Epilepsy

Question 1

What sequence would you see cavernomas on?

Answer 1

T2*/ SWI for susceptibility and booming artefact

Question 2

How would cavernomas look like on MRI?

Answer 2

1. Popcorn ball with haemosiderin rim
2. T2/ SWI for susceptibility / bloom artefact- Punctate low foci- black dots on T2
3. DVA: Developmental venous anomaly
4. CT -v in 50%
   Ca++ 50%

Question 3

Hippocampal hyperintenity without volume loss (3)

Answer 3

1. Status epilepticus
2. Low grade tumours: DNET and Astrocytoma
3. Encephalitis

Question 4

Ddx for black dots on T2*

Answer 4

1. Cavernomas
2. Cerebral Amyloid Angiopathy- CAA
3. Hypertensive micro haemorrhage - DAI

Question 5

What are the features of CAA

Answer 5

• In old demented patients
• normotensive with lobar haemorrhage
• peripheral location

Question 6

Name the tumours associated with epilepsy: (4)

Answer 6

1. Ganglioglioma
2. PXA
3. DNET
4. Hypothalamus hamartoma

Question 7

What type of epilepsy does ganglioglioma cause?

Answer 7

TL epilepsy

Question 8

Appearance of ganglioglioma?

Answer 8

cystic with enhancing mural nodule

Ca++ in 50%

Question 9

What feature distinguishes ganglioglioma from PXA or DNET?

Answer 9

Ca++

Question 10

Appearance of DNET

Answer 10

Bubbly cystic mass
Wedge shaped
swollen gyri
FCD
\+/- enhancement

Question 11

Appearance of PXA

Answer 11

supratentorial cyst with enhancing nodule
Meningeal enhancement- characteristic
If enhancement absent: PXA/ Ganglioglioma

Question 12

Location of PXA

Answer 12

Spratentorial

Question 13

Characteristic of PXA

Answer 13

Peritumeral oedema

Meningeal enhancement

Question 14

Define hemimegalencephaly:

Answer 14

This is an enlarged hemisphere with ipsilateral ventriculonegaly.

Big volume = big ventricle

Question 15

How would patients with hemimegacenphaly usually present with?

Answer 15

Developmental delay
Seizures
Contralateral hemiparesis

Question 16

Define polymicrogyria;

Answer 16

Small gyri- usually affects the Sylvian fissures

Atrophy- affects posteriorly
Anomalous venous return

Question 17

Define heterotopia

Answer 17

This is arrested migration of neurons. There is nodular foci of grey matter intensity on all sequences.

No enhancement

Types:

• subependymal
• subcortical

Question 18

Define schizencephaly

Answer 18

Cleft in brain connecting the lateral ventricle to subarachnoid space

This is lined by grey matter.

Open vs closed lip

Question 19

Schizencephaly vs porencephaly

Answer 19

Schizencephaly is lined by grey matter porencephaly is not

Question 20

Key MRI features of Sturge Webber (3)

Answer 20

1. Leptomeningeal enhancement
2. Cortical tram track Ca++, low signal
3. Atrophy - post

High T2 signal - gliosis

Question 21

What eye problem is seen in patients with sturge webber syndrome?

Answer 21

Vascular malformation of choroid of eye - enlarged eye secondary to increased pressure. Hemianopia

Choroid haemangioma

Also be aware of the port wine strain on face