Memory & TLE

Question 1

Underlying pathology of TLE

Answer 1

> Hippocampal sclerosis – 22%
Developmental tumours – 40%
Cortical Dysplasia – 30%
Tuberous Sclerosis – 2%

Question 2

TLE & medication

Answer 2

Often medication resistant

Question 3

Epilepsy surgery in TLE

Answer 3

23% of cases

Question 4

What is hippocampal sclerosis

Answer 4

Neuronal loss

Question 5

Left Temporal lobe associated with _ memory

Answer 5

Verbal Memory

Question 6

Right Temporal lobe associated with _ memory

Answer 6

Visual Memory

Question 7

Anterior Temporal lobe associated with _ memory

Answer 7

Semantic memory

• General knowledge of objects
• No reference to time/space
• Shared across human cultues

The ATL is a hub where all information gets stored and consolidated
e.g. semantic dementia starts in ATL

Question 8

Hippocampus associated with _ memory

Answer 8

Episodic Memory

• unique to time & place
• Specific to that individual

Question 9

Hierarchical organisation of memory is…

Answer 9

Mischkin Hierarchical organisation

Question 10

According to MHO ventral visual stream feeds into…

Answer 10

Perirhinal Cortex

‘What’

Question 11

According to MHO Dorsal visual stream feeds into…

Answer 11

Parahippocampal Cortex

‘where’

Question 12

Part of the MHO that interfaces the hippocampus & neocortex

Answer 12

Entorhinal cortex

Question 13

IQ in epilepsy is correlated with

Answer 13

age of onset

Cormack et al. 2007

Question 14

Hippocampal Scleorsis & dysembryoplastic neuroepithelial tumours has no impact on which type of memory?

Answer 14

STM memory - Digit Span

Question 15

How is semantic memory impacted

Answer 15

lower in Left HS

but general reduction for all

Question 16

Impact of TLE on regions connected to atrophic hippocampues

Answer 16

focal grey matter reductions controlatterally

Therefore there is a global impact

In adults - there was limbic system atrophy - all the parts that connect to the Hippocampus

Question 17

What impacts degree of hippocampal atrophy?

Answer 17

Duration of TLE negatively impacted hippocampal volume
+
increase seizures

Cormack (2005)
Duzel (2006)

Question 18

Decline in hippocampal volume correlates with:

Answer 18

decline in episodic memory

Skirrow et al. ICE abstracts (2014)

Question 19

Wilson 2012 developmental statistics

Answer 19

52% - normal
37% altered
11% delayed

Question 20

Predictors of developmental impact

Answer 20

• FSIQ
• Seizure Freedom
• Surgical intervention
• Male

Question 21

What is the ‘release effect’?

Answer 21

release of skills as a result of seizure freedom

- they go closer to their pre-epilepsy developmental path

Question 22

Seizure freedom after epilepsy surgery

Answer 22

87%

Question 23

Cognitive outcomes after Epilepsy Surgery

Answer 23

More educational attainments
Less diability
Independent living
improved QoL
Employment (N.S.)

Question 24

IQ increase of >15

Answer 24

in 26% of patients

Question 25

IQ decrease od >10

Answer 25

2%

Question 26

When were the greatest IQ gains seen?

Answer 26

6 years post op | - related to AED withdrawal

Question 27

IMP note for neurosurgeons

Answer 27

the higher the brain volume the better the increase in IQ - take out least possible Semantic memory = extent of L. TL resection -Verbal Episodic Memory extent of hippocampal resection (more left = lower score)

Question 28

Difference in PIQ and VIQ improvements

Answer 28

PIQ improved in both VIQ improved in left side surgery - despite tissue loss = release effect - due to seizure freedom

Question 29

Release effect & Left resection

Answer 29

Verbal memory returns to pre-operative level - but dips initially after surgery - semantic memory was linked to extent of L.TL resection Visual Memory: increases and follows a +ve developmental trajectory

Question 30

Right Resection & release effect

Answer 30

Visual memory: returns to pre-op level - | Verbal memory: increases

Question 31

Interesting finding... resection & release effect

Answer 31

improvement on the 'contra-lateral memory'

Question 32

Outcomes of epilepsy surgery impacted by:

Answer 32

Seizure Freedom - release effect AED discontinuation Follow-up time Maybe: duration of epilepsy Seizure Frequency Seizure type/severity