Epilepsy Flashcards
spell
non-specific term for a sudden paroxysmal event
seizure
manifestation of abnormal excitation and synchronization of a group of cortical neurons
epilepsy
a diagnosis of two or more unprovoked seizures separated by greater than 24 hours or one seizure with studies (EEG/MRI) suggesting further risk of seizures.
syndrome
a constellation of common clinical pathological and electrographic features (lennox-gastaut syndrome)
provoked seizure
a seizure triggered by a brain injury or insult that would have reasonably resulted in a seizure in any person and if removed or avoided would likely lead to cessation of seizures (alcohol, TBI, hypoglycemia, febrile seizures)
types of seizures
focal onset
generalized onset
unknown onset
most common area of seizures
temporal or frontal lobes
types of epilepsy
generalized
focal
combines
unknown
pathology of seizures
1) too much excitation - ionic (inward Na and Ca currents) and neurotransmitters (glutamate and aspartate)
2) too little inhibition - ionic (inward Cl and outward K currents) and neurotransmitters (GABA)
B6
cofactor that converts glutamate to GABA (from excitation to inhibition)
complications of generalized convulsive status epilepticus
rhabdomyolysis hyperthermia orthopaedic aspiration pneumonia neuronal injury (cerebral edema) cardiac/Resp. arrest hepatic failure renal failure hypotension death
evolution of seizures
!) precipitating injury or initial epileptogenic trigger
2) latent period for months to years
3) emergence of chronic epilepsy/spontaneous recurrent seizures
non-epileptic spells
also called psychogenic seizures/pseudoseizures
a form of conversion disorder
1/3 have identifiable risk factors (depression, anxiety, PTSD, abuse history, combat)
can coexist with epilepsy (mixed disorder)
treat with CBT
seizure recurrence rates
about 50% with new onset seizures will have recurrence
factors for treating seizures
focal neuro exam lesion on imaging unprovoked abnormal EEG focal seizure long seizure
factors against treating seizures
normal neuro exam normal imaging provoked normal EEG generalized seizure short seizure
AEDs for generalized/partial seizures
ethosuximide (absence only) valproate lamotrigine topiramate levetiracetam felbamate rufinamide (gen. only) clobazam (gen. only)
AEDs for partial-only seizures
phenobarbital phenytoin carbamazepine oxcarbazepine gabapentin tiagabine zonisamide pregabalin lacosamide ezogabine
special populations with AEDs
elderly: reduce doses, avoid certain meds
pregnancy: close monitoring, dose changes, concern about birth defects
children: liquid formulations, reduced doses, certain meds approved
AEDs without interactions
gabapentin, pregabalin, levetiracetam
risks with surgical treatment of seizures
memory loss, language problems, weakness, incoordination, vision problems, common surgical risks
vagal nerve stimulation for seizures
palliative, seizure freedom is rare, 50% have 30-70% reduction of symptoms
most common side effect is hoarseness
responsive neurostimulation for seizures
neurostimulator implanted in the skull at sites of seizure onset, records and responds to seizures by delivering electrical impulses
DBS for seizures
DBS for bilateral ant. nuclei of the thalamus, median seizure reduction 69% at 5 years, improved QOL
factors that promote seizures
missing meds, sleep deprivation, alcohol use, recreational drug use, infections, menstration
seizures and driving restriction
varies by state from no restriction to a while year restriction in NY and VT, mandatory reporting in western coast states
treating drug resistant epilepsy
50% are seizure free with 1st drug
12% are seizure free with 2nd drug
4% are seizure free with 3rd drug
34% are drug resistant (pharmaco-resistant epilepsy)
*only do surgery if they fail at least 2 different treatments that are appropriately selected
absence seizures
characteristic 3Hz spike and wave discharge on EEG
febrile seizures
seizure in infancy or childhood associated with fever but without evidence of intracranial infection or defined cause. Most common childhood seizure, usually presents 6months - 3 years.
*seizure with fever in kids who have had previous non-febrile seizures are excluded
simple febrile seizures
generalized (both sides)
less than 10-15 minutes
don’t reoccur within 24 hours
complex febrile seizures
focal at onset or during
longer than 10-15 minutes
recur in less than 24 hours
*20-30%
timing of febrile seizures
usually within first 24 hours of illness
not due to rapid rise in fever, preventing fever with tylenol wont stop them
can begin to tolerate a higher fever over the course of the illness
recurrence with febrile fever
25-40% recur
50% with one recurrence will have a third
risk factors for recurrence of febrile fevers
less than 1 y/o positive family history low grade fever brief fever complex febrile fever baseline neurodevelopmental abnormality day care attendance (more frequent illnesses)
development of epilepsy after febrile fevers
increased risk with complex febrile seizures, neurologically abnormal prior to seizures, family history of afebrile fevers
treating with AEDs doesn’t prevent later epilepsy
lennox-gastaut syndrome
multiple seizure types (tonic - often nocturnal - atonic, myoclonic, atypical absence - slower 2Hz spike and wave - focal
cognitive dysfunction can evolve later but not always
onset usually 1-7y/o with first seizure 3-5y/o but can happen into adulthood
*have to diagnose over time not at the first seizure
causes of lennox-gastaut syndrome
cerebral malformations, hypoxic-ischemic injury, encephalitis, meningitis, tuberous sclerosis, preceeded by infantile spasm (9-40%)
how long must you be on AEDs before considering weaning off
2 years seizure free
consider EEG prior to weaning
medications that can worsen some seizures
lamotrigine: can worsen myoclonic seizures
phenytoin, carbamazepine, oxcarbazepine, and gabapentin can worsen generalized seizures
important side effects of AEDs
avoid valproic acid in teenagers b/c polycystic kidney disease and fetal issues
no valproic acid for children under 2y/o b/c fatal liver toxicity
avoid topiramate or zonisamide with acidosis in kids
ketogenic diet for drug resistant epilepsy
high fat, low carbs, protein control
useful for kids more than adults
useful for all seizure types, but less so for partial seizures
7% seizure free
20% have at least 90% seizure reduction
50% have at least 50% seizure reduction
*b/c limited efficacy only use after meds fail
adverse effects of ketogenic diets
hunger, hypoglycemia, drowsy, lethargy, irritability, nausea, vomiting (because of low blood sugar and ketone buildup), dehydration, refusal to eat, excessive ketosis (acidosis)
chronic effects of ketogenic diets
refusal to eat, hyperlipidemia, low free and total carnitine, constipation or diarrhea, Zn deficiency (hair thinning and loss), acidosis, hyperuricemia, hypocalcemia, suboptimal growth, kidney stones, prolonged QT interval, increased bruising and bleeding, pancreatitis, immunosuppression
