23.1 NS: Cellular basis of epilepsy

Question 1

What is the lifetime prevalence of:
seizures
epilepsy
?

What is the SMR with epilepsy vs. the general population?

Answer 1

Seizures: 9%
Epilepsy: 2-4%

3.0 and SUDEP is higher

Question 2

What are the three main categories of seizures?

Answer 2

Partial (focal): arise in a limited no. of neurons (1 hemisphere)

Generalised: arise simultaneously in both hemispheres

Unclassifiable

Question 3

What is genetic epilepsy due to?

Age of onset?

Treatment?

Answer 3

Ion channel basis (brain structure normal)

Childhood/teenage years (can grow out of it)

Responds well to medication

Question 4

What is structural/metabolic epilepsy due to?

Treatment?

Answer 4

Seizure originating from an area of brain damage (identifiable cause)

Difficult to medicate, surgery can help

Question 5

Who first developed the modern concept of epilepsy (and pathology)?

Answer 5

Jackson (focal motor ‘Jacksonian’ seizures)

Question 6

What is the current concept epileptic pathology?

Answer 6

An increase in excitability arising in the grey matter. Networks fire in an uncontrolled, hyper-synchronous, self sustained manner

Question 7

What do we see in epileptic remodelling of the hippocampus?

Answer 7

Cell loss, mossy fibre sprouting and gliosis

Question 8

What is the relationship between epileptogenesis and disease progression?

Answer 8

Seizures beget seizures

Question 9

When are the peaks for the age of onset?

Answer 9

Child/teenagehood and over 60s

Question 10

What are the inheritance patterns and causes for genetic epilepsy?

Answer 10

5-10% Mendelian, most:complex

Ion channel (ligand/voltage gated) and non-ion channel abnormalities

Question 11

What is important when evaluating patients with focal epilepsy?

Answer 11

MRI identification of pathology e.g. focal lesion (70-80% have pathology)

Question 12

What is the most common pathology in adults with partial epilepsy?

Answer 12

Mesial temporal sclerosis (treat with surgery, increased T2 signal)

Question 13

What do we see on an MRI for focal cortical dysplasis?

Answer 13

Blurring of grey/white

Gyral abnormalities

Question 14

What is periventricular nodular heterotropia due to?

Answer 14

Abnormal neural migration (can be inherited)

Question 15

What is the most common cause of new onset partial seizures?

What is the most common type?

Answer 15

Low grade tumour

gliomas are most common

Question 16

What do 10% of patients with chronic drug-resistant partial epilepsy have?

Answer 16

Vascular lesion

Question 17

What is focal encephalomalacia due to? What do we see on an MRI?

Answer 17

Focal lesion from previous insult

MRI: atrophy of cortex, gliosis (increased T2)

Question 18

When do we use surgery to treat epilepsy?

Answer 18

Focal epilepsy where the origin can be localised to a brain region (that is able to be resected with low risk)