Elaine Wirrell

Mayo Clinic - Rochester, Рочестер, Minnesota, United States

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Publications (155)456.44 Total impact

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    ABSTRACT: To prospectively evaluate the etiology of new-onset infantile spasms and evaluate the yield of genetic and metabolic investigations in those without obvious cause after initial clinical evaluation and magnetic resonance imaging (MRI). Twenty-one U.S. pediatric epilepsy centers prospectively enrolled infants with newly diagnosed West syndrome in a central database. Etiology and investigations performed within 3 months of diagnosis were documented. From June 2012 to June 2014, a total of 251 infants were enrolled (53% male). A cause was identified in 161 (64.4%) of 250 cases (genetic,14.4%; genetic-structural, 10.0%; structural-congenital, 10.8%; structural-acquired, 22.4%; metabolic, 4.8%; and infectious, 2.0%). An obvious cause was found after initial clinical assessment (history and physical examination) and/or MRI in 138 of 161, whereas further genetic and metabolic studies were revealing in another 23 cases. Of 112 subjects without an obvious cause after initial evaluation and MRI, 81 (72.3%) had undergone genetic testing, which showed a causal abnormality in 23.5% and a variant of unknown significance in 14.8%. Although metabolic studies were done in the majority (serum, 79.5%; urine, 69.6%; and cerebrospinal fluid [CSF], 38.4%), these revealed an etiology in only five cases (4.5%). No correlation was found between type of health insurance (public vs. private) and either genetic or metabolic testing. Clinical evaluation and MRI provide a specific diagnosis in 55% of children presenting with West syndrome. We propose that a cost-effective workup for those without obvious cause after initial clinical evaluation and MRI includes an array comparative genomic hybridization (aCGH) followed by an epilepsy gene panel if the microarray is not definitive, serum lactate, serum amino acids, and urine organic acids. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.
    Epilepsia 03/2015; DOI:10.1111/epi.12951 · 4.58 Impact Factor
  • Umut Aypar, Elaine C. Wirrell, Nicole L. Hoppman
    American Journal of Medical Genetics Part A 03/2015; DOI:10.1002/ajmg.a.36902 · 2.05 Impact Factor
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    ABSTRACT: To describe the detection frequency and clinical associations of immunoglobulin G (IgG) targeting dipeptidyl-peptidase-like protein-6 (DPPX), a regulatory subunit of neuronal Kv4.2 potassium channels.
    Neurology 10/2014; DOI:10.1212/WNL.0000000000000991 · 8.30 Impact Factor
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    ABSTRACT: Objective To determine the outcome of implanting fewer electrodes over the hemisphere with less supporting presurgical localizing data.Methods We retrospectively reviewed our epilepsy surgery database at Mayo Clinic, Rochester, Minnesota, between January 1, 1999, and December 31, 2011, to identify patients who had an asymmetric number of electrode contacts implanted in each hemisphere for seizure localization. We scored each presurgical noninvasive data point (0, 0.5, or 1) to predict the likelihood of identifying seizure onset in the hemisphere with fewer intracranial electrode contacts (HFEC). An aggregate score was obtained for each patient.ResultsThirteen (37%) of 35 patients had HFEC-onset seizures on intracranial electroencephalography (iEEG). The following factors predicted HFEC-onset seizures: (1) temporal lobe epilepsy (p = 0.02); (2) interictal scalp electroencephalographic discharges at the HFEC (p = 0.04); and (3) both interictal and ictal scalp EEG discharges at the HFEC (p = 0.01). The median (range) aggregate score was 2 (1–3) for patients with HFEC-onset seizures recorded on iEEG and 1 (0–3) for patients without HFEC-onset seizures (p = 0.001). Using this scoring model, the odds ratio of identifying HFEC-onset seizures on iEEG was 6.4 for each one-point increment in the aggregate score. The area under the receiver operating characteristic curve for this model was 0.84, suggesting excellent ability of the aggregate score to discriminate between patients with and without HFEC-onset seizures on iEEG.SignificanceImplanting electrodes on the basis of limited supporting presurgical data may be useful in selected patients, especially those with temporal lobe epilepsy, interictal scalp discharges involving the HFEC, or both interictal and ictal scalp discharges involving the HFEC. In addition, our proposed scoring system may be helpful in selecting patients with complicated epilepsy for implantation of an asymmetric number of intracranial electrodes in the hemispheres.
