EEG Benign Variants Flashcards
Midline theta rhythm of drowsiness (Ciganek)
- Drowsiness
- Most prominent in central vertex
- 5-7 Hz smooth, sinusoidal, arciform, spikey or mu-like
Wicket Spikes
- 6-11 Hz
- Temporal
- Unilateral/bilateral
- Medium-high amplitude
- Older adults
- Drowsy/light sleep
- Arciform/wicket-like appearance
RMTTD (Psychomotor variant)
- Theta
- Midtemporal
- Unilateral/bilateral
- Does not evolve or spread to other sites
- 5-15 seconds duration
- Wake (less during drowsiness and disappears during light NREM sleep) (? Research this)
- Teen/adult
Small sharp spikes
Beneign sporadic sleep spikes
Beneign epileptiform transients of sleep
- Drowsiness or light sleep (disappears during deeper sleep) in adults
- Low amplitude and duration (no repetitive trains or slow waves after)
- Usually unilateral but can be b/l independent
- Temporal or broad field of distribution
14 and 6 Hz Positive Spikes
- 20-60% of normal population
- 12-20 years
- 6 Hz < 1 y/o
- 14 Hz adolescents (more commonly seen)
- Both can be seen in the same study
- Drowsiness and light sleep
- Posterior temporal and parietal
- Trains of arch shaped waveforms with alternating positive spikey components and negative smooth rounded waveform
- Looks a little like a sleep spindle
- Usually < 2 seconds
- Best seen in referential montages
6 Hz Phantom Spike and Wave
- Diffuse, anterior or posterior predominant bursts
- Posterior dominant: drowsiness
- Mitten-like morphology
- Small spike (often not visible, i.e. phantom) followed by slow wave
- Also phantom in that it is very brief
- Drowsiness and light sleep
- Adolescents and adults
SREDA (Subclinical Rhythmic Electrographic Discharges in Adults))
- 5-6 Hz sharply contoured theta
- Diffuse but maximal over parietal and posterior temporal regions
- Seconds - 2 min (usually > 30 seconds)
- Drowsiness
- Usually abrupt onset and termination
- Hyperventilation can trigger
- Older adults (usually > 50 y/o)
If a patient is aroused from N1 sleep and the posterior alpha activity reappears with a higher amplitude then the individuals regular rhythm it is called ________
Paradoxical alpha
What is the rhythm?
Mu
- Alpha rhythm
- Represents sensory-motor cortex at rest
- Suppressed by contralateral opening and closing fist (or thinking about it)
- Non reactive to blink/eye closure
- Awake only
- Max central
What 2 wave forms do you see?
Lambda waves (mu later on)
- Occipital region
- Surface positive (actually negative?)
- Triangular in shape and generally symmetric
- Looks like POSTS (except with lambda the patient is awake)
- Brought out by scanning of a textured image
What are the benign variants that occur during drowsiness?
WoRMS 6 or 14?
- Wicket Spikes
- RMTTD (psychomotor variant)
- Midline Theta Rhythm of Drowsiness (ciganek)
- SREDA (Subclinical Rhythmic Electrographic Discharges in adults)
- 6 Hz phantom spike and wave
- 14 and 6 Hz Positive Spikes
All are drowsy but what is speical about:
Wicket Spikes
- 6-11 Hz temporal
- Older adults
All are drowsy but what is speical about:
RMTD (Psychomotor)
- Temporal
- Teen/adult
All are drowsy but what is speical about:
Midline theta rhythm of drowsiness (ciganek)?
- Central/vertex
All are drowsy but what is speical about:
SREDA?
- Parietal/posterior temporal
- 5-6 Hz sharply contoured theta
- Older adults
- Hyperventilation trigger
- Usually abrupt onset and termination
- Usually > 30 seconds
All are drowsy but what is special about:
14 and 6 Hz Positive bursts
- Looks like sleep spindle
- < 2 seconds
- Posterior temporal/parietal
- Young adults
Diagnosis?
Ocular flutter
Eye may or may not be open
Posterior slow waves of youth
Typically seen ages 6 to 12
Diagnosis?
Glossokinetic artifact.
Diagnosis?
Lambda waves
Diagnosis?
Eye rubbing artifact
Diagnosis?
Diagnosis?
These are 6 Hz
Diagnosis?
Diagnosis?
Tremor artifact
(Lots of muscle as well)
