Conventional Electroencephalography Research Articles

Developing clinical trials for the diagnosis and treatment of neonatal seizures

Seizures, a common clinical manifestation of neurological dysfunction in the neonate, occur in 1-4 per 1000 live births and are associated with very poor outcomes. However, the role of seizures as merely associative or contributory to poor outcomes remains unclear. Clinical and laboratory studies have demonstrated a deleterious effect of seizures on the developing brain. There is a lack of consensus among the neonatal and neurologic community about how to monitor and treat patients at risk for seizures. Currently used antiepileptic drugs lack efficacy and may potentially cause apoptosis in the developing brain. Continuous conventional electroencephalography with video is the gold standard for detection and monitoring of electrographic seizures but may not be practical in a study design or 24 h widespread clinical use. New drugs such as bumetanide, levetiracetam, and topiramate hold promise as new therapies, but safety, pharmacokinetic, and efficacy data remain limited. In this article, current challenges in designing seizure trials are discussed including potential options to accurately assess the seizure burden, possible antiepileptic drug choices, and potential outcome measures. Ongoing trials in the field of neonatal seizures are also discussed including two separate drug trials and a multicenter trial evaluating the impact of subclinical seizure treatment using limited channel amplitude-integrated electroencephalography.

Detection of electrographic seizures by critical care providers using color density spectral array after cardiac arrest is feasible.

To determine the accuracy and reliability of electroencephalographic seizure detection by critical care providers using color density spectral array electroencephalography. Tutorial and questionnaire. Critical care providers (attending physicians, fellow trainees, and nurses). A standardized powerpoint color density spectral array tutorial followed by classification of 200 color density spectral array images as displaying seizures or not displaying seizures. Using conventional electroencephalography recordings obtained from patients who underwent electroencephalography monitoring after cardiac arrest, we created 100 color density spectral array images, 30% of which displayed seizures. The gold standard for seizure category was electroencephalographer determination from the full montage conventional electroencephalography. Participants did not have access to the conventional electroencephalography tracings. After completing a standardized color density spectral array tutorial, images were presented to participants in duplicate and in random order. Twenty critical care physicians (12 attendings and eight fellows) and 19 critical care nurses classified the color density spectral array images as having any seizure(s) or no seizures. The 39 critical care providers had a color density spectral array seizure detection sensitivity of 70% (95% CI, 67-73%), specificity of 68% (95% CI, 67-70%), positive predictive value of 46%, and negative predictive value of 86%. The sensitivity of color density spectral array detection of status epilepticus was 72% (95% CI, 69-74%). Determining which post-cardiac arrest patients experience electrographic seizures by critical care providers is feasible after a brief training. There is moderate sensitivity for seizure and status epilepticus detection and a high negative predictive value.

Effect of caffeine on preterm infants’ cerebral cortical activity: an observational study

Objective: Our first aim was to investigate the effects of caffeine on preterm infants' respiratory functions and brain cortical activity (conventional and amplitude-integrated electroencephalography (cEEG and aEEG)). Secondary aim was to study its long-term effects on respiratory system and electroencephalographic maturation by 36 weeks post-menstrual age. Methods: Prospective observational study on 33 consecutively admitted preterm infants less than 34-weeks-gestation. cEEG and aEEG, cardiopulmonary and sleep state were recorded in 20 preterm infants, before, during and 2-hours after intravenous (IV) caffeine (caffeine Group), and for 13 preterms (control group). Both groups were subjected to assessment of cerebral cortical maturation by cEEG and aEEG at 36-weeks post-menstrual age as an outcome measure. Results: IV caffeine administration significantly increased heart rate (p = 0.000), mean arterial blood pressure (p = 0.000), capillary oxygen saturation (p = 0.003), arousability (p = 0.000) and aEEG continuity (p = 0.002) after half an hour. No clinical seizures were recorded and non-significant difference was found in electrographic seizures activity in cEEG. At 36-weeks post-conceptional age, NICU stay was significantly longer in controls (p = 0.022). aEEG score was significantly higher in caffeine group than the control group, (p = 0.000). Conclusions: Caffeine increases preterm infants’ cerebral cortical activity during infusion and results in cerebral cortical maturation at 36weeks, without increase in seizure activity.

