid enhancement usually
- haemorrhage uncommon
- more diffusion retriction
- increased choline
- increased rCBV
- high signal thallium
Toxoplasmosis
- BG and CMJ
- multiple
- ring or nodular enhancement
- haemorrhage may be seen
- more facilitated diffusion
- decreased choline
- decreased rCBV
- low signal thallium
CMV encephalitis is
CNS infection, almost always profoundly immunocompromised. Affects entire neural axis.
CMV encephalitis imaging
meningoencephalitis and ventriculitis/ependymitis
MRI
- non spec increased WM T2 signal, periventricular
- no enhancement, unless ventriculitis
- no mass affect
CMV encephalitis ddx
HIV encephalitis
PML
CNS lymphoma
Neurotoxoplasmosis ddx
CNS lymphoma
Cerebral mets
Other infection- TB, crypto, bacterial, neurocysticercosis
CNS cryptococcosis is
most common fungal infection and second most common opportunistic infection of the CNS. Predominantly AIDS, but if competent than history of birds. Can be meningeal, parenchymal or perivascular space predominant
CNS cryptococcosis imaging
range of appearance influenced by degree of immunocompromise and therapy. more effective therapy has enhancement.
range includes
- hydrocephalus
- dilated perivascular spaces coalescing
- leptomeningeal/pachymeningeal enhancement
- cryptococcomas
- miliary nodules
- choroid plexus plexitis
perivascular/BG pattern is common, but also white matter, brainstem, cerebellum
MRI
Meningeal
- leptomeningeal/pachymeningeal enhancement
- FLAIR C+ enhancement
Cryptococcomas
- T1 low
- T2/FLAIR high
- C+ variable
- DWI variable
Perivascular
- T1 low to intermediate
- T2 high
- FLAIR variable
- DWI variable
CNS aspergillosis is
one of the most common fungal CNS infections, resulting from angioinvasive infection from aspergillus spp. Typically AIDS, steroid use, neutropaenia or GVHD
CNS aspergillosis imaging
Variable but three main patterns;
- brain abscess; often multiple, rando distribution
- cerebral infarctions, more likely perforators
- invasive paranasal rhinosinusitis
MR
Abscess
- often multiple, rando distribution
- ring enhancing with high DWI
- DWI can be variable
- may also have peripheral low T2 signal, low GRE (perilesional hamorrhage or iron in fungi) without inner high signal rim (absent dual rim)
Infarction
- multiple, random
- haemorrhage/mycotic aneurysms can be present
Rhinosinusitis
- paranasal disease, invasive features
- OM
- dural enhancement and subdural empyema
Other
- can have a granulomatous mass lesion
- hypo to iso T1
- hypo T2
Progressive multifocal leukoencephalopathy is
a demyelinating disease resulting from reactivation fo the JC virus infecting oligodendrocytes in patients with compromised immune systems.
Typically AIDS CD4 50-100.
Non HIV
- post transplant
- leukaemia
- solid malig
- isolated CD4 lymphocytopaenia
- MABs
Can also be encountered in immune reconstitution inflammatory syndrome.
Progressive multifocal leukoencephalopathy imaging
CT
- asymm focal zones of low attenuation involving periventricular and subcortical white matter. HIV more symmetrical
MR
- Typically multifocal, asymmetric, periventricular, subcortical
- little to no mass effect or enhancement
- subcortical U fibres
- parieto occipital predilection
T1
- hypo
T2
- hyper
- multiple punctate T2 lesions (milky way sign)
- barbell sign; PO region crossing splenium
C+
- typically no enhancement
- can be seen in IRIS, natalizumab
DWI
- patchy leading edge restriction
Spectro
- reduced NAA, lactate presence, incr choline/lipids
MRP
- increased leading edge
Progressive multifocal leukoencephalopathy ddx
MS (more well defined, periventricular)
HIV encephalopathy (more diffuse, atrophic, symmetric, no U fibres)
PRES (different hx, grey and white matter)
ADEM (hx, grey and white matter, enhances)
Progressive multifocal leukoencephalopathy signs
milky way
- punctate T2 foci around primary lesion
barbell
- extending across splenium
Creutzfeldt Jakob disease is
a transmissable spongiform encephalopathy resulting in rapidly progressive dementia and death. Sporadic, but familial and acquired occasionally. Typically hyperintense DWI in cerebral grey matter - cortex, striatum, thalamus.
