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35 Cards in this Set
- Front
- Back
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The onset of seizure disorders is most likely to occur in what age groups?
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Children: d/t genetic problems from birth
Elderly: d/t brain injury/ stroke |
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Define a Seizure
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A transient occurrence of signs and/or symptoms d/t abdormal, excessive, or synchronous neuronal activity in the brain.
Can be convulsive or nonconvulsive. Can be provoked (non-epileptic) or unprovoked (epileptic). |
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Define Epilepsy
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Disorder of the brain characterized by an enduring predisposition to generate epileptic seizures (requires the occurrence of at least one epileptic seizure.)
AND ...by the neurobiological, cognitive, psychological (psychosis), and social consequences (social w/drawal) of the condition. SO, epilepsy is not JUST seizures. It's a brain disorder w/ symptoms that include seizures. |
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List and define the different stages of seizures.
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AURA
---> a subjective disturbance of perception that represents the start of certain seizures. The type of aura depends on the part of the brain that is seizing. It can be a color or a taste, etc. ICTAL PHASE ---> The seizure itself POST-ICTAL PHASE ---> The period after the seizure when the individual is amnesic, confused, and/or disoriented. INTERICTAL ---> The time between seizures. |
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Differentiate b/n Generalized and Partial Seizuresq
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GENERALIZED SEIZURES
* Occur over the ENTIRE brain/ cortex at once. * LOSS of conciousness. * EEG shows a general spike and wave. * 2 Types: ABSENCE and GEN. TONIC CLONIC PARTIAL SEIZURES * Occurs in a SPECIFIC part of the brain. * Concious is NOT lost...may be changed. * EEG is FOCAL * May spread and turn into a General Tonic Clonic Seizure. * 2 Types: SIMPLE AND COMPLEX ---> Simple is very focal (hand, etc) ---> Complex spreads to other parts of the brain |
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Describe Grand mal/ Tonic Clonic Seizures
How long do they last? |
Duration: 2-5 min.
1) Unprovoked/ unwarned LOSS OF CONCIOUSNESS 2) TONIC STAGE: Muscles contract, including the diaphragm. This squeezes air out of lungs and the pt cries out. "Epileptic Cry". 3) CLONIC STAGE ---> Bisynchronous and rhythmic jerking. Pt may become cyanotic b/c not breathing (if pregnant..this can endanger the fetus.). 4) POST-ICTAL STAGE ---> Exhaustion, sleep,disorientation, amnesia. |
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Describe Absence Seizures
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These are GENERALIZED SEIZURES that occur in CHILDREN.
* Can occur 100's of times a day! * Can be provoked by HYPERVENTILATION * EEG shows a 3 Hz Spike and wave. * Will stop when child reaches puberty. DURATION: 2-20 sec. 1) Abrupt Loss of Conciousness with no warning. No posture loss. 2) CLONIC movements (twitching, blinking eyes). (2-20 secs) 3) Abrupt return to conciousness and resumption of normal activities. |
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Describe Simple Seizures
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These are FOCAL/ PARTIAL seizures that occur in a specific part of the brain with a focal EEG.
* Can cause a seizure in one part of the body. * Can also cause an aura (or just an aura). The aura can be altered sensations or hallucinations (seizure of visual cortex). The pt has no loss of conciousness, then starts having assymetric convulsions in one part of the body, then returns to normal. No postictal state. * Can progress to tonic-clonic seizures. |
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T/F a seizure that has an aura can be a focal or a general seizure.
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False
Generally…a seizure with an aura is a partial seizure…a generalized seizure will never have a aura because the whole brain goes at once. The aura indicated what part of the brain a partial seizure is starting in. |
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Describe a Complex Partial Seizure
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FOCAL SEIZURE in the PSYCHOMOTOR OR TEMOPORAL LOBE.
DURATION: 30 sec to 1 min *Causes IMPAIRMENT OF CONCIOUSNESS. ...prominent disturbances in psychological and behavioral function. * Can have an OLFACTORY OR EPIGASTRIC AURA * AUTOMATISMS: wandering, lip-smacking, fumbling, fidgeting, repetitive behaviors, complex behaviors (acting weird). * Can progress into a tonic clonic seizure. 4 A's OF COMPLEX PARTIAL SEIZURE: Aura, AMS, Automatisms, Amnesia 1) Aura develops (olfactory or epigastric) 2) There is an alteration of conciousness. 3) Automatisms and strange behavior develop. 4) POST-ICTAL STATE - Pt has Amnesia...cannot remember what has happened. |
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What is the most common type of seizure in adults?
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Complex Partial Seizures
These are often acquired with epilepsy. |
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What type of seizure can be mistaken for night terrors?
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Complex Partial Seizure...if it happens when someone is sleeping they will wake up after and have terror and not know why...just like night terrors.
Night terrors are diff from nightmares b/c they occur during non-REM sleep. |
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Define Status Epilepticus
How do you treat it? |
Status Epilepticus is
1) TWO OR MORE seizures w/o recovery of conciousness in between. OR 2) A single seizure > 20-30 min long *Can be one of the following: --> TONIC CLONIC --> ABSENCE --> SIMPLE PARTIAL SEIZURE MUST STOP THE SEIZURE..CAN CAUSE BRAIN DAMAGE IN 5-10 MIN!!! TX * IV Lorazepam or Diazepam * If sz continues...IV Phenytoin or Fosphenytoin * If sz continues...IV Phenobarbital * If sz continues...propofol gtt...put them in a coma until it is over. |
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What is the goal of all anti-seizure treatments?
