Epilepsy

Question 1

What is the underlying cause of genetic epilepsy?

Answer 1

An inherited abnormality in the central nervous system (CNS), for which some genetic mutations have been identified.

Question 2

What type of information is important for assessing a potential genetic link to seizures?

Answer 2

A detailed family history.

Question 3

Name three potential causes of structural/metabolic epilepsy.

Answer 3

Illicit drug use, tumor, head injury, hypoglycemia, meningeal infection, or rapid alcohol withdrawal.

Question 4

Under what circumstance might medication not be necessary for a structural/metabolic seizure?

Answer 4

When the cause of the seizure can be determined and corrected.

Question 5

A seizure caused by a drug reaction is not considered _____ and does not require chronic therapy.

Answer 5

epilepsy

Question 6

When is a patient diagnosed with epilepsy of an unknown cause?

Answer 6

When no specific anatomic cause, such as trauma or neoplasm, is evident.

Question 7

What portion of epilepsy cases is attributed to an unknown cause?

Answer 7

Most cases of epilepsy are due to an unknown cause.

Question 8

What two chronic treatments are mentioned for epilepsy of unknown cause?

Answer 8

Antiepilepsy medications or vagal nerve stimulation.

Question 9

What organization’s nomenclature is considered the standard for classifying seizures and epilepsy syndromes?

Answer 9

The International League Against Epilepsy.

Question 10

Into what two broad groups are seizures classified?

Answer 10

Focal and generalized.

Question 11

What part of the brain is involved in a focal seizure?

Answer 11

Only a portion of the brain, typically part of one lobe of one hemisphere.

Question 12

What determines the symptoms of a focal seizure?

Answer 12

The site of the neuronal discharge and the extent to which the electrical activity spreads.

Question 13

Focal seizures may progress to become what type of seizure?

Answer 13

Generalized tonic–clonic seizures.

Question 14

What is the state of consciousness during a simple partial seizure?

Answer 14

The patient does not lose consciousness or awareness.

Question 15

What are the typical motor symptoms of a simple partial seizure?

Answer 15

Abnormal activity of a single limb or muscle group.

Question 16

In a simple partial seizure, the electrical discharge is confined to a single locus and does not _____.

Answer 16

spread

Question 17

What is the state of consciousness during a complex partial seizure?

Answer 17

Consciousness is altered.

Question 18

What type of sensory and mental symptoms can occur in complex partial seizures?

Answer 18

Complex sensory hallucinations and mental distortion.

Question 19

Name one type of motor dysfunction that can occur in a complex partial seizure.

Answer 19

Chewing movements, diarrhea, and/or urination.

Question 20

What is the definition of a generalized seizure in terms of brain involvement?

Answer 20

They involve abnormal electrical discharges throughout both hemispheres of the brain.

Question 21

What is the immediate effect on consciousness in a primary generalized seizure?

Answer 21

The patient usually has an immediate loss of consciousness.

Question 22

What are the two distinct phases that follow the loss of consciousness in a tonic-clonic seizure?

Answer 22

The tonic phase (continuous contraction) and the clonic phase (rapid contraction and relaxation).

Question 23

What is the typical state of a patient after a tonic-clonic seizure?

Answer 23

A period of confusion and exhaustion.

Question 24

What is the primary characteristic of an absence seizure?

Answer 24

A brief, abrupt, and self-limiting loss of consciousness.

Question 25

What is the typical age of onset for absence seizures?

Answer 25

Generally 3 to 5 years of age.

Question 26

What are the observable signs of an absence seizure?

Answer 26

The patient stares and exhibits rapid eye-blinking.

Question 27

What is the characteristic electroencephalogram (EEG) finding in an absence seizure?

Answer 27

A distinct three-per-second spike and wave discharge.

Question 28

What are myoclonic seizures?

Answer 28

Short episodes of muscle contractions that may recur for several minutes.

Question 29

When do myoclonic seizures generally occur and how do they present?

Answer 29

They generally occur after wakening and exhibit as brief jerks of the limbs.

Question 30

How does consciousness impairment in clonic seizures compare to myoclonic seizures?

Answer 30

Consciousness is more impaired with clonic seizures.

Question 31

What muscle groups are primarily affected in tonic seizures?

Answer 31

Extension muscles, which exhibit increased tone.

Question 32

What is another name for atonic seizures and what is their main characteristic?

Answer 32

They are known as drop attacks and are characterized by a sudden loss of muscle tone.

Question 33

What is the primary effect of antiepilepsy medications on epilepsy?

Answer 33

They suppress seizures but do not “cure” or “prevent” epilepsy.

Question 34

Name one of the three general mechanisms of action for antiepilepsy drugs.

