Epilepsy Monitoring Unit Admission Research Articles

P.037 Role of epilepsy monitoring unit in the investigation of patients with epilepsy and developmental delay

Background: A significant part of the developmental delay (DD) population has epilepsy (26-70%) and live in an institution. These patients tend to have atypical presentation of epileptic seizures with higher risk of misdiagnosis. Distinguishing their ictal events from paroxysmal behaviors can be challenging.There often is a lack of description of the spells or inadequate history from the caregivers or the patients. These patients often have drug resistant epilepsy requiring polypharmacy with increased risk of morbidity and mortality. The aim of this study was to determine usefulness of Epilepsy Monitoring Unit (EMU) in diagnosis and management of these patients. Methods: This is a retrospective observational study of the patients with epilepsy and DD living in institutions that were admitted to the EMU. Results: Four patients met the inclusion criteria for this study. The mean age was 45(29-71), 3/4 (N=3) were male and 3/4 had focal epilepsy. All patients had mood disorders and 2 were taking antipsychotic medication. The mean admission-time was 6,25 days(2-15) and there was a correlation with the events and seizures in 2/4 of the patients and the rest had a combination of behavioural-changes and seizures. Conclusions: EMU admission can provide an accurate diagnosis of spells in patients with DD and epilepsy, and improve their quality of life.

Utility of long-term video-EEG monitoring for children with staring.

Staring spells are a common reason for referral to overnight epilepsy monitoring unit (EMU) evaluation. However, inpatient EMU admissions are expensive and time consuming. This study determined what percentage of those referred for staring had a confirmed epileptic seizure on long-term video-EEG monitoring (LTM) and developed a scoring system to help prioritize which patients should undergo this procedure. We performed a four-year retrospective chart review of all children at a tertiary pediatric hospital who received LTM (long-term monitoring) for the purposes of characterizing staring. The two goals were to: a) assess how often an LTM admission captured a staring spell that was diagnosed as a seizure and b) determine if any baseline factors predicted this particular positive result. We coded several characteristics of the most recent prior routine EEG if available. We also coded parental reports of the duration, frequency, and breakability of the events as well as post-ictal mental status and the presence/absence of automatisms. Finally, we coded previous neurological and psychiatric diagnoses and medications, as well as family history of epilepsy. Of the 276 admissions, only 29 (11%) captured a staring spell and diagnosed it as seizure. Several baseline variables predicted the likelihood of this positive result. Based on this information, we created a scoring system as follows: -3 points if the previous EEG was normal, -1 point if the child took a medication for a psychiatric condition, +1 point if the child took an anti-epileptic drug for epilepsy, and +1 point if the spells lasted less than 1min. If the total score was zero or less, staring spells diagnosed as seizures rarely occurred (less than 5% of the studies). Our scoring system shows how consideration of prior EEG findings, medication history, and staring spell duration can help prioritize patients for LTM admission to evaluate if staring spells are epileptic seizures.

Quality and safety in adult epilepsy monitoring units: A systematic review and meta-analysis.

The epilepsy monitoring unit (EMU) is a valuable resource for optimizing management of persons with epilepsy, but may place patients at risk for adverse events due to withdrawal of treatment and induction of symptoms. The purpose of this study was to synthesize data on the safety and quality of care in EMUs to inform the development of quality indicators for EMUs. A systematic review was conducted according to the Preferred Reporting and Items for Systematic Review and Meta-Analysis (PRISMA) statement. The search strategy, which included broad search terms and synonyms pertaining to the EMU, was run in six medical databases and included conference proceedings. Data abstracted included patient and EMU demographics and quality and safety variables. Study quality was evaluated using a modified 15-item Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist. Descriptive statistics and meta-analyses were used to describe and synthesize the evidence. The search yielded 7,601 references, of which 604 were reviewed in full text. One-hundred thirty-five studies were included. The quality and safety data came from 181,823 patients and reported on 34 different quality and safety variables. Included studies commonly reported the number of patients (108 studies; median number patients, 171.5), age (49 studies; mean age 35.7 years old), and the reason for admission (34 studies). The most common quality and safety data reported were the utility of the EMU admission (38 studies). Thirty-three studies (24.4%) reported on adverse events, and yielded a pooled proportion of adverse events of 7% (95% confidence interval [CI] 5-9%). The mean quality score was 73.3% (standard deviation [SD] 17.2). This study demonstrates that there is a great deal of variation in the reporting of quality and safety measures and in the quality and safety in EMUs. Study quality also varied considerably from one study to the next. These findings highlight the need to develop evidence-based, consensus-driven quality indicators for EMUs.