PS-110 Does Amplitude-integrated Electroencephalography (aeeg) Monitoring Add Diagnostic Value In Asphyxiated Neonates In A Non-nicu Setting?

<h3>Background and aims</h3> Asphyxiated neonates are at risk for developing hypoxic ischaemic encephalopathy and seizures. Although conventional electroencephalography (cEEG) is the standard method to detect subclinical seizures and encephalopathy, aEEG is a validated bedside screening tool used in routine clinical practice in many NICUs. Our Hospital is a non-referral hospital without NICU facilities. Neonates meeting the criteria for therapeutic hypothermia need to be transported to a NICU. The diagnostic value of aEEG monitoring in a non-NICU setting is unknown. We hypothesised aEEG monitoring in a non-NICU setting adds value to diagnostic and therapeutic decision making in asphyxiated neonates. <h3>Methods</h3> A retrospective analysis was performed on all asphyxiated neonates born from January 2011 untill July 2013 in our hospital. Asphyxia was defined as Apgar score ≤5 after 5 min or rescusitation or ventilation from birth for 10 min or pH &lt;7.0 and base deficit &gt;16 mmol/L or lactic acid &gt;10.0 mmol/L. <h3>Results</h3> We evaluated 57 asphyxiated neonates of which 12 neonates were directly intubated and transported to NICU. In 7 out of 45(15,5%) asphyxiated neonates the performed aEEG had diagnostic consequences. Finally, 4 out of 7 neonates (9%) were treated for subclinical seizures (n = 3) or therapeutic hypothermia (n = 1). <h3>Conclusions</h3> aEEG monitoring in a non-NICU setting adds diagnostic and therapeutic value in asphyxiated neonates, especially in the recognition of subclinical seizures.

Comparison of three types of dry electrodes for electroencephalography

A potential new area of routine application for electroencephalography (EEG) is the brain-computer interface, which might enable disabled people to interact with their environment, based on measured brain signals. However, conventional electroencephalography is not suitable here due to limitations arising from complicated, time-consuming and error-prone preparation. Recently, several approaches for dry electrodes have been proposed. Our aim is the comparison and assessment of three types of dry electrodes and standard wet silver/silver-chloride electrodes for EEG signal acquisition. We developed novel EEG electrodes with titanium and polyurethane as base materials, which were coated with nanometer sized titanium-nitride films. Furthermore gold multi-pin electrodes were arranged on printed circuit boards. The results of the comparison of these electrodes with conventional wet silver/silver-chloride electrodes in terms of electrode impedances are presented, as well as open circuit potentials and biosignal measurements. Impedances were significantly higher for all dry electrode types compared to wet electrodes, but still within the measurement range of today’s standard biosignal amplifiers. It was found that the novel dry titanium and polyurethane based electrodes show biosignal quality equivalent to conventional electrodes. In conclusion, the novel dry electrodes seem to be suitable for application in brain-machine interfaces.

Equivalency between emulated disc electrodes and conventional disc electrode human electroencephalography.

We have previously shown that tripolar concentric ring electrode (TCRE) Laplacian electroencephalography (tEEG) has significantly better signal-to-noise ratio, spatial resolution, and mutual information than disc electrode electroencephalography (EEG). This paper compares the EEG signals acquired simultaneously from the outer ring of the TCRE (oTCRE), shorting all three elements of the TCRE (sTCRE) and disc electrode (disc) concurrently from nearly the same location on the human scalp. We calculated the average correlation for the time series between each pair of signals and average coherence over the pass-band frequencies between all pairs of signals as well. All the correlations and coherences were above 0.99. The results suggest that the oTCRE can be used to record EEG concurrently with tEEG from the same sensor at the same location.

The use of amplitude-integrated electroencephalography combined with continuous conventional electroencephalography during therapeutic hypothermia for an infant with postnatal cardiac arrest.

