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Robert White, MDMedical Director, Pediatrix Medical GroupMemorial Hospital, South Bend, IN

� I have been a paid speaker for Natus

� For diagnosis/prognosis following HIE� For seizure detection and monitoring� For developmental evaluation, and perhaps for

prematurity assessment� To better understand what is going on in our

babies’ brains, real-time

***Why not?▪ Cost

▪ Unconvinced of value

▪ Potential for misuse▪ Conflict with neurologists

� Concepts/Analogies

� Yes, you can read EEGs� How can you use this new ability?

� Big picture thoughts, cautions, training,

resources

� EKGs – single lead vs. “full montage”� “Scanning the room”

� aEEG = amplitude-integrated EEG, a method for

extracting key information from the EEG

� The EEG signal has two primary components -

background + transients

� aEEG displays information on both by recording peak

amplitude of each wave

� The EEG signal is processed through filtering

(reducing artifact) and rectification (since only the

amplitude of the signal matters, not its polarity)

� Compressed – one screen vs reams in standard EEG

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Courtesy T. Weiler, Olympic Medical

Raw EEG aEEG

Continuous

Discontinuous

Burst-

Suppression

Courtesy T. Weiler, Olympic Medical

6 seconds EEG display (@ 30 cm/sec)

Courtesy T. Weiler, Olympic Medical

Raw EEG aEEG

Continuous Low

Voltage

Inactive

Seizures

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DeVries L, Toet M, Clin. Perinatol., 2006

Term infant with middle cerebral artery infarct25 wk. infant with Grade 4 IVH

DeVries L, Clin. Perinatol., 2006

Brief description Background Transients

Continuous Always something going on, with or without sleep-wake cycling

Modest voltage (5-10 uV)

Modestly higher than background

Discontinuous Periods of activity interspersed with quiet periods

Low voltage (2-5 uV)

Significantly higher than background

Burst-Suppression Mostly near-silence, with occasional high-voltage bursts

Near-silence (1-3 uV)

High-voltage bursts (25-100 uV)

Continuous Low Voltage

Low-voltage background with little or no spontaneous activity

Near-silence (1-3 uV)

Rare or absent

Inactive No detectable cortical activity Artifact only None

Seizure Rhythmic, stereotypical, high-voltage spikes

NA NA

background

activity

brain injury due

to HIE

postmenstrual age

continuous little or none ~30 weeks, with

hemispheric synchrony at

~34 weeks

discontinuous mild ~24-30 weeks, with

cycling at ~26-28 weeks

burst-

suppression

indeterminate

(mild to severe)

<24 weeks

continuous low

voltage

severe early 2nd trimester?

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� 26 weeks

(Burdjalov, et al)

� With advancing age, the CFM pattern becomes increasingly continuous, with progressive elevation of the minimum electrical amplitude and narrowing of the bandwidth (images on this and following slides from Burdjalov, et al.)

29 weeks PCA

� Cyclic 20 - 30 minute periods of wider amplitude began to emerge after the third week of life, and were recognizable by 30 - 31 weeks post-conceptional age in the healthy pre-term infant

31 weeks PCA

30 weeks

PCA

� In babies with grade III

and grade IV IVH, discontinuity of the tracing, and the

degree of electrical amplitude depression were even more

marked than normal for gestational age

31 weeks PCA, Grade 3 IVH

31 weeks PCA, no IVH

� In all patients with IVH, there was delay in the appearance of maturational changes and emergence of the cyclic pattern of cerebral activity, with persisting discontinuity compared to infants without IVH of comparable developmental age

34 weeks PCA, IVH

33 weeks PCA,

IVH

� Courtesy of Dr. Bob Clancy, CHOP

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HIE Evaluation, Treatment and Prognosis

� Al Naqueeb et al (Pediatrics 1999)

� 56 cases of neonatal encephalopathy

� 21 infants with normal aEEG▪ 19 were normal at 18-24 month follow-

up� 35 infants with abnormal aEEG

▪ 27 died or had neurological abnormalities

� Toet et al (Arch Dis Child Neo Ed 1999)

� 33 infants normal or mildly abnormal aEEG

▪ 30 were normal at follow-up, 1 died, and 2 had global delay

� 35 infants burst-suppression or low voltage

▪ 22 died; 8 major handicaps; 5 normal

� Subsequent studies show that combining aEEG with

exam and imaging provides earlier prognostic

information, with better sensitivity and specificity,

than exam and imaging alone

� Therapeutic hypothermia delays the prognostic

value of aEEG but does not obscure it:

▪ Hallberg, et al (Acta Paediatr 2009): 11 of 12 babies with burst-suppression or seizures at 6 hours of age

who normalized by 48 hours of age had normal 1 year outcomes, but all 4 who still had severe abnormalities at 48 hours of age had poor outcomes

Seizure Detection and Management � Majority of seizures (70% or more) in neonates are

electrographic, without clinical correlates

� Electrographic seizures carry the same prognostic

implications as electroclinical seizures (those with

clinical manifestations)

� Continuous recording detects/documents seizure

frequency better than observation + conventional EEG

alone

� Anticonvulsant therapy can produce electro-clinical

dissociation, obscuring continued seizure activity

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� Continuous EEG is a supplement to

conventional EEG, not a substitute

� No guidance yet on treatment

Developmental Care

� Allows identification of sleep/wake periods, which might improve care practices and provide an additional parameter in research trials

� Normal developmental progression of aEEG by gestational age has been described, which might assist in providing age-appropriate care and in identifying high-risk infants for follow-up

� When would be the

most inopportune times to disturb these infants for

routine care procedures?

