Seizures (Exam IV) Flashcards
How much of the world’s population is affected by seizures?
1%
Differentiate seizures and Epilepsy.
Epilepsy is a disease. Seizures are a symptom.
What treatments (prior to modern medicine) were used to treat seizures?
- Trephining (Drilling into skull)
- Cupping
- Herbal remedies
- Animal Extracts
Virtually all seizure medications involve the ______ of _______ neurons.
Suppression; Ectopic
What are the three main mechanism of action’s of Anti-Epileptic Drugs?
- Modification of ion conductance (Na⁺ K⁺ Ca⁺⁺)
- Enhancing GABA
- Inhibiting Glutamate
What are the three types of focal onset seizures?
Which one of these is essentially a generalized seizure?
- Focal Aware
- Focal Impaired Awareness
- Focal to bilateral tonic-clonic (same as generalized)
What occurs to muscle tone in atonic/tonic seizures?
Extreme muscle tone to no muscle tone
Focal seizures begin in a ___________ of the brain.
specific area
What are characteristics of simple focal seizures?
- Minimal spread
- Unaffected consciousness/awareness
- EEG may show fairly normal.
What EEG is depicted below?
Normal
What EEG is depicted below?
Pre-seizure
What EEG is depicted below?
Generalized Seizure
What EEG is depicted below?
Post-Seizure (Post-Ictal)
What are the three characteristics of Complex Focal seizures?
- Consciousness/Awareness is affected
- May become unresponsive
- Usually arises from temporal lobes
What are automatisms?
Repetitive motions (lip-smacking, swallowing, scratching , pacing, etc.)
If focal seizures become generalized what state of seizure do they become?
- Generalized Tonic-Clonic
Differentiate Tonic & Clonic phases.
- Tonic = ↑ muscle tone
- Clonic = rapid movement
If a generalized seizure occurs for greater than 30 minutes it is known as….
Status Epilepticus
Generalized seizures, formerly known as ___________, begin over the ________ surface of the brain.
Grand mal; entire
Differentiate Tonic and Atonic seizures.
Which will result in a fall?
- Tonic = sudden contraction of muscle
- Atonic = sudden loss of muscle tone
Both will result in a fall.
What type of generalized seizure is marked by symptoms like staring into space and waking up with no notice of the seizure?
Absence seizure (the artist formerly known as petite mal)
What are generalized clonic seizures?
How do myoclonic seizures differ?
- Seizures marked by the body jerking like its being shocked.
- Myoclonic seizures involve one muscle group jerking.
Infantile spasm’s, also known as _______ Syndrome, are marked by what?
When do these usually begin?
-West’s
- Spasm’s affecting child’s whole body
- These usually begin before 6months of age.
Phenytoin alters conductance of which ion in particular?
- Na⁺
What is the mechanism of action of Phenytoin?
- Alteration of Ion conductance
- ↑ GABA
- ↓ Glutamate
What is the more soluble proform of phenytoin?
Fosphenytoin
What drug can cause local necrosis if given too much via the IM route?
Phenytoin (Dilantin)
What drug would be a great choice for partial and tonic-clonic seizures?
Phenytoin (Dilantin)
What drug is dangerous with low albumin levels?
Why?
- Phenytoin (Dilantin)
- Highly protein bound, if no albumin is available for binding, toxic levels can quickly accumulate.
What are therapeutic serum levels of Phenytoin?
What would free levels of Phenytoin ideally be?
What would a toxic serum level of Phenytoin be?
What would a lethal serum level of Phenytoin be?
- 10-20 mcg/ml
- 1-2.5 mcg/ml
- 30-50 mcg/ml
- > 100 mcg/ml
What drugs compete for Phenytoin binding?
Which of these is most dangerous if given in conjunction with Phenytoin & why?
- Carbamazepine, sulfonamides, & Valproic Acid
- Valproic Acid; actively ejects phenytoin off albumin; ↑ serum free phenytoin
What might some signs/symptoms of Phenytoin (Dilantin) toxicity be?
- Ocular stuff (Diplopia, Nystagmus, loss of eye tracking)
- Ataxia
- Sedation
- Gingival Hyperplasia
- Hirsutism
Why might folic acid be supplemented in conjunction with Phenytoin?
Folic Acid is given w/ phenytoin to combat gingival hyperplasia, hirsutism, & coarsening facial features.
What is Carbamazepine’s mechanism of action?
- Blockade of Na⁺ channels to slow down excitation of neurons.