IntroductionAmplitude-integrated electroencephalography (aEEG) has been employed in therapeutic hypothermia (TH) trials of neonates after perinatal hypoxic-ischemic encephalopathy (HIE). We present a case report involving the use of aEEG during TH with continuous conventional electroencephalography (cEEG) for an infant who experienced postnatal intraoperative cardiac arrest.Case descriptionA five-month-old infant developed cardiac arrest during operation. Return of spontaneous circulation was achieved after one hour of cardiopulmonary resuscitation. Therapeutic hypothermia was applied with neuromuscular blockades. During the TH, the brain function and seizures were monitored with aEEG, which can also display continuous cEEG. Intermittent and discrete seizures were detected on aEEG and confirmed with raw cEEG during the TH and rewarming periods. Several kinds of antiepileptic drugs (AEDs) were administered to manage seizures according to the findings of aEEG with cEEG. Seizures were controlled by the treatments, and she showed no clinical seizures after TH and AED discontinuation.Discussion and evaluation, conclusionsThis case indicated the possibility that the use of aEEG with continuous cEEG for a postnatal infant after cardiac arrest was feasible to detect and assess seizures and the effects of antiepileptic therapy while undergoing TH.

Simultaneous Recording of Single-Neuron Activities and Broad-Area Intracranial Electroencephalography

There has been growing interest in clinical single-neuron recording to better understand epileptogenicity and brain function. It is crucial to compare this new information, single-neuronal activity, with that obtained from conventional intracranial electroencephalography during simultaneous recording. However, it is difficult to implant microwires and subdural electrodes during a single surgical operation because the stereotactic frame hampers flexible craniotomy. To describe newly designed electrodes and surgical techniques for implanting them with subdural electrodes that enable simultaneous recording from hippocampal neurons and broad areas of the cortical surface. We designed a depth electrode that does not protrude into the dura and pulsates naturally with the brain. The length and tract of the depth electrode were determined preoperatively between the lateral subiculum and the lateral surface of the temporal lobe. A frameless navigation system was used to insert the depth electrode. Surface grids and ventral strips were placed before and after the insertion of the depth electrodes, respectively. Finally, a microwire bundle was inserted into the lumen of the depth electrode. We evaluated the precision of implantation, the recording stability, and the recording rate with microwire electrodes. Depth-microwire electrodes were placed with a precision of 3.6 mm. The mean successful recording rate of single- or multiple-unit activity was 14.8%, which was maintained throughout the entire recording period. We achieved simultaneous implantation of microwires, depth electrodes, and broad-area subdural electrodes. Our method enabled simultaneous and stable recording of hippocampal single-neuron activities and multichannel intracranial electroencephalography.

Epidemiology of uncontrolled epilepsy in the Al-Kharga District, New Valley, Egypt

BackgroundDespite advances in treating epilepsy, uncontrolled epilepsy continues to be a major clinical problem. Therefore, this work aimed to study the epidemiology of uncontrolled epilepsy in Al-Kharga District, New Valley. MethodsThis study was carried out in 3 stages via door-to-door screening of the total population (62,583 persons). All suspected cases of epilepsy were subjected to case ascertainment, conventional ElectroEncephaloGraphy (EEG), and the Stanford-Binet Intelligence Scale. Patients who had been receiving suitable anti-epileptic drugs (AEDs) over the previous 6 months and were having active seizures were considered uncontrolled, according to Ohtsuka et al.23 The patients underwent serum AED level estimation, video EEG monitoring, and brain MRIs. Fifty age- and gender-matched patients with controlled epilepsy were chosen for statistical analysis and compared with true intractable patients. ResultsA total of 437 patients with epilepsy were identified, 30.7% of whom (n=134/437) were uncontrolled, with a prevalence of 2.1/1000. A total of 52.2% of uncontrolled patients (n=70/134) were inappropriately treated, while 47.8% (n=64/134) were compliant with appropriate treatments. Video monitoring EEG of compliant uncontrolled patients demonstrated that 78.1% patients (n=50/64) had definite epilepsy, while 21.9% (n=14/64) had psychogenic non-epileptic seizures (PNES). A logistic regression analysis revealed that status epilepticus, focal seizures, and mixed seizure types were risk factors for intractability.

