Card Set Information
What is the definition of a seizure?
Unusual electrical activity in the brain resulting in abnormal movement or behavior.
What is a convulsion?
paroxysms of involuntary muscular contractions and relaxations
What is epilepsy?
a group of related disorders characterized by a tendency for unpredictable recurrent seizures, which vary widely in severity, appearance, cause, consequence and management
Whar are epilepsy syndromes?
collections of different seizure types, patterns of onset and family history
What are the seizure pathophysiologies?
defective synaptic function triggers seizures
neuronal membrane instability
What defective synaptic functions trigger seizures?
reduction of inhibition (GABA)
enhancement of excitatory activity (glutamate, aspartate, ACh, NE, etc)
What causes neuronal membrane instability in seizures?
abnormality with K
defect in voltage sensitive ion channels
deficiency in membrane ATPase linked to ion transport
What is the definition of epilepsy?
chronic disorder of recurrent seizures
2 or more seizures not provoked by other illnesses or circumstances
How are epileptic seizures classified?
Where does it start?
What type - simple or complex?
What are the characteristics of generalized seizures of epilepsy?
no local onset
bilateral symmetry (all over both lobes)
How are partial, or focal, seizures characterized?
start in one lobe and may or may not spread to both lobes
What is a simple seizure?
no loss of consciousness or alteration of psychic function
What is a complex seizure?
What is a tonic-clonic (grand mal) seizure?
onset < 35 years
immediate onset (loss of consciousness, falling)
5 phases - flexion, extension tremor, tonic/clonic, postictal
: may see tonic or clonic alone or atonic: drop attack
: confused and lethargic minutes to hrs
preceded by aura
seizures last 2-5 min
amnesia of seizure
What is an absence (petit mal) seizure?
onset 4-12 years
short duration EEG spike/wave at freq of 3Hz confirms
Brief loss of consciousness
Brief staring into space
: regains consciousness quickly, alert and able to resume activity
seizures last 3-30 sec, can occur >100 times/day
amnesia of seizure
What is a myoclonic seizure?
onset usually as infant/young child
brief jerking movements of the face and upper or whole body, may become tonic-clonic
consciousness is usually preserved
What is a simple partial seizure?
onset at any age
motor and sensory changes signal onset
no loss of consciousness
: Todd's paralysis (weakness in body part involved)
last +/- 90 sec
may become generalized
What is a complex partial seizure?
onset in adulthood
aura, anxiety, automatisms, psychiatric features, sharp EEG waves signal onset
loss of consciousness
rigid posturing of head/eyes
: variable period of confusion, Todd's paralysis, aura/confusion
last 2-5 min
may become generalized
amnesia of seizure
What are the causes of new-onset seizures in adults?
What events can mimic a seizure?
psychogenic or pseudoseizures
What sorts of things can cause seizures?
nutritional deficiencies (B
antibiotics (fluoroquinolones, B-lactams, carbapenems)
psychiatric meds (antidepressants - bupropion, maprotiline; antipsychotics)
analgesics (meperidine, tramadol)
w/d of CNS stimulants
What are EEGs good for in seizures?
DO NOT rule in or out epilepsy used alone
can identify seizures as focal or generalized
can identify pseudoseizures
What types of imaging can be used to evaluate seizures?
MRI (more useful)
CT (quick, less expensive)
What blood tests should be done to evaluate a seizure?
renal function - renally adjust drugs
albumin (phenytoin or valproate)
substance abuse screen - unexplained generalized seizures
What are the effects of epilepsy on patients?
social functioning (loss of bladder or bowel)
QOL (driving, swimming/bathing alone)
What are some caveats to treating a first-time single seizure?
no differences in 3-5 yr seizure-free rates whether treated at first or second seizure
failure of first antiepileptic drug increases the likelihood of nonresponse
What are the effects of poor control of epilepsy?
new seizure forms
increased frequency of seizures
How should drug therapy be initiated in epilepsy?
start with 1/4 to 1/3 of anticipated maintenance dose
titrate to maintenance dose over 3-4 wks
What should you do if monotherapy is ineffective?
Change to a new monotherapy drug and repeat the titration, keeping one concentration therapeutic at all times
When should combination therapy be tried?
after 2-3 unsuccessful monotherapies have been tried
What are the antiepileptic combinations used in refractory seizures?
VPA and lamotrigine or levetiracetam - partial or generalized seizures
CBZ and VPA - complex partial seizures
vigabatrin and lamotrigine or tiagabine - partial seizures
topiramate and lamotrigine or levetiracetam - numerous types
VPA and ethosuxamide - generalized absence seizures
How long should drugs be tapered when taking off of antiepileptics?
3-6 months minimum
What antiepileptics work via GABA?
What antiepileptics work via Na channels?
What antiepileptics work via Ca channels?
What antiepileptics work by unknown/unique methods?