Reasons for prolonged length of stay in the epilepsy monitoring unit

Epilepsy monitoring unit (EMU) admissions are essential for the classification/localization of epileptic seizures (ES) and psychogenic non-epileptic seizures (PNES). However, the duration of admissions is highly variable. Accordingly, we evaluated the duration of 596 EMU admissions and reasons for prolonged (>7 days) lengths of stay (LOS). The average LOS was longer for patients diagnosed with ES (8.0 days, SD 4.1 days) than all others (6.0 days, SD 3.9 days, p<0.001). Of the 596 admissions, 231 (38.8%) had prolonged LOS. The most commonly reported reason for prolonged stay was need to record additional seizures (33%). Other contributors included complications such as seizure clusters (6.9%), status epilepticus (1.6%), test complications (3.7%), psychiatric concerns (4.3%), and medication side effects (1.6%). Our results suggest multiple factors produce prolonged LOS with no factor accounting for the majority. Recording an insufficient number of all habitual seizures was the leading cause, which was over twice the percentage of reported complications (17.6%). However, being able to prolong admissions when necessary resulted in only 14.9% of admissions being inconclusive, potentially justifying the extra expense. Efforts to shorten LOS may be best directed at faster recording of seizures, but this may increase LOS due to complications. Our results may be helpful when assessing whether efforts to shorten LOS are useful in improving the quality and cost of care.

Video-EEG results and clinical characteristics in patients with psychogenic nonepileptic spells: The effect of a coexistent epilepsy.

Epilepsy and psychogenic nonepileptic spells (PNES) can coexist, often posing diagnostic and therapeutic challenges. We sought to identify clinical and historical characteristics of two groups of patients, those with coexisting epilepsy and PNES and those with PNES alone, and determine the prevalence of coexisting epilepsy/PNES with strict diagnostic criteria in a large group of epilepsy monitoring unit (EMU) patients. We reviewed the medical records of all consecutive patients admitted to the Vanderbilt University Medical Center Adult EMU between July 1, 2007 and June 30, 2012. We identified patients with recorded PNES and classified them as having coexisting epilepsy/PNES or PNES alone and then systematically compared the clinical characteristics of these two groups. A total of 1567 patient medical records were reviewed. The prevalence rate of coexisting epilepsy/PNES was 5.2% among all EMU admissions (12.3% of all patients with epilepsy and 14.8% of all patients with PNES). These rates were lower when patients with interictal epileptiform activity (IEA) alone and no recorded ictal discharges were not included in the group with epilepsy (2.6%, 6.2%, and 7.4%, respectively). The accuracy of pre-EMU clinical suspicion was significantly higher in the group with PNES-only. Patients with epilepsy/PNES were significantly more likely to require more than one EMU admission for definitive diagnosis. The first PNES event preceded an epileptic seizure (ES) in 94.4% of patients with epilepsy/PNES. The group with PNES-only had significantly higher suggestibility, and the group with epilepsy/PNES had a significantly higher presence of epilepsy risk factors. Abnormal neurological examination and abnormal brain MRI were also significantly more common in the group with epilepsy/PNES. Our study defined the prevalence of coexisting epilepsy/PNES in a large cohort with strict diagnostic criteria and outlined specific clinical and historical characteristics differentiating the two groups of patients with coexisting epilepsy/PNES and PNES-only. These findings should help guide clinicians to reach the correct diagnosis faster and provide appropriate treatment earlier.

Epilepsy monitoring unit length of stay.

With an increasing focus on quality metrics, hospital length of stay (LOS) in the U.S. has garnered significant scrutiny. To help establish evidence-based benchmarks for epilepsy monitoring unit (EMU) metrics, we evaluated the impact of multiple variables on LOS through a retrospective analysis of 905 consecutive inpatient adult EMU admissions. The most common reasons for admission were event characterization (n=494), medication adjustment (n=189), and presurgical evaluation (n=96). Presurgical evaluations experienced a longer average LOS (aLOS) of 7.1days versus patients admitted for other indications (p<0.001). Patients with symptomatic generalized epilepsy (n=22) had a longer aLOS (6.9days) than patients with other types of epilepsy/events (p<0.001). Patients admitted on two or fewer antiepileptic drugs (AEDs) had a shorter aLOS than patients admitted on three or more AEDs (4.3days vs 6.3days, respectively; p<0.001). A history of previous invasive epilepsy management was associated with a longer aLOS than those without (6.2days vs 4.7days, respectively; p<0.0001). Epilepsy monitoring unit aLOS is influenced by admission indication, epilepsy classification, medication burden, and having had prior invasive management. Multiple variables should be considered when analyzing LOS EMU metrics, arguing against a "one size fits all" approach.