The American Clinical Neurophysiology Society's Guideline on Continuous Electroencephalography Monitoring in Neonates

This article offers the preferred methods and indications for longterm, conventional electroencephalography (EEG) monitoring for selected, high-risk neonates of postmenstrual age less than 48 weeks. The authors recognize that there may be significant practical barriers to the implementation of these recommendations for many caregivers and institutions, particularly with regard to the availability of equipment, and technical and interpretive personnel. A wide range of clinical circumstances dictates the implementation of EEG monitoring, frequency of EEG review, and the subsequent treatment of seizures or EEG background abnormalities detected by neonatal EEG. Consequently, this article should be considered as an expression of idealized goals and not as a mandated standard of care.

Amplitude-Integrated Electroencephalography in Neonates

Conventional electroencephalography (EEG) has been used for decades in the neonatal intensive care unit for formulating neurologic prognoses, demonstrating brain functional state and degree of maturation, revealing cerebral lesions, and identifying the presence and number of electrographic seizures. However, both the immediate availability of conventional EEG and the expertise with which it is interpreted are variable. Amplitude-integrated EEG provides simplified monitoring of cerebral function, and is rapidly gaining popularity among neonatologists, with growing use in bedside decision making and inclusion criteria for randomized clinical studies. Nonetheless, child neurologists and neurophysiologists remain cautious about relying solely on this tool and prefer interpreting conventional EEG. The present review examines the technical aspects of generating, recording, and interpreting amplitude-integrated EEG and contrasts this approach with conventional EEG. Finally, several proposed amplitude-integrated EEG classification schemes are reviewed. A clear understanding of this emerging technology of measuring brain health in the premature or sick neonate is critical in modern care of the newborn infant.

The value of video-EEG monitoring to diagnose juvenile myoclonic epilepsy

Objective A diagnostic accuracy of conventional electroencephalography (EEG) is approximately 50% at best. We aimed to determine the accuracy of video-EEG monitoring (VEM) for a correct diagnosis and the feasibility of its clinical application. The data from all 55 patients (M:F = 31:24) with juvenile myoclonic epilepsy (JME) who underwent VEM were reviewed according to the clinical history, brain imaging and video-EEG findings. Results Age at seizure onset ranged from 10 to 25 (15.5 ± 2.7 years). The age at VEM ranged from 15 to 46 (21.8 ± 5.8 years) and 57% (29/51) showed seizures. Of those, 20 patients (69%) showed myoclonic jerks alone, whereas 3 (10%) showed generalized seizures alone. Both of these conditions were observed in 6 patients (21%). Interictal abnormalities alone without clinical seizures were detected in 16 patients (31%). Atypical semiologies such as asymmetric myoclonus or versive seizures were observed in 18 patients (35%) during video monitoring. Interestingly three patients complained of visual aura on history. The duration of VEM ranged from 1 to 6 days (1.8 ± 1.1). Overall, 88% of patients showed an EEG abnormality with/without seizure, concordant with JME. Among 10 patients with a normal conventional EEG before VEM, 9 showed interictal or ictal EEG abnormalities during approximately 1-day of VEM. Conclusions VEM for 1 or 2 days is appropriate for making a correct diagnosis of JME, especially in patients having an atypical semiology and a normal result on the conventional EEG.