What are the 5 psychological effects that would achieve this? |
Goal: To stop the SPREAD of seizures.
* PVT POST-TETANIC POTENTIATION: ---> Inc ACh in the synapse d/t tetanus strengthens synaptic connections. Normally this enables learning. But in epilepsy, it enables seizures to SPREAD. ---> SE: Inhibits learning..bad cognitive effects!!. * PROLONG REFRACTORY PERIOD ---> Epileptics have short refractory periods d/t fast K channels. Blocking or slowing K channel-repolarization will stop/ slow seizure spread. ---> Deep brain stimulation/ Drugs * POTENTIATE INHIBITORY ACTIVITY (GABA) ---> Barbs and benzos * REDUCE EXCITATORY ACTIVITY * INCREASE EXCITATORY SYNAPTIC THRESHOLD ---> Hyperpolarizes the neuron...harder to start at AP. |
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Explain the mechanism of epilepsy
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A seizure/ epilepsy is due to either too much excitation or too little inhibition in the brain. This is imbalance is what allow seizures to SPREAD.
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What are the three Mechanisms of Action of Anit-Epileptic/Seizure Drugs?
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1) Block Na Channels
(Used for TONIC CLONIC SEIZURES) --> Phenytoin --> Carbamazepine --> Valproic Acid 2) Potentiate GABA (Used to tx STATUS EPILEPTICUS) --> Barbituates --> Benzos --> Valproate 3) Block Ca Channels (Used to tx ABSENCE SEIZURES). ---> Ethosuximide |
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What drugs are used to tx Tonic Clonic Seizures?
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Phenytoin
Phenobarbital Primidone Carbamazepine Valporic Acid Lamotrigine |
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What drugs are used to tx Absence Seizures?
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Ethosuximide (DOC)
Clonazepam Valproic Acid Lamotrigine |
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What drugs are used to treat Status Epilepticus?
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IV Diazepam or Lorazepam
Followed by: * IV Phenytoin or Fosphenytoin IV DRUGS ONLY!!!!!! |
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T/F Anti-seizure drugs are the cure for epilepsy?
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False!
Anti-convulsants STOP the convulsions…..they do not cure or tx epilepsy.! So the tx of epilepsy is symptomatic only…there is nothing you can do to cure it. |
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Why can't a blood sample tell you if you have Phenytoin toxicity d/t displacement from albumen?
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Blood tests measure both free and protein bound drug.
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Why is it so easy to have phenytoin toxicity?
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* Phenytoin is 70-95% protein bound, has a narrow therapeutic window, and is eliminated by zero order kinetics.
So if you give a drug that displaces it from proteins...the excess free drug cannot be cleared. Also...there is no halflife, so there is no set dose. You dose it based on effects. |
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What do you do if you see a rash with Phenytoin tx?
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Taper down the drug!
This is a Type 4 Hypersensitivity Rxn and can develop into Steven Johnson's Syndrome...which is life threatening. |
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How does Phenytoin cause a folic acid deficiency?
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Dietary Folate is in leafy green veggies. It is absorbed by intestinal deconjugases.
AED's block the intestinal deconjugases. Tx is to give it as a supplement. |
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What did the ineffectiveness of Gabapentin tell use about seizures disorders?
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There is more to seizures than just a lack of CNS inhibition.
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Tiagabine
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Narrow Spectrum Anti-seizure med
Second-line Tx: (add-on agent to standard AEDs) MOA * GABA uptake Inhibitor USE * Refractory partial and secondary generalized seizures. |
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Describe initiation of therapy for seizures
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Diagnose based on the symptoms...get a hx, exam, EEG, MRI..decide to tx or not to tx
Start with monotherapy. Increase dose until you get to therapeutic effect or intil SE appear. Monitor serum drug conc as a guide to assess compliance and optimize therapy. Use to tease out drug drug interactions. Consider polytherapy if monotherapy inadequate or is mixed seizure disorder. |
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Causes of failure of anti-epileptic tx
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Improper Diagnosis
Inadequate dosage Non-compliance Too frequent changes of medication Failure to use polytherapy when monotherapy fails. Avoidable seizure precipitant |
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Define Refractory Epilepsy
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Failure of three major AED’s at maximal tolerated dosages means that success with additional AEDs is extremely unlikely
Hard to tx...vagal nerve stimulators may help. |
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Pts on seizures med have a greater than 60% chance of successful withdrawal if they've been seizure free for how long?
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2 years.
Maybe you can stop the med. |
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Rapid withdrawal from anti seizure meds can do what?
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Precipitate the seizure.
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Why might a pregnant woman take anti-seizure drugs...even though they are a category D??
What else can you do? |
Because if she has seizures while pregnant, the hypoxic episode that goes along with a tonic clonic seizure can cause fetal hypoxia and birth defects. Seizures can also induce uterine contractions and cause premature labor.
GIVE THE LOWEST POSSIBLE DOSE!!! Switch to Cat C drugs before a planned pregnancy, |
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What AED's are categoryD and waht ones are category C?
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Phenytoin, carbamazepines, and valproic acid ---. CATEGORY D
The newer AEDs: Gabapentin, Topramax, etc---> CATEGORY C |
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Describe the altered pharmacokinetics of anti-seizure drugs during pregnancy
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GFR goes up...clearance of the drug goes up.
Fat stores in the body increase, volume of distribution and blood volume increases...plasma protein concentrations go down. Incr in sex hormones in pregnancy will effect CYP450's and metabolism of AED's. |
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Which Antiseizure drugs cause neural tube defects?
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Valproate
Phenytoin Fosphenytoin Phenobarbital Carbamazapine Primadone |
