Anti Convulsants Flashcards
Define seizure:
rapid synchronous and uncontrolled spread of electrical actiivy
What are the 4 stages of a seizure?
Prodrome
Aura
Ictus
Post-ictal phase
Prodrome
behavioral changes days before the seizure
Aura
conscious warning telling something is coming
Ictus
seizure event
Post-ictal ohase
behavior changes, dazed and confused after event
What is epilepsy?
recurrent unprovoked seizures
What are the 3 classifications of Epilepsy
focal
partial
generalized
Focal seizure
in one brain region, no spread, seen only on EEG
Partial seizure
focal limited spread and observed clinically, structural lesions in the forebrain might be a contributing factor
What are the two types of partial seizures? what is the difference?
simple partial- no alteration in consciousness, seizure located in motor area of the cerebral hemisphere
complex partial- psychomotor epilepsy; altered consciousness, repetitive behavior, think temporal lobe
Generalized seizure
most common form in domestic animals
abrupt loss of consciousness, aka grand mal seizure
What is the neurobiology of a seizure?
synchronous neural discharges of a particular population of neurons
imbalances in inhibitory/excitatory neurotransmission
symptoms dependent on brain region affected
extracellular calcium necessary for the initiation and spread of seizures
What is “Ictal”
EEG descriptor that that refers to seizure-like; interictal is between seizures
What are the general therapeutic strategies available for seizure management?
inhibit voltage gated Na/Cl channels
enhance GABAnergic channels
blockade of excitatory glutamatergic neurotransmitters
What are the 4 anti-seizure agents we covered?
Benzodiazepines
barbiturates.
Potassium bromide
carbamazepine/phenytion
what is the action/adverse effects of using benzodiazepines as anti-seizure meds?
action: targets GABA receptor, results in hyperpolarization
adverse effects: addictive, hepatotoxic. sedation, not suitable fopr chronic treatment
Diazepam: uselul in stopping cluster seizures,
what is the action/adverse effects of using potassium bromide as anti-seizure meds?
action: hyperpolarizes membrane through Br- competing with CL- (forces more Cl- into cell would be my guess
adverse effects: sedation/ataxia main limiting factors
what is the action/adverse effects of using barbiturates as anti-seizure meds?
action: raises the seizure threshold
adverse effects: sedation, ataxia, PU/PD, polyphagia, weight gain, hepatoxic in dogs
plasma monitoring necessary to make sure w/in therapeutic range
what is the action/adverse effects of using carbamazepine/phenytoin as anti-seizure meds?
action: target inactivation gate of Na channel to keep it open longer-> cannot repolarize, stabilization of neuronal mebrane and decreased excitability
adverse effects:
What is the drug of choice for status epilepticus?
Diazepam
