Use Of aEEG Research Articles

Impact of ambulatory EEG in the management of patients with epilepsy in resource-limited Latin American populations

ObjectiveAmbulatory electroencephalography (AEEG) monitoring allows for prolonged recordings in normal environments, such as patients’ homes, and is recognized as a cost-effective alternative to inpatient long-term video-EEG primarily in resource-limited countries. We aim to describe the impact of AEEG on the assessment of patients with suspected or confirmed epilepsy in two independent Latin-American populations with limited resources. MethodsWe included 63 patients who had undergone an AEEG due to confirmed/suspected epilepsy. Clinical (demographic, current antiseizure medication and indication) and electroencephalographic (duration of the study, result, and impact on clinical decision-making) were reviewed and compared. ResultsThe main indication for an AEEG was the differentiation of seizures from non-epileptic events with 57% of patients. It was categorized as positive in 36 patients and did have an impact on the clinical decision-making process in 57% of patients. AEEG captured clinical events in 35 patients (20 epileptic and 15 non-epileptic). ConclusionsAEEG proves to be a valuable tool in resource-limited settings for assessing suspected or confirmed epilepsy cases, with a significant impact on clinical decisions. SignificanceOur study provides valuable insights into the use of AEEG in under-resourced regions, shedding light on the challenges and potential benefits of this tool in clinical practice.

Neuromonitoring in neonatal critical care part II: extremely premature infants and critically ill neonates.

Neonatal intensive care has expanded from cardiorespiratory care to a holistic approach emphasizing brain health. To best understand and monitor brain function and physiology in the neonatal intensive care unit (NICU), the most commonly used tools are amplitude-integrated EEG, full multichannel continuous EEG, and near-infrared spectroscopy. Each of these modalities has unique characteristics and functions. While some of these tools have been the subject of expert consensus statements or guidelines, there is no overarching agreement on the optimal approach to neuromonitoring in the NICU. This work reviews current evidence to assist decision making for the best utilization of these neuromonitoring tools to promote neuroprotective care in extremely premature infants and in critically ill neonates. Neuromonitoring approaches in neonatal encephalopathy and neonates with possible seizures are discussed separately in the companion paper. IMPACT: For extremely premature infants, NIRS monitoring has a potential role in individualized brain-oriented care, and selective use of aEEG and cEEG can assist in seizure detection and prognostication. For critically ill neonates, NIRS can monitor cerebral perfusion, oxygen delivery, and extraction associated with disease processes as well as respiratory and hypodynamic management. Selective use of aEEG and cEEG is important in those with a high risk of seizures and brain injury. Continuous multimodal monitoring as well as monitoring of sleep, sleep-wake cycling, and autonomic nervous system have a promising role in neonatal neurocritical care.

EEG monitoring during anesthesia in children aged 0 to 18\u2009months: amplitude-integrated EEG and age effects

BackgroundThe amplitude-integrated EEG (aEEG) is a widely used monitoring tool in neonatology / pediatric intensive care. It takes into account the amplitudes, but not the frequency composition, of the EEG. Advantages of the aEEG are clear criteria for interpretation and time compression. During the first year of life, the electroencephalogram (EEG) during sedation / anesthesia changes from a low-differentiated to a differentiated EEG; higher-frequency waves develop increasingly. There are few studies on the use of aEEG during pediatric anesthesia. A systematic evaluation of the aEEG in defined EEG stages during anesthesia / sedation is not yet available. Parameters of pediatric EEGs (power, median frequency, spectral edge frequency) recorded during anesthesia and of the corresponding aEEGs (upper and lower value of the aEEG trace) should be examined for age-related changes. Furthermore, it should be examined whether the aEEG can distinguish EEG stages of sedation / anesthesia in differentiated EEGs.MethodsIn a secondary analysis of a prospective observational study EEGs and aEEGs (1-channel recordings, electrode positions on forehead) of 50 children (age: 0–18 months) were evaluated. EEG stages: A (awake), Slow EEG, E2, F0, and F1 in low-differentiated EEGs and A (awake), B0–2, C0–2, D0–2, E0–2, F0–1 in differentiated EEGs.ResultsMedian and spectral edge frequency increased significantly with age (p < 0.001 each). In low-differentiated EEGs, the power of the Slow EEG increased significantly with age (p < 0.001). In differentiated EEGs, the power increased significantly with age in each of the EEG stages B1 to E1 (p = 0.04, or less), and the upper and lower values of the aEEG trace increased with age (p < 0.001). A discriminant analysis using the upper and lower values of the aEEG showed that EEG epochs from the stages B1 to E1 were assigned to the original EEG stage in only 19.3% of the cases. When age was added as the third variable, the rate of correct reclassifications was 28.5%.ConclusionsThe aEEG was not suitable for distinguishing EEG stages above the burst suppression range. For this purpose, the frequency composition of the EEG should be taken into account.