Accuracy of Bedside Electroencephalographic Monitoring in Comparison With Simultaneous Continuous Conventional Electroencephalography for Seizure Detection in Term Infants

Our goals were to compare (1) single-channel amplitude-integrated electroencephalography alone, (2) 2-channel amplitude-integrated electroencephalography alone, and (3) amplitude-integrated electroencephalography plus 2-channel electroencephalography with simultaneous continuous conventional electroencephalography for seizure detection in term infants to check the accuracy of limited channels and compare the different modalities of bedside electroencephalography monitoring. Infants referred to a tertiary center with clinical seizures underwent simultaneous continuous conventional electroencephalography and 2-channel (C3-P3 and C4-P4) bedside monitoring. Off-line analysis of the continuous conventional electroencephalographic results was performed independently by 2 neurologists. Two experienced neonatal readers reviewed results obtained with amplitude-integrated electroencephalography and 2-channel electroencephalography combined and single-channel and 2-channel amplitude-integrated electroencephalography. All readings were performed independently and then compared. Twenty-one term newborns were monitored. Seizures were detected in 7 patients who had up to 12 electrical seizures, with 1 infant in status epilepticus. Seizures were identified correctly in 6 of 7 patients with amplitude-integrated electroencephalography plus 2-channel electroencephalography. The missed infant had an isolated 12-second seizure. With amplitude-integrated electroencephalography plus 2-channel electroencephalography, 31 of 41 non-status epilepticus seizures were correctly identified (sensitivity, 76%; specificity, 78%; positive predictive value, 78%; negative predictive value, 78%), with a substantial level of interrater agreement. The seizures missed were predominantly slow sharp waves of occipital origin from a single patient (7 of 10 seizures). Nine false-positive results were obtained in 351 hours of recording (1 false-positive result per 39 hours). These were thought to be related to muscle, electrode, and patting artifacts. Use of amplitude-integrated electroencephalography alone (1 or 2 channel) provided low sensitivity (27%-56%) and low interobserver agreement. Limited-channel bedside electroencephalography combining amplitude-integrated electroencephalography with 2-channel electroencephalography, interpreted by experienced neonatal readers, detected the majority of electrical seizures in at-risk newborn infants.

Assessment of Neonatal Electroencephalography (EEG) Background by Conventional and Two Amplitude-Integrated EEG Classification Systems

To determine the agreement among conventional electroencephalography (CEEG) terminology background classification and a simple and an advanced amplitude-integrated EEG (aEEG) system, and to evaluate whether aEEG interpreter experience or electrographic seizures affect this agreement. CEEG background was classified by traditional interpretive criteria for 144 neonatal recordings, from which a single channel was converted to aEEGs. These aEEGs were independently interpreted by neonatologists according to the simple and advanced classification systems. Interreader agreement was better with the simple aEEG system compared with the advanced aEEG system (multirater kappa, 0.66 vs 0.44). Fair-to-moderate agreement was found between both of the aEEG classification systems and CEEG (simple: kappa, 0.34 to 0.45; advanced: kappa, 0.36 to 0.45). Agreement did not vary significantly based on the aEEG interpreter experience or the presence of seizures. Neonatologists found better agreement using the simple aEEG system regardless of their expertise or the presence of seizures. This finding has implications for patient selection in future multicenter neonatal neuroprotection studies.

Benign Rolandic Epilepsy—Perhaps Not So Benign: Use of Magnetic Source Imaging as a Predictor of Outcome

The purpose of this study was to evaluate children with benign rolandic epilepsy, a childhood epilepsy characterized by centrotemporal/rolandic spike-wave discharges with infrequent partial seizures that may secondarily generalize. Recently, some investigators have questioned whether benign rolandic epilepsy is indeed "benign" or whether long-term cognitive outcome may be adversely affected. We initiated an ongoing study to identify children with benign rolandic epilepsy. The children were evaluated in the Texas Comprehensive Epilepsy Program using outpatient or continuous video-electroencephalographic monitoring, brain magnetic resonance imaging, magnetoencephalography, and neuropsychological testing. Neuropsychological testing revealed fine motor dysfunction, visuomotor integration deficits, dyscalculia, and/or expressive language deficits in all of the 9 patients evaluated, reaffirming that benign rolandic epilepsy is not necessarily a benign disorder. Our study shows a high concordance of motor and cognitive deficits in benign rolandic epilepsy, as others have previously suggested. Furthermore, magnetic source imaging shows a higher resolution of dipole localization compared with conventional electroencephalography, which may ultimately improve prediction of deficits. This reaffirms that magnetoencephalography is a valuable diagnostic tool in the evaluation of children with benign rolandic epilepsy.