What drug is the drug of choice for focal seizures & Trigeminal Neuralgia?
Carbamazepine
What is unique about Carbamazepine’s metabolism?
Carbamazepine increases the count of CYP450 enzymes thus ↑ its own metabolism as well as other drugs.
What drug induces a sodium channel blockade, is used for focal seizures, and whose effect hardly changes with increased dosing?
What might increasing dosages with this drug actually help?
- Lacosamide
- Generalized seizures
What is the oldest currently available anti-seizure drug?
What is this drug’s MOA?
What does toxicity of this drug look like?
- Phenobarbital
- ↑ GABA
- Sedation
What derivative of Phenobarbital is useful in some tremor disorders?
Primidone
What types of seizures is Phenobarbital useful for?
- Focal
- Tonic-Clonic
What types of seizures can Phenobarbital worsen?
- Absence
- Atonic
- Infantile spasms
What is Levetiracetam’s usefulness as an anti-seizure medication?
- Useful as an adjunct to other therapies.
What drug is a useful adjunct in focal seizures specifically?
Lamotrigine
What are GABA analogs useful for?
Give an example of two GABA analogs.
- Pain disorders, neuralgia, CNS suppression in general.
- Gabapentin, Pregabalin
What is the drug of choice for absence seizures?
What is this drug’s MOA?
What occurs with toxicity with this drug?
- Ethosuximide
- Ca⁺⁺ Channel Inhibition
- Gastric Distress & Lethargy (↓ toxicity)
What is the mechanism of action of Valproic Acid?
- Affects are three modalities of seizure treatment
What is the organic structure of a Benzodiazepine?
- Benzene Ring + Diazepine Ring
What drug class is really useful for status epilepticus?
Benzodiazepines
What is the MOA of Benzodiazepines?
- CNS depression through ↑ GABA
What is Diazepam (Valium) useful for?
What is it not useful for?
- IV/PR; useful in stopping continuous seizure activity
- Not effective for chronic therapy
What long-acting drug is effective against absence seizures and is only available in an oral form?
Clonazepam (Klonopin)
What benzodiazepine is more effective than diazepam for status epilepticus in its IV form?
Lorazepam (Ativan)
Infantile spasms are a ________ disorder (not seizure).
Developmental
What three facets of treatment are there for infantile spasms?
- Palliative
- Corticotropins (ex. prednisone)
- Vigabatrin (GABA analog)
How does Vigabatrin work?
- Blocks enzymatic hydrolysis = ↑ GABA
What dietary change for children can help with seizure activity? Why?
- Ketogenic Diet
- ↑ fatty acids slow neuron firing
What radical surgery for children can treat seizures originating from one side of the brain?
Hemispherectomy
What type of seizure condition is life-threatening?
What specific type of seizure is the most common cause?
- Status Epilepticus
- Generalized Tonic-Clonic
What three drugs are usually given first during status epilepticus? Which one of these is longer acting?
- Diazepam & Lorazepam
- Fosphenytoin (longer acting; 15-20mg/Kg LD)
What drug should be given for status epilepticus that is refractory to fosphenytoin?
Phenobarbitol (20mg/Kg)
What is the most important thing to ensure during the treatment of status epilepticus?
What lab value should be checked as well?
- ABC (airway, breathing, circulation)
- BG (blood glucose)
What percentage of epileptic cases are refractory after 1st & 2nd dose administration?
40%
What should be known about perioperative care of patients with known seizures on pharmacologic therapy?
- Important to maintain adequate levels of anti-seizure drug during perioperative period.
What is the only narcotic that stimulates seizure activity?
Meperidine (Demerol)
Chronic phenytoin therapy makes patients ______ to neuromuscular blocking drugs. Why is this?
Conversely, active dosing of phenytoin does what when NMBs are administered?
- Resistant; ↓ GABA channels (verify, doesn’t make sense)
- Active Phenytoin = ↑ NMBs
What is the last-ditch effort in treating seizures?
- Craniotomy with resection of epileptic foci.
Which two drugs blockade Na⁺ channels to treat seizures?
- Lacosamide
- Carbamazepine
Which drug classes increase GABA as their only MOA in treatment of seizures?
- GABA analogs
- Benzodiazepines
Which two drugs exhibit all known MOA’s for treatment of seizures?
- Phenytoin
- Valproic Acid
Which drug exhibits Ca⁺⁺ channel blocking effects in treatment of seizures.
Ethosuxamide
