Seizure Flashcards
clinical features of phenytoin toxicity
hypertrichosis, gingival hyperplasia folic acid deficiency peripheral neuropathy osteomalacia, vitamin D deficiency drug induced lupus anticonvulsant hypersensitivity syndrome
dose dependent side effects of phenytoin
rash, horizontal nystagmus, ataxia slurred speech lethargy and confusion coma can also develop a DRESS like syndrome
IV infusion side effects of phenytoin
hypotension bradyarrhythmias and possible asystole
pt with history of seizure and on phenytoin starts to have horizontal nystagmus and gaint unsteadiness. Also has slurred speech and lethargy or coma.
Phenytoin toxicity can be result of drug drug interactions - like omeprazole which inhibits cytochrome P450 and increases phenytoin levels
do all PPI increase phenytoin levels?
no, just omeprazole
what can also lead to phenytoin toxicity in pts who are malnourished
hypoalbuminemia - can have higher free phenytoin levels since this drug is protein bound. Can have toxicity even if phenytoin is normal levels.
how to treat phenytoin toxicity?
manage with supportive care stop drug
complex partial seizure characteristics
localized semipurposeful movements and generally have an aura (sensory symptoms prior)
simple seizure vs complex partial seizure
simple - pt has awareness and can see jerking muscle rigidity, unusual sensations (affecting smell, vision, hearing, taste or touch) and can have memory or emotional
disturbance complex partial - pt loses awareness and see lip smacking, chewing, fidgeting and walking,
myotonic seizure is defined by
sporatic (isolated) jerking movements, can have sporatic jerks on both sides of body and described as electrical shocks.
absence seizure
brief loss of consciousness
clonic seizure
repetitive jerking movements see repetitive rhythmic jerks that involve both sides of body at the same time
tonic seizure
muscle stiffness rigidity- see only muscles stiffning
atonic seizure
loss of muscle stone
Grand Mal seizure or generalized seizure
called tonic (stiffening)-clonic (jerking) seizure see unconsciousness, convulsions, muscle rigidity
Tonic phase - see eyes are wide open while body stiffens and there is a single loud groan or ictal cry (not actual crying or sobbing)
clonic phase - rhythmic jerking occurs synchronously in all limbs initially at the high frequency with eventual slowing and cessation.
partial seizures are divided into
simple, complex and focal seizure (those that evolve into secondary generalized seizure)
simple partial seizure
broken down into 4 different categories based on symptom: motor, autonomic, sensory or psychological
Complex partial seizure
loss of consciousness and can have automatisms of involuntary but coordinated movements that are purposeless and repetitive.
focal seizure
starts a partial seizure and then becomes a generalized seizure or a Grand Mal seizure.
management of first unprovoked seizure?
need rule out structural brain abnormality
may get CT head for someone who has emergent pathology to exclude hemorrhage, but MRI is required in most pts.
get brain MRI. MRI is more sensitive than CT in identifying lesions such as cortical dysplasias and infarcts and tumors, try to focus on temporal lobe epilepsy (most common form of epilepsy in adults)
Out patinet EEG in pts who have first seizure. highest yield is in 1st 24 hrs of seizure.
prognosis after single seizure and see abnormal MRI and EEG
high risk for recurrent seizures and so they benefit from antiepileptic drugs.
triggers for seizures
lack of sleep, emotional distress, loud music and flashing lights.
physical exam findings with seizures
post ictal phase with confusion and disorientation and prodromal aura and head deviation and unusual body posturing and tongue laceration.
what is valproic acid induced hyperammonemic encephalopathy?
this is from doubling of valproic acid increasing ammonia levels valproic acid can stop enzymes in the urea cycle and cause elevated serum ammonia
what are symptoms of valproic acid induced hyperammonemic encephalopathy?
see confusion. lethargy, coma and rarely death after recent increase in valproic acid dose
all pts on valproic acid should have get this checked
serum ammonia and valproic acid levels checked as part of work up
valproic acid levels do not
Valproic acid levels do not always correlate to their degree of encephalopathy and can be normal at times.
what happens to the liver enzymes in pts who have valproic acid induced hyperammonemic encephalopathy
they can be normal
treatment of valproic acid induced hyperammonemic encephalopathy?
discontinuation of valproic acid lactulose can lower serum ammonia and L carnitine can improve valproic acid metabolism and lower serum ammonia level too
automatism is
semi purposeful behaviors during seizure (lip smacking, pacing, grooming behavior and repetitive swallowing) seen in complex partial seizure. pts are not aware of behaviors and have no memory after seizure
complex partial seizures can
arise from any region of cortex but seen in pts with mesial temporal lobe epilepsy
when do you start a antiepileptic drug?
after the patient has had TWO unprovoked seizures separated by more than 24 hrs.
anti seizure medication with least teratogenic effects
lamotrigine alone or levetiracetam since there are the fewest teratogenic side effects
which anti seizure medication is contraindicated in young women
valproic acid because of potential teratogenic effects
initial drug of choice for status epilepticus?
lorazepam
status epilepticus
prolonged single seizure >5-10 minutes of repetitive seizures without return to baseline clinical status.
fever, rash, LAD, and eosinophilia and elevated LFTs after starting a medication like phenytoin, carbamazepine or phenobarbital
anticonvulsant hypersensitivity syndrome - form of DRESS, SJS or TEN.