Sensitivity of Amplitude-Integrated Electroencephalography for Neonatal Seizure Detection

Conventional electroencephalography remains the gold standard for the diagnosis and quantification of neonatal seizures. However, amplitude-integrated electroencephalography (aEEG) is being introduced to neonatal intensive care as an adjunct for neonatal seizure detection. This study's purpose was to determine the sensitivity of neonatal seizure detection in a single electroencephalogram channel (C3-->C4), used to simulate the raw signal from which aEEG is derived. We also aimed to determine the sensitivity of seizure detection by neonatologists by using aEEG and to establish those neonatal seizure characteristics that are associated with their correct detection by aEEG. Conventional electroencephalograms with neonatal seizures were reviewed for electroencephalogram background and neonatal seizure characteristics (site of onset, duration, and peak-to-peak amplitude). The presence, duration, and peak-to-peak amplitude of each seizure were simultaneously noted in a single electroencephalogram channel (C3-->C4). aEEGs generated from this channel were reviewed for background and seizures by 6 neonatologists with varying aEEG interpretation expertise. A total of 851 neonatal seizures from 125 conventional electroencephalograms were analyzed. The patients' conceptional ages were 34 to 50 weeks. Because 94% of the conventional electroencephalograms had > or = 1 neonatal seizure visible in C3-->C4, and 78% of all neonatal seizures appeared in the C3-->C4 channel, the theoretical sensitivity of seizure detection in a single electroencephalogram channel was high. However, seizures were briefer and lower in amplitude in C3-->C4 compared with conventional electroencephalography. Neonatologists identified seizures in 22% to 57% of the 125 records of neonatal seizure. They detected 12% to 38% of the 851 individual seizures. Multivariate analysis revealed that the appearance of seizures in C3-->C4, neonatal seizure duration, seizure amplitude, seizure count per hour, and neonatologists' experience with aEEG interpretation all correlated with neonatal seizure detection. Even among physicians who have extensive experience, many neonatal seizures are difficult to detect on an aEEG, especially when they are infrequent, brief, or of low amplitude.

Measuring depth of sedation in intensive care patients with the electroencephalographic Narcotrend Index

The electroencephalographic Narcotrend Index was evaluated as a measure of sedation in mechanically ventilated intensive care unit patients. Narcotrend Index and conventional electroencephalography parameter values were compared to the Richmond Agitation-Sedation Scale and a simplified three-level sedation scale. In all, 100 mechanically ventilated patients, admitted to the cardiac surgical intensive care unit after open-heart surgery, were enrolled in this prospective observational study. The Narcotrend Index was recorded while patients were either sedated by propofol infusion or without sedative medication while being weaned off the ventilator. Clinical assessment of the patients' level of sedation was performed by means of the Richmond Agitation-Sedation Scale by a single observer who was blinded to the Narcotrend Index. With the six-level Richmond Agitation-Sedation Scale, the prediction probability (PK) for the Narcotrend Index (0.81) was better than for all other electroencephalography parameters (P < 0.01) except for relative power in the beta band (PK 0.75). Using the three-level sedation scale instead, PK values for the Narcotrend Index (0.88) and all electroencephalography parameters improved (P < 0.01), and the Narcotrend Index was now superior to all electroencephalography parameters. Narcotrend Index values were distributed among the various sedation levels with significant overlap. When used for assessment of propofol sedation in postsurgical cardiac intensive care unit patients, the Narcotrend Index can distinguish between very light and deep sedation. With respect to differentiation between light and moderate or moderate and deep sedation, the Narcotrend Index was not reliable in this study.

