05/14/2012. I have been a paid speaker for Natus

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1 I have been a paid speaker for Natus Robert White, MD Medical Director, Pediatrix Medical Group Memorial Hospital, South Bend, IN 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 1

2 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 Courtesy T. Weiler, Olympic Medical 2

3 Term infant with middle cerebral artery infarct DeVries L, Toet M, Clin. Perinatol., 2006 DeVries L, Clin. Perinatol., wk. infant with Grade 4 IVH Continuous Discontinuous Burst-Suppression Continuous Low Voltage Brief description Background Transients Always something going on, with or without sleep-wake cycling Periods of activity interspersed with quiet periods Mostly near-silence, with occasional high-voltage bursts Low-voltage background with little or no spontaneous activity Modest voltage (5-10 uv) Low voltage (2-5 uv) Near-silence (1-3 uv) Near-silence (1-3 uv) Modestly higher than background Significantly higher than background High-voltage bursts ( uv) Rare or absent Inactive No detectable cortical activity Artifact only None Seizure Rhythmic, stereotypical, highvoltage 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 burstsuppression continuous low voltage indeterminate (mild to severe) severe <24 weeks early 2nd trimester? 3

4 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 minute periods of wider amplitude began to emerge after the third week of life, and were recognizable by weeks postconceptional age in the healthy pre-term infant 30 weeks PCA 31 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 33 weeks PCA, IVH 34 weeks PCA, IVH Courtesy of Dr. Bob Clancy, CHOP 4

5 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 month followup 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 5

6 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 ageappropriate 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? 30 weeks PCA 31 weeks PCA Indication Diagnosis/prognosis of HIE Seizure detection/monitoring Potential breadth of application Limited Moderate Level of supportive evidence High 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 6

7 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 7

8 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 anyseizures 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 8

9 Preliminary training Read the Atlasand 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 - 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 Neuroprotection in the Newborn - Clin Perinatol Dec 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 how you treatseizures, but it does make sense to change how we have typically diagnosed and followedthem in the past Please feel free to reach me at: Robert_White@pediatrix.com 9