Normal EEG Patterns in Infants a Children.textbook.final (1)

8/18/2019 Normal EEG Patterns in Infants a Children.textbook.final (1)

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EEG in the diagnosis & management of epilepsyin neonates and children

Normal EEG in infants and Children

Magda Lahorgue Nunes, MD, PhD

Division of Neurology and INSCER

Pontificia Universidade Católica do Rio Grande do SulHospital Sao Lucas PUCRS!

"v! Ipiranga ##$% roo& '()

$%#(%*%%% Porto "legre RS+ ,ra-il

E&ail. nunes/pucrs!0r

12e content of t2is docu&ent reflects t2e position of t2e individual contri0utor3s4 and &ay not necessarily re*flect t2e opinions of IL"E and ot2er contri0utors to t2e course!

/International League "gainst Epilepsy 5%(5

(

mailto:[email protected]:[email protected]


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Table of ContentsForeword.....................................................................................................................................31 Introduction to this unit............................................................................................................32 EEG in infancy (2 -12 months)................................................................................................43 EEG in early childhood (1-3 years)..........................................................................................54 EEG in reschool a!e (3-5 years)............................................................................................"5 EEG in older children ("-12 years)..........................................................................................#" EEG in adolescents (13-2$ years)............................................................................................%# Glossary....................................................................................................................................&% 'e!ister of Fi!ures a*les.................................................................................................1$& 'eferences .............................................................................................................................11

5


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6ore7ord

ore!ord

It is a +leasure to start this unit with you. I am a ediatric ,eurolo!ist thathas wor ed since I was in edical /chool with research in different as-

+ects of the de0elo+in! *rain. I am also *oard certified in /lee+ edicineand dedicate my research to as+ects of onto!enesis and *ioeletro!enesisof +reterm new*orns. It is 0ery im+ortant to reco!ni e normal +atterns ofEEG de0elo+ment in order to *e an e +ert linical ,euro+hysiolo!ist. Iho+e you en oy this cha+ter as much as I en oyed +re+arin! it.

" #ntroduction to this unit

he maturation of the EEG across childhood is a challen!e su* ect for theneuro+hysiolo!ists as +atterns may 0ary accordin! to a!e. 6esidessometimes the +resence of +hysiolo!ical acute or s+i e-li e transients ore0en the +resence of slow +atterns may lead to a misdia!nosis. It is 0eryim+ortant to *e aware of those 0ariants. In this cha+ter we will e +osestudents to different sam+les of children recordin!s in order to hel+ thereco!nition of normal +atterns and to a0oid misdia!nosis.

'

Learning Goals

"t t2e end of t2is learning unit you s2ould 8no7 2o7 to identifynor&al EEG age related patterns and its variants duringc2ild2ood+ in 7a8e and sleep recordings!


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5 EEG in infancy 35 *(5 &ont2s4

$ EEG in infancy %$ "$ months'

7fter the neonatal +eriod (that is considered the first four wee s of lifefor term infants) and durin! the first three months of life the EEG is char-acteri ed *y a !radual transition from neonatal to infantile +atterns. In0ery +reterm neonates the neonatal +atterns may *e seen for lon!er +eri-ods durin! the first year of life as accordin! to conce+tional a!e (!esta-tional a!e +lus days8wee s of life).

he technical a++roach to record an EEG in an infant is stron!ly relatedto the technician s ills and e +erience on handlin! an awa e and a slee+infant. he 1$-2$ International Electrode /ystem should *e used for elec-trode +lacement.

Table 1: Maturation of EEG across childhood: Infancy

Pattern/Age 2-12 months

Basal rhythm (sleep) ransition from tracé alternant to continuousslow wa0e ,o si!nificant asynchrony. 7fter diffuse slow acti0ity ($.#5-39 ) with ma im-um +osterior 0olta!e and moderate fast acti0-ity.

Posterior basalrhythm (awake)

,o al+ha rhythm wa0es at a*out 4 9 around3-4 months and "9 around 12 months

Other characteristics(awake)

onsidera*le slow acti0ity and 0ery moderatefast acti0ity. 9y+er0entilation not feasi*le in-termittent +hotic stimulation with im+ro0in!dri0in! to low flashes rates *y " months

Drowsiness 7fter " th month rhythmic theta

N !" Increase +ercenta!e with increasin! a!e

/+indles 7++ear after the 2 nd month shar+ contoured

12-14 9:erte wa0es and ;com+le es

none

!" ostly slow acti0ity. ?ecrease +ercenta!e dur-in! the first years of life

#leep starts in N !" a$ter the 1st month o$ li$e

*POSTS (positive occipital sharp transients of sleep

!or illustration see !i"ures 1 to #$

9

Figures 1 – 6 –see separate file


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' EEG in early c2ild2ood 3(*' years4

% !!& in early chil'hoo' (1-% years)

7t this a!e it is !enerally difficult to !et a !ood wa in! record. EEG fea-tures are e0ol0in! to more mature +atterns.