Improving Consistency and Accuracy of Neonatal Amplitude-Integrated Electroencephalography.

This study aimed to improve the utilization of amplitude-integrated electroencephalography (aEEG) in a neonatal unit by improving aEEG documentation, aEEG knowledge, and pattern recognition ability of neonatal staff. A quality improvement (QI) program comprising the two Plan-Do-Study-Act (PDSA) cycles was conducted in a level-3 neonatal intensive care unit. The first cycle was focused on improving aEEG documentation with the primary outcome indicator being compliance with aEEG documentation. The second cycle was focused on aEEG interpretation in a health care professional education program with the outcome indicators being accuracy of seizure identification on aEEG and change in conventional EEGs (cEEG) performed. Other outcome indicators included accuracy in identification of background pattern, sleep-wake cycles and artifacts. Process indicators included improvement in aEEG-related knowledge. First PDSA cycle includes lectures on aEEG interpretation, a bedside key, and documentation form. Second PDSA cycle includes online aEEG education pack and detailed aEEG guideline. There was a significant improvement in aEEG documentation after the implementation of both PDSA cycles. Seven of the 46 patients (15.2%) had isolated electrographic seizures which would not have been identified in the pre-aEEG monitoring era. There was an increase in the number of patients with cEEGs done but a steady decrease in number of cEEGs per patient. With the successful application of standardized QI methods, improvements in outcome indicators, such as correct aEEG pattern recognition and improved coverage of at risk infants with cEEGs, were observed. Our QI measures were associated with improvement in aEEG pattern recognition. · Consistent and accurate use of aEEG is challenging.. · Standardized forms and guidelines improve aEEG interpretation consistency and documentation.. · Interactive self-paced online education packs can improve aEEG knowledge and pattern recognition..

Amplitude-integrated electroencephalography signals in preterm infants with cerebral hemorrhage

ObjectiveTo evaluate whether preterm infants with cerebral hemorrhage show alterations of aEEG signals in the first four weeks of life. Study designPreterm infants (n = 536) born before 32 completed weeks of pregnancy at Innsbruck Medical University Hospital were included in the study. AEEG recordings were evaluated for the Burdjalov score and cerebral hemorrhage was diagnosed by cerebral ultrasound. ResultsEighty preterm infants with cerebral hemorrhage (median gestational age 28.9 weeks, median birth weight 1157 g) and 456 preterm infants without cerebral hemorrhage (median gestational age 30.0 weeks, median birth weight 1300 g) were investigated. Burdjalov total scores were significantly lower in infants with cerebral hemorrhage. Infants with mild cerebral hemorrhage showed higher Burdjalov total scores compared to infants with severe cerebral hemorrhage in the first days of life. A Burdjalov total score of seven or more was predictive for no development of a cerebral hemorrhage, with a highest area under the curve (0.613) at postnatal day three. ConclusionPreterm infants with cerebral hemorrhage show alterations in aEEG signals in the newborn period. In future aEEG could be used as a supplemental method to monitor preterm infants at risk for cerebral hemorrhage. The use of aEEG in early life could reduce the number of ultrasound examinations and limit cumulative stress and discomfort in preterm infants.

AEEG as a useful tool for neuromonitoring in critically ill children – Current evidence and knowledge gaps

Amplitude-integrated electroencephalography (aEEG) is used in children beyond neonatal age, but systematic investigations have been lacking. This mini-review summarised aEEG studies on children aged one month to 18years, evaluated the usefulness of aEEG and identified knowledge gaps or limitations. We searched the PubMed database for articles published in English up to September 2020, and 23 papers were identified. aEEG was frequently used to compensate for the absence of continuous full-channel EEG monitoring, particularly for detecting seizures. Interpreting background patterns was based on neonatal classifications, as reference values for older infants and children are lacking. It is possible that aEEG could predict outcomes after paediatric cardiac arrests and other conditions. Gaps in our knowledge exist with regard to normal values in healthy children and the effects of sedation on aEEG background patterns in children. The main application of aEEG was detecting and treating paediatric seizures. Further research should determine reference values and investigate the potential to predict outcome after critical events or in acute neurological disease. It is likely that aEEG will play a role in paediatric critical care in the future.