Management of a severe forceful breather with Rett Syndrome using carbogen

We have used a novel neurophysiological technique in the NeuroScope system in combination with conventional electroencephalography (EEG) to monitor both brainstem and cortical activity simultaneously in real-time in a girl with Rett syndrome. The presenting clinical features in our patient were severe sleep disturbances, irregular breathing in the awake state dominated by Valsalva’s type of breathing followed by tachypnoea and very frequent attacks of seizures and vacant spells. Our novel neurophysiological data showed that the patient was a Forceful Breather according to the breathing categories in Rett syndrome. She had frequent abnormal spontaneous brainstem activation (ASBA) preceded by severe attacks of hypocapnoea, which was caused by a combination of Valsalva’s type of breathing and tachypnoea and all these together were responsible for the seizures and non-epileptic vacant spells. The ASBA was not detectable in conventional EEG and there were no epileptiform changes in the EEG during the seizures and vacant spells caused by the hypocapnic attacks, therefore these were pseudo-seizures. The record of brainstem activity confirmed that these were autonomic events, a kind of “brainstem epilepsy”. We successfully treated the sleep disturbance with Pipamperone, a 5-hydroxytryptophan antagonist of receptor type 2 and we prevented the severe hypocapnoea during Valsalva’s type of breathing and during tachypnoea using carbogen (a mixture of 5% carbon dioxide and 95% oxygen), which we gave by inhalation. Our treatment drastically reduced the autonomic events, promoted whole night sleep and significantly improved the quality of life in our patient. She can now participate in normal family activity which was previously impossible before treatment.

PREDICTION OF OUTCOME IN PRETERM INFANTS USING COTSIDE TWO-CHANNEL EEG MONITORING

Objectives: Conventional electroencephalography (EEG) may help predict outcome in preterm infants but is not always accessible. The aim of this study was to assess the value of two-channel cotside EEG to predict long-term outcome in preterm infants, comparing specialist interpretation and quantitative analysis.

414 Comparison of Quantitative Measures and Neurophysiologist Assessment Using Cotside EEG Monitors to Predict Outcome in Preterm Infants

Background Conventional electroencephalography (EEG) may help predict outcome in preterm infants, but requires specialist interpretation. Some cotside EEG devices provide quantitative analyses assisting non-specialists with interpretation.Aim to compare quantitative measures of continuity with interpretation by a neurophysiologist using early cotside EEG recordings to predict outcome of preterm infants.Methods in infants <32 weeks gestation 60 minute epochs of EEG recorded using research BRM cotside monitors (BrainZ Instruments Ltd, Auckland, New Zealand) were analysed for continuity (percentage of each minute with EEG amplitude >10μV) and categorised as normal (100%, 62% of cohort), moderate (80–99%) or low (<80%, lowest 10% of cohort). The same portion of EEG was graded by a neurophysiologist, blinded to infant outcome, as 'normal' or 'abnormal' using interburst interval and seizure activity. Surviving infants had Bayley-II examinations at 18 months. Outcome was 'poor' if the infant died or had a Mental or Psychomotor Developmental Index (MDI/PDI) <70, 'moderate' if MDI or PDI=70–84, and 'normal' if MDI and PDI>=85.Results Analyses were performed for 29 infants with median (range) gestation at delivery 26(24–31)weeks, birthweight 910(605–1250)grams and postnatal age at EEG 22(2–53)hours. Outcomes were 'poor' in 7 (3 died, 4 had PDI<70), 'moderate' in 8 and 'normal' in 14. Three infants with low continuity had 'poor' outcome. Moderate continuity was found in 2/7 infants with 'poor' outcome, 3/8 infants with 'moderate' outcome and 5/14 with 'normal' outcome. The remainder had normal continuity (Cramer's V=0.43, Chi-squared p=0.03). The neurophysiologist graded traces as abnormal in 6/7 infants with 'poor' outcome, 1/8 with 'moderate' and 0/14 with 'normal' outcome (Cramer's V=0.82, Chi-squared p<0.0001). Categorisation by continuity measures and neurophysiologist assessment were dissimilar, Chi-squared p=0.19.Conclusion Both techniques offer some potential, but continuity measures performed less well than neurophysiologist interpretation in predicting outcome from early cotside EEG recordings. MB is a consultant for BrainZ Instruments Ltd.