Evaluating the utility of inpatient video-EEG monitoring

PURPOSE: Inpatient video-EEG monitoring (VEM) is widely used for the diagnosis, seizure classification, and presurgical evaluation of patients with seizure disorders. It is resource intensive and relatively expensive, so its utility continues to be debated. Few studies have specifically evaluated the utility of inpatient VEM in altering diagnosis or management of patients with seizure disorders. We sought to assess the proportion of patients for whom the preadmission diagnosis and management were altered after inpatient VEM of patients admitted for diagnostic and presurgical evaluation of seizure disorders. METHODS: Data from a consecutive cohort of patients admitted over a 3-year period to an inpatient VEM unit in a tertiary referral hospital were retrospectively analyzed. The preadmission diagnosis and management by the referring neurologist was compared with the diagnosis and management after the VEM. RESULTS: Of 131 patients, 91 (70%) were admitted for diagnostic evaluation and 39 (30%) for a presurgical workup. Mean evaluative period was 5.6 days. Mean number of seizures recorded was 2.9. No seizures were recorded in 31% of patients. Interictal EEG showed epileptiform changes in 56 (43%). In 76 (58%), the diagnosis was altered as a result of the VEM, with the greatest change being an increase in the nonepileptic diagnosis group (7% to 31%) and the generalized diagnosis group (5% to 11%). Management was changed after the VEM in 95 (73%). CONCLUSIONS: The results of this study demonstrate that inpatient VEM has a high yield in changing diagnosis and management. Future long-term cost-benefit studies of the management changes resulting from VEM evaluation will aid in further reinforcing its role.     

Ictal asystole in epilepsy patients undergoing inpatient video-EEG monitoring

Ictal asystole (IA) is uncommonly diagnosed and has been implicated as a potential cause of sudden unexpected death in epilepsy. Sudden unexpected death in epilepsy is an increasingly recognizable condition and is more likely to occur in patients with medically intractable epilepsy and those suffering from convulsive epilepsy. We report 2 cases of recent onset of prolonged syncope and unrevealing cardiac work up. The inpatient video-EEG monitoring recorded left temporal ictal discharges followed by IA. Although the role of cardiac pacing is controversial in these patients, both patients had favorable outcome following cardiac pacemaker insertion. This report demonstrates the variability in IA pathophysiology and clinical manifestations. It also advocates that cardiac pacing might have a role in the management of IA.Ictal asystole (IA) is an uncommon event that occurs in 0.1-0.4% of patients experiencing seizures during inpatient video-electroencephalography monitoring (VEEG).1 Ictal asystole is more likely to occur in patients with focal seizures originating from the temporal region.2 It has been implicated as a potential cause for sudden unexpected death in epilepsy patients (SUDEP) that carry an incidence of 0.09-9.3 per 1000 patient-years.1 Although controversial, cardiac pacing has been suggested as a possible preventive measure against IA and SUDEP.3 We report 2 cases of IA encountered at our epilepsy monitoring unit between June 2010 and October 2011, and their clinical outcomes after cardiac pacemaker insertions. These 2 cases highlight the importance in considering IA as a potentially fatal complication of epileptic seizures that might be circumvented by good seizure control, and in some cases cardiac pacing.     

Risk of choking and aspiration during inpatient video-EEG monitoring

Seizures can cause airway compromise and aspiration. This is a potential concern during inpatient video-EEG monitoring (vEEG), where seizures are provoked for diagnostic purposes. The frequency of aspiration and efficacy of nursing interventions to protect the airway were evaluated in this retrospective study of 590 partial complex (PC) and generalized tonic clonic (GTC) seizures recording during vEEG. 33 seizures (5.6%) occurred while patients were eating or drinking, 14 with food in the mouth at onset. 4 (0.6%) were followed by post-ictal emesis. Supplemental oxygen was provided in 93% of GTC seizures, and oral suctioning in 85%. Lateral decubitus positioning was used in 53%. These interventions were applied in a minority of PC seizures. There were no choking events, one suspected aspiration without subsequent complication, and no aspiration pneumonia. It is uncertain if interventions such as oral suctioning, lateral decubitus positioning, or oxygen administration reduce the risk of aspiration during vEEG.     

