Neuro - Vasc

Question 1

What connects superior sagittal sinus into superficial middle cerebral vein?

Answer 1

Trolard

Additional
Labbe - transverse sinus and superfical middle cerebral

Top Trolard
Lower Labbe

Question 2

Where do basal veins of rosenthal drain?

Answer 2

Deep veins, pass lateral to midbrain within ambient cistern draining into vein of Galen.

Additional:
Vein of Galen formed by two internal cerebral veins. Drains into the staight sinus.

Question 3

Nenatal Brain MRI
Is Baby brain T1 bright or T1 dark?

Answer 3

T1 dark
T2 bright

Why?
Immature myelin has high water content (ie T2 bright)
As it matures water descreases and fat increases (ie T1 bright(
Nb. T1 changes precede T2.

Question 4

Decribe myelination pattern

Answer 4

Inferior to superior
Posterior to anterior
central to peripheral

Subcortical white matter last to myelinate.

Question 5

What gives steer horn (coronal) or racing car (axial) ventricular appearance?

Answer 5

Corpus callosum agenesis

additional:
You will see asymmetric occipital horn dilatation (Colpocephaly)

Other association: Pericallosal lipoma

Callosum forms from genu to splenium (then rostrum last)

Question 6

Heriation of brain tissue through cranial defect (neural tube)

Answer 6

Meningioencephalocele

Fronto ethmoidal is common

Question 7

What is cause of ‘single lobed’cerebellum?

Answer 7

Rhomboencephalosynapsis
(vermis is absent)

Associated with holoprosencephaly spectrum.

Addition: Remeber normal primary fissure (dorsal) and fastigial point (v

Question 8

Name the conditon:
Vermis hypoplasia
Vermis elevation and rotation
Dilated 4th Ventricle

Answer 8

Dandy walker malformation
(Torcula, lamboid inversion)
Most common manifestation is macrocepahly

The cerebellar volume is preserved - just displaced anterior & lateral

Normal varient - mega cisterna magna.

Question 9

Holoprosencephaly
Least Severe : Lobar
Semi-Lobar
Most Sever: Alobar

Answer 9

What?
Failure of midline cleavage.

Lobar - Variable frontal horn fusion (absent septum pellucidum)

Semi - lobar : Back is cleaved, not the front. occiptal and temporal horns partially developed.

Alobar : zero midline cleavage

Question 10

What causes anterior falx absence, absent septum pellucidum and anterior interhemispheric fissure. Partial thalmus fusion.

Answer 10

Semi-Lobar holoprosencephaly

Question 11

What casues absent falx, absent corpus callosum and interhemispheric fissure?

Answer 11

Alobar holoprosencephaly.

Question 12

What is polymicrogyria PMG

Answer 12

Overfolding of superficial layers of cortex. Resulting nodular bumpy cortex.
(can be caused by Zika virus)

Question 13

What is split brain?

Answer 13

Schizencephaly
-secondary to vascular insult
closed lip (20%)
open lip (80%)

Question 14

Differentiate schizencephaly and porencephalic cyst

Answer 14

Schizencephaly cleft is lined by gray matter
Porencephalic cyst is not

Porencephalic cyst is caused by ischaemic/traumatic event - encephalomalacia (looks developmental)

Most severe - hydraencephaly (cerebelleum, falx and midbrain remain)

Question 15

Differentiate:
MENINGOCELE
MENINGO-ENCEPHALOCELE
CYSTOCELE
MYELOCELE

Answer 15

meningocele - csf, meninges NO BRAIN
meningo-encephalocele - csf, meninges, brain
cystocele - csf, meninges, brain, ventricle
myelocele - spinal cord

cephalocele - hernial of cranial contents

Question 16

Cerebellar tonsillar descent (5mm ) and syrinx

Answer 16

Chiari I malformation

Cervical syrinx not always associated
Can have either occipital headache secondary to pressure or weakness, spasticitym proprioception loss from cord pressure.

Less classic association - Klippel - Feil syndrome (congenital c-spine fusion)

Question 17

Features:
Thin 4th ventricle
Interdigitated gyri
Myelomeningocele

Answer 17

Chiari II

• result of neural tube defect and lumbar myelomeningocele causing downward cerebellar displacement
• clival hypoplasia
• long skinny 4th ventricle
• interdigitated cerebral gyri
• low lying torcula (opposite DW)

Has to have neural tube defect
Associations - lumbar myelomeningocele/spina bifida

Chiari III = Chiari II + occipital encephalocele.