Inter-rater reliability of amplitude-integrated EEG for the detection of neonatal seizures

BackgroundAmplitude-integrated electroencephalogram (aEEG) is being used increasingly for seizure detection in neonates. However, data regarding inter-rater reliability among neonatologists for the use of aEEG for the detection of neonatal seizures is lacking. MethodsTerm and late-preterm infants at risk of seizures were monitored simultaneously with 24-h video-electroencephalography (vEEG) and aEEG. vEEG was interpreted by an experienced neurologist. Five neonatologists with experience in aEEG interpretation from four different neonatal units interpreted aEEG recordings independently. The Brennan and Prediger kappa coefficient and Intra-class Correlation Coefficients (ICC) were used to assess inter-rater reliability between the neonatologists. ResultsThirty-five infants at risk of seizure with gestational age at birth 35–42 weeks were recruited for the study after informed parental consent. vEEG detected seizures in seven infants with a total of 169 individual seizure episodes. Neonatologists detected seizures in 10 to 15 infants on aEEG. The sensitivities for the detection of individual seizures by neonatologists ranged from 18% to 38%. The inter-rater reliability for detection of: individual seizure was “fair” (kappa = 0.37; 95% CI: 0.32–0.42), infant with seizure was “moderate” (kappa = 0.60; 95% CI: 0.44–0.75), duration of individual seizure (ICC: 0.22; 95% CI: 0.18–0.28) and total duration of seizures in an infant (ICC: 0.46; 95% CI: 0.30–0.63) was “poor”. The neonatologists missed 77–90% of the duration of seizures. ConclusionThe inter-rater reliability of aEEG for the detection of neonatal seizures was suboptimal. Even when interpreted by experienced and trained clinicians, seizure detection with aEEG has limitations and can miss large number and duration of seizures.

Implementation of amplitude-integrated electroencephalography in tertiary Canadian Neonatal Intensive Care Units—a longitudinal study

To investigate the implementation of amplitude-integrated electroencephalography (aEEG) as bedside monitoring tool of cerebral function in tertiary Canadian Neonatal Intensive Care Units (NICU) over the past decade. Longitudinal study consisting of online surveys of neonatologists on the use of aEEG in 2009 and 2018. The response rate to the survey was 72 of 149 (49%) in 2009 and 18 of 30 (60%) in 2018, respectively. aEEG has been implemented in almost all (2009: 62.5%; 2018: 94%) tertiary Canadian NICUs. Two-thirds (2009: 67%; 2018: 71%) of the respondents considered information from aEEG tracing helpful in clinical practice. The main indications for aEEG were term neonates with hypoxic ischemic encephalopathy (2009 and 2018: 76%) and seizure detection/surveillance (2009: 88%; 2018: 94%). Teaching on aEEG has been implemented for neonatologists (2018: 100%) and health care providers (2018: 50%) in tertiary Canadian NICUs but there is a lack of standardization of training. Use of aEEG in preterm neonates (2009: 37%, 2018: 33%) and application of aEEG in research (18% reported occasional use) is less common. aEEG is well established in tertiary Canadian NICUs to monitor cerebral function and detect seizure activity. There is a need to develop formalized aEEG training programs and methods to assess competence. Further implementation of aEEG in preterm neonates and research is desirable.

Amplitude-Integrated Electroencephalography and Brain Oxygenation for Postcardiac Arrest Patients with Targeted Temperature Management.

Brain injury is the most common cause of death postcardiac arrest. Amplitude-integrated electroencephalography (aEEG) is suggested to be useful in the prognostication in cases of postcardiac arrest brain injury. However, combined monitoring with aEEG and regional oxygen saturation (rSO2) for postcardiac arrest syndrome (PCAS) patients to improve accuracy has not been reported. The purpose of this prospective observational study is to assess the usefulness of aEEG and rSO2 for PCAS patients with targeted temperature management (TTM) to predict neurological outcome and possibly identify the pathophysiology of postcardiac arrest brain injury. PCAS patients with TTM at 34°C were monitored by aEEG and rSO2 immediately after admission to the intensive care unit and evaluated at the start of monitoring, and 24 and 48 hours after return of spontaneous circulation (ROSC). Patients were divided into two groups according to electroencephalography (EEG) pattern: a continuous EEG (C) pattern group and a noncontinuous EEG (NC) pattern group. Patients with C pattern had a significantly more favorable neurologic outcome compared with patients with an NC pattern at each point in time. No significant difference in rSO2 values was observed between the C pattern and the NC pattern at any time point. Variation coefficient at rSO2 in the NC group was significantly greater than that in the C group from the start of the monitoring to 24 hours. aEEG is useful in predicting outcome for PCAS patients whereas rSO2 is not.

