Epilepsy Flashcards
what is epilepsy
- neurological disorder/disease characterized by recurring epileptic seizures
- actually a collection of neurological disorders of varying etiologies
what are the Common diagnostic criteria of epilepsy
Any one of:
(1) At least two unprovoked seizures occurring more than 24 hrs apart
(2) One unprovoked seizure and a probability of further seizures similar to
the general recurrence risk (at least 60%) after two unprovoked
seizures, occurring over the next 10 years
(3) Diagnosis of an epilepsy syndrome
What are general etiologies?
- a brain injury or damage to the brain (physical, stroke, tumor)
- structural abnormalities that arise during brain development
- genetic factors (either inherited or random)
- a combination of two or more of the above
What is a Seizure?
- an electrical disturbance where neurons fire in a highly coordinated /
rhythmic manner
what is Focal / Partial Seizures
Focal seizure with retained awareness
- activity is localized to one area with a related effect (sensory, motor, etc.)
Focal seizure with a loss of awareness
- loss of consciousness and responsiveness; mobile or immobile
what is Generalized Seizures
Absence seizure
- brief loss of awareness; staring into space and subtle body movements
Tonic-clonic seizure
- abrupt loss of consciousness; loss of motor control including stiffening
and rhythmic contraction of muscles; loss of bodily function
- usually lasts less than two minutes and followed by confusion + lethargy
Status epilepticus
- a seizure that lasts more than five minutes
- can be life-threatenin
what are the Treatments
Pharmaceutical
- 50% success, 30% some improvement, 20% unresponsive
Surgery
- removal of the seizure focus
- corpus callosotomy (to prevent the generation of generalized seizures)
- hemispherectomy (totally malfunctioning hemisphere; rare)
Ketogenic diet
- high fat, sufficient protein, low carbohydrate
Deep brain stimulation
- permanent electrodes; pulses can prevent hypersynchronous activity
what is the pharmaceutical target
GABAergic control of excitatory
neurotransmission is critical for
normal brain electrophysiology
what are Inhibition of Nav channels meds work
- most common class of anti-epileptic drugs
- inhibit Nav channels, which are critical for action potential generation
what are examples of the Nav channels meds
Phenytoin: extended-release capsules for tonic-clonic seizures
Carbamazepine: tablets and extended-release tabs for focal or tonic-clonic
seizures; NOT for absence seizures
Valproic Acid: capsules for focal and generalized seizures
potential additional effect to increase GABA levels
Topiramate: tablets and capsules for focal and generalized seizures
also inhibits glutamate receptors and augments GABAA receptors
what is the med for the Inhibition of T-type Ca 2+ channels
Ethosuximide
- indicated for absence seizures only
- inhibits low-voltage T-type Ca2+ channels, which regulate oscillations
what is the med for the Inhibition of L-type Ca 2+ channels
Gabapentin: capsules and tablets for focal and generalized seizures
what is the example for the nhibition of synaptic vesicle glycoprotein 2A (SV2A)
Levetiracetam: tablets for focal and generalized seizures
Brivaracetam: tablets, liquid, injection for focal (partial) seizures only
what is the med for the Inhibition of AMPA + kainate receptors
Perampanel: tablets for focal and generalized seizures
non-competitive antagonist at AMPA receptors
Topiramate: tablets and capsules for focal and generalized seizures
antagonist at both AMPA and kainate receptors
what are the Positive allosteric modulation of the GABA A receptor
- many anti-epileptic agents work in this manner
- bound drug increases the receptor ion channel open time and frequency
- as discussed previously, many agents have anxiolytic, sedative, hypnotic,
and anti-convulsive properties