    Epilepsia 09/2014; 55(10). DOI:10.1111/epi.12766 · 4.58 Impact Factor
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    ABSTRACT: This chapter covers the syndromes of benign epilepsy with centrotemporal spikes (BECTS), nonlesional focal epilepsy in otherwise normal children (NLFN), and the genetic generalized epilepsies. BECTS is an epilepsy syndrome that always enters terminal remission before the general age of a planned transition of adolescents. This is also the case for the majority (65%) of those with childhood absence epilepsy (CAE). Approximately 15% of patients with CAE who initially remit during their childhood years later develop juvenile myoclonic epilepsy (JME) as teenagers. They will have many issues for continuing medical care and transition, because their seizure disorder generally persists into adulthood. A significant minority of NLFN (~35%) and most patients with JME continue to have active epilepsy into adulthood. In addition, CAE, JME, and NLFN patients are at risk of a number of significant adverse social outcomes that require ongoing advice and counseling.
    Epilepsia 08/2014; 55 Suppl 3:16-20. DOI:10.1111/epi.12706 · 4.58 Impact Factor
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    ABSTRACT: We evaluated the outcomes of intracranial electroencephalography (iEEG) recording and subsequent resective surgery in patients with magnetic resonance imaging (MRI) − negative temporal lobe epilepsy (TLE). Thirty-two patients were identified from the Mayo Clinic Epilepsy Surgery Database (Arizona, Florida, and Minnesota). Eight (25.0%) had chronic iEEG monitoring that recorded neocortical temporal seizure onsets; 12 (37.5%) had mesial temporal seizure onsets; 5 (15.6%) had independent neocortical and mesial temporal seizure onsets; and 7 (21.9%) had simultaneous neocortical and mesial seizure onsets. Neocortical temporal lobe seizure semiology was the only factor significantly associated with neocortical temporal seizure onsets on iEEG. Only 33.3% of patients who underwent lateral temporal neocorticectomy had an Engel class 1 outcome, whereas 76.5% of patients with iEEG-guided anterior temporal lobectomy that included the amygdala and the hippocampus had an Engel class 1 outcome. Limitations in cohort size precluded statistical analysis of neuropsychological test data.
    Epilepsy research 07/2014; 108(5). DOI:10.1016/j.eplepsyres.2014.03.013 · 2.19 Impact Factor
  • Leeda Ahmadi, Elaine Wirrell
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    ABSTRACT: We present a case of a young boy with a large hemispheric dysplasia, generalized EEG abnormalities and intractable epilepsy who achieved seizure freedom and markedly improved cognitive outcome after functional hemispherectomy.
    Seminars in Pediatric Neurology 06/2014; 21(2):73-5. DOI:10.1016/j.spen.2014.04.005 · 1.88 Impact Factor
  • Elaine Wirrell
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    ABSTRACT: An infant with infantile spasms is presented. Surgical treatment of spasms has increasingly become an option for the management of this difficult disease. This case reviews the issues related to, and the criteria necessary for the successful surgical management of infantile spasms.
    Seminars in Pediatric Neurology 06/2014; 21(2). DOI:10.1016/j.spen.2014.04.011 · 1.88 Impact Factor
  • Seminars in Pediatric Neurology 06/2014; 21(2). DOI:10.1016/j.spen.2014.04.024 · 1.88 Impact Factor
  • Elaine Wirrell
    Seminars in Pediatric Neurology 06/2014; 21(2):137-8. DOI:10.1016/j.spen.2014.05.004 · 1.88 Impact Factor
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    ABSTRACT: We aimed to determine the yield of revising intracranially implanted electrodes and the factors contributing to the yield.
    Journal of clinical neurophysiology: official publication of the American Electroencephalographic Society 06/2014; 31(3):199-202. DOI:10.1097/WNP.0000000000000047 · 1.60 Impact Factor
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    ABSTRACT: Distinguishing between seizures and nonepileptic events is a key challenge in pediatric neurology. The diagnostic gold standard is prolonged inpatient video electroencephalogram monitoring. However, little is known about preadmission characteristics that are predictive of recording an event during such monitoring. This is a retrospective chart review of children undergoing prolonged inpatient video electroencephalogram monitoring between 2009 and 2012 at a tertiary referral center for the purpose of distinguishing between seizures and nonepileptic events. Demographic information, medical history, event characteristics, and inpatient monitoring course were abstracted. Two-hundred thirteen children were identified. The median recording duration was 25 hours (interquartile range 22.4-48.5), and median time to event of interest (among those with an event recorded) was 4.5 hours (interquartile range 1.4-18.8). An event of interest was recorded in 66% of patients. At the event level, 20% of recorded events were associated with an electroencephalogram correlate, which refers to a change in the pattern seen on the electroencephalogram during a seizure. At the patient level, 112 (79.4%) with events recorded had only nonepileptic events recorded, 25 (17.7%) had only seizures recorded, and 4 (2.8%) had both recorded. Recording an event was predicted by the presence of intellectual disability (P = 0.001), greater preadmission event frequency (P < 0.001), and shorter latency since most recent event (P < 0.001). Prolonged inpatient electroencephalogram monitoring captured an event of interest in two-thirds of patients, with most of these events captured within less than four and a half hours of recording onset. Several factors predict a greater yield with prolonged inpatient video electroencephalogram monitoring-including event frequency, latency since the most recent event, and the presence of intellectual disability-and can be used to counsel patients regarding this study for the purpose of event capture in the context of shared decision making.