What are the broad-spectrum antiepileptics?
Reasonable choices in most adults, regardless of seizure type:
What are the narrow-spectrum antiepileptics?
limit to focal epilepsy with partial and secondarily generalized seizures. no good for juvenile myoclonic epilepsy and childhood absence seizures, may exacerbate these types
Which antiepileptics are effective for partial seizures?
What is the narrowest spectrum antiepileptic and what is it good for?
ethosuximide - absence seizures
AEDs are the 3
most common cause of what?
acute liver failure
Which AED increases ammonia levels?
Which AEDs increase hepatic enzyme levels?
Which AEDs cause loss of bone density?
Which AEDs cause hyponatremia?
Which AEDs should not be used in pts with renal calculi (stone formation)?
Which AEDs are neutral or promote weight
Which AEDs cause modest weight gain?
Which AEDs cause substantial weight gain?
Which AED causes heart block and aggrevates sick sinus syndrome?
Which AEDs prolong T interval?
Which AED reduces white-cell count?
Which AED causes dose-related thrombocytopenia?
Which AED causes gingival hyperplasia?
Which AEDs cause severe rash?
(asian descent 10x higher chance - check for HLA-B*1502 gene)
The previous 4 have significant cross-reactivity
Which AEDs are not associated with SJ syndrome and are good alternatives?
Which AED causes target lesions?
Which AEDs have adverse cognitive effects?
Which AEDs cause the fewest cognitive effects?
Which AED inhibits 2C9 and 2C19?
Which AEDs induce P450s?
Which AEDs are greater than 80-90% ppb?
Which AEDs have the least chance of DI potential?
good for HIV!!!!
Which AEDs cause decreased folic acid levels?
What is the best reason to obtain AED serum concentrations?
use as a surrogate marker for adherence
a person has an aura and unifocal convulsions which progress to bilateral convulsions involving the entire body. Which type of seizure is this most consistent with?
Why is phenobarbital not a first line AED?
high incidence of cognitive impairment
How can you help avoid skin rashes from lamotrigine?
avoid concommittant use of VPA
start dose low (<25 mg/d)
What are the first line AEDs for absence seizures?
avoid CBZ, phenytoin, gabapentin, pregabalin, vigabatrin
What is the first line therapy for myoclonic seizures?
avoid CBZ, phenytoin, gabapentin, lamotrigine, vigabatrin
What are the first line AEDs for tonic-clonic seizures?
What are the first line AEDs for partial seizures?
What AED is good for head trauma, neurosurgery, or post-stroke seizures?
What drug in particular has a role in worsening polycystic ovary syndrome?
Which AEDs increase the clearance of OCs?
Which AED has its clearance increased by OCs?
What contributes to decreased seizure control in pregnancy?
increased drug clearance (esp
Which AED is the worst drug to use during pregnancy d/t increased risk of birth defects and lowering of IQ scores?
What AEDs in particular require administration of supplemental folic acid in women of childbearing age?
What AEDs require additional vitamin K during pregnancy and at birth?
Which AEDs cause fetal hydantoin syndrome?
What should be monitored in a breast feeding infant whose mother is on an AED?
What is status epilepticus?
30 minutes in duration
2 or more seizures without recovery of consciousness
Any seizure lasting 5 minutes should be considered impending status epilepticus
This is a medical emergency!
most episodes occur in people with no hx of epilepsy
75% are tonic clonic
What are the high risk factors for status epilepticus?
acute w/d of AED
CNS lesion (anoxia, stroke, tumor trauma)
What are the treatments for status epilepticus?
supportive care (ABCs - airway, breathing, circulation)
diazepam (rectal gel)
DOC #1 (administer SLOWLY d/t dessicant- could lose blood vessel)
VPA (second after BZD for non-tonic clonic)
monitor for cardiorespiratory toxicity d/t propylene glycol diluent (esp. phenytoin, diazepam and lorazepam)
What is a
otherwise normal child between 6 and 60 months
<15 min duration
occur once during a 24 hr period
child has a fever
What constitutes higher risk of developing epilepsy by the age of 25 in children who have febrile seizures?
multiple febrile seizures
younger than 12 mo at time of first febrile seizure
family hx of epilepsy
How do you treat a febrile seizure?
continuous tx - phenobarbital, primidone, or VPA
intermittent tx - diazepam or midazolam
potential toxicities outweigh relatively minor risk of simple febrile seizures
What is the therapeutic range for CBZ?
What is the therapeutic range for phenobarbital?
What is the therapeutic range for VPA?
Which AEDs are eliminated via the kidney?
What is induction and how long does it take to occur?
adaptive increase in enzyme activity in responst to anothe agent, to protect cells from toxic substances by increasing detoxification activity
slow, regulatory process
maximal effect usually within
What is inhibition and how long does it take to occur?
direct action on an enzyme which renders the enzyme inactive
maximal effect usually