Table %: Maturation of EEG across childhood: Early &hildhood

Pattern/Age 1 % years

Basal rhythm (sleep) 9i!h 0olta!e slow +attern (1-39 ) and medi-um 0olta!e(4-"9 ) ma imum am+litude atocci+ital re!ion

Posterior basal

rhythm (awake)

"-# 9 at 2 years #-%9 at a!e 3 years


6loc in! res+onse to eyes o+enin! +resentslower acti0ity (2-59 )widely scattered

Drowsiness Generali ed hi!h 0olta!e rhythmic theta acti0-ity(4-"9 )-@hy+na!o!ic theta hy+ersyn-chronyA

N !"

/+indles resent 12-14 9 shar+ ma imum at 0erte

:erte wa0es and ;

com+le es


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9 EEG in Presc2ool age 3'*) years4

( EEG in Preschool age %) * years'

7t this a!e recordin! the awa e EEG *ecomes a little easier as childrenmay understand the +rocedures and colla*orate. 7ll +atterns had de-0elo+ed in a more mature +resentation.

Table ): Maturation of EEG across childhood: Preschool a"e

Pattern/Age % years

Basal rhythm (sleep) ?iffuse delta acti0ity +osterior ma imum am+-litude not so +ronounced

Posterior basal

rhythm (awake)

7l+ha ran!e (%9 ) am+litude reaches 1$$u:

hi!her am+litudes may *e seen o0er the nondom-inant hemis+here. Intermi ed delta wa0es (1.5-49 ) may interru+t the al+ha train.


7++earance of rolandic mu rhythm. ronouncedslow res+onses to hy+er0entilation.

Drowsiness 7dmi ture of +osterior slow acti0ity hy+na!o!ictheta acti0ity tends to disa++ear until a!e " years

N !"

/+indles Bell defined ma imum am+litude o0er 0erte

:erte wa0es and ;com+le es ore +rominent shar+ com+ounds

=/ / 7*sent or +oorly delineated

!"


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) EEG in older c2ildren 3#*(5 years4

* EEG in older children %+ "$ years'

7t this a!e a com+lete EEG with awa e record hy+er0entilation inter-mittent +hotic stimulation and s+ontaneous slee+ is easier to *e o*tainedas children are much more colla*orati0e. In the slee+ EEGs 0erte wa0esof hi!h 0olta!e can *e seen. he differentiation from +atholo!ical roland-ic s+i es and 0erte wa0es remains in the sli!ht lon!er duration andhi!her 0olta!e of the +hysiolo!ic 0erte acti0ity.

Table +: Maturation of EEG across childhood: Older &hildren

Pattern/Age * - 12 years

Basal rhythm (sleep)

Posterior basalrhythm (awake)

7l+ha rhythm !radually reaches 1$9 around1$ years hi!her am+litude at nondominanthemis+here. onsidera*le admi ture of +os-terior slow acti0ity.


9y+er0entilation with +ronounced slowin!startin! in +osterior re!ions. Intermittent +hot-ic stimulation with a more mature ty+e of oc-ci+ital dri0in! res+onse.

Drowsiness Increasin! theta and delta freCuencies with

!radually fadin! of +osterior al+ha rhythm.N !"

/+indles Features of maturity wa0es rounded with 1$-12 9 trains usually shorter than1 second.

:erte wa0es and ;com+le es

:erte wa0es a++ear *efore the transitionfrom sta!e I to II. ; com+le es a++ear in asso-ciation with s+indles at sta!e II

=/ / 7++ears +rior to onset of sta!e II

!"


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# EEG in adolescents 3('*5% years4

+ EEG in adolescents %") $ years'

7lthou!h si!nificant *iolo!ical and +sycholo!ical alterations occurs inthe transition from the last years of childhood to adolescence the EEGmaturation does not shows stri in! chan!es.

Table , - Maturation of EEG across childhood: .dolescence

Pattern/Age 1% - 2+ years

Basal rhythm (sleep) ,'E and 'E slee+ with +attern similar toadulthood

Posterior basal

rhythm (awake)

Entire al+ha ran!e +resent mean freCuency

around 1$9 !radual decrease and disa++ear-ance of admi ture slow acti0ity


Fast acti0ity o0er frontal areas rolandic murhythm and lam*da wa0es with ty+ical matureconfi!uration low 0olta!e records may occur.7nterior rhythmical "-#9 acti0ity has its

+ea +re0alence at a!es 13-15 years. 9y+er-0entilation without +ronounced slowin!.

Drowsiness Gradual al+ha dro+out

N !" (*y a!e 1" years around #5D of the slee+cycle)

/+indles /imilar to adults

:erte wa0es and ;com+le es

/imilar to adults

=/ / /imilar to adults

!" ?esynchroni ed (*y a!e 1" years around 25Dof slee+ cycle)

#leep starts in N !"

;


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: Glossary

- Glossary

!" sleep, ra+id eyes mo0ement slee+ its +ercenta!e decreases dramat-ically from the neonatal +eriod (around %$D of the slee+ cycle). 6y %

months acti0e slee+ occu+ies a++ro imately 3$D of the slee+ cycle andat a!e 5 years the adult 0olume is reached (2$ to 25D of the slee+ cycle).