    Pediatric Neurology 05/2014; 50(5):458-63. DOI:10.1016/j.pediatrneurol.2014.01.038 · 1.50 Impact Factor
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    ABSTRACT: Background Mutations in the voltage-gated sodium channel SCN1A gene are responsible for the majority of Dravet syndrome cases. There is evidence that Nav1.1 channel coded by the SCN1A gene is involved in sleep regulation. We evaluated sleep abnormalities in children with Dravet syndrome using nocturnal polysomnography. Methods We identified six children at our institution with genetically confirmed Dravet syndrome who had also undergone formal sleep consultation with nocturnal polysomnography. Indications for polysomnography were parental concern of daytime fatigue or sleepiness, hyperactivity, inattention, disruptive behavior, nighttime awakenings or nocturnal seizures. Sleep studies were scored according to guidelines of the American Academy of Sleep Medicine and NREM cyclic alternating pattern was visually identified and scored according to established methods. Results The mean age of the subjects at the time of polysomnography was 6 years. Standard polysomnography did not show any consistent abnormalities in the obstructive or central apnea index, arousal index, sleep efficiency or architecture. Cyclic alternating pattern analysis on 5 subjects showed an increased mean rate of 50.3% (vs 31-34% in neurological normal children) with a mild increase in A1 subtype of 89.4% (vs. 84.5%). A2/A3 subtype (5.3% vs. 7.3%), and B phase duration (22.4 vs. 24.7 seconds) were similar to previously reported findings in neurologically normal children. Conclusion Despite parental concerns for sleep disturbance in patients with Dravet syndrome, we could not identify abnormalities in sleep macroarchitecture. NREM sleep microarchitecture was, however, abnormal, with increased A1 subtype; resembling a trace´ alternant pattern of neonates and possibly suggestive of cortical synaptic immaturity in Dravet syndrome. Larger studies are needed to replicate these results.
    Pediatric Neurology 05/2014; DOI:10.1016/j.pediatrneurol.2014.01.017 · 1.50 Impact Factor
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    ABSTRACT: Background Predictors of ketogenic diet success in treating pediatric intractable epilepsy are not well understood. The aim of this study was to determine if initial body mass index and weight percentile impact early efficacy of the traditional ketogenic diet in children initiating therapy for intractable epilepsy. Methods This retrospective study included all children initiating the ketogenic diet at Mayo Clinic, Rochester from January 2001-December 2010 who had body mass index (children >2 years of age) or weight percentile (those <2 years of age) documented at diet initiation and seizure frequency recorded at diet initiation and one month. Responders were defined as achieving a >50% seizure reduction from baseline. Results Our cohort consisted of 48 patients (20 male) with a median age of 3.1 years. There was no significant correlation between initial body mass index or weight percentile and seizure frequency reduction at one month (P = 0.72, r = 0.26 and P = 0.91, r = 0.03). There was no significant association between body mass index or weight percentile quartile and responder rates (P = 0.21 and P = 0.57). Children considered overweight or obese at diet initiation (body mass index or weight percentile ≥85) did not have lower responder rates than those with body mass index or weight percentiles <85 (6/14 vs 19/34, respectively, P = 0.41). Conclusions Higher initial body mass index and weight-for-age percentiles do not adversely affect the efficacy of the ketogenic diet.