Creutzfeldt Jakob disease types
Sporadic
Variant
Familial
Iatrogenic
Creutzfeldt Jakob disease variants
Sporadic - rapidly progressive dementia and other features of neuropsychiatic decline
Heidenhain - isolated visual
Brownell oppenheimer - cerebellar ataxia
Vairant - psychiatric symptoms
Creutzfeldt Jakob disease markers
EEG findings
S100
CSF 14 3 3 protein
CSF RT QulC seeding assay
Creutzfeldt Jakob disease affected regions (good luck idiot)
Sporadic distribution: cortex and deep grey matter. from most to least;
- insula, cingulate, superior frontal
- striatum (caudate and putamen)
- precuneus, cuneus, paracentral lobule, medial frontal, occipital, angular/supramarginal, superior parietal, inferior frontal
- thalamus
- post central, pre centra, medial and superior temporal
Usually bilateral.
Heidenhain - parietooccipital
Bronwell Oppenheimer - cerebellum, BG
Variant - hockey stuck/pulvinar (although more commonly seen in sporadic due to overall greater prevalence)
Creutzfeldt Jakob disease imaging and ddx
MRI
DWI: hyperintensity
ADC: variable, depends on timging
FLAIR/T2: hyperintense, more subtle
T1: high signal globus pallidus
C+ no enhancement
DDX
- autoimmune encephalitis
- hypoxic injury
- osmotic demyelination
- hepatic encephalopathy
- hypoglycaemic encephalopathy
- mitochondrial disease
Autoimmune encephalitis is
antibody mediate brain inflammatory process, typically involving the limbic system. Broadly divided into
- paraneoplastic
- non neoplastic
Autoimmune encephalitis causes
tumouts
- small cell
- testicular
- thymic
- breast
- ovarian
- haemotological
- GI
- neuroblastoma
non paraneoplastic
- VGKC antibody
- anti NMDA receptor
- systemic autoimmune conditions
Autoimmune encephalitis imaging
most common location limbic system
cortical thickening and increased T2/FLAIR
bilateral is most common
basal ganglia are frequently involved
patchy enhancement can be seen
restriction and haemorrhage uncommon
Primary ameorbic meningoencephalitis is
rare, usually fatal CNS infection of naegleria fowleria. non specific imaging features in keeping with a haemorrhagic meningoencephalitis
Rocky mountain spotted fever is
an infectious disease caused by Rickettsia rickettsii transmitted by tick bites
Lyme disease is
caused by borrelia burgdorferi. non specific features including periventricular subcortical T2 hyperintensity, nerve root enhancement (esp facial), meningeal enhancement
Immune reconstitution inflammatory syndrome is
paradoxical deterioration following abrupt improvement in immune function. Classiccally seen in HIV patients on ART, but also mabs in MS
Immune reconstitution inflammatory syndrome imaging
underlying pathogen or may mimic woresening of underlying condition or be atrypical. typically enhancing masses gain mass effect rapidly. enhancement is variable and may be bizarre
mycobacterial TB
- new lns may be necrotic, pulmonary nodules or new abscesses
PML
- new enhancement and mass effect in exisiting white matter lesions
pulmonary kaposi sarcoma
- similar but increasing in extent
HHV 6 encephalitis is
rare CNS infection in immunosuppressed patients, esp following haematopoietic cell trnasplant who develop limbic encephalitis syndrome with MRI signal intensity abnormalities of the medial temporal lobe
Subacute sclerosing panencephalitis is
also known as Dawsons disease. rare, chronic progressive fatal encephalitis. persistent measles infection immune resistant.
Subacute sclerosing panencephalitis imaging
T2/FLAIR: high in parietal and temporal lobes
C+ enhancement early
lateral more extensive, atrophic
Rasmussen encephalitis is
a chronic inflammatory disease of unknown origin affecting one hemisphere
Rasmussen encephalitis imaging and ddx
MRI
unilateral cortical atrophy with exvacuo dilatation starting in caudate
T2 hyperintense
DWI restricted can be seen
no enhancement\
DDX
Dyke Davidoff Massson
Sturge Weber
unilateral megaencephaly
hemiconvulsion hemiplegia epilepsy syndrome
CLIPPERS is
chronic lymphocytic inflammation with pontine perivascular enhancement response to steroids
predilection for the pons. characteristic curvilinear regions of enhancement.
Rasmussen encephalitis imaging
multiple punctate patchy and linear regions of contrast enhancement confined to the pons. can also be in the cerebellar peduncles, cerebellar hemispheres and cervical cord/ reatively little oedema. SWI signal loss.