Sleep deprivation does not affect seizure frequency during inpatient video-EEG monitoring

OBJECTIVE: To determine whether acute sleep deprivation facilitates seizures during inpatient monitoring in a controlled protocol. METHODS: Eighty-four patients with medically refractory partial epilepsy undergoing inpatient monitoring were assigned in consecutive blocks to either sleep deprivation every other night or to normal sleep. In both groups, subjects were requested to stay awake during the day, from 6 AM to 10 PM. In the sleep deprivation group, patients also stayed awake between 10 PM and 6 AM every other night beginning with Day 2. Patients were removed from sleep deprivation if they had two or more secondarily generalized seizures within 24 hours. Patients were removed from the normal sleep group and were sleep deprived if they did not have a complex partial or secondarily generalized seizure by Day 6 of monitoring. In these patients removed from sleep deprivation or from normal sleep, data were analyzed up to and including the day of removal from the protocol. RESULTS: The sleep deprivation and normal sleep subjects did not differ in age, sex, seizure localization, or percent dosage reduction in antiepileptic drugs from baseline at days 1 to 3 of monitoring. Protocol duration was 6.5 +/- 2.4 days (mean +/- SD) for the sleep deprivation group and 5.8 +/- 2.0 days for the normal sleep group. Seizures per day for complex partial, secondarily generalized, and combined complex partial and secondarily generalized, calculated from admission until end of protocol, did not differ significantly between the two groups. CONCLUSION: Acute sleep deprivation did not affect seizure frequency during inpatient monitoring in our patients with intractable complex partial seizures with secondary generalization.     

Daytime outpatient versus inpatient video-EEG monitoring for presurgical evaluation in temporal lobe epilepsy.

Video-EEG monitoring documentation of seizure localization is one of the most important aspects of a presurgical investigation in refractory temporal lobe epilepsy (TLE) patients. The objective of this study was to evaluate the efficacy of inpatient versus daytime outpatient telemetry. The authors evaluated prospectively 73 patients with medically intractable TLE. Ninety-one telemetry sessions were performed: 35 as inpatients and 56 as outpatients. Outpatient monitoring was performed in the EEG laboratory. They used 18-channel digital EEG. Medications were not changed in the outpatient group. For analysis of the data, time was counted in periods (12 hours = 1 period). Statistical analyses were performed using Student's t-test and the chi2 test. There were no differences between the two groups (outpatient versus inpatient) with respect to age and mean seizure frequency before monitoring, mean time to record the first seizure (1.1 versus 1.4 periods), mean number of seizures per period (0.6 for both groups), lateralization by interictal spiking (46% versus 57%), and lateralization by ictal EEG (59% versus 77%). Daytime outpatient video-EEG monitoring for presurgical evaluation is efficient and comparable with inpatient monitoring. Therefore, the improved cost benefit of outpatient monitoring may increase the access to surgery for individuals with intractable TLE.     

Patients with epilepsy and psychogenic non-epileptic seizures: an inpatient video-EEG monitoring study

Seizure and EEG characteristics of patients with epilepsy and concomitant psychogenic non-epileptic seizures (PNES) were compared to age and sex matched controls with epilepsy alone in a retrospective case control study. 39 patients with clearly documented epileptic and non-epileptic events were compared to 78 age and sex matched controls, sequentially admitted for video-EEG monitoring with documentation of epilepsy alone. Frontal seizures were higher in prevalence in patients with PNES who had concomitant epilepsy (P<0.001), while temporal seizures were higher in prevalence in patients with epilepsy alone (P<0.04). On regression analysis, the odds of having a frontal seizure was found to be significantly lower in the epilepsy alone group compared to the epilepsy+PNES group (odds ratio 0.13, 95% CI, 0.033-0.51). This significant association between frontal lobe epilepsy and PNES may be related to misattribution of frontal seizures for PNES events, or may reflect frontal lobe cortical dysfunction in this subgroup.     

Diagnostic usefulness and duration of the inpatient long-term video-EEG monitoring: Findings in patients extensively investigated before the monitoring

Inpatient long-term video-EEG monitoring (LTM) is an important diagnostic tool for patients with seizures and other paroxysmal behavioural events. The main referral categories are diagnosis (epileptic versus non-epileptic disorder), seizure classification and presurgical evaluation. The diagnostic usefulness of the LTM varies considerably (19–75%) depending on how this was defined and on the selection of the patients. The purpose of this study was to assess the diagnostic usefulness and the necessary duration of the LTM for the referral groups, in patients extensively investigated before the monitoring. An LTM was considered diagnostically useful when it provided previously not reported, clinically relevant information on the paroxysmal event. For the presurgical group, reaching a decision concerning surgery was an additional requirement.We reviewed data from 234 consecutive LTM-sessions (221 patients) over a 2-year period. In 44% of the cases the LTM was diagnostically useful. There were no significant differences concerning diagnostic usefulness among the main referral groups: diagnostic (41%), classification (41%) and presurgical (55%). Diagnostic usefulness did not differ among the age groups either. The duration of the successful LTM-sessions was significantly longer in the presurgical group (mean: 3.5 days) than in the diagnostic and classification groups (2.4 and 2.3 days, respectively). We conclude that LTM is a valuable diagnostic tool even in patients extensively investigated before the monitoring, and is equally effective in the referral and age groups. However, patients referred for presurgical evaluation need considerably longer LTM, and this should be taken into account when planning the resources and calculating the costs.     