N !" sleep non ra+id eyes mo0ement slee+ di0ided in three sta!es(,1 ,2 and ,3) were n1 is the more li!ht slee+ ,2 +hase characteri ed

*y the a++earance of slee+ s+indles and ; com+le es) and ,3 (dee+ slowwa0e slee+). Its +ercenta!e increases from the neonatal +eriod to adoles-cence. he com+lete differentiation of the three ,'E slee+ sta!es can

*e done around the " th month of life. In normal healthy youn! adultssta!e 1 accounts for less than 5D of the cycle sta!e 2 from 45-55D andsta!e 3 13 to 23D.

Drowsiness, the EEG features that re+resent the transition from awa estate to slee+ modify accordin! to a!e. ?urin! the first year of life it iso*ser0ed a transition to theta acti0ity latter from 1 to " years the hy+n-a!o!ic theta hy+ersynchrony is the +rominent +attern after an increasedtheta and delta freCuencies with !radually fadin! of +osterior al+harhythm and the more mature +attern is the al+ha dro+out.

ypnagogic hypersynchrony, !enerali ed hi!h 0olta!e rhythmic theta

acti0ity(4-"9 ) mar er of drowsiness from a!e 1 to " years.

.erte wa0es, hallmar of dee+ drowsiness they are secondary e0o ed +otentials the mor+holo!y 0aries accordin! to onto!enesis and the ma-ture +attern is a small s+i y dischar!e of +ositi0e +olarity the +recedes alar!e ne!ati0e wa0e (more +rominent).

#leep spin'les, also called si!ma acti0ity or si!ma wa0es they arerhythmic wa0es with a freCuency 0aryin! from 1$-14 9 with wa in!and wanin! am+litude. ?urin! childhood they ha0e a more shar+ con-

toured mor+holo!y faster freCuency and lon!er duration of the trains.

comple es , considered a res+onse to arousin! stimuli. he s+atial dis-tri*ution shows a ma imum o0er 0erte . he mor+holo!y consists of aninitial shar+ com+onent followed *y a slow that fuses with a su+erim-

+osed fast com+onent. In older children and early adolescence the shar+com+onent is im+ressi0e.

Positi0e occipital sharp transients o$ sleep, they a++ear in dee+ drowsi-ness and may +ersist durin! li!ht and dee+ slee+ the mor+holo!y is a

+ositi0e s+i e-li e wa0es in the occi+ital areas. hey are more commonin adolescents and youn! adults.

$


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: Glossary

amb'a wa0es, shar+ transients (*i+hasic or tri+hasic with a +ositi0emost +rominent +hase) sawtooth sha+ed with am+litude *etween 2$-5$u: occurrin! o0er the occi+ital re!ion of su* ects in the awa e statedurin! 0isual e +loration.

"3 rhythm, rolandic mu rhythm or wic et rhythm is related in fre-Cuency and am+litude to +osterior al+ha rhythm. his +attern can *e o*-ser0ed in children and adult EEGs *ut it is more +re0alent in adolescents(11 to 15 years) and adults.

Patterns o$ marginal an' possibly abnormal character occ3rring'3ring wake$3lness an' sleep

hythmical $rontal theta (*-4 5) acti0ity, this +attern that occurs dur-

in! wa efulness has two main +ea s of a++earance *ein! the first *etween "-12 years and the second *etween 13-15 years. It is not con-sidered a clear a*normality as it a++ears in the EEGs on health youn!su* ects howe0er some authors ha0e related it to children with +redis-

+osition to !enerali ed e+ile+sies. (!i"ure %1

16an' */secon's positi0e spikes, are seen durin! drowsiness and slee+form a!e " to 12 years. here is *y now e0idence that this +attern is notcate!orically a*normal unless if 0ery freCuent.

Psychomotor 0ariant, ?escri*e in the si ties *y Gi**s and Gi**s theyare +redominantly seen durin! slee+ in adolescents and youn! adults.

haracteri ed *y *ursts of tem+oral theta (5-".59 ) rhythmical acti0itywith a ma imum o0er midtem+oral areas and considera*le s+read into

+osterior and anterior tem+oral and occi+ital re!ions. (!i"ure %%

. /egister of igures & Tables

igures/ee the se+arate fileA Normal !!& patterns in in$ants 7 chil'ren8 9ig-3res: +osted within this unit.

Tablesa*le 1 aturation of EEG across childhood Infancy.............................4a*le 2 aturation of EEG across childhood Early hildhood..............5a*le 3 aturation of EEG across childhood reschool a!e ................."

a*le 4 aturation of EEG across childhood =lder hildren ...............#a*le 5 - aturation of EEG across childhood 7dolescence...................%

(%

Figure 21 –see separate file

Figure 22 –see separate file


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$ References

0 /eferences

(not poste' within the .irt3al ibrary '3e to copyright restrictions)

,iedermeyer E. aturation of the EEG de0elo+ment of wa in! andslee+ +atterns. In ,iedermeyer E

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Normal EEG Patterns in Infants a Children.textbook.final (1)