Multiple sclerosis classification
Variants:
Classic (Charcot)
Tumefactive
Marburg (acute malignant)
Schilder type
Balo concentric sclerosis
Patterns:
Relapsing remirrting
Secondary progressive
Primary progressive
Progressive with relapses
Benign
Multiple sclerosis imaging
Plaques in the CNS system, typically ovoid and perivenular
MRI
T1
- iso to hypointense
- callososeptal interface many small lesions (venus necklace)
T2
- hyper
- acute have oedema
SWI
- central vein
FLAIR
- hyperintense
- epndymal dot dash sign
- perpindicular to lat ventricles (dawsons fingers)
C+
- active enhance
- usually incomplete, open ring of enhancement at the periphery
DWI
- active may be high or low ADC
- typically open ring
Multiple sclerosis complications
PML
PML IRIS
CNS lymphoma
Multiple sclerosis ddx
Intracranial
- CNS fungal infection
- mucopolysaccharidosis
- Marchiafava Bignami disease
- Susac syndrome
- antiphospholipid syndrome
- CLIPPERS
Spine
- Transverse myelitis
- infection
- tumours
Tumefactive MS is
an MS variant where patients develop large aggressive demyelinating lesions
Marburg variant MS is
Extensive and fulminant acute demyelination. Typically youynger patients, die within a year. Extensive confluent areas of tumefactive demyelination are seen with mass effect, defined rings and incomplete rim enhancement.
Schilder type MS is
an extremely rare, progressive demyelinating process that begins in childhood.
Balo concentric sclerosis is
a rare and severe monophasic demyelinating disease. Considered an MS variant. Rounded lesion with alternating layers of high and low signal intensity “bullseye” “onion bulb”.
Balo concentric sclerosis imaging
Alternating bands of demyelinated and myelinated white matter, seen as concentric rings.
T1: irregular, concentric rings of iso to low signal
T2: irregular concentric rings of iso to hyper
C+ usually periphal enhnacement in the area of active demyelination
DWI: some restriction in outer ring
Neuromyelitis optica (NMO) and NMO spectrum disorder (NMOSD) is
severe demyelinating disease caused by autoantibody to aquaporin 4 water channel. classic triad of optic neuritis, longitudinally extensive myelitis and postive anti AQP4. Previously known as Devic disease.
Neuromyelitis optica imaging
Orbits
- swollen/hyperintense/enhancing CN2
- bilateral involvement, to optic chiasm
- atrophy in chronic
Brain
- periventricular (no dawsons fingers)
- periaqueductal GM
- hypothalamus/medial thalamus
- dorsal pons/medulla
- CC
- deep punctate white matter lesions
- corticospinal trtact invovlement
- larger >3cm hemispheric lesions (radially orientated, little mass effect)
- fever juxtacortical lesions
- larger, more confluent, more CC
Spine
- at least three levels (long extensive)
- ring enhancing, or patchy enhancement
- prefers central cord
Neuromyelitis optica ddx
cerebral
- MS
- Susac
- Neuro Behcet
- Primary angiitis of the CNS
- ADEM
- ALS
Optic neuritis
Spinal
- NMO
- MS (confluent lesions)
- anti MOG encepha
- Systemic (neurosarcoid, sjogrens, SLE, behcet)
- other causes transverse myelitis
- vascular (AVF, infarct)
Acute disseminated encephalomyelitis ADEM is
a monophasic acute inflammation and demyelination of white matter following viral infection or vaccination,
ADEM imaging
Vary from small punctate to tumefactive
Callososeptal interface involvment is less typical
Bilateral but asymmetrical
Can sometimes involve subcortical grey matter and brainstem unlike MS
Acute haemorrhagic leukoencephalitis is
also known as Hurst or Weston Hurst syndrome. Very rare form of demyelinating disease. Acute rapidly progressive fulminant inflammation of the white matter. Typically young adults (ADEM kids).
Large tumefactive lesions, sparing the cortex. Assoc punctate haemorrhage. POssible BG/thalami involvement.
Acute necrotising encephalopathy is
a rare encephalopathy with bilateral brain lesions, involving the thalami, putamina, internal/external capsule, cerebellar white matter and tegmentum.
Typicall bilateral and symmetrical thalamic involvement. Canhave restricted diff, haemorrhage, cavitation and enhancement.
