Few normal EEG waves which some time misinterpreted while reporting

1. Positive Occipital Sharp Transients of Sleep,
Posterior slow-wave transients associated with eye
movements and Occipital Slow Transients
By: Mohibullah Fazli Kakar
French Medical Institute for Children
Kabul Afghanistan

2. Positive occipital sharp transients
of Sleep
Best seen at the age of 15–35 years and rarely <3 years.
Seen in 50–80% of healthy adults.
Amplitude 20–75 μV;
duration 80–200 msec.
Absent in individuals with poor central vision.
Sharply-contoured, surface positivity, occurring in trains
with a repetitive rate of 4–5 Hz, and monophasic
checkmark-like waveform seen singularly or in clusters
over the occipital regions.

3. Positive occipital sharp transients
of Sleep
Always bilaterally synchronous but are
commonly asymmetric on the two sides.
Asymmetry of 50% is normal.
POSTS occur during deep drowsiness and
stage 2 sleep.
Rare in REM sleep.

4. Posterior slow-wave transients
associated with eye movements
Seen in children age 6 months to 10 years, but most
commonly in children aged 2–3 years.
Consisting of a monophasic or biphasic slow
transient with a duration of 200–400 msec and a
voltage of up to 200 μV in the occipital regions.
A latency of 100–500 msec is noted after the
eyeblinks or eye movements.
The initial component of the transient is surface
positive. The ascending phase is steeper than the
descending phase

5. Occipital slow transients
Physiologic waves presenting during non-REM sleep,
especially a transition from light to deep sleep in infancy
until 5 years of age
Bilateral, isolated, medium- to high-amplitude,
monomorphic, triangular-shaped, delta waves with a
typical duration greater than 250 msec in the occipital
regions.
These waves vary from a cone-shaped confi guration
(cone waves or “O” waves) to a biphasic slow transient.
These transients occur every 3–6sec during light sleep
and more frequently during deeper stages of sleep.

6. Positive Occipital Sharp Transients of
Sleep (POSTs)
EEG of a 4-year-old asymptomatic male during drowsiness.
Characteristics of POSTS include
sharply-contoured, surface positive, occurring in trains with a
repetitive rate of 4–5 Hz, and monophasic checkmark-like
waveform seen singularly or in clusters over the occipital
regions. POSTS are always bilaterally synchronous but are
commonly asymmetric on the two sides and should not be
misinterpreted as epileptiform activity or focal nonepileptiform
activity.10,14 POSTS occur during drowsiness and stage 2 sleep.

7. Positive Occipital Sharp Transients of Sleep (POSTs)

8. Positive Occipital Sharp Transients of
Sleep (POSTs)
EEG of a 3-year-old asymptomatic male during stage 2
sleep. Characteristics of POSTS are sharp-contoured,
surface positivity, occurring in trains with a repetitive rate of
4–5 Hz, and monophasic checkmark-like waveform seen in
singly or in clusters over the occipital regions. POSTS are
always bilaterally synchronous but are commonly
asymmetric on the two sides and should not be
misinterpreted as epileptiform activity or focal
nonepileptiform activity.10,14
POSTS occur during, drowsiness and stage 2 sleep.

9. Positive Occipital Sharp Transients of Sleep (POSTs)

10. Positive Occipital Sharp Transients of
Sleep (POSTs)
POSTS (Box) can simulate epileptiform activity.
Their triangular morphology, persistent lack of slow
wave following sharp transients, positive polarity,
constant symmetry, and occurrence during sleep
differentiate them from epileptiform activity.

11. Positive Occipital Sharp Transients of Sleep (POSTs)

12. Asymmetric Posterior Occipital Sharp
Transient of Sleep (POSTS)
A 7-year-old boy with recurring staring episodes and
behavioral issues.
The routine EEG during sleep shows bilaterally
synchronous but asymmetric POSTS.
Characteristics of POSTS are surface positivity, occurring
in trains with a repetitive rate of 4–5 Hz, and monophasic
checkmark-like waveforms.
POSTS are always bilaterally synchronous but are
commonly asymmetrical on the two sides and should not
be misinterpreted as epileptiform activity or focal
nonepileptiform activity.

13. Aymmetric Posterior Occipital Sharp Transient of Sleep
(POSTS)

14. Pathologically Asymmetry of Positive Occipital Sharp
Transients of Sleep (POSTS)
A 7-year-old girl born 24 weeks gestational age with grade 4 intraventricular
hemorrhage (IVH).
Subsequently, she developed spastic quadriparesis and global developmental
delay.
Cranial MRI showed periventricular leukomalacia with bilateral white matter
involvement, greater on the left.
Prolonged 72-h-video-EEG demonstrates persistent suppression of POSTS
and anterior beta activity in the left hemisphere throughout the drowsy and
sleep EEG recording.
Although persistent asymmetric POSTS in this case are pathologic,
physiologic POSTS can be quite asymmetric and may be present on only one
side in the routine EEG.
Therefore, asymmetric POSTS without other associated abnormalities should
not be misinterpreted as abnormal

