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Flashcards in Head & neck Deck (53)
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1

Bad signs of acute subdural haematoma
4

Heterogeneity
Convexity
Inc Mass effect
SAH

2

Features of isodense SDH
Further imaging

Unexplained mass effect
Effaced sulci
"thick' cortex"
WM buckling

Do contrast
MR diagnostic

3

Traumatic brain haematoma - ring enhancing lesion
Diagnostic aids/clues
4

Bilateral
Orbitofrontal
Haemosiderin ring
Other injuries

4

Diffuse axonal injury
Grading - 3
Deeper lesions worse prognosis

1 : lobar WM. Lesions bloom
2: involves corpus callosum typically splenium
3: Dorsolateral midbrain

5

Worrying features of skull fractures
7

Overlies a dural sinus
Overlies MMA
Overlies eloquent cortex
Depressed > table width
Open/compound
Traverses ICA canal
Temporal bone # ( opacification of mastoid air cells)
Skull base # ( blood in sphenoid sinus)

6

Carotico-cavernous fistula CT findings
5

Proptosis
Enlarged extra ocular muscles
Convex ipsilateral CS
Enlarged superior opthalmic vein
Retrobulbar fat stranding
Check Brain - venous infarcts

7

Early NCCT signs of stroke
3

Penumbra on PWI : at risk area

DWI : infarct core

Loss of GW differentiation : insular ribbon sign, BG effacement (less delineation)

Dense artery sign (30%) - asymm, correlates c Sx

Hypodensity

Subacute : gyriform CE

8

Distal Carotid artery dissection features

mid to distal ICA below cavernous segment
Bulb spared
NO false lumen
Subintimal haematoma ( do MRI T1 FS - methaemaglobin in wall)
DSA may be normal!

9

Proximal carotid artery dissection features

Progression of aortic dissection
CCA
ICA extension uncommon
False lumen
May be asymptomatic

10

ICA dissection imaging signs

location unusual for atherosclerosis ( bulb spared)
string sign
aneurysmal dilatation
occlusion
intimal flap may be seen

11

Amyloid angiopathy
features
B-amyloid peptide deposition

Lobar haemorrhage in elderly (15% >60y, 50%>70y)
Subcortical microhaemorrhages, spares BG cf HTN

12

Non traumatic ICH
causes

Underlying lesion: tumour, AVM, cavernoma, aneurysm
Amyloid angiopathy
Dural sinus thrombosis
Hypertension
Coagulopathy

13

Hypertensive haemorrhage
locations & pattern

Putamen/EC - 60%
Thalamus - 15-25%
Pons/CBL - 10%
Lobar 5-15%

Acute focal haematoma
Subacute/ch microbleeds

CTA dot sign - active bleed

14

Cavernous malformation
features

Discrete collections of endothelial lined sinusoids

Vascular hamartoma

ICH risk - 0.15-1% annually

Sporadic- 75%, familial 10-30% ( fam cavernomatosis)

Angiographically occult

Associated DVA

COMPLETE haemosiderin rim

Variable SI locules

Popcorn appearance

15

Capillary telangiectasia in brain

Brainstem
Ass with radiation
No T2 abnormality
Brush like Ca+
GRE blooming
Do not touch

16

Spetzler-Martin Grading AVM
Size
Eloquence
Venous drainage

<3cm - 1
3-6cm -2
>6cm - 3

Eloquence 1 - 0

Venous drainage superficial/deep

17

RF for intracranial aneurysms
9

Smoking
Cocaine
Age > 50y
Female > Male
FMD
Anatomic variants eg trigem artery
Type IV Ehlers Danlos
NF 1
ADPCKD

18

Trigeminal artery vs Persistent fetal PCA

Trigeminal originates from CAVERNOUS ICA to BA
persist fetal from supraclinoid ICA (above sella)

19

PseudoSAH
causes
4

Cellular material ( infection, carcinomatosis, granulomatous etc, clean ventricles)
Iodinated contrast (myelogram, leak due to RF etc)
CSF Hypotension
Anoxia

20

Pseudopseudo SAH

Global anoxia/hypoxia due to dense venous stasis (white cerebellum, indistinct BG, no hydrocephalus)

CSF hypotension : ?crowded normal blood vessels, SD collections and large dural sinuses

No hydrocephalus

21

Idiopathic intracranial hypertension
( BIH, pseudotumour cerebri)
Features
RF

Women
3rd decade
Obese/weight gain
May be drug induced(steroids)
Papilloedema
Headaches, visual obs, diplopia, pulsatile tinnitus

Look for secondary causes
Empty sella
Flat post globe
Vert tortuous , distended ON sheath
Slit like ventricles - rare
Focal compression mid transverse sinuses (pseudostenosis)

22

Infarcts in young patients
4 main cause categories

Cardiovascular: CHD, valve disease, LA myxoma

Prothrombotic: SCD

Inherited: vascular - neurocut, CADASIL ; metabolic : MELAS, homocystinuria

Acquired : dissection, NAI, moya-moya, systemic angiitis, migraines, OCP, street drugs

23

Paediatric BG calcification
4 main

Fahr's

Hypo/hyper parathyroidism

MELAS - stroke like cortical lesions that cross vascular territories, parieto-occipital, inc lactate on MRS ( in normal brain regions)

HIV

24

MELAS

mitochondrial myopathy/angiopathy
encephalopathy
lactic acidosis
stroke-like episodes

2nd decade
parieto-occipital
inc lactate in normal brain
progressive with periodic exacerbations

25

Pontine hyperintensity
causes
4 main

Ischaemia

Infection

Neoplasm - glioma

WM pathology: demyelination, myelinolysis, PML

26

Central pontine myelinolysis
( osmotic myelinolysis)

alcoholics, malnutrition, Tx, burn

spastic quadraparesis
pseudobulbar palsy
often rapidly progressive

non-inflammatory, non vascular
acute destruction of myelin

Symmetrical T2/FL hyper
Diff +
No post CE
batwing contour
Spares corticospinal and peripheral tracts

Can have symmetrical extrapontine lesions : BG, thalami, midbrain

27

Posterior reversible encephalopathy syndrome

clinical
CT
MRI - locations (5)

acute encephalopathy
WM hyperintensity
vasogenic oedema (no DWI unless non reversible component))
No CE

posterior fossa
parietal
occipital
posterior frontal
temporal

many associations!

10% have haemorrhage/infarcts

28

Mural nodule with cyst
intracranial

Juvenile pilocytic astrocytoma (CE wall)
Pleomorphic xanthoastrocytoma
Ganglioglioma
Haemangioblastoma ( non CE wall, PF)

29

Pleomorphic xanthoastrocytoma
Demo
location
RF
prognosis

rare
astrocytoma subtype
children and young adults
superficial cortical location
Temporal most common
Cyst with mural nodule
minimal oedema
good prognosis

30

Oligodendrogliomas

low grade and anaplastic
younger patients
better prognosis cf astro
frontal lobe most common
Cortical expansion
cortical involvement
Ca 2+ > 80%
Can appear aggressive
Variable CE