A screening tool to identify surgical candidates with drug refractory epilepsy in a resource limited settings

ObjectivesAccess to epilepsy surgery remains a considerable challenge in contemporary healthcare systems. Given the limitations in resources and demand for Epilepsy Monitoring Unit (EMU) assessments, information that can be used to expedite the process is of great value. The purpose of this study was to identify variables prior to EMU admission that may be associated with candidacy for prospective epilepsy surgery. MethodsThis was a prospective study conducted at the Department of Neurology, All India Institute of Medical Sciences, New Delhi, India. We identified two subgroups of patients from 501 drug refractory epilepsy (DRE) patients admitted in EMU of Neurology Department, AIIMS from 2006 onwards following validation of proposed tool in 40 patients. They on subsequent investigations were either cleared or not cleared for epilepsy surgery. A tool consisting of variables likely to predict surgical candidacy in persons with DRE in Indian settings was developed for identification of patients who might benefit from an early epilepsy surgery evaluation. ResultsStatistical analysis revealed significant differences between the two groups for several variables. Non-surgical candidates had non-disabling seizures, seizures improved with a combination of drugs, had little/no AEDs side effects and had near normal or normal scalp EEG and MRI brain. SignificanceUsing the best available evidence, we developed a decision making tool which can provide a comprehensive quick guide for determining candidacy for epilepsy surgery evaluations in resource limited settings. Given the demand for EMU assessments, information that can be used to expedite the process is of value.

The number of seizures needed in the EMU.

The purpose of this study was to develop a quantitative framework to estimate the likelihood of multifocal epilepsy based on the number of unifocal seizures observed in the epilepsy monitoring unit (EMU). Patient records from the EMU at Massachusetts General Hospital (MGH) from 2012 to 2014 were assessed for the presence of multifocal seizures as well the presence of multifocal interictal discharges and multifocal structural imaging abnormalities during the course of the EMU admission. Risk factors for multifocal seizures were assessed using sensitivity and specificity analysis. A Kaplan-Meier survival analysis was used to estimate the risk of multifocal epilepsy for a given number of consecutive seizures. To overcome the limits of the Kaplan-Meier analysis, a parametric survival function was fit to the EMU subjects with multifocal seizures and this was used to develop a Bayesian model to estimate the risk of multifocal seizures during an EMU admission. Multifocal interictal discharges were a significant predictor of multifocal seizures within an EMU admission with a p<0.01, albeit with only modest sensitivity 0.74 and specificity 0.69. Multifocal potentially epileptogenic lesions on MRI were not a significant predictor p=0.44. Kaplan-Meier analysis was limited by wide confidence intervals secondary to significant patient dropout and concern for informative censoring. The Bayesian framework provided estimates for the number of unifocal seizures needed to predict absence of multifocal seizures. To achieve 90% confidence for the absence of multifocal seizure, three seizures are needed when the pretest probability for multifocal epilepsy is 20%, seven seizures for a pretest probability of 50%, and nine seizures for a pretest probability of 80%. These results provide a framework to assist clinicians in determining the utility of trying to capture a specific number of seizures in EMU evaluations of candidates for epilepsy surgery.

Epilepsy surgery in the United States: Analysis of data from the National Association of Epilepsy Centers

ObjectiveTo examine trends in epilepsy-related surgical procedures performed at major epilepsy centers in the US between 2003 and 2012, and in the service provision infrastructure of epilepsy centers over the same time period. MethodsWe analyzed data from the National Association of Epilepsy Centers’ (NAEC) annual surveys. The total annual figures, annual average figures per center and annual rates of each surgical procedure based on US population numbers for that year were calculated. Additional information on center infrastructure and manpower was also examined. ResultsThe number of the NAEC's level 3 and level 4 epilepsy centers submitting annual survey reports increased from 37 centers in 2003 to 189 centers in 2012. The average reported number of Epilepsy Monitoring Unit (EMU) beds per center increased from 7 beds in 2008 to 8 beds in 2012. Overall annual EMU admission rates doubled between 2008 and 2012 but the average number of EMU admissions and epilepsy surgeries performed per center declined over the same period. The annual rate of anterior temporal lobectomies (ATL) for mesial temporal sclerosis (MTS) declined by >65% between 2006 and 2010. The annual rate of extratemporal surgery exceeded that of ATL for MTS from 2008 onwards, doubled between 2007 and 2012 and comprised 38% of all resective surgeries in 2012. Vagus nerve stimulator implant rates consistently increased year on year and exceeded resective surgeries in 2011 and 2012. ConclusionThe last decade has seen a major change in the US epilepsy surgery landscape. Temporal lobectomies, particularly for MTS, have declined despite an increase in EMU admissions. On the other hands, case complexity correspondingly increased as evidenced by more extratemporal surgery, intracranial recordings and palliative procedures.