Amplitude-Integrated EEG for Neurological Assessment and Seizure Detection in a German Pediatric Intensive Care Unit.

Objective: The aim of our study was to assess the use of aEEG in our pediatric intensive care unit (PICU), indications for neuromonitoring and its findings, utility for seizure detection, and associations with outcome.Design: We retrospectively analyzed non-neonates who were treated in our PICU and received amplitude-integrated EEG (aEEG).Patients: 27 patients aged between 29 days and 10 0/12 years (median 7.3 months) were included, who received a total of 35 aEEGS.Measurements: aEEG tracings were assessed for background (BG) pattern and its evolution, seizures, and side differences using a visual classification (Hellström-Westas). Clinical data were collected from patients' histories and analyzed for correlation with aEEG findings.Main results: While rare in early years, there was an increase in use over time. Most aEEGs were conducted because of (suspected) seizures or for management of antiepileptic treatment. aEEG had low sensitivity but high specificity for recognition of pathological BG pattern with reference to conventional EEG. Worsening of BG pattern or failure to improve was associated with death. Seizure detection rates by aEEG were higher than by clinical observation, especially for identification of non-convulsive epileptic state (ES). Side differences in aEEG were rare, but if present, they were associated with unilateral brain injury.Conclusions: aEEG is useful for the detection of seizures and ES in pediatric intensive care patients. Abnormal BG pattern and poor evolution of BG are negatively associated with survival. aEEG is a potential supplement to conventional EEG, facilitating long-term surveillance of cerebral function when continuous full-channel EEG is not available. Further investigation is needed.

Chapter 10 - Ambulatory EEG

Ambulatory electroencephalography (aEEG) is a technique of continuous EEG recording while ensuring maximum mobility of the patient in a more naturalistic setting. The initial technological drawbacks of aEEG have been circumvented by incorporating digital and computer technology. Some of the current devices provide the facility of synchronous video recording. Low cost, convenience, higher diagnostic yield, and the ability to capture circadian patterns are the main advantages of aEEG. It is a useful tool in the diagnosis of epilepsy and nonepileptic paroxysmal disorders. Ambulatory EEG is superior to routine EEG in capturing interictal epileptiform abnormalities particularly in relation to natural sleep. However, the use of aEEG in presurgical workup is still unclear and more research is needed. At present, the place of EEG in the decision making for antiepileptic drug withdrawal is unclear and aEEG is an ideal tool to study this research question. Well-designed studies are needed to evaluate the use of aEEG in the assessment of response to antiepileptic therapy and occupational safety. Ambulatory EEG is an underutilized tool and more research is needed to expand the horizon of its applications in clinical practice.

The Role of Amplitude Integrated Electroencephalogram in Very Low-Birth-Weight Preterm Infants: A Literature Review.

AbstractNeurological sequelae are common in very low-birth-weight preterm infants. The prevention of brain injury and development of neuroprotective strategies have been the main objectives of modern neonatal neurology. Amplitude integrated electroencephalogram (aEEG) is a continuous brain monitoring method that can aid in early diagnosis and detect patients who are at risk. While its role in the assessment of full-term newborn infants is already well established, there are still doubts about its use in preterm infants. The objective of this review was to describe the main recommendations for the use of aEEG in very low-birth-weight preterm infants and its accuracy in assessing the prognosis and detecting epileptic seizures in this population.

Inter-observer reliability in reading amplitude-integrated electroencephalogram in the newborn intensive care unit.

