General about epilepsy

Question 1

Types of seizures - 3 main groups

Answer 1

Partial (focal) - simple or complex.
Generalized seizures.
Jacksonian epilepsy/march)

Question 2

What is the difference between simple and complex partial seizures?

Answer 2

Simple partial seizures: No alteration in consciousness.

Complex partial seizures: Altered consciousness, automatisms (repetitive behaviours), behavioral changes

Question 3

Partial seizure may develop into…

Answer 3

Secondarily generalized seizure

Question 4

Types of generalized seizures - 6 types

Answer 4

Tonic-clonic (grand mal).
Tonic seizure.
Clonic seizure.
Myoclonic seizure.
Atonic seizure.
Absence seizure.

Question 5

What is status epilepticus?

Answer 5

Recurrent episodes of tonic-clonic seizures without regaining consciousness or normal muscle movement between episodes

Question 6

Pathologic neurotransmission during seizures

Answer 6

Excessive activation of NMDA receptors. Ca2+ entry and long-term potentiation of glutamate neurotransmission by activating nitric oxide synthesis. Nitric oxide diffuse backwards and facilitates glutamate release. Further NMDA receptor activation and Ca2+ influx. Suppression of GABA neurotransmission.
Increase activity of T-type Ca2+ channels in thalamic neurons.

Question 7

Explain the depolarization shift in seizure foci

Answer 7

Abnormally prolonged action potentials. The shift recruits and synchronizes depolarizations by surrounding neurons and initiates seizure.

Question 8

Main mechanisms of antiepileptic drugs - 3 MOAs

Answer 8

1. Inhibition of Na+ or Ca2+ influx responsible for neuronal depolarization.
2. Augmentation of inhibitory GABA neurotransmission.
3. Inhibition of excitatory glutamate neurotransmission.

Question 9

Drugs that act on Na+ influx - 4 drugs

Answer 9

Carbamazepine.
Lamotrigine.
Phenytoin.
Topiramate.

Question 10

Detailed MOA for drugs acting on Na+ channels

Answer 10

Prolonging Na+ inactivation gate remains closed. Delays formation of next action potential.
Bind to the channel when it is opened.
Use dependent blockade. Suppress abnormal repetitive depolarizations in seizure foci more than normal neuronal activity.

Question 11

Drugs that act on Ca2+ influcx - 2 drugs and MOA

Answer 11

Ethosuximide
Valproate
Block T-type (low-threshold) Ca2+ channels in thalamic neurons

Question 12

Drugs enhancing GABA activation of GABAa receptor

Answer 12

Benzodiazepines
Barbiturates
Topiramate

Question 13

Drugs acting on GABA transmission without binding to GABAa receptor. And their MOA

Answer 13

Gabapentin: Increases GABA release.
Valproate: inhibits GABA degradation

Question 14

Drugs that inhibit glutamate neurotransmission

Answer 14

Felbamate.
Topiramate.
Valproate.

Question 15

Antiepileptic drugs - common side effect for all drugs

Answer 15

Suicidal thoughts and behavior

Question 16

First line drugs for partial seizures and generalized tonic-clonic seizures

Answer 16

Carbamazepine, phenytoin, valproate

Question 17

Second line drugs for partial seizures and generalized tonic-clonic seizures

Answer 17

Phenorbital

Promidone

Question 18

First line drugs for generalized absence seizures

Answer 18

Children: Ethosuximide.
Adults: Valproate

Question 19

Valproate is first-line treatment for…

Answer 19

Pts with multiple types of seizures.
Generalized absence seizures.
Partial seizures and generalized tonic-clonic seizures.
Generalized myoclonic and atonic seizures.

Question 20

Status epilepticus - first line treatment

Answer 20

IV diazepam/lorazepam followed by fosphenytoin/phenobarbital