15. Pathologically Asymmetry of Positive Occipital Sharp Transients of Sleep
(POSTS)

16. Posterior Slow-Wave Transients (Occipital Sharp Transients);
Associated with Eye Movements
Posterior slow-wave transients associated with eye movements is an EEG
pattern consisting of a monophasic or biphasic slow transient with a duration
of 200–400 msec and a voltage of up to 200 μV in the occipital regions (*).
The latency of 100–500 msec is noted after the eye blinks or eye movements.
The initial component of the transient is surface positive.
The ascending phase is steeper than the descending phase. This EEG
pattern is seen in children age 6 months to 10 years, but seen most commonly
in children aged 2–3 years.
This EEG pattern is a normal phenomenon but may be misinterpreted as
epileptiform activity

17. Posterior Slow-Wave Transients (Occipital Sharp Transients); Associated
with Eye Movements

18. Posterior Slow-Wave Transients (Occipital Sharp Transients);
Associated with Eye Movements
Posterior slow-wave transients associated with eye
movements is an EEG pattern consisting of a monophasic or
biphasic slow transient with a duration of 200–400 msec and a
voltage of up to 200 μV in the occipital regions (open arrow).
The latency of 100–500 msec is noted after the eyeblinks or
eye movements. The initial component of the transient is
surface positive.
The ascending phase is steeper than the descending phase.
This EEG pattern is seen in children age 6 months to 10 years,
but seen most commonly in children aged 2–3 years.
This EEG pattern is a normal phenomenon but may be
misinterpreted as epileptiform activity

19. Posterior Slow-Wave Transients (Occipital Sharp Transients); Associated
with Eye Movements

20. Posterior Slow-Wave Transients (Occipital Sharp Transients);
Associated with Eye Movements
Posterior slow-wave transients associated with eye
movements is an EEG pattern consisting of a monophasic or
biphasic slow transient with a duration of 200–400 msec and a
voltage of up to 200 μV in the occipital regions (*).
The latency of 100–500 msec is noted after the eyeblinks or
eye movements.
The initial component of the transient is surface positive. The
ascending phase is steeper than the descending phase.
This EEG pattern is seen in children age 6 months to 10 years,
but seen most commonly in children aged 2–3 years.
This EEG pattern is a normal phenomenon but may be
misinterpreted as epileptiform activity

21. Posterior Slow-Wave Transients (Occipital Sharp Transients); Associated
with Eye Movements

22. Posterior Slow-Wave Transients (Occipital Sharp Transients);
Associated with Eye Movements
Posterior slow-wave transients associated with eye movements is an
EEG pattern consisting of a monophasic or biphasic slow transient with
a duration of 200–400 msec and a voltage of up to 200 μV in the
occipital regions.
The latency of 100–500 msec is noted after the eyeblinks or eye
movements.
The initial component of the transient is surface positive.
The ascending phase is steeper than the descending phase.
This EEG pattern is seen in children aged 6 months to 10 years, but
seen most commonly in children aged 2–3 years.
This EEG pattern is a normal phenomenon but may be misinterpreted
as epileptiform activity

23. Posterior Slow-Wave Transients (Occipital Sharp Transients); Associated
with Eye Movements

24. Occipital Slow Transients; Cone Wave and
Diphasic Slow Transient
In children, the transition from light to deep sleep
may be associated with bilateral high-voltage slow
transients in the occipital regions.
These waves vary from a cone-shaped
configuration (double arrows) to a biphasic slow
transient (open arrow).
These transients occur every 3–6 sec during light
sleep and more frequently during deeper stage of
sleep

25. Occipital Slow Transients; Cone Wave and Diphasic Slow Transient

26. Occipital Slow Transients; Cone Waves
In children, the transition from light to deep sleep may be associated
with bilateral high-voltage slow transients in the occipital regions.
These waves vary from a cone-shaped configuration to a biphasic slow
transient.
These transients occur every 3–6 sec during light sleep and more
frequently during deeper stages of sleep.
10 Cone waves or “O” waves (arrow) are physiologic waves presenting
during non-REM sleep from infancy until 5 years of age.
They are isolated, medium- to high-amplitude, monomorphic, triangular
shaped, delta waves with a typical duration greater than 250 msec that
occur over the occipital region

27. Occipital Slow Transients; Cone Waves

28. Occipital Slow Transients; Cone Wave
In children, the transition from light to deep sleep may be associated
with bilateral high-voltage slow transients in the occipital regions.
These waves vary from a cone-shaped configuration to a biphasic slow
transient.
These transients occur every 3–6 sec during light sleep and more
frequently during deeper stage of sleep.
Cone waves or “O” waves (arrow) are physiologic waves presenting
during non-REM sleep from infancy until 5 years of age.
They are isolated, medium- to high-amplitude, monomorphic, triangular
shaped, delta waves with a typical duration greater than 250 msec that
occur over the occipital region

29. Occipital Slow Transients; Cone Wave