Vascular dementia is
second most common after alzheimers. seen in atherosclerosis and htn. MRI more sensitive to white matter change, changes of amyloid and chronic htn encephalopathy.
patterns of vascular damage
- binswanger (small vessel)
- cerebral infarct
- lacunar infarctr
- hjaemorrhage
Binswanger disease is
a slowly progressive non hereidtary white matter vascular dementia.
subcortical and periventricular hjypertinscve T2/FLAIR
usually small lesions
moderate diffuse atrophy
ddx
CADASIL (hereditary, genetic, anterior temporal and superior frontal)
CNS vasculitis
Alzheimers imaging
most common degenerative disease. most common cerebral amyloid deposition disease.
characteristic volume loss
1. mesial temporal lobe
- particularly hippocampus, entorhinal cortex and perirhinal cortex
2. temporoparietal cortical atrophy
NM
SPECT/PET to see hypoperfusion/metabolism om a biparietal bitemporal distribution with amyloid/tau agents in the grey matter and medial temporal lobes respectively
PRES three main patterns
Holohemispheric at watershed zones
Superior frontal sulcus
Parieto occipital dominance
PRES is
an acute hypertensive encephalopathy secondary to inability of the posterior circulation to autoregulate in response to bp changes. Hyperperfusion with disruption in the BBB resulting in vasogenic oedema.
PRES aetiology
Severe HTN
Haemolytic uraemic syndrome
TTP
SLE
Drugs
BM t/p
PRES imaging
Bilateral vasogenic oedema, typically parietooccipital
Can also be non posterior; frontal, inferior temporal, cerebellar, central. Can be unilateral.
MRI
T1 hypo
C+ patchy, variable
T2 hyper
DWI vaRIABLE
SWI may have haemorrhage
PRES differential
inflammatory cerebral amyloid angiopathy
PML
hypoglycaemia
posterior infarct
hypertensive brainstem encephalopathy
gliomatosis
Hypertensive brainstem encephalopathy is
severe htn, brainstem vasogenic oedema and various neurology. Can be isolated or with PRES.
Hypertensive brainstem encephalopathy imaging and differentials
CT: diffuse hypoattenuation, mostly at the pons
MRI: increased FLAIR/T2 brainstem, lack of diffusion restriction
ddx
- PRES
- osmotic demyelination
- infarct
- neoplasia
Hypoglycaemic encephalopathy is
brain injury from severe/prolonged hypoglycaemia. Typically affects posterior internal capsule, cerebral cortex, hippocampus and basal ganglia.
Hypoglycaemic encephalopathy imaging
Typically bilateral
characteristically
- posterior limb internal capsule
- cerebral cortex (PO and insula)
- hippocampus and basal ganglia
- cerebellum, brainstem, thalami (spared in adults, present in neonates)
- splenium of CC (boomerang)
Osmotic demyelination syndrome is
seen in the setting of osmotic changes typically with rapid correction hyponatremia
Osmotic demyelination syndrome imaging
T2 bright
DWI bright
T1 hypo
piglet sign
trident sign
Status epilepticus imaging
Increased T2/FLAIR, increased DWI.
Variable distribution
- cerebral cortex and subcorticla WM
- hippocampi and mesial temporal lobes
- thalamus, pulvinar region
- cerebellum
Carbon monoxide poisoning imaging
Bilateral with globus pallidus most commonly affected
CT
GP low attenuation
Can have diffuse white matter hypoattenuation
MRI
T1 low, can have areas of haemorrhage
T2/FLAIR high
C+ can have peripheral enhancement
DWI: increased restriction
Carbon monoxide differentials
Mitochondrial encephalopathies
- leigh
- kearns sayre
Other toxic encephalopathies
- cyanide
- methanol
- organophsophate
Other causes of anoxia
Metabolic
- Wilsons
Prion
- CJD
Hepatic encephalopathy imaging
T2/FLAIR
- mild; symmetric high in insula, thalamus, posterior internal capsule, cingulate
- severe; diffuse cortical.
perirolandic/occpital spared.
DWI
- similar to t2
SWI
- 50% have microhaemorrhage
Fahr syndrome is
abnormal vascular calcium deposition in the basal ganglia, cerebellar dentate nuclei, white matter, with subsequent atrophgy. Can be primary or secondary.
Fahr syndrome secondary causes
Endocrinopathies
- hypoparathyroidism/hyper
Vasculitis
Mitochondrial disorders
Infection
- brucellosis
- EBV
-HIV
Inherited
- neuroferritonpathy
- other conditions
Radiation
Chemo
CO poisoning
Fahr disease imaging
Symmetrical calcification of the causate, lentiform, thalamus and dentate nuclei
Globus first
Subcortical white matter later