Rare but with serious side effects and mortality rate up to 10%
this occurs after starting some new antiseizure medications about 2 months from starting
need to make sure there is no TEN
other causes of anticonvulsant hypersensivity syndrome
lamotrigene, allopurinol, carbamazepine, phenytoin and phenobarbital also happens with ACEi and antidepressants and beta blockers.
anticonvulsant hypersensivity syndrome presents
presents about 2 months after starting therapy with fever, rash, pharyngitis and LAD and facial edema
rash seen with anticonvulsant hypersensivity syndrome is
classic erythematous papules and pustules and possible toxic epidermal necrolysis can see eosinophilia and anemia severe cases have rhabdomyolysis
diagnosis of anticonvulsant hypersensivity syndrome
based on high index of suspicion treatment is supportive care and prompt discontinuation of drug. can treat with steroids
osteoporosis can be worsened by these medications
carbamazepine, phenytoin and phenobarbital all i_nduces of cytochrome P450 system and can increase breakdown of vitamin D_ which can increase PTH and cause osteoporosis
Valproic acid can also increase bone loss (unclear mechanism)
which anti seizure medications are safer to use with pts who have osteoporosis?
lamotrigine and levetiracetam don’t induce P450 system
osteoporosis screening for people who have seizures?
need DEXA scan if on phenytoin, carbamazepine, phenobarital or valproic acid get one after 5 years of therapy regardless of age, sex or menopausal status.
every pt on antiseizure medications should get
assessment if they are taking in enough calcium and vitamin D. supplementation is needed if low.
anti seizure medication of choice in older pts
lamotrigine due to good evidence for safety and effectiveness in epilepsy and focal seizures in older pts
Lamotrigine is unlikely to cause cognitive dysfunction and does not affected blood counts, liver, kidney or electrolytes.
also can use levetiracetam and gabapentin
what is an adverse side effect of lamotrigene to beware of?
steven johnson’ syndrome can avoid or minimize risk by slowly titrating up the drug.
what anti seizure medication causes hyponatremia
ozcarbazepine can cause hyponatremia esp in older people on thiazide diuretics.
dizziness, ataxis, tremor , peripheral neuropathy and cerebellar atrophy and agranulocytosis. which antiseizure medication causes this?
phenytoin also has a narrow therapeutic window
topiramate side effects /makes these medical conditions worse?
kidney stones and cognitive impairment
valproic side effects
cognitive dysfunction (including parkinsonism associated dementia in older persons) and causes tremor causes thrombocytopenia.
which antibiotics lower seizure threshold?
cefepime, carbapenems fluoroquinolones can lower seizure threshold too
how to tell the difference between seizures and syncope and psychogenic loss of consciousness need to get
video EEG and table tilt testing.
Goal standard for caputring epilepsy is
24 hr video EEG moniotring - performed in multiple elective hospitalization in which AEDs are decreased or withdrwan under close supervision.
what medications can lower a seizure threshold or cause a seizure?
tramadol,
meperidine
bupropion
fluoroquionlones
carbapenems
cefepine
-marijuana
dose dependent reactions of oxcarbazepine is
hyponatremia
dose dependent reaction of valproic acid
thrombocytopenia
which antiseizure medications are mood stabilizing?
lamotrigene and valproic acid
What to screen for before starting a antiseizure medication?
What are relative contraindications?
all AEDs carry a warning about worsening depression and suicidality and all pts must be screened prior and monitored during treatment
levetiracetam worsens depression, anxiety, anger or agitation
Perampanel - can cause homicidal ideation
topiramate may cause pscyhosis
what medications should be avoided in Asian pts who have seizures? Unless what is found to be negative?
Phenytoin, carbamazepine, phenobarbital, lamotrigene = can cause rash and DRESS, SJS, TEN
Need to screen for HLA-B1502 allele and if negative ok to use. If positive, avoid.
seizure medications can interfere with tehse drugs?
interfere with statins
can increase statin clerance and so may need to have higher than normal statin doses or use alternatives.
when to consider tapering off of antiseizure medications?
consider taping off these anti seizure meds if remain seizure free for 2-5 years and no other risk factors
risk factors for seizure: juvenile myoclonic epilepsy, history of difficulties in early seizure control and presence of significant epilepsy risk factors.
lifestyle restrictions for people with seizures:
- no driving for 3-12 months
- avoid common triggers and provoking factors
- can work even if not completely seizure free;
- need to avoid operating heavy machinery
- no using firearms, lifting more than 20 lbs
- no tub baths or swimming unsupervised
- cannot be near open flames or heights.
AEDs are given prophylactically after severe head trauma when
only for 1st week if there was loss of consciousness >12-24 hrs
intracranial hemorrhage
depressed skull fracture
brain contusion
Done to prevent any acute seizure complications (hemorrhage, edema and ICP)
with acute stroke seizure meds doesn’t reduce risk for epilepsy later.
what antiseizure medication can cause anovulation and polycystic ovary syndrome?
valproic acid.
best seizure medication for people who are of childbearing age and least amount of tetraogencity
levetiracetam and lamotrigene
Medications to avoid: (associated with major congenital malformations)
Valproic acid
phenobarbitual
phenytoin
Note that these medications should be continued even if pregnancy is discovered especially if woman’s epilepsy is well controlled.
in pregnancy these antiseizure medications can change
they decrease by up to 50%
lamotrigene and oxcarbazepine and levetiracetam - so need to dose escalation of 50% to keep up the same therapeutic effect
- will need rapid drop in dose after delivery to avoid sudden increase in serum levels which can precipitate Steven Johnson syndrome.
what is the interaction with antiseizure medications and OCPs?
they increase the metabolism and so can decrease effectiveness of OCPs
need to change contraception to IUD or barrier methods
OCPs can increase lamotrigene metabolism which needs to have a dose adjustment.
ethosuximide is used to treat
absence seizures only.
drug of choice for seizures is
lamotrigene
- best for women of childbearing years,
- good option for older people
- those who have depression or mood disorders.