The influence of staffing on diagnostic yield of EMU admissions: A comparison study between two institutions

Patients with recurrent, stereotyped neurological events of unclear etiology often warrant admission for continuous video-EEG monitoring in an epilepsy monitoring unit (EMU) for diagnosis. Epilepsy monitoring unit admission duration has been reported to range from days to weeks. To date, there are limited data on the average duration of admission for patients admitted to the EMU for spell classification. Many EMUs are forced to limit the overall duration of admission for numerous reasons including limited resources. It is unclear if a time-limited EMU stay reduces the event capture rate and, therefore, diagnostic yield of event classification admissions. The goal of this study was to determine how a time-limited length of stay strategy impacted event capture in patients admitted for spell classification. A retrospective chart review was performed at two comparable adult epilepsy monitoring units, Mayo Clinic Hospital (MCH) in Phoenix, Arizona, and Banner Good Samaritan Medical Center (BGSMC) in Phoenix, Arizona. Banner Good Samaritan Medical Center is only staffed Monday through Friday, thereby limiting the total possible duration of admission to five days. The goal was to determine if the rate of event capture differed between two institutions employing a time-limited EMU admission (BGSMC) when compared with the nonlimited admission (MCH). A total of 300 patient admissions at MCH and 260 patient admissions at BGSMC were reviewed over a comparable time period. The event capture rates at MCH and BGSMC were 74% and 72%, respectively. There was a greater percentage of patients with nonepileptic events (NEEs) at MCH than at BGSMC (62.7% vs. 47.3%). The mean duration until first event was 31h at MCH and 38h at BGSMC. The mean length of stay was greater at MCH (4.5days) when compared with BGSMC (3.3days). The overall diagnostic yield of a time-limited EMU admission was similar to that of a nonlimited admission for the purpose of spell classification. There was a statistically significant difference when comparing the time until first event at both institutions; however, this still fell within the 5-day duration that the time-restricted admission was limited to. These results may be important in optimizing an EMU practice in patients requiring admission for spell classification.

Access to surgery for paediatric patients with medically refractory epilepsy: A systems analysis

A systems analysis perspective was undertaken to evaluate access to surgery for children with medically refractory epilepsy (MRE) in Ontario, the largest province in Canada. The analysis focused on the assessment of referral patterns, healthcare utilization, time intervals and patient flow to determine surgical candidacy in children with MRE. The purpose of this systems analysis study was to identify rate limiting steps that may lead to delayed surgical candidacy decision and surgery. Prolonged video electroencephalography (vEEG) is the common entry point into the process for all potential epilepsy surgery candidates. Therefore, a single centre retrospective chart review of children and adolescents referred to the epilepsy monitoring unit (EMU) for vEEG monitoring at the primary referral centre for paediatric epilepsy surgery in the province. Basic demographic and referral data were abstracted for all screened cases. Included cases were: (1) age <19 years old at time of first EMU admission, (2) date of EMU admission between April 1, 2004 and March 31, 2006 and (3) referral for elective vEEG and/or overnight with vEEG greater than 8h duration. Data were collected on number of seizure conferences, surgical candidacy, surgical outcomes (seizure free and seizure reduction), resource utilization, and recorded time stamps for each event to estimate system delays. During the two-year period, 463 patients were referred to the EMU of whom 349 received prolonged vEEG (>8h). Forty five percent (n=160) of patients came to seizure conference for discussion of their data, of whom 40% (64/160) were considered surgical candidates. Time from first seizure to EMU referral was approximately 4.6 years. Time from referral to admission and admission to first seizure conference were approximately 103 days and 71 days, respectively. From initial EMU referral to surgery ranged from 1.6 to 1.1 years depending on whether the patient required invasive monitoring with intracranial EEG. Overall, 95% of surgical patients had a reduction in seizure frequency, 74% were seizure free after one year post-surgery. Referral rates for surgical assessment are low relative to the estimated number of children living with MRE in Ontario, less than 2%. Hence, only a limited number of children with this disorder in the province of Ontario who could benefit from epilepsy surgery are being assessed for surgical candidacy. The majority of Ontario children with MRE are not being provided the potential opportunity to be seizure free and live without functional limitations following surgical intervention. These data document the critical need for health system redesign in Ontario, the goal of which should be to provide more consistent and just access to evidence-based medical and surgical care for those citizens of the province who suffer from epilepsy.

