Seizures Flashcards
seizure
abnormal synchronous discharge of neurons in cortex
-sec - min. goes away
risk of 2nd seizure after 1st unprovoked is 50% in 2 yrs.
Types of seizures
- Generalized
- Partial
a. Simple
b. Complex
causes of seizures
1ry: Idiopathic epilepsy
2ry: structural vs metabolic
a. space occupying lesions: tumour, pus, blood; Cortical stroke
b. non-d to meds; hypoglycemia; hypoNa, Ca, Mg; alcohol withdrawal, drugs
Tests
Ask about diabetes!
Blood: CBC, electrolytes: Na, Ca, Mg, glucose, albumin, cretinine, toxicology screen, antiepi drugs
Imaging: MRI>CT, EEG (although can miss!) so dx based on clinical presentation
-LP if high WBC
Drugs for seizures mech
- increase GABA-A to inihibit activity by Cl influx > stabilize membrane
BARBITUATES, BENZOS - decrease glutamate to decrease activity
- alter ion channels for Na, Ca: inhibit and keeps inactive state to decrease rapid fire
ex: inhibit voltage-dependent Na channels (PHENYTOIN, CARBAMAZEPINE, LAMTROGINE) and T-type voltage-dep Ca channels (ETHOSUXIMIDE) - combo
Unprovoked: If tests are all fine (PE, imaging, EEG) then no tx because risk of another is 25% unless pt wants.
if abnormal findings, start on monotherapy (risk is 75%)
epilepsy
2 or more unprovoked seizures
- prev: 1%, M=F
- young and the old
Describe generalized seizure. Types
- both hemisphere - involve cortex
- NO aura
- LOC
- post ictal confusion in most
Types: Tonic-Clonic: fall and shake Atonic: fall, lose tone only Myoclonic: irreg jerky movements Absence: in kids. phase our 10sec, come back. prob THALAMUS involved. no post ictal confusion. tx with ethoxsumide
Describe partial seizures. Types
- focal lesion, 1 hem
- aura
- complex partial: LOC and postictal confusion but simple does not (simple still able to talk, action…)
- complex can become genralized seizure
Seizure vs syncope:
scenerio, timing, motor, autonomic, afterwards
Seizure: awake or alseep. trigger by sleep loss
- sudden onset
- yelp
- tonic-clonic, tongue bitting
- incontinence, cyanosis (normal or blue)
- injury, post-ictal confusion
SYNCOPE: awake and upright. trigger by emotion, heat, injury
- gradul onset
- no vocalization
- maye tonic-clonic but no tongue bitting
- no incontinence
- turn pale
- afterwards tired but alert
Wht is Status Epilepticus?
seizure > 5min without going back to baseline
but really we treat if it lasts 2 min.
ER response. check glucose. give D50WIV incse of dm. give ativan (benzo) and phenytoin IV
-if doesn’t work, use general anesthesia
Management
- no driving within 6 mo
- safety - have ppl close by, don’t do certian things alone, modify work
- drugs if needed (antiepileptic drugs)
- surgery is the only cure
What is anticonvulsant hypersensitivity syndrome? which drugs?
- rare but fatal
- dverse rxn to AEDs in 1-8wks
- fever, rash, internal organs - looks like viral infection
- common in Hn chinese
- drugs: PHENYTOIN, CARBAMAZEPINE, LAMOTRIGINE, PHENOBRBITAL
What is intractable pt?
- does not get drug control
- 1/3 no response to therapy after 2 drugs used
- refer to specialist for surgery, diet therapy, vagus stimulation….
- common in complex partial seizures
Important drug interactions of AEDs
- Valproate increase blood levels of other drugs
- phenobarbital, phenytoin, carba decrease blood levels of other drugs
- phenytoin and warfarin
- AEDS and oral contraceptives fail
- phenytoin and valproate = teratogens
Drugs for Absence type
-Ethosuximide - t Ca channel blocker
Drugs for Tonic-Clonic and partial
Phenobarbital: GABA enhancer
Phenytoin: Na channel blocker - major side effects
Carbamazepine: Na channel blocker (1st line)
Levetiracetam: don’t really know mech. maybe with Nt release
Drugs for many types of seizures (broad spectrum)
Valproate: unknown mech
Clobazam: GABA enhancer (benzo). sedating
Lamotrigine: Na channel blocker. (1st line)
Topiramate: combo mech. sedating, wt loss
Where are most focal seizures found?
temporal lobe
ex: Temporal Lobe epilepsy
- candidate for surgery!
what is TLE, stages.
Prodrome: -deja vu (hippocampus - memory) -smell (uncus, amygdala) -fear, anxiety (amygdala) -autonomic signs, abdo rising Seizure: -blank stare -autonomic: picking, fumbling, repeition -speech arrest -wandering Post-ictal: -disorient, tired, headache, psychosis, LOC decrease
What is mesial temporal scleoris
- lesion associated with TLE
- hippocampus atrophy
- loss of neurons and gliosis
Complictions to temporal lobectomy
-memory defecit
-language
-field cut
-stroke
-infection and hemmorahageduring
risk = 3-5% (low)
benefits of surgery
- 80% seizure free!
- cost saving, psychosocia…
- candidcy determine withn 2 yrs of initial diagnosis
