Ns: 13 14 Seizures And Epilepsy

Front 1

what is epilepsy

Back 1

chronic, unprovoked, unavoidable seizures

Front 2

what is a symptomatic seizure

Back 2

results from a known lesion

Front 3

what is an idiopathic seizure

Back 3

cause is not known
ex. genetic cause

Front 4

what is a cryptogenic seizure

Back 4

from a suspected lesion whose location is not known

Front 5

focal onset vs generalized onset

Back 5

focal - restricted to a specific area or hemisphere

generalized - bilateral, symmetric seizure

focal may spread and become secondarily generalized

Front 6

___ is req'd to diagnose seizure

Back 6

EEG

Front 7

generalized seizure vs. partial seizure?

Back 7

generalized
-affects both hemispheres
-all EEG channels affected
-loss of awareness

partial
-affects limited area of brain
-only a few EEG channels are activated
-patient is aware, but may or may not be responsive

Front 8

what is a generalized tonic-clonic seizure?

Back 8

generalized tonic-clonic seizure is a grand mal (primary) seizure with a sudden onset, tonic, then clonic, abrupt offset

Front 9

what is an absence seizure

Back 9

absence seizure is a petit mal sz where the patient is totally unaware and unresponsive then rapidly returns to normal. cut and splice

Front 10

what is the difference between a simple partial and a complex partial seizure

Back 10

in a simple partial the patient is aware and can respond.

in a complex partial, the patient is aware but unresponsive. may have secondary generalization. bottom line- in a complex partial, the patient cannot interact with the environment.

Front 11

what is ictal semiology

Back 11

the symptoms of a seizure relate to the location of the seizure in the brain

Front 12

this kind of seizure has motor symptoms, bizarre behaviors and beliefs, people act like they're crazy

Back 12

frontal lobe sz

Front 13

this kind of seizure may produce fear, loss of consciousness, deja vu, amnesia, and automatisms

Back 13

temporal lobe sz

Front 14

this kind of seizure may cause somatosensory problems, dizziness

Back 14

parietal lobe sz

Front 15

this kind of seizure may cause visual changes

Back 15

occipital lobe sz

Front 16

what is an interictial spike?

Back 16

an EEG spike inb/t seizures. may be the trigger

Front 17

what kind of imaging is appropriate for someone presenting to the ER with a seizure?

Back 17

MRI

Front 18

in prescribing anticonvulsants, the physician must balance __ and ___

Back 18

efficacy in preventing seizures and side effects/ Q of L

Front 19

how does vagal nerve stimulation treat seizures?

Back 19

tickling this nerve may disrupt rhythmicity of ongoing seizures

Front 20

how is icital SPECT useful in treating seizures?

Back 20

seizures use a lot of glucose at their location, so icital SPECT can be used to determine the location of hyperactivity

Front 21

how does an implantable electrode treat seizures?

Back 21

it record brain waves and senses the onset of seizure activity and stimulates the cortex to prevent the rhythmic rise

Front 22

what is status epilepticus and why is it bad?

Back 22

an unresolving seizure of more than 30 minutes whose metabolic activity literally cooks the brain

Front 23

how do you treat status epilepticus?

Back 23

1. IV benzodiazepines (stimulate GABA release)
2. IV Anti convulsants
3. pharmacologically induce coma (general anesthesia) for 24 hrs

Front 24

how do female hormones play into seizures?

Back 24

estrogen may irritiate, progesterone is protective. females may get more seizures at diff times in their menstrual cycle

Front 25

describe the EEG conventions for pos and negative deflection

Back 25

pos deflection = negative current = sink (synapse) is close than source

neg deflection = pos current = source is closer than sink

Front 26

if the EEG measures a negative deflection, are you measuring the sink or the source?

Back 26

source

Front 27

if the EEG measures a positive deflection, are you measuring the sink or the source?

Back 27

sink

Front 28

how could modification of intrinsic membrane currents cause hyperexcitability?

Back 28

gaining Na currents or losing K currents cause them membrane to depolarize, making it more excitable

Front 29

how is rewiring of the brain relate to seizures?

Back 29

if the brain is rewired, and synapses are gained/lost, a cell could gain more excitatory synapses or lose its inhibitory synapses. also the cell could synapse on a cell it shouldnt resulting in new circuits w/in the brain that could cause the kind of rhythmic increase in activity needed to trigger a seizure

Front 30

what is a paroxysmal depolarization shift?

Back 30

when a cell's RMP depolarizes so it is hyperexcitable. in neurons with NMDA receptors, these receptors become active as the cell depolarizes. the loss of hyperpolarization can lead to a seizure

Front 31

what is kindling?

Back 31

electrical stimulation of the brain to produce a seizure. electrodes are implanted in the amygdala or hippocampus

Front 32

where is synaptogenesis observed in the kindling model?

Back 32

reorganization (sprouting) of the dentate gyrus of the hippocampus. the mossy fibers sprout and synapseback on the granule cells, where NMDA receptors will be opened by GABA due to paroxsymal depolarization shift. the dentate granule cells are hyperexcitable and are responsible for the seizures

Front 33

how does a paroxysmal depolarization shift affect glutamate receptors?

Back 33

NMDA receptors are not active at resting membrane potential. they are blocked by Mg unless the membrane is depolarized. with a paroxysmal depolarization shift, the NMDA receptors can be stimulated to open by GABA.

Front 34

how does cortical displasia cause seizures?

Back 34

some neurons are not located where they are supposed to be and also lack K channels they should have. these heterotypic cells are hyperexcitable

Front 35

the kindling model sheds light on human ___ lobe seizures

Back 35

temporal