Question 18

Most common cause of partial complex epilsepy.

Answer 18

Mesial temporal sclerosis

1. Hippocampal volume loss
2. Scar / gliosis - high T2 signal
3. Temporal horn ex vacuo

Question 19

what is pseudotumour cerebri?

Answer 19

IIH (Idiopathic intracranial HYPERtension)

-too much csf

CT findings:
slit like ventricles
venous sinus compression
partially empty sella
vertical optic nerve tortuosity
flattened posterior sclera

Clinical: downward brainstem displacement may result in 6th nerve palsy.

Question 20

What causes
-ataxia
and incontinence in elderly persion

Answer 20

Normal pressure hydrocephalus

Imaging features:
Out of proportion ventricular size
Trans-ependymal oedmea
Upward bowing corpus callosum.

Question 21

Most common cause of obstructive hydrocephalus?

Answer 21

Cerebral aqueduct stenosis

Question 22

Na/K pump malfunction and gray/white matter differentiation loss

Answer 22

Cytotoxic ordema

Classic: Ischaemia
also with trauma

Question 23

BBB malfunction with white matter oedema

Answer 23

Vasogenic oedema (extracellular)
Classic: Tumour, infection and late ischameia

Question 24

Which is more asscoiated with ACA compression: cingulate or uncal herniation

Answer 24

Cingulate (Subfalcine) herniation

Uncal (transtentorial) herniation, can causes ipsilateral suprasellar effacement and CN3 compression.

Question 25

Lissencephaly

Question 26

High T2/FLAIR medial/dorsal thalamus, peri-aqueductal gray matter.

Answer 26

Wernicke Encephalopathy
B1 deficiency

Question 27

T2 bright central pons

Answer 27

Central Pontine Myelinolysis

Question 28

T2 bright signal corpus callosum
Body - genu - splenium
Thinned corpus callosum, cystic cavities - genu and splenium

Answer 28

Marchiafava - Bignami

Question 29

CT hypodensity/ T2 bright Globus Pallidus

Answer 29

Carbon monoxide (causes global warming)

Question 30

T2 bright putamen

Answer 30

Methanol

Question 31

Post partum, eclampsia, subcortical and cortical asymmetric white matter oedema parietal and occipital lbes

Answer 31

PRES Posterior Reversible Encephalopathy Syndrome

Other classic history: acute HTN, chemotherapy.

Question 32

Transverse Myelitis + Optic neuritis

Answer 32

Neuromyelitis optica

Question 33

Young patient (30-40), migraines, strokes, dementia.

Answer 33

CADASIL
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy

High T2 / FLAIR - frontal and temporal lobes. (Tempoal lobe involvement is classic!!)

Question 34

Caudate head atrophy and frontal horn ex vacuo dilatation

Answer 34

Huntington disease

Question 35

Lactic acidosis, Seizures, Strokes

Answer 35

MELAS syndrome

Question 36

Tegmentum atrophy, sparing of tectum and peduncles

Answer 36

Progressive supranuclear palsy
Parkinson plus

Question 37

T1 high in substantia nigra
DAT scan - loss of commas

Answer 37

Parksinons disease

Question 38

Panda sign - bright tegmentum with normal dark nuclei and substantia nigra
T1 bright basal ganglia

Answer 38

Wilson disease

Question 39

Most common solitary brain tumour in adult population?

Answer 39

Metastatic carcinoma

Question 40

Blue mass behind tympanic membrane
Bright on T1

Answer 40

Cholesterol granuloma
T1 bright as it contains mix of blood and cholesterol crystals

A glomus tympanicum will present with pulsatilla tinnitus, and red lesion behind TM.

Cholesteatoma - white behind TM + I so intense on T1.

Question 41

Sinus mass differentials ..

Answer 41

Older -
1. SCC - generally involves maxillary antrum. Low T2 signal
2. Sinonasal lymphoma - Usually nasal cavity rather than sinus.

Adolescent/Young adults7 -
1. Nasopharyngeal angiofibroma - dark flow voids on T1 + mass will be brightly enhancing.