EEG Maturation - Serial evolution of changes from Birth to Old Age
-
Upload
drrahulkumarsingh -
Category
Health & Medicine
-
view
743 -
download
1
description
Transcript of EEG Maturation - Serial evolution of changes from Birth to Old Age
EEG Maturation
From Infancy to Adolescence
Dendritic Spreading
11
2233
33
33
2211
11
ContinuityInterhemispheric
synchronyDifferentiation of
waking and sleepingPosterior basic (alpha)
rhythmSlow activity (awake)
Temporal thetaOccipital theta
Fast activity (awake)Low voltage
HyperventilationIntermittent photic
stimulation
DrowsinessTracé alternant
SpindlesVertex waves and K complexes
Positive occipital sharp transients of sleep
Slow and fast activity in sleepREM sleep
Rhythmical frontal theta activity (6–7/sec)
14 and 6/sec positive spikesPsychomotor variant (marginal
abnormality)Sharp waves, spikes
Full Term (36-41 week)Continuity Continuous except for tracé alternant in non-
REM (quiet) sleep
Interhemispheric synchrony Minor asynchronies still present
Differentiation of waking and sleeping Good
Posterior basic (alpha) rhythm None
Slow activity (awake) Slow (delta), mostly of moderate voltage
Temporal theta Disappearing or absentOccipital theta AbsentFast activity (awake) Decreasing ripples, sparse fast activity
Low voltage Very low-voltage records are due to severe cerebral pathology; prognosis ominous
Hyperventilation Not feasibleIntermittent photic stimulation Driving response below 4 flashes/sec may occur,
not easily elicited
Drowsiness UndifferentiatedTracé alternant Present in non-REM (quiet) sleep
Full Term (36-41 week), contd…
Spindles None (but scanty ripples)Vertex waves and K complexes None
Positive occipital sharp transients of sleep None
Slow and fast activity in sleep Much delta and theta activity, continuous in REM sleep
REM sleep Continuous slow activity, REM in EOG (more REM or “active†than non-REM �
sleep)
Rhythmical frontal theta activity (6–7/sec)
None
14 and 6/sec positive spikes NonePsychomotor variant (marginal
abnormality)None
Sharp waves, spikes Some minor sharp transients (normal) (abnormal spikes more consistent and
prominent)
Infancy (2-12 months)Continuity Continuous
Interhemispheric synchrony No significant asynchronyDifferentiation of waking and sleeping Good
Posterior basic (alpha) rhythm Starting at age 3–4 mos at 4/sec, reaching about 6/sec at 12 mos
Slow activity (awake) ConsiderableTemporal theta NoneOccipital theta None
Fast activity (awake) Very moderateLow voltage Uncommon, usually abnormal
Hyperventilation Not feasibleIntermittent photic stimulation Improving driving to low flash rates after age 6
mosDrowsiness Around age 6 mos, appearance of rhythmical
theta
Infancy (2-12 months), contd…
Tracé alternant Disappears in 1st (seldom 2nd) mo
Spindles Appear after 2nd mo; 12–15/sec, sharp, shifting
Vertex waves and K complexes Appear mainly at 5 mos, fairly large, blunt
Positive occipital sharp transients of sleep None
Slow and fast activity in sleep Much diffuse 0.75–3/sec activity with posterior maximum; moderate fast activity
REM sleep REM portion decreasing; mostly slow activity
Rhythmical frontal theta activity (6–7/sec) None
14 and 6/sec positive spikes NonePsychomotor variant (marginal abnormality) None
Sharp waves, spikes Essential as abnormal phenomena
9 months
9 months
10 months
Early Childhood (12 to 36 months)
Continuity ContinuousInterhemispheric synchrony No significant asynchrony
Differentiation of waking and sleeping Good
Posterior basic (alpha) rhythm Rising from 5–6/sec to 8/sec (seldom 9/sec)
Slow activity (awake) ConsiderableTemporal theta NoneOccipital theta None
Fast activity (awake) Mostly moderateLow voltage Uncommon, usually abnormal
Hyperventilation Mostly not feasibleIntermittent photic stimulation Often good driving response to low flash
ratesDrowsiness Marked “hypnagogic†rhythmical theta �
(4–6/sec)Tracé alternant None
Early Childhood (12 to 36 months) contd…Spindles In 2nd yr, sharp and shifting, then
symmetrical with vertex maximum
Vertex waves and K complexes Large, becoming more pointed
Positive occipital sharp transients of sleep Poorly defined
Slow and fast activity in sleep Marked posterior maximum of slow activity; often a good deal of fast activity
REM sleep Mostly slow, starting to become more desynchronized
Rhythmical frontal theta activity (6–7/sec)
Seldom in 3rd yr of life
14 and 6/sec positive spikes RarePsychomotor variant (marginal
abnormality)None
Sharp waves, spikes Spikes in seizure-free children, mainly occipital (mild abnormalities)