Diagnostic yield of sequential routine EEG and extended outpatient video-EEG monitoring.

OBJECTIVE: To investigate the diagnostic yield of outpatient video-EEG monitoring (OVEM) in patients with suspected but unconfirmed epilepsy. METHODS: OVEM data, comprised of 20-min video-EEG (REEG) followed by 4h of video-EEG monitoring (EXM), from 179 consecutive patients were retrospectively analyzed. Three diagnostic categories were defined: localization-related epilepsy (LRE), generalized epilepsy (GE), and nonepileptic seizures (NES). Outcome measures were: frequency of events; diagnostic yield of entire OVEM; relative yields of REEG alone and EXM after nondiagnostic REEG; EXM diagnostic rate (yield of EXM after nondiagnostic REEG/yield of entire OVEM). RESULTS: Habitual events occurred in 14 (8%) and 25 (15%) patients during REEG and EXM, respectively. Overall, OVEM was diagnostic in 90/179 patients (50%): LRE 21%; GE 15%; NES 15%. REEG alone was diagnostic in 49/179 patients (27%): LRE 7%; GE 13%; NES 7%. After nondiagnostic REEG, the subsequent EXM was diagnostic in 41/130 patients (32%): LRE (n=24); GE (n=2); NES (n=15). The EXM diagnostic rate (95% confidence interval) was 0.65 (0.47-0.80) for LRE, 0.08 (0.01-0.25) for GE, and 0.56 (0.35-0.75) for NES. CONCLUSIONS: OVEM is useful in establishing and classifying epilepsy. Compared to REEG, EXM is relatively more beneficial in the diagnosis of LRE and NES rather than GE. SIGNIFICANCE: This study outlines the benefits of extended outpatient video-EEG monitoring after nondiagnostic routine EEG.     

Challenges in pediatric video-EEG monitoring

Video-EEG (VEEG) monitoring is now commonly used in children. When designing a pediatric video-EEG monitoring unit, there are many issues that need to be considered to take full advantage of this technology. Topics such as the physical layout of the VEEG unit, VEEG equipment, networking, staffing, and lines of communication regarding referrals and VEEG interpretation must be considered. Only after careful consideration of these issues, can video-EEG monitoring be successful and provide safe, state of the art clinical care in an efficient manner.     

The role of patient companions in long-term video-EEG monitoring.

In developing countries it is difficult to have full-time dedicated nurses in Epilepsy Monitoring Units (EMU). Our one-bed EMU is within the Neurology Service and is adequately staffed during daytime working hours only. So we created a new model where the patient’s companion was asked to press a nurse call button, allowing the examination of the patient by the nurse. In this study we aimed to understand how patient companions behaved and which factors influenced their behaviour. Patients were allowed to choose a single companion who were educated by the specialist monitoring nurse according to a protocol. Only the first recorded seizures of the patients were included in the study. The seizures were reviewed from the video-cassette recordings and the behaviour of the companions was scored according to the results of the following three questions: (1) when was the seizure noticed?; (2) was the nurse call button pushed?; and (3) did the companion prevent the recording of the seizure by the camera? The companions were grouped according to the following criteria; age, sex, level of education, type of relationship. The scores were compared for each criterion separately. The behaviours of the 50 companions (34F, 16M; age: 25–72) were studied. When statistically compared for age, sex and level of education, there were no significant differences between different groups. However, the mean score of the 47 companions who were immediate family members (3.72) was greater than those three who were not (1.66) In one-bed EMUs, patient companions who are family members can help nurses in the early detection of seizures.     

