Epilepsy & Seizure Disorders Flashcards
What is the definition of a seizure?
Abnormal electrical activity in the brain caused by the hyperexcitability of neurons, especially in cortical area
What is the definition of epilepsy?
2 or more unprovoked seizures (recurrent)
At what time point in a seizure does an “aura” occur?
the actual start of a seizure & may be though of as a ‘warning’
What is an “ictal”?
the period during a sudden attack, sucha s seizure or stroke
What does “refractory” mean with reference to seizures?
treatment fails to achieve seizure freedom for 12 months or more
What is the term for a prolonged seizure or a series of repeated seizures?
status epilepticus
How long does a seizure have to go to be considered status epilepticus?
Is this serious?
5 minutes
medical emergency
What are the 3 major etiologies of seizures?
- genetic
- cryptogenic
- structural/metabolic
What are the genetic etiologies of seizures?
- mutations of ion channels (NMDA, Ca2+, Cl-)
- mutations of transmitter receptors
- chromosomal abnormalities
What are the 3 general seizure classifications?
Focal onset
Generalized onset
Unkown onset
What are the subclssifications of Focal Onset Seizure?
- Aware / Impaired awareness
- Motor onset / Non-motor onset
Focal onset seizures may progress to what type of seizure?
bilateral tonic-clonic
What the subclassifications of Generalized onset seizures?
- motor
- tonic clonic
- other motor
- Non-motor
- (absence seizures)
What are the subclassifications of unkonwn onset seizures?
- motor
- tonic clonic
- other motor
- Non-motor
- unclassified
What type of seizure often begins with a blank dazed stare?
focal with impaired awareness
When should a patient be worked up for a febile seizure with an MRI & an EEG?
Todds paralysis or anything that might suggest prolonged seizure or focal nature
How many unprovoked seizures can a person have before they should be on seizure medication?
1 unprovoked
How many provoked seizures can a person have before they should be on seizure medication?
provoide seizures do not warrant seizure medication
What are the steps in evaluating a patient with a seizure disorder?
- History
- EEG
- Neuroimaging
- Lab studies
- prolactin
- CSF
What hormone is often elevated in indicituals who recently had a convulsive episode?
prolactin
What questions should you ask a patient when working up a seizure?
- What were they doing before it started?
- How long did it last?
- What did it look like?
- Awareness during episode?
- Incontinence?
- Recovery?
- What do you remember about the episode?
If a patient is experiencing a generalzed seizure where the whole brain is involved, what
generalized - whole brain is involved
What is the direction that results in a “positive” in an EEG & a “negative”?
positivity - downward deflection
negativity - upward deflection
Odd numbered electrodes in an EEG correleate to what side?
Even numbered?
odd - left
even - right
What are you looking for when evaluating an EEG?
- state of patient
- background activity
- asymmetry
- focality (slowing / irritability)
- events
- seizures?
- evolution of the pattern (frequency, rhythmicity, topogrophy)
What abnormality is shown in the provided EEG?
Do we treat them with seizure medication?
PLED
downward & upward deflection localized to T5
no- we do not treat with medication (but can see electrical strom potential)
What abnormality is shown in the provided EEG?
Triphasics
What is the of recurrance for a first time unprovoked seizure?
30%
Why might you start someone on a seizure medication after their first unprovoked seizure?
abnormality on EEG or MRI
What is the of recurrance after a second unprovoked seizure?
75%
What is the of recurrance after a third unprovoked seizure?
90%
Describe the characteristics of a temporal lobe epilepsy
- aura
- psychic, gastric rising, olfactory hallucination
- LOC / loss of awareness
- oral/manual automatisms
- contralateral limb dystonic posturing w/ ipsilateralhand automatism
- ictal spitting or nose wiping
- 60-90s
What is the most common etiology of temporal lobe epilepsy?
mesial temporal sclerosis
What is the EEG pattern of a temporal lobe epilepsy?
5-7 Hz
Which patients with temporal lobe epilepsy are ideal surgical candidates?
non-dominant temporal lobe
What condition is shown in the provided image?
mesial temporal sclerosis
hippocampal atrophy
Describe the characteristics of a frontal lobe epilepsy
dorsolateral vs. frontopolar
- nocturnal; hypermotor activity
- dorsolateral
- primary motor cortex
- focal clonic or spread to other areas
- head turning / eye deviation contralateral to seizure focus
- supplementary motor cortex: fencing (contralateral arm extension)
- primary motor cortex
- frontopolar/orbitofrontal
- staring, unresponsiveness
- speech & motor arrest w/ late motor elements
- automatisms, complex prodimal motor activity
What are the main causes of frontal lobe epilepsy?
- cortical malformations > tumors > encephalomalacia
In a focal seizure, there is conjugate gaze deviation in what directon?
stroke?
toward the abnormal limbs
stroke - AWAY from abnormal limbs
What is a febrile seizure?
- occurring in child after 1 month of age associated with febrile illness
- not caused by CNS infection
- no prior neonatal seizure or unprovoked seizure
- usually occurrign when patient is rapidly cooled
- have to exlude toxometabolic abnormalities
Does younger age at onset or duration of first event increase risk of recurrance for a febrile seizure?
younger age - YES
duration - NO
What are the risk factors for epilepsy in febrile seizure that warrant complete seizure workup?
- developmental delay
- abnormal neurological examination
- lateralizign feature and prolonged
- first degree relative with epilepsy