Pre School Age (3 to 5 yrs)Continuity Continuous
Interhemispheric synchrony No significant asynchronyDifferentiation of waking and sleeping Good
Posterior basic (alpha) rhythm Rising from 6–8/sec to 7–9/sec
Slow activity (awake) Marked admixture of posterior slow activity (to alpha rhythm)
Temporal theta NoneOccipital theta None
Fast activity (awake) Mostly moderateLow voltage Uncommon, usually abnormal
Hyperventilation Often marked delta response
Intermittent photic stimulation Often good driving response to low flash rates
Drowsiness Rhythmical theta gradually vanishing, other types of slow activity predominant
Tracé alternant None
Pre School Age (3 to 5 yrs), contd…
Spindles Typical vertex maximumVertex waves and K complexes Large with an increasingly impressive
sharp component
Positive occipital sharp transients of sleep
Poorly defined
Slow and fast activity in sleep Predominant slowing but less prominent posterior maximum
REM sleep Slow activity with some desynchronization
Rhythmical frontal theta activity (6–7/sec)
May occur, not very common
14 and 6/sec positive spikes May occur, not very commonPsychomotor variant (marginal
abnormality)Probably none
Sharp waves, spikes Spikes in seizure-free children, mainly occipital, also Rolandic (slight
abnormalities)
Older Children (6-12 years)Continuity Continuous
Interhemispheric synchrony No significant asynchronyDifferentiation of waking and sleeping Good
Posterior basic (alpha) rhythm Reaching 10/sec at age 10 yr
Slow activity (awake) Varying degree of posterior slow activity mixed with alpha
Temporal theta NoneOccipital theta None
Fast activity (awake) Mostly moderateLow voltage Seldom as variant of normalcy
Hyperventilation Often marked delta response
Intermittent photic stimulation Often good driving response, chiefly at medium flash rates (8–16/sec)
Drowsiness Gradual alpha dropout with increasing slow activity
Tracé alternant None
Older Children (6-12 years) contd…
Spindles Typical vertex maximumVertex waves and K complexes Large with a prominent sharp component
Positive occipital sharp transients of sleep
Still poorly defined but gradually evolving
Slow and fast activity in sleep Much diffuse slowing, slightly decreasing voltage
REM sleep Less slowing and increasing desynchronization
Rhythmical frontal theta activity (6–7/sec)
A bit more common
14 and 6/sec positive spikes Fairly commonPsychomotor variant (marginal
abnormality)Uncommon
Sharp waves, spikes Spikes in seizure-free children, mainly Rolandic (central-mid-temporal), slight to
moderate abnormalities; physiological occipital spikes in congenitally blind
children
Adolescents Continuity Continuous
Interhemispheric synchrony No significant asynchronyDifferentiation of waking and sleeping Good
Posterior basic (alpha) rhythm Averaging 10/sec
Slow activity (awake) Posterior slow activity diminishing
Temporal theta NoneOccipital theta None
Fast activity (awake) Moderate, except for low voltage fast records
Low voltage Occasionally and (at end of teenage period more often) as variant of normalcy
Hyperventilation Delta responses become less impressive
Intermittent photic stimulation Often good driving response, chiefly at medium flash rates
Drowsiness Gradual alpha dropout with low-voltage stretches (mainly slow)
Tracé alternant None
Adolescents, contd…
Spindles Typical vertex maximumVertex waves and K complexes Not quite as large, sharp component not
quite as prominent
Positive occipital sharp transients of sleep Often very well developed
Slow and fast activity in sleep Much diffuse slowing with further attenuation of voltage
REM sleep Mature desynchronizationRhythmical frontal theta activity
(6–7/sec)A bit more common, declining at end of
period14 and 6/sec positive spikes Fairly common
Psychomotor variant (marginal abnormality)
More common (although relatively rare)
Sharp waves, spikes Benign Rolandic spikes usually disappear before beginning of this period
ContinuityInterhemispheric
synchronyDifferentiation of
waking and sleepingPosterior basic (alpha)
rhythmSlow activity (awake)
Temporal thetaOccipital theta
Fast activity (awake)Low voltage
HyperventilationIntermittent photic
stimulation
DrowsinessTracé alternant
SpindlesVertex waves and K complexes
Positive occipital sharp transients of sleep
Slow and fast activity in sleepREM sleep
Rhythmical frontal theta activity (6–7/sec)
14 and 6/sec positive spikesPsychomotor variant (marginal
abnormality)Sharp waves, spikes