Diagnostic yield of short-term video-EEG monitoring for epilepsy and PNESs: A European assessment

IntroductionAlthough long-term video-EEG monitoring (LVEM) is routinely used to investigate paroxysmal events, short-term video-EEG monitoring (SVEM) lasting < 24 h is increasingly recognized as a cost-effective tool. Since, however, relatively few studies addressed the yield of SVEM among different diagnostic groups, we undertook the present study to investigate this aspect.MethodsWe retrospectively analyzed 226 consecutive SVEM recordings over 6 years. All patients were referred because routine EEGs were inconclusive. Patients were classified into 3 suspected diagnostic groups: (1) group with epileptic seizures, (2) group with psychogenic nonepileptic seizures (PNESs), and (3) group with other or undetermined diagnoses. We assessed recording lengths, interictal epileptiform discharges, epileptic seizures, PNESs, and the definitive diagnoses obtained after SVEM.ResultsThe mean age was 34 (± 18.7) years, and the median recording length was 18.6 h. Among the 226 patients, 127 referred for suspected epilepsy — 73 had a diagnosis of epilepsy, none had a diagnosis of PNESs, and 54 had other or undetermined diagnoses post-SVEM. Of the 24 patients with pre-SVEM suspected PNESs, 1 had epilepsy, 12 had PNESs, and 11 had other or undetermined diagnoses. Of the 75 patients with other diagnoses pre-SVEM, 17 had epilepsy, 11 had PNESs, and 47 had other or undetermined diagnoses. After SVEM, 15 patients had definite diagnoses other than epilepsy or PNESs, while in 96 patients, diagnosis remained unclear. Overall, a definitive diagnosis could be reached in 129/226 (57%) patients.ConclusionsThis study demonstrates that in nearly 3/5 patients without a definitive diagnosis after routine EEG, SVEM allowed us to reach a diagnosis. This procedure should be encouraged in this setting, given its time-effectiveness compared with LVEM.     

Interictal and ictal video-EEG monitoring

PURPOSE: The purpose of this paper is to demonstrate the diagnostic efficacy and therapeutic relevance of video-EEG monitoring in an large patient population with long-term follow-up. PATIENTS AND METHODS: Between October 1990 and May 1997, 400 patients were monitored at the Epilepsy Monitoring Unit (EMU) of the University Hospital in Gent. In all patients, the following parameters were retrospectively examined: reason for referral, tentative diagnosis, prescribed antiepileptic drugs (AEDs), seizure frequency, number of admission days, number of recorded seizures, ictal and interictal EEG, clinical and electroencephalographic diagnosis following the monitoring session. During follow-up visits at the Epilepsy Clinic, we prospectively collected data on different types of treatment and post-monitoring seizure control. RESULTS: 255/400 (64%) patients were referred for refractory epilepsy. 145/400 (36%) patients were evaluated for attacks of uncertain origin. Mean follow-up, available in 225 patients, was 28 months (range: 6-80 months). Mean duration of a single monitoring session was 4 days (range: 2-7 days). Prolonged interictal EEG was recorded in all patients and ictal EEG in 258 (65%) patients. Following the monitoring session, the diagnosis of epilepsy was confirmed in 217 patients. Pseudoseizures were diagnosed in 31 patients (8%). AEDs were started in 19 patients, stopped in 6 and left unchanged in 110. The type and/or number of AEDs was changed in 111 patients. Sixty patients underwent epilepsy surgery. In 48 surgery patients, follow-up data were available, 29 of whom became seizure-free, and 16 of whom experienced a greater than 90% seizure reduction. Vagus nerve stimulation was performed in 11 patients, 2 became seizure-free, and 7 improved markedly. Of the non-invasively treated patients in whom follow-up was available (n = 135), 70 became seizure-free or experienced a greater than 50% reduction in seizure frequency; 51 patients experienced no change in seizure frequency. Outcome was unrelated to the availability of ictal video-EEG recording. In patients with complex partial seizures, seizure control was significantly improved when a well-defined ictal onset zone could be defined during video-EEG monitoring. CONCLUSION: Prolonged interictal EEG monitoring is mandatory in the successful management of patients with refractory epilepsy. Ictal video-EEG monitoring is very helpful but not indispensable, except in patients enrolled for presurgical evaluation or suspected of having pseudoseizures.     