Amplitude-integrated electroencephalogram (aEEG) is widely used in neonates to detect electrical seizure and predict outcome following hypoxic ischaemic encephalopathy and other encephalopathy. Because accurate interpretation is important for clinical decision-making and family counselling, inter-observer reliability is a major concern. We aimed to evaluate inter-observer reliability in the interpretation of aEEG tracings in a neonatal intensive care unit. Three neonatal intensive care unit clinicians with different levels of experience in reading aEEG independently reviewed and scored aEEG traces using standardised criteria, categories and interpretation rules. Inter-observer reliability was evaluated using weighted Cohen's κ and intra-class correlation coefficients. All 131 tracings from 120 neonates were reviewed by the neontalogist, 128 (97.7%) by the clinical nurse specialist, 73 (55.7%) by the nurse educator and 70 (53.4%) by all three clinicians. The majority (88 of 120, 73.3%) were term infants (mean gestational age 38 weeks, standard deviation 3.2). Average duration of recording was 27 h (standard deviation 19.1, range 1-105 h). Inter-observer reliability varied across categories and observers - from very good to excellent for the main background activity (intra-class correlation coefficients 0.93-0.98); good to very good for seizures; and moderate to very good for sleep-wake cycle and quality of recording (weighted κs' 0.71-0.85, 0.50-0.75, 0.46-0.81, respectively). While certain aEEG features appear challenging to inter-observer reliability, our findings suggest that with training and consensus guidelines, levels of reliability needed to enhance clinical and prognostic usefulness of aEEG are achievable across clinicians with different levels of experience in reading aEEG.

Amplitude-Integrated Electroencephalography Interpretation During Therapeutic Hypothermia: An Educational Program and Novel Teaching Tool.

Therapeutic hypothermia (TH) is now considered a standard in tertiary NICUs. Amplitude-integrated electroencephalography (aEEG) is an important adjunct to this therapy and is gaining acceptance for use on the neonatal population. It can be easily incorporated into practice with appropriate education and training. Current publications are lacking regarding nursing care of neonatal patients undergoing th with the use of aEEG. This article presents a broad educational program as well as novel teaching tool for neonatal nurses caring for this population.

The role of outpatient ambulatory electroencephalography in the diagnosis and management of adults with epilepsy or nonepileptic attack disorder: A systematic literature review.

Electroencephalography (EEG) is an established diagnostic tool with important implications for the clinical management of patients with epilepsy or nonepileptic attack disorder. Different types of long-term EEG recording strategies have been developed over the last decades, including the widespread use of ambulatory electroencephalography (AEEG), which holds great potential in terms of both clinical usefulness and cost-effectiveness. In this paper, we present the results of a systematic review of the scientific literature on the use of AEEG in the diagnosis of epilepsy and nonepileptic attacks in adult patients. Taken together, our findings confirmed that AEEG is a useful diagnostic tool in patients with equivocal findings on routine EEG studies and influences management decisions in the majority of studies. There is evidence that AEEG is also more likely to capture events than sleep-deprived EEG; however, there are currently insufficient data available to compare the diagnostic utility of modern AEEG technology with inpatient video-telemetry. Further research on the combined use of AEEG and home-video recording is, therefore, warranted.

Amplitude-integrated EEG abnormalities in two neonates with encephalopathy due to mitochondrial dysfunction (respiratory chain complex I deficiency)

Amplitude-integrated electroencephalography (aEEG) findings in hypoxic-ischemic encephalopathy characterized by secondary energy failure have been described in detail. In contrast, reports of use of aEEG in patients with encephalopathy due to primary energy failure as seen in inherited metabolic disorders are sparse. We report two cases of lethal mitochondrial encephalopathy due to mitochondrial respiratory chain complex I deficiency. We present clinical course, laboratory evaluations, aEEG, conventional electroencephalography, magnetic resonance imaging and magnetic resonance spectroscopy findings of two cases identified with mitochondrial encephalopathy between 2002 and 2007. Both infants were born at term. Both presented with intractable seizures and mild hypotonia within the first days of life, in the absence of any evidence suggestive of hypoxic- ischemic encephalopathy. Both cases were treated with multiple anticonvulsants and in neither case were seizures fully controlled. Magnetic resonance imaging in both cases revealed a structurally normal brain and case one showed subtle diffuse deep white matter signal abnormality. Magnetic resonance spectroscopy revealed no elevation of lactate. In both cases, aEEG tracings were markedly abnormal, confirmed by electroencephalography. Case one showed status epilepticus on an abnormally high amplitude background and case two presented with a mainly discontinuous background pattern with intermittent burst-suppression pattern activity. Complex I activity in skeletal muscle homogenate was abnormally low in both patients. The use of aEEG as a valuable assessment and monitoring tool in patients with metabolic encephalopathy should be further promoted.

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.

Outpatient ambulatory EEG as an option for epilepsy surgery evaluation instead of inpatient EEG telemetry.

