10.7 Seizures And Epilepsy

Question 1

Define epilepsy

Answer 1

condition of recurrent seizures
- Seizures arise from groups of neurons firing in an abnormal way in the cerebral cortex of the cerebral hemispheres.
- One seizure does not signify epilepsy (up to 10% of people worldwide have a single seizure during their lifetime
- Many individuals with a single seizure have a clear predisposing cause: infection, electrolyte abnormalities, sleep deprivation: these are labelled “acute symptomatic seizures” and do not typically equate to the chronic condition of having epilepsy.

Question 2

Classification of epilepsy

Answer 2

EEG based

Genetic
- generalised EEG pattern
- “all over the place”

Acquired
- Focal EEG pattern
- focal onset (aware & awake / not aware & awake)

Question 3

Acquired epilepsy
Seizure Manifestations

Answer 3

1. Focal onset in motor cortex
   - aware with focal motor seizure
   → focal twitching of hand
2. Focal onset in visual cortex
   - Aware with focal occipital seizure
   → Flashing lights (non formed hallucinations)
3. Focal onset in hippocampus/temporal cortex
   - Aware with focal hippocampal seizure
   → Psychic experience
   - Aware with focal seizure of limbic system
   - Aura of psychic experience (déjà vu, jamais vu etc etc)
   - An aura is a seizure that occurs when the patient is awake (so the memory can be laid down).
   - Sometimes, after the aura, the seizure can spread to other parts of the brain
   - hippocampus is critical structure for memory (memory loss)
4. Focal onset in temporal lobe, cingulate gyrus
   - Altered alertness
   - Staring (in a blank way)
   - Head Turning
   - Lip smacking (automatic behaviour is termed automatisms)
5. Focal onset spread
   - Focal to bilateral tonic-clonic
   - Aware -> not aware -> bilateral tonic-clonic
   - Tonic: limbs held stiff & straight
   - Clonic: rhythmic jerks of body
   - Focal to bilateral frontal lobe: characterized by excessive motor activity

Question 4

Genetic epilepsy
Seizure manifestations

Answer 4

• Genetic; also called “Primary Generalized”, or Idiopathic Generalized Epilepsy (IGE)
• age dependant

Myoclonus
- Rapid, shock-like movement

Absence
- A specific term for a staring spell during childhood.

Tonic-clonic

Atonic - NOT IN ADULTS!
- An infantile seizure disorder. (in adults, typically a functional disorder)

Question 5

Epileptic syndromes
4 Types

Answer 5

Types in order
1. Childhood absence epilepsy
2. Juvenile absence
3. Juvenile myoclonic
4. Epilepsy with generalised tonic-clonic seizures alone

• mostly pt are <20years
• should ask about myoclonus or absence

Question 6

Differential Diagnosis

Answer 6

1. Deja vu on its own
2. Panic attacks
3. Migraine
4. Syncope
5. Narcolepsy

6. Non-Epileptic Seizures
Revision: seizure presentations in teenagers and adults
- Tonic-Clonic seizures
- Frontal lobe seizures (lot of motor activity)
- Focal onset with impaired awareness
Clinical features:
- Unusual in epilepsy to have daily seizures (Most seizures respond to treatment, even if imperfectly)
- Combination of frequent seizures, poor drug response and normal EEG: unusual for diagnosis of epilepsy.
- Diagnosis usually requires neurological evaluation, and, in some cases, video-EEG monitoring