The diagnostic value of initial video-EEG monitoring in children--review of 1000 cases

OBJECTIVE: We retrospectively reviewed the clinical utility of initial video-EEG monitoring in a series of 1000 children suspected of epileptic disorders. METHODS: The ages of patients (523 boys and 477 girls) ranged from 1 month to 17 years (median age: 7 years). The mean length of stay was 1.5 days (range: 1-10 days). Outcomes were classified as: 'useful-epileptic' (successful classification of epilepsy), 'useful-nonepileptic' (demonstration of nonepileptic habitual events), 'uneventful' (normal EEG without habitual events captured), and 'inconclusive' (inability to clarify the nature of habitual events with abnormal interictal EEG findings). RESULTS: A total of 315 studies were considered 'useful-epileptic'; 219 'useful-nonepileptic'; 224 'uneventful'; 242 'inconclusive'. Longer monitoring was associated with higher rate of a study classified as 'useful-epileptic' in all age groups (Chi square test: p<0.001). In addition, longer monitoring was associated with lower rate of a study classified as 'inconclusive' in adolescences (p<0.001). Approximately half of the children with successful classification of epilepsy were assigned a specific diagnosis of epilepsy syndrome according to the International League Against Epilepsy (ILAE) classification. We found only 22 children with ictal EEG showing a seizure onset purely originating from a unilateral temporal region. CONCLUSION: Video-EEG monitoring may fail to capture habitual episodes. To maximize the utility of studies in the future, a video-EEG monitoring longer than 3 days should be considered in selected children such as adolescences with habitual events occurring on a less than daily basis. We recognize a reasonable clinical utility of the current ILAE classification in the present study. It may not be common to identify children with pure unilateral temporal lobe epilepsy solely based on video-EEG monitoring.     

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

ObjectiveA 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.ResultsAge 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.ConclusionsVEM 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.     

The usefulness of video-EEG monitoring in elderly patients with seizure disorders.

The purpose of this paper was to evaluate the use of inpatient video-EEG (VEEG) monitoring in the evaluation of seizure disorders in elderly subjects. We retrospectively identified 36 patients aged 60 years old or over from a total of 849 patients studied at the VEEG unit of the Tampere University Hospital. Sixteen of the patients (44%) experienced at least one habitual seizure during the recording. Seven patients had epileptic seizures including two cases with status epilepticus. Nine patients had various non-epileptic disorders. VEEG had a clinically significant impact on the diagnosis and treatment in 14 of the 16 patients in whom paroxysmal events were recorded and proved to be useful in the evaluation of seizure disorders in elderly subjects.     

Continuous video-EEG monitoring in pediatric intensive care units

Purpose: Several studies indicate a higher occurrence than might be expected of seizures in intensive care unit patients, many of which are not clinically apparent. Few of these studies are devoted exclusively to pediatric patients. The purpose of this study is to determine the occurrence of seizures in a cohort of pediatric and neonatal intensive care unit patients. Methods: Long‐term video electroencephalography (EEG) monitoring studies performed in the pediatric and neonatal intensive care units were reviewed. Age, gender, diagnosis, EEG background, epileptiform activity, time of onset and duration of seizures, presence of electroclinical or electrographic seizures, and survival were collected. Key Findings: One hundred thirty‐eight recordings encompassing 122 patients were identified. Thirty‐four percent of the sessions identified seizures in the first 24 h (38% of the cohort experienced a seizure at some time during monitoring, which ranged from 1–22 days): 17% captured only electroclinical seizures, 49% were electrographic only, and 34% had both electroclinical and electrographic seizures. Seventy percent of those patients experiencing seizures had their first seizure within the first hour of EEG recording. Younger age and epileptiform activity (including periodic) were associated with the occurrence of seizures. Diagnoses of head trauma and status epilepticus/recent prior seizure were more likely than other at‐risk diagnoses to be associated with seizures; cardiac arrest managed with hypothermia was less likely to be associated with seizures. One‐fourth of the recordings identified nonepileptic events. Significance: Seizures occurred in one‐third of critically ill pediatric patients at risk for seizures who underwent video‐EEG monitoring, and many of these seizures did not have a clinical correlate. In those at risk for seizures in intensive care units, there should be a low threshold for obtaining long‐term monitoring.     

Utility of video-EEG monitoring in a tertiary care epilepsy center

Our video-EEG monitoring (VEEG) unit is part of a typical metropolitan tertiary care center that services a diverse patient population. We aimed to determine if the specific clinical reason for inpatient VEEG was actually resolved. Our method was to retrospectively determine the stated goal of inpatient VEEG and to analyze the outcome of one hundred consecutive adult patients admitted for VEEG. The reason for admission fit into one of four categories: 1) to characterize paroxysmal events as either epileptic or nonepileptic, 2) to localize epileptic foci, 3) to characterize the epilepsy syndrome, and 4) to attempt safe antiepileptic drug adjustment. We found that VEEG was successful in accomplishing the goal of admission in 77% of cases. The remaining 23% failed primarily due to lack of typical events during monitoring. Furthermore, of the overall study cohort, VEEG outcomes altered medical management in 53% and surgery was pursued in 5%.