Neurophys - EEG

Electrode Pop

Eye Blinks

Slow roving eye movements

• 14 and 6
• Bursts of arch shaped waves maximal over the
• posterior temporal area
• Most common in deep drowsiness and light sleep
• 3 y/ - young adult peaking at 13 – 14 years old

Benign Epileptiform Transients of Sleep (BETS)

• sharps that occur bilaterally in the temporal lobes during sleep
• Normal variant that is rare in children but more common in adults / elderly where they may be seen in 20-25%
• Occur during deep drowsiness

K-Complexes

• High-amplitude, delta frequency waves with sharp apex
• Generalized and symmetric with a frontal predominance
• Noted during Stage II sleep and with arousals
• Followed by runs of rhythmic theta

Lambda Waves

• Sharp transients in the occipital region while awake
• Bilateral, positive, triangular, symmetrical, occipital
• Occurs with visual scanning
• Most common in 3-12 y/o (80%)
• Usually bilaterally synchronous and will attenuate with eye closure or darkness

Mu

• Runs of central alpha frequency (8-10 HZ)
• <5% of children <4 and 18-20% of children 8-16
• Thought to be sensorimotor cortex at rest
• Always rounded in one direction and sharp in the other
• Disappear with motor activity in the contralateral arm / hand but unlike alpha are not affected by visual stimuli
• More common after surgery when the skull have been removed

Positive Occipital Sharp Transients of Sleep (POSTS)

Bilateral, positive, triangular, symmetrical, occipital that occur during sleep ("reverse check mark")

Posterior Slow Waves of Youth

V Waves

Wicket Spikes

• Most common >30 y/o and usually >50 y/o - ~1%
• 6-11 Hz negative sharps seen in the anterior / mid temporal
• Facilitated by drowsiness
• Unilateral with a shifting asymmetry

REM Sleep

Stage 1 Sleep

Stage 2 Sleep

Stage 3 sleep

Stage 4 Sleep