    Pediatric Neurology 05/2014; DOI:10.1016/j.pediatrneurol.2014.01.014 · 1.50 Impact Factor
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    ABSTRACT: Objective This study aimed to identify long-term seizure outcome in pediatric nonsyndromic focal epilepsy after failure of serial antiepileptic drugs (AEDs) due to lack of efficacy. Methods Children (1 month–17 years) with new-onset focal epilepsy not meeting the criteria for a defined electroclinical syndrome diagnosed between 1980 and 2009 while residing in Olmsted County, MN, were retrospectively identified. Medical records of those followed for ≥ 2 years were reviewed to assess etiology, the number of AEDs that failed due to lack of efficacy, and seizure outcome at final follow-up. Etiology was classified into structural/metabolic, genetic, or unknown. Favorable outcome was defined as seizure freedom ≥ 1 year, on or off AEDs, without prior epilepsy surgery. Poor outcome was defined as ongoing seizures in the preceding year or having undergone prior epilepsy surgery. Results Nonsyndromic focal epilepsy accounted for 275/468 (59%) of all patients with newly diagnosed epilepsy — of these, 256 (93%) were followed for a minimum of two years and were included in the study. Median duration of follow-up was 10.0 years. At least one AED had failed due to lack of efficacy in 100 (39.1%) children. Favorable outcomes occurred in 149/156 (95.5%) children with no AED failure, 16/30 (53.3%) with one AED failure, 8/25 (32%) with two AED failures, and only 2/45 (4.4%) with three AED failures. After two AED failures, the seizures of nearly one-quarter of children who had epilepsy with an unknown cause responded favorably to the third AED compared with only 7.8% of the cohort that had epilepsy with a structural/metabolic cause. Children with a remote brain insult had a significantly higher likelihood of favorable outcome with serial AEDs than those with other structural abnormalities. Significance Etiology is an important determinant of pharmacoresistance in nonsyndromic focal epilepsy. Surgical evaluation should be considered after failure of 1–2 AEDs in those who have epilepsy with structural causes, excluding remote brain insults. Conversely, as surgical success is lower with normal MRI or more diffuse brain insults, it appears reasonable to hold off surgical evaluation until 2–3 AEDs have failed in such children.
    Epilepsy & Behavior 05/2014; 34:20–24. DOI:10.1016/j.yebeh.2014.02.032 · 2.06 Impact Factor
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    ABSTRACT: To evaluate a trial of immunotherapy as an aid to diagnosis in suspected autoimmune epilepsy. We reviewed the charts of 110 patients seen at our autoimmune neurology clinic with seizures as a chief complaint. Twenty-nine patients met the following inclusion criteria: (1) autoimmune epilepsy suspected based on the presence of ≥1 neural autoantibody (n = 23), personal or family history or physical stigmata of autoimmunity, and frequent or medically intractable seizures; and (2) initiated a 6- to 12-week trial of IV methylprednisolone (IVMP), IV immune globulin (IVIg), or both. Patients were defined as responders if there was a 50% or greater reduction in seizure frequency. Eighteen patients (62%) responded, of whom 10 (34%) became seizure-free; 52% improved with the first agent. Of those receiving a second agent after not responding to the first, 43% improved. A favorable response correlated with shorter interval between symptom onset and treatment initiation (median 9.5 vs 22 months; p = 0.048). Responders included 14/16 (87.5%) patients with antibodies to plasma membrane antigens, 2/6 (33%) patients seropositive for glutamic acid decarboxylase 65 antibodies, and 2/6 (33%) patients without detectable antibodies. Of 13 responders followed for more than 6 months after initiating long-term oral immunosuppression, response was sustained in 11 (85%). These retrospective findings justify consideration of a trial of immunotherapy in patients with suspected autoimmune epilepsy. This study provides Class IV evidence that in patients with suspected autoimmune epilepsy, IVMP, IVIg, or both improve seizure control.
    Neurology 04/2014; 82(18). DOI:10.1212/WNL.0000000000000383 · 8.30 Impact Factor
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    ABSTRACT: Medically refractory epilepsy remains a major medical problem worldwide. Although some patients are eligible for surgical resection of seizure foci, a proportion of patients are ineligible for a variety of reasons. One such reason is that the foci reside in eloquent cortex of the brain and therefore resection would result in significant morbidity. This retrospective study reports our experience with a novel neurostimulation technique for the treatment of these patients. We identified three patients who were ineligible for surgical resection of the intracranially identified seizure focus because it resided in eloquent cortex, who underwent therapeutic trial of focal cortical stimulation delivered through the subdural monitoring grid. All three patients had a significant reduction in seizures, and two went on to permanent implantation, which resulted in long-term reduction in seizure frequency. In conclusion, this small case report provides some evidence of proof of concept of the role of targeted continuous neocortical neurostimulation in the treatment of medically refractory focal epilepsy, and provides support for ongoing investigations into this treatment modality. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
    Epilepsia 02/2014; 55(3