Epilepsy Flashcards by Lizzie Sellers

What are the main categories of epilepsy?

Focal
Generalised
Unknown

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What is a focal aware seizure?

No loss of consciousness or post-ictal confusion

Symptoms dependent on focal site - commonly temporal lobe (due to plasticity leading to over-excitation)

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What are the signs and symptoms of a seizure originating in the frontal lobe?

Motor seizures - often bilateral

Including kicking, cycling, violent movements

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What are the signs and symptoms of a seizure originating in the parietal lobe?

Sensory (e.g. tingling or warm sensation)

Auras (e.g. nausea, sinking, choking, body distortion)

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What are the signs and symptoms of a seizure originating in the occipital lobe?

Visual hallucinations (can be simple or complex) 
Black outs 
Visuo-spatial distortion 
Headache 
Nausea

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What is non-epileptic attack disorder (NEAD)?

Characterised by similar symptoms to a tonic-clonic seizure however with no physical reason/ change in electrical activity in brain

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What are Jacksonian seizures?

Short-lasting rippling effect as activity passes over cortical region.
Can be motor or sensory.

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What is a generalised tonic clonic seizure?

No warning of onset
Tonic phase can involve whole body stiffness, cyanosis, loss of bladder control
Clonic phase involves muscle jerks
Post-ictal phase can include unconsciousness, muscle relaxation, slow regain of consciousness, headaches, aching limbs, no recall of episode

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What is a generalised absence?

Low level activity
Individual appears to ‘switch off’ and can not be alerted or woken up
More common in girls and tends to be most common in children (onset age 6-12)

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What is a status epilepticus?

Generalised tonic clonic activity
Ictal period of more than 5 minutes OR repeated seizures with no recovery between for more than 30 minutes

MEDICAL EMERGENCY

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What are the sub-types of generalised seizure according to the ILAE?

Motor or non-motor (absent) seizures

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What are the characteristics of a focal to bilateral tonic clonic seizure?

Focal seizure progressing to a generalised seizure as activity from the thalamus projects to other regions.
Can experience auras prior to onset.
Can have unilateral motor effects.

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How is status epilepticus classified?

Prolonged seizure state

ICD-10, G41

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What is a generalised myoclonic seizure?

Sudden jerk movements

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What is a generalised clonic seizure?

Repeated twitches and jerks (with no stiffness)

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What is a generalised tonic seizure?

Whole body stiffness

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What is a generalised atonic seizure?

Loss of muscle tone
‘Drop attacks’
Quick recovery

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How can NEAD be diagnosed?

Video EEG

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How does non-epileptic attack disorder appear on EEG?

Normal brain activity

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What are the advantages of EEG?

Useful for investigating gross cortical activity
Non-invasive/ painless
Can be used over long periods of time (e.g. video EEG)
Cost effective

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What is the aetiology of seizures?

Reduced GABAergic transmission and K+ channel activity
Increased ACh transmission and Na+ channel activity
Channelopathies - mutations in K+, Na+, ACh and GABA receptors linked to congenital forms of seizures

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What are the signs and symptoms of a seizure originating in the temporal lobe?

Auras
Deja vu/ Jamais vu
Emotional changes
Oral automatisms

What are the differences between epileptic seizures and a NEAD seizure?

Eyes: open (epileptic) vs closed (psychogenic/ NEAD)
Memory: no memory (epileptic) vs memory of seizure (NEAD)

How can EEG be used to diagnose epileptic seizures?

Determines type through distinct patterns and pinpointing focal activity (and progression of seizure throughout brain)

What are EEGs recording?

Changes in gross current flow | Levels of synchrony between neurons causes changes in patterns (firing together causes larger amplitude oscillations)

What brain waves can be seen on EEG?

``` Alpha Beta Gamma Theta Delta ```

How are alpha waves characterised?

8-13 Hz Mainly occipital activity Eyes shut/ meditation

How are beta waves characterised?

>14 Hz Parietal and frontal activity Slow wave sleep

How are gamma waves characterised?

40 Hz | Learning and memory

How are theta waves characterised?

4-7 Hz Parietal and temporal activity Alertness, learning and memory

How are delta waves characterised?

<3.5 Hz Cortical activity Deep sleep or coma

What are the treatment options for epilepsy?

Pharmacological (AEDs) Surgical Implants (VNS/ DBS)

What is the best treatment for non-epileptic seizures?

CBT | Antidepressants or antipsychotics

What are the disadvantages of surgical treatment for epilepsy?

Scar tissue can cause seizures

What are the pharmacological options for treating epilepsy (focal/ focal to generalised/ generalised tonic clonic)?

Lamotrigine Carbamazepine Sodium Valproate

When should sodium valproate not be used?

Women of child-bearing age (due to teratogenicity causing birth defects)

What drug can be used only to treat absent seizures?

Ethosuximide

What is the emergency treatment for status epilepticus?

1. IV Lorazepam/ Diazepam or Buccal Midazolam (in resusc) 2. Phenobarbital sodium (after 25 mins) 3. Anaesthetise (after 45 minutes)

What can be used instead of IV medication to treat status epilepticus (e.g. oustide of resusc)?

Buccal Midazolam | Rectal Diazepam

What is the first line treatment for generalised myoclonic seizures?

Sodium valproate

What types of seizures tend to respond poorly to typical AEDs?

Generalised absence atypical Generalised atonic Generalised tonic

What is antiepileptic hypersensitivity syndrome?

Major side effects of AEDs including fever, rash and swollen lymph nodes (typical onset = 1-8 weeks from treatment initiation)

What should you do in the case of Antiepileptic Hypersensitivity Syndrome?

1. Withdraw treatment immediately 2. Topical steroids and antihistamines 3. Systemic corticosteroids (?) 4. Be aware of potential rebound seizure activity

What is the mechanism of action of Sodium channel blockers?

Block voltage-dependent Na+ channels | Only block in inactivated state

Which AEDs are sodium channel blockers?

Lamotrigine Carbamazepine Sodium valproate

What are the potential side effects of sodium channel blockers?

``` CNS effects Peripheral neuropathy Skin problems Gum hyperplasia Anaemia/ blood disorders Osteomalacia (bone weakness) Teratogenicity ```

How do GABA targets work?

Indirectly enhance activation of GABA mediated channels via: - action at co-agonist site - inhibition of GABA breakdown - inhibition of GABA uptake - GABAmimetics

What drugs are GABA targets?

Gabapentin Pregabalin (both GABAmimetics)

What is the mechanism of action of Benzodiazepines?

Co-agonist of GABA receptor (gamma subunit) to increase activity Reduces neuronal transmission by enhancing inhibition

What is the mechanism of action of Barbiturates?

Co-agonist of GABA receptor (beta subunit) to increase activity Reduces neuronal transmission by enhancing inhibition

What are the side effects of Benzodiazepines and Barbiturates?

Tolerance/ dependency (should only be used short term) Withdrawal Impaired motor coordination/ decreased muscle tone Impaired cognitive performance Sedation Disturbed sleep Retrograde amnesia

What is the mechanism of action of calcium channel blockers?

Blocks voltage dependent or low threshold Ca+ channels

What are some common calcium channel blockers?

Ethosuximide Gabapentin [Possibly lamotrigine]

What are possible future targets that could be used to treat epilepsy?

``` Glutamate antagonists Gap junction inhibitors Enzymes Cannabinoids Steroids CO2 ```