Outpatient ambulatory EEG is more cost-effective than inpatient EEG telemetry and may provide adequate seizure localization in a presurgical evaluation. A 51-year-old right-handed male had been unable to work or drive since the age of 35 due to intractable partial onset epilepsy. A 72-hour outpatient ambulatory EEG recorded 18 seizures from the right temporal region. No epileptiform activity was seen in the left hemisphere. Magnetic resonance imaging showed right mesial temporal sclerosis as well as an area of encephalomalacia at the medial inferior right temporal lobe. Neuropsychological assessment found that the patient was a good neurosurgery candidate. At this point, the patient was considered to be a candidate for a right temporal lobectomy. A standard right temporal lobectomy was performed. The patient has been seizure-free for 10 months after the surgery. Follow-up EEGs show no epileptiform activity. The patient is preparing to go back to work, and his driver's license was reinstated 9 months postsurgery. Neuropsychological reassessment is pending, but no apparent change in cognition has been noticed by the patient or his family. Cases with a high congruence between diagnostic imaging and the EEG abnormalities identified in the portable EEG may provide enough information regarding seizure frequency and localization to eliminate the need for inpatient EEG telemetry in the evaluation of patients for epilepsy surgery. We believe that the use of aEEG in preoperative planning should be restricted to cases of TLE and to patients with a high frequency of seizures.

Ambulatory EEG: a cost‐effective alternative to inpatient video‐EEG in adult patients

Ambulatory electroencephalography (AEEG) is a monitoring technique that allows the recording of continuous EEG activity when patients are at home, without the necessity of admission to the hospital for prolonged video-EEG monitoring. This is a prospective cohort study performed in a Canadian academic centre in order to assess the yield and tolerability of AEEG in the adult population. Over a period of three years, 101 patients were included. The yield of AEEG was assessed by taking into account the questions asked by the clinician before and after the investigation. One hundred and one patients undergoing AEEG were prospectively recruited during a three-year-period. Our population consisted of 45 males (44.6%) and 56 females (55.4%). The mean age of the group was 36.6 ± 16.1 years. Most of the patients had at least one previous routine EEG (93%). The primary reasons for the AEEGs were subdivided into four categories: a) to differentiate between seizures and non-epileptic events; b) to determine the frequency of seizures and epileptiform discharges; c) to characterize seizure type or localization; and d) to potentially diagnose epilepsy. The mean duration of AEEG recording was 32 ± 17 hours (15-96 hours). For 73 (72%) patients, the AEEG provided information that was useful for the management. For 28 (28%) patients, the AEEG did not provide information on diagnosis because no events or epileptiform activity occurred. In only 1 patient was the AEEG inconclusive due to non-physiological artefacts. Three patients were referred for epilepsy surgery without the necessity of video-EEG telemetry. In this study, we found that AEEG has a high diagnostic yield (72%) and believe that careful selection of patients is the most important factor for a high diagnostic yield. The main use of AEEG is the characterization of patients with non-epileptic events, in patients with a diagnosis of epilepsy that is not clear, and quantification of spikes and seizures to improve the medical management. Ambulatory EEG is a cost-effective solution for increasing demands for in-hospital video-EEG monitoring of adult patients.

Epilepsy, unawareness of seizures and driving license: The potential role of 24-hour ambulatory EEG in defining seizure freedom

IntroductionSeizures represent a potential source of accidents/death. Permission to drive may, therefore, be granted in a seizure-free period. Laws and regulations regarding this issue vary widely, and the onus of reporting seizures ultimately rests on the individual. Unfortunately, as some patients are unaware of their seizures, their reports may be unreliable. MethodsIn this retrospective study, we selected, from a group of 1100 consecutive patients, 57 cases (26 males/31 females; mean age: 42.5years) in whom the AEEG documented ictal events (UIEs) not reported in a self-kept diary. By means of a simple questionnaire, we interviewed all these patients to collect information on driving licenses. We, thus, assessed how many of these patients (both drug resistant and seizure free) drove regularly. ResultsOur study shows a relatively large number of patients with epilepsy and UIEs. Fifteen patients suffered from idiopathic generalized epilepsy (IGE) while 42 had partial epilepsy (PE). The patients were seizure free in 21 cases and 36 had drug-resistant seizures. Many patients in both these subgroups had a driving license and drove normally (active driving in 12/36 drug-resistant patients and in 18/21 seizure-free patients). Worthy of note is the finding that an “apparently” seizure-free group of patients drove regularly. ConclusionsThis study revealed a large number of patients (both drug resistant and seizure free) with AEEG-documented UIEs. This finding highlights the usefulness of AEEG in clinical practice as a means of more accurately ascertaining seizure freedom and supporting decisions involving the renewal or granting of a driving license.