EEG: NORMAL & NORMAL VARIANTS QUESTIONS WITH
CORRECT ANSWERS
Lambda Waves - ANSWER-a. similar morphology and location as POSTs
b. positive triangular waves present when viewing an image using lateral scanning
c. seen in occipital regions during wakefulness, more common in children
d. blocked by eye closure or looking at blank page, and sleep
Mu Rhythm - ANSWER-a. negative arch shaped rhythm of about 8-10 Hz
b. prominent at C3 and C4
c. Seen during wakefulness in late childhood into the adult years
d. typically unilateral or asymmetrical
e. Key to identification is movement of contralateral arm, thought of movement, or tactile stimuli (touching the
arm)
Hypnagogic Hypersynchrony - ANSWER-normal variant of drowsiness in children aged 3 months to 13 years.
This is described as paroxysmal bursts (3-5 Hz) of high-voltage (as high as 350 µV) sinusoidal waves, maximally
expressed in the prefrontal-central areas, that brake after the cerebral activity amplitude drops during
drowsiness.
Wicket Spikes - ANSWER--midtemporal
, -similar to Mu, but occur in drowsyness, can be seen in each temporal region independently
-often occur in short trains or clusters
-frequently 6-11 Hz
- no slow wave after
-no disruption of backgrownd
BETS/SSS - ANSWER-Benign Epileptiform Transients of Sleep/ Small Sharp Transients
Occur in light sleep (non-REM 1 and 2 sleep)
Located frontal, temporal uni- or bilateral
Shifts side to side and can be negative or positive
**more common in adults
Usually monophasic, occasionally diphasic
Occasionally followed by a slow wave, however do not disturb the background
6 hz spike and wave - ANSWER-small spike followed by slow wave
-4-7hz frequency
-bursts of less than 1 sec duration
-sometimes maximal in anterior (more likely correlating with seizures), sometimes maximal in posterior regions
-appear in awake state, sometimes activated by photic
14 & 6Hz Positive Spikes - ANSWER-sharply contoured/comb shaped positive spikes
-maximal over posterior temporal and occipital regions
CORRECT ANSWERS
Lambda Waves - ANSWER-a. similar morphology and location as POSTs
b. positive triangular waves present when viewing an image using lateral scanning
c. seen in occipital regions during wakefulness, more common in children
d. blocked by eye closure or looking at blank page, and sleep
Mu Rhythm - ANSWER-a. negative arch shaped rhythm of about 8-10 Hz
b. prominent at C3 and C4
c. Seen during wakefulness in late childhood into the adult years
d. typically unilateral or asymmetrical
e. Key to identification is movement of contralateral arm, thought of movement, or tactile stimuli (touching the
arm)
Hypnagogic Hypersynchrony - ANSWER-normal variant of drowsiness in children aged 3 months to 13 years.
This is described as paroxysmal bursts (3-5 Hz) of high-voltage (as high as 350 µV) sinusoidal waves, maximally
expressed in the prefrontal-central areas, that brake after the cerebral activity amplitude drops during
drowsiness.
Wicket Spikes - ANSWER--midtemporal
, -similar to Mu, but occur in drowsyness, can be seen in each temporal region independently
-often occur in short trains or clusters
-frequently 6-11 Hz
- no slow wave after
-no disruption of backgrownd
BETS/SSS - ANSWER-Benign Epileptiform Transients of Sleep/ Small Sharp Transients
Occur in light sleep (non-REM 1 and 2 sleep)
Located frontal, temporal uni- or bilateral
Shifts side to side and can be negative or positive
**more common in adults
Usually monophasic, occasionally diphasic
Occasionally followed by a slow wave, however do not disturb the background
6 hz spike and wave - ANSWER-small spike followed by slow wave
-4-7hz frequency
-bursts of less than 1 sec duration
-sometimes maximal in anterior (more likely correlating with seizures), sometimes maximal in posterior regions
-appear in awake state, sometimes activated by photic
14 & 6Hz Positive Spikes - ANSWER-sharply contoured/comb shaped positive spikes
-maximal over posterior temporal and occipital regions
