Epilepsy, Seizures and Anti-seizure Drugs Flashcards
What is the cause of primary epilepsy?
Cause is unknown
What is the cause of secondary epilepsy?
Cause is related to a particular event (TBI/stroke)
Epilepsy
Sudden excessive electrical discharge from large groups of neurons
Neurons are tonically depolarized and fire continuously at high freq (tonic phase/mm spasms) followed by phasic re-polarization interruption (clonic phase) and gradual return to normal membrane potentials
Generalized Seizures
Involve both hemispheres (depol in thal and substantia nigra)
Complex Seizures
Loss of consciousness (temporal/limbic lobe)
Partial Seizures
Originate in localized area of 1 cerebral hemisphere
Drug of Choice: Carbameazepine
Simple Seizure
Consciousness is intact
Simple Partial Seizure
Unilateral hemispheric involvement, no impaired consciousness. Jerking commonly in face/arm/leg, “fencer’s posture”, may have hallucinations of sigh, hearing or taste, ANS response nausea, pallor/flushing, pupillary dilation
Complex Partial Seizure
Localized onset that progresses to bilateral involvement, impaired consciousness. Amnesic about event, see clumsy perseveration of ongoing motor events (chewing, drawing, walking, hand rubbing)
Tonic-Clonic Seizure (grand-mal)
Sudden loss of consciousness, sudden extensor spasm followed by flexor spasm, respiration ceases, defecation, micturation or salvation may occur. Alertness slowly returns w/period of confusion.
Drug of choice: Dilantin
Absence Sizures (petit mal)
Occur freq in children and disappear in adolescence, abrupt brief loss of consciousness w/ amnesia. Stares blankly for a few minutes.
Drug of Choice: Depakote
Myoclonic Seizures
Single contraction or multiple sudden brief contractions confined to face, trunk, or extremities lasing only seconds
Drug of Choice: Depakote
Atonic Seizures
Often in kids, drop attacks, a sudden reduction in mm tone, brief loss of consciousness
Status Epilepticus
Seizures are prolonged or repeated that recovery doesn’t occur btw attacks=medical emergency!
Main mechanism of action for current antieplieptic drugs (AED)
Enhancement of GABA activity and the blockade of the voltage gated Na and Ca channels
Side effect of AED
Drowsiness, ATAXIA, nystagmus, vertigo, skin rash, cognitive disorders, neg implications w/motor learning
Dilantin (my ant named dil has seizures)
Primary drug for seizure control (-absence seizure), alters conductance of K and Ca channels and blocks Na channel
Carbamazepine (eat a lot of carbs b/c you burn a lot of kcals wehn you seizure)
Second most common AED, drug of choice for partial seizures
-blocks Na channels and Ca uptake
Depakote (when you seizure you defecate (depakote)
Increases synthesis of GABA in synapse and prevents GABA re-uptake
These drugs can induce seizures
ketamine, cocaine