Answer 34

Blocking voltage-gated channels (Na+ or Ca2+), enhancing GABA-ergic impulses, or interfering with glutamate transmission.

Question 35

What is the mechanism of action of Carbamazepine?

Answer 35

It blocks sodium channels, thereby inhibiting the generation and spread of repetitive action potentials.

Question 36

For which seizure types is Carbamazepine effective?

Answer 36

Focal seizures and generalized tonic–clonic seizures.

Question 37

For which seizure type should Carbamazepine NOT be prescribed, as it may worsen them?

Answer 37

Absence seizures.

Question 38

What is the mechanism of action for Ethosuximide?

Answer 38

It reduces propagation of abnormal electrical activity, most likely by inhibiting T-type calcium channels.

Question 39

What is the only seizure type Ethosuximide is effective in treating?

Answer 39

Absence seizures.

Question 40

Name one proposed mechanism of action for Felbamate.

Answer 40

Blocking sodium channels, competing at the NMDA glycine site, blocking calcium channels, or potentiating GABA action.

Question 41

Why is the use of Felbamate reserved for refractory epilepsies?

Answer 41

Because of the risk of aplastic anemia and hepatic failure.

Question 42

Though its precise mechanism is unknown, Gabapentin is an analog of _____, but does not act at its receptors.

Answer 42

GABA (γ-aminobutyric acid)

Question 43

For what conditions is Gabapentin approved?

Answer 43

As adjunct therapy for focal seizures and for treatment of postherpetic neuralgia.

Question 44

What is the in vitro mechanism of action of Lacosamide?

Answer 44

It affects voltage-gated sodium channels, stabilizing hyperexcitable neuronal membranes and inhibiting repetitive firing.

Question 45

What protein does Lacosamide bind to, though its role in seizure control is unknown?

Answer 45

Collapsin response mediator protein-2 (CRMP-2).

Question 46

What is the approved use for Lacosamide?

Answer 46

Adjunctive treatment of focal seizures.

Question 47

Oxcarbazepine is a prodrug that is rapidly reduced to what active metabolite?

Answer 47

The 10-monohydroxy (MHD) metabolite.

Question 48

What is the primary mechanism of action of Oxcarbazepine's active metabolite (MHD)?

Answer 48

It blocks sodium channels, preventing the spread of the abnormal discharge.

Question 49

What is the approved use for Oxcarbazepine?

Answer 49

For use in adults and children with focal seizures.

Question 50

What is the primary mechanism of action of Phenobarbital?

Answer 50

Enhancement of the inhibitory effects of GABA-mediated neurons.

Question 51

What is the primary use of Phenobarbital in treating seizures?

Answer 51

Treatment of status epilepticus when other agents fail.

Question 52

What is the mechanism of action of Phenytoin?

Answer 52

It blocks voltage-gated sodium channels by selectively binding to the channel in the inactive state and slowing its recovery.

Question 53

For which seizure types is Phenytoin effective?

Answer 53

Focal seizures, generalized tonic–clonic seizures, and status epilepticus.

Question 54

Depression of the CNS by Phenytoin, particularly in the cerebellum and vestibular system, can cause what two side effects?

Answer 54

Nystagmus and ataxia.

Question 55

What oral adverse effect can be caused by Phenytoin?

Answer 55

Gingival hyperplasia, causing the gums to grow over the teeth.

Question 56

What are two potential long-term effects of Phenytoin use?

Answer 56

Development of peripheral neuropathies and osteoporosis.

Question 57

What is the mechanism of action of Pregabalin?

Answer 57

It binds to the α2-δ site, an auxiliary subunit of voltage-gated calcium channels, inhibiting excitatory neurotransmitter release.

Question 58

Besides focal-onset seizures, name one other condition for which Pregabalin has proven effects.

Answer 58

Diabetic peripheral neuropathy, postherpetic neuralgia, or fibromyalgia.

Question 59

Topiramate has multiple mechanisms of action, including blocking voltage-dependent _____ channels.

Answer 59

sodium

Question 60

Name one of Topiramate's mechanisms of action besides blocking sodium channels.

Answer 60

Reducing high-voltage calcium currents (L type), inhibiting carbonic anhydrase, or acting at glutamate (NMDA) sites.

Question 61

For what types of epilepsy is Topiramate effective?

Answer 61

Partial and primary generalized epilepsy.

Question 62

Besides epilepsy, what other condition is Topiramate approved to prevent?

Answer 62

Migraine.

Question 63

Name two common adverse effects of Topiramate.

Answer 63

Somnolence, weight loss, and paresthesias.

Question 64

What serious adverse effects, including renal stones and glaucoma, have been reported with Topiramate?

Answer 64

Renal stones, glaucoma, oligohidrosis (decreased sweating), and hyperthermia.