Epilepsy.2

Question 1

Definition?

Answer 1

tendency to recurrent, usually spontaneous, epileptic seizures

Question 2

What happens in the brain for epileptic seizures to occur? (4)

• how long do they last?
• Why do they occur? (6)
• what are some causative factors?

Answer 2

abnormal synchronisation of neuronal activity
(usually excitatory with high frequency APs, sometimes predominantly inhibitory)
Get an interruption of normal brain activity either focally or generalised

-usually for secs-mins

-too much excitation/too little inhibition
Changes to: cell no./type, connectivity, synaptic function, voltage gated ion channel function

-genetic, acquired, metabolic, toxic and environmental

Question 3

Classification of epileptic seizures

-give the 3 broad categories and their subtypes (2,5,0)

Answer 3

-partial and generalised

partial
simple (without impaired consciousness)
complex (with impaired consciousness)

Generalised
(These can start focally)
absence
Myoclonic
Atonic
Tonic
Tonic clonic (primary generalised)

Unclassified

Question 4

Partial seizures

-what 3 different forms are there?

Answer 4

Motor
(rhythmic jerking, posturing, head and eye deviation, other movements, automatisms, vocalisation)
Sensory
(somatosensory, olfactory, gustatory, visual, auditory)
Psychic
(memories, deja vu, depersonalisation, aphasia, hallucinations)

Question 5

Primary generalised epilepsy

• onset?
• inv?
• treatment?
• example?

Answer 5

• childhood or teens
• EEG
• sodium valproate or lamotrigine

-juvanile myoclonic epilepsy
(early morning jerks, generalised seizures, risk with sleep deprivation and flashing lights)

Question 6

Focal onset epilepsy

• cause?
• onset?
• treatment?
• what kind of seizure occurs often?

Answer 6

• underlying structural cause
• any age, focal onset which can then generalise
• Carbamazepine or lamotrigine
• complex partial seizures with hippocampal sclerosis

Question 7

Anti-epileptic drugs 
name the drugs that act on the following aspects of neurotransmission and their effect:
-Voltage gated Na channels (3)
-Voltage gated K channels (1)
-SV2A (1)
-Voltage gated Ca channel (2) 

Name the drugs that acts in the following aspects of the GABA system and their effect

• GABA synthesis (1)
• GABA transporter (1)
• GABA transaminase (1)
• GABAa receptor (4)

Answer 7

-Na influx increases excitability an drives APs so inhibition reduces this
carbamazepine, lamotrigine, oxcarbazepine

-K efflux reduces neuronal excitability so activity is increased by retigabine

• required from the release of NTs from vesicles
  Inhibited by levetiracetam
• Ca influx drives NT release so inhibited by pregabalin & gabapentin
• sodium valproate enhances synthesis
• normally removes GABA from the synapse, inhibited by tiagabine
• degrades GABA, inhibited by vigabatrin
• reduces neuronal excitability, activity increased by Benzodiazepines, barbiturates, felbamate, topiramate

Question 8

What drugs are first line in the following types of epilepsy?

• Partial seizures (3)
• absence seizure (2)
• Myoclonic (3)
• Atonic, tonic, generalised tonic clonic (2)

Answer 8

-Carbamazepine
Lamotrigine
add on = gabapentin

• Sodium valproate, ethosuximide
• Sodium valproate, levetiracetam, clonazepam
• socium valproate, levetiracetam