Utility and safety of prolonged video-EEG monitoring in a tertiary pediatric epilepsy monitoring unit

Prolonged video-EEG (vEEG) monitoring helps characterize paroxysmal events and epilepsy. There is limited literature in pediatrics describing the safety and utility of vEEG. We retrospectively reviewed 454 pediatric epilepsy monitoring unit admissions over two years. Final event diagnoses, duration of seizures, and medical complications were analyzed. Two hundred twenty admissions (48.4%) captured epileptic seizures, 150 (33.0%) captured nonepileptic events, and 84 (18.5%) failed to capture any events. Medical complications were seen in 4 patients (1.8%) with no long-term complications. Seventeen episodes of status epilepticus occurred in 13 patients. This constituted 2.9% of all admissions and 5.9% of admissions with epileptic seizures. The median duration of status was 26min, and three patients required transfer to the pediatric intensive care unit. Video-EEG monitoring had a high yield in capturing events and differentiating epileptic from nonepileptic events. Our pediatric patients experienced greater risk of status epilepticus but lesser risk of injury.

Efficacy of safety signals in the epilepsy monitoring unit (EMU): Should we worry?

There is little consensus regarding the critical safety measures to prevent harm in epilepsy monitoring units (EMUs). We sought to determine whether the safety signals (SS) triggered during EMU events differed by seizure type and the efficacy of SS in alerting responders. We screened 468 consecutive EMU admissions from January 2008 until April 2011 for definitive events to evaluate the first 50 events of complex partial seizures (CPS), generalized tonic-clonic seizures (GTC), and psychogenic non-epileptic seizures (PNES). Response to telemetry signal was slower than to push button (PB). When there was PB alarm, response time was slower in patients with PNES. A higher proportion of PNES were triggered by PB. A greater percentage of epileptic seizures were missed compared with PNES. Future studies investigating more effective techniques to capture every epileptic seizure are warranted as 24/7 monitoring by healthcare professionals is not feasible in many settings.

Indeterminate EMU admissions: Does repeating the admission help?

Epilepsy monitoring unit (EMU) admissions during 2007–2009 at Mayo Clinic Hospital Arizona were reviewed. Of the 106 indeterminate admissions, 13 (12%) went on to have a second admission. During the second admission, 8 (62%) were diagnosed. Five patients went on to have a third or fourth admission, with none of them receiving a diagnosis. Nineteen (18%) patients had ambulatory EEG monitoring after an indeterminate admission, with only one (5%) receiving a diagnosis after ambulatory EEG monitoring. Even in patients who were initially indeterminate, medication management changed 37% of the time. Admission to the EMU was helpful for spell classification, with 80% of the patients receiving a diagnosis after the first admission. Based on this study, a second admission should be considered if no diagnosis is reached after the first admission. If no diagnosis is made after the second EMU admission, subsequent admissions are unlikely to produce a definitive diagnosis.

Transient improvement after brief antiepileptic drug withdrawal in the epilepsy monitoring unit—possible relationship to AED tolerance

A drug holiday seems to produce seizure interval prolongation (SIP) after reinstitution of antiepileptic drugs (AEDs). This effect was demonstrated mainly with carbamazepine. We evaluated SIP with newer AEDs and tested the relationship of SIP to history of AED tolerance. We prospectively studied patients with refractory epilepsy admitted to the Vanderbilt epilepsy monitoring unit (EMU) over a period of 12 months. We included only patients on levetiracetam, lamotrigine, or oxcarbazepine who had their AEDs withdrawn on admission and reinstituted without change upon discharge. We defined SIP as the interval from EMU discharge to first seizure minus the interval between the last two seizures before EMU admission. A total of 43 patients completed the study; 15 were on monotherapy. SIP was greater than zero in this patient group (p < 0.0001), with a mean prolongation of 19.4 +/- 28.0 days. The average SIP was higher (p = 0.01) in patients on monotherapy (29.7 +/- 23.8 days) than patients on polytherapy (13.9 +/- 29.0 days). SIP tended to be greater in patients with a prior history of AED tolerance (25.7 +/- 36.8 days) compared to patient with no prior history of AED tolerance (14.0 +/- 16.3 days). SIP does occur after brief AED withdrawal. This effect is greater in patients on monotherapy and tends to be larger in patients with a history of AED tolerance. The SIP effect may be related to the phenomenon of tolerance, clinically seen as resistance to AED therapeutic effect.