31 weeks PCA

30 weeks

PCA

Indication

Potential breadth of

application

Level of supportive

evidence

Diagnosis/prognosis of HIE

Limited High

Seizure detection/monitoring

Moderate Moderate

Developmental Care Broad Limited

� BrainZ (Natus) – BRM2

� Two channels, surface or needle electrodes� Day One – Neurotrac

� Eight channels, surface electrodes� Nervus

� 1-20 channels� Olympic (Natus) – CFM 6000

� One channel, surface or needle electrodes� VIASYS – NicoletOne

� 16 channels, surface electrodes

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� Two-channel recording allows

detection of some

asymmetries

� Single channel

� Surface or needle electrodes (less

prone to artifact)

� Can be covered by a

headband, if desired

� Who should be monitored?

� What seizures to treat?

� Can additional diagnostic/prognostic info be

provided by aEEG in high-risk infants?� Appropriate training/documentation

� Without formal training/certification, the

potential for misadventure is considerable

� Costs/charges/reimbursement

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� Clinical evidence for HIE

� Clinical suspicion of seizures

� Severe apnea

� IVH/ICH� Sarnat stage 2-3

� High-risk infants during paralysis

� Infants requiring ECMO or surgery for CHD

� ELBW infants

� Status epilecticus

� Repetitive, prolonged seizures in a child,

especially when clinical indicators of seizure

activity (e.g., severe apnea) might be

obscured or misinterpreted as “normal”

� If any seizures treated (94% of neonates with seizures in

2007 Bartha survey), then aEEG probably better than clinical evaluation and conventional EEG alone

� If in a given situation you would treat seizures seen on

conventional EEG, it is logical to use same criteria when seizures identified by aEEG, since clinical implications are similar. aEEG should not change your criteria, only your

awareness of which kids meet those criteria� If you could get a reliable conventional EEG at 0200 on a

ventilator + other devices and monitor for hours, aEEG

might not be needed, but since most of us can’t do that...

� ABGs – more info, more accurately, but SaO2 allows

real-time monitoring

� Conventional EEG – more info, more precise, but

continuous EEG allows real-time monitoring

� In a stable baby, monitoring O2 sat for 45 min/day

may be OK, but in a sick infant, it’s inadequate

� If 45 minute EEG gave representative picture of full

24 hr activity, one could use it to base decisions, but

we now know that it often doesn’t

� Use of aEEG has not increased frequency of our

infants who go home on anticonvulsants (much lower

than the 75% found in the Bartha survey)

� Everybody intervenes with some seizures!

� Example – seizure leading to severe apnea,

requiring ventilatory assistance – isn’t it better to know if a seizure was the cause for the apnea?

So, bottom line suggestion is to –

monitor aggressively, treat cautiously

� Continuous EEG monitoring has the potential to make our treatment of neonatal seizures more informed and more rational

� On the other hand, it also has the potential to make our treatment of neonatal seizures more irrational, more invasive, and more expensive

So...monitor aggressively; treat cautiously

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� Preliminary training

� Read the Atlas and Clinics

� Review key references

� Attend pertinent conferences

� Establish contact with mentor(s)

� Attend in-service by manufacturer’s representative

� Early clinical use

� Daily “EEG review” rounds

� Review challenging tracings with mentor

� Attend a formal training course

� Continuing Education

� Regular “journal club”

� Competency checks

� Conferences

� More screening/diagnostic tools – e.g., NIRS,

multiple-array EEG and others?

� New neuroprotective interventions may

require screening devices available 24/7.� Window into the neonatal brain is opening for

real-time evaluation of well-intended but not

always benign interventions – we need better

monitoring tools!

� 7th International Conf. on Neonatal Brain

Monitoring and Neuroprotection, Sep 13-15, 2012, Tampa, FL - www.cme.hsc.usf.edu

� Hellstrom-Westas L, deVries L, Rosen I.

An Atlas of Amplitude-integrated EEGs in the Newborn (2nd ed.)

� Brain Monitoring in the Neonate - Clin Perinatol

Sept. 2006� Neuroprotection in the Newborn - Clin Perinatol

Dec. 2008

� Many seizures have no clinical component, especially in the highest-risk infants

� Video EEG is the gold standard, but is not practical for most clinical situations

� aEEG with real-time EEG is the next best way to monitor high-risk infants

� There is currently no reason to change howyou treat seizures, but it does make sense to change how we have typically diagnosed and followed them in the past

Please feel free to reach me at:

Robert_White@pediatrix.com