EEG Terms/ Seizure Classification Flashcards
Epileptic seizures fall broadly into 3 main types
1.) Focal
2.) Generalized
3.) Uknown
How to classify/ describe focal onset seizures?
Aware or Impaired Awareness
&
Motor onset
Non motor onset (sensory, cognitive, emotional, autonomic, behavioral arrest)
automatic behaviors
automatisms
extension or flexion postures
tonic
flushing/ sweating/ piloerection
autonomic
jerking arrhythmically
myoclonus
jerking rhythmically
clonus
loss of tone/ limp
atonic
thrashing/ pedaling
hyperkinetic
trunk flexion
spasm
Elements of Consciousness
AWARENESS of ongoing activities
MEMORY of time during the event
RESPONSIVENESS to verbal or nonverbal stimuli
SENSE OF SELF as being distinct from others
Definition of Epilepsy
- At least two unprovoked seizures occurring >24 hr apart
- 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
- Diagnosis of an epilepsy syndrome
Epilepsy is considered to be resolved when…
individuals who had an age-dependent epilepsy syndrome are now past the applicable age
Or for those who have remained seizure-free for the last 10 years, with no seizure medicines for the last 5 years
How to classify epilepsy type per the ILEA (International League Against Epilepsy).
classification at three levels
1.) the seizure type
2.) epilepsy type
3.) epilepsy syndrome.
Imaging, EEG and other investigations contribute to optimized classification at all three levels.
Recommended settings for ECOG (Electrocorticography) Mapping
Bandpass 1-70Hz
Sampling Rate >1000kOhms
Sensitivity 70-100uV
Name the two different forms of the normal variant:
6 Hz spike and wave discharge
WHAM (Wake High-Amplitude Male), which is frontally dominant
FOLD (Female Occipital Low-amplitude Drowsiness)
What does the normal variant SREDA acronym mean?
Subclinical Rhythmic EEG Discharge of Adults (SREDA)
characterized as symmetrical, diffuse, rhythmic monomorphic theta waves with sharp contours, maximally on the parietal and posterior temporal regions.
What does the normal variant RMTD acronym mean?
Rhythmic Mid-temporal Theta of Drowsiness (RMTDs)
Other than RMTD, what other normal variants come from the temporal region?
Wickets, 14 and 6 Hz Positive Spikes, BETS or BSSS (benign epileptiform transient of sleep) or (Benign sporadic sleep spikes),
What is Ciganek’s Rhythm?
a nonspecific benign theta rhythm of drowsiness occurring at the midline
What is Bancaud phenomenon?
Uncommon unilateral failure of the alpha to attenuate with eye opening. It may occur in lesions of the temporal or parietal lobes.
The temporal factor refers to the ________ and the spatial factor refers to the __________.
timing and location
Most common form of focal epilepsy
temporal lobe epilepsy
to prevent** Aliasing**
waveforms must be sampled at a rate at least half as fast or faster than their actual frequency
This is the Nyquist Frequency
EEG changes with CBF (cerebral blood flow)
loss of faster frequencies and increased slower frequencies as CBF decreases