Epilepsy + seizures [SYMPOSIUM]

Question 1

Provoked seizure

Answer 1

Provoked seizure
- Acute symptomatic seizure provoked by acute insults.

Examples of acute insults:

• Stroke
• Alcohol withdrawal
• Metabolic disturbance

Question 2

Epilepsy

- Definition

Answer 2

Recurring, unprovoked spontaneous seizures

Question 3

Causes of epilepsy [5]

Answer 3

Mainly idiopathic

Post-traumatic

Chronic alcohol use

Tumour

CVD

Question 4

Generalised onset seizure

Answer 4

Seizures characterised by electrical discharges all over the brain.

Can be primary- electrical discharges start all over the brain.

Secondary- electrical discharges started locally then spread all over the brain

Question 5

Partial/focal onset seizures

Answer 5

Seizures characterised by electrical discharge starting from a region in the cortex.
- In EEG, seizure activity is localised

The discharge can remain localised or spread to the whole brain [causes secondary generalised]

Mainly occurs in the temporal lobe [then frontal]

Question 6

Primary generalised seizures

- Classificaions

Answer 6

Seizures associated:

• Tonic-clonic
• Absences
• Myoclonic seizure

Tonic and atonic seizure

Question 7

Idiopathic generalised seizures

- Description

Answer 7

Onset
- Childhood/ adolescence

Cluster of seizure types

Cause:
- Possible polygenic, no identifiable structural lesion

Photosensitivity may be present

Question 8

Juvenile myoclonic epilepsy [JME]

• Type
• Proportion of epilepsy
• Onset
• Characteristics

Answer 8

Type
- Primary generalised epilepsy

Proportion
- 3-12% of all epilepsy

Onset:
- Juvenile, lasts lifelong

Characteristics:

• Early morning myoclonic jerks
• Photosensitivity [triggered by sleep deprivation]
• Possible absences
• Generalised TC seizures [without warning]

Question 9

Tonic clonic seizures

Answer 9

‘Grand mal’

Seizures occur WITHOUT warning

Tonic phase

• Continuous muscle spasm
• Fall
• Cyanosis
• Tongue biting
• Incontinence

Clonic phase
- Rhythmic jerking that slows and increases in amplitude

Post-ictal phase

• Coma
• Drowsiness
• Confusion
• Muscle ache
• Headache

Question 10

Temporal lobe seizure aetiology

Answer 10

Hippocampal sclerosis
- Accounts of half of them

Tumour

Hypoxia at birth

Vascular

Post-traumatic

Question 11

Temporal lobe seizure physical symptoms

Answer 11

Usually emotional

Hallucinations
- Taste, speech, smell

Visual distortions

Epigastric rising sensation

Pallor/flushing/ increased HR

Automatism [actions performed unconsciously]

Lip smacking, chewing

Dystonic posture

Question 12

Temporal lobe seizure cognitive symptoms

Answer 12

Deja vu

Speech arrest [Broca’s area]
- In dominant hemisphere

Non-speech arrest implies non-dominant hemisphere affected.

Question 13

Frontal lobe seizure

-Symptoms

Answer 13

Eye and head deviation to contralateral side

Thrashing motor activity

Automatisms
Dystonic posturing

Question 14

Jacksonian march

Answer 14

Simple, partial seizure
- Patient aware, localised discharge

Symptoms

• Lip smacking
• Sudden muscle contractions
• Sudden head and eye movements
• Last very briefly

Indications:

• Requires monitoring if very frequent
• Could indicate space occupying lesion

Question 15

Parietal lobe epilepsy symptoms

Answer 15

Postive sensory symptoms

• Tingling
• Pain

Distortion of body shape

Sensory Jacksonian march

Question 16

Occipital lobe epilepsy symptoms

Answer 16

Visual hallucinations

Amaurosis at onset
- Blackout

Question 17

Antiepletic drugs that exacerbate myoclonic jerks and absences

Answer 17

Phenytoin

Carbamazepine

Gabapentin

Pregabalin

Question 18

Alcohol withdrawal seizure

Answer 18

Type of acute, provoked seizure

Only scanned if subdural haematoma is suspected

Question 19

Characteristics of single neurones that contribute to epileptogenicity

Answer 19

Instability and intrinsic excitability

Action potentials
- Positive feedback mechanism is unstable

Intrinsic excitability
- Single neurones can fire without external stimulation [pacemaker]

Question 20

Characteristics of neuronal networks that contribute to epileptogenicity

Answer 20

One neurone has the ability to initiate a chain reaction of APs in other neurones
- Divergent and convergent synapses

Question 21

Physiological components of seizure

Answer 21

Explosion of synchronous activity by many neurones at one

• Can spread to cortex
• Due to dysregulation of inhibitory synapses

Question 22

Channelopathy- Na+

• Mechanism
• Example

Answer 22

Point mutation in beta Na+ channel subunit

• Makes Na+ channel inactivation very slow.
• Impairs action potential repolarisation

Examples
- Generalised epilepsy with febrile seizures [fever induced in children]

Question 23

Channelopathy- K+

• Mechanism
• Example

Answer 23

Reduction in the number of K+ channels

• Defect in KCNQ2/3 K+ channel subunit
• Defect impairs its activation = AP repolarisation impaired

Example
- Benign familial neonatal convulsions

Question 24

Physiological difference

• Primary generalised
• Secondary generalised

Answer 24

Secondary

• Originates from focal seizure
• Starts from group of neurones as synchronised paroxysmal depolarising shift overcomes inhibition [increases EC K+ or increases glutamate]
• Causes trains of APs
• When spread to thalamus =secondary

Primary

• From the thalamus to cerebral cortex
• Neuronal pathways in thalamus to cortex are excited

Question 25

Issues women face with epileptic treatment

Answer 25

Dysregulation of menstrual cycle

Teratogenic

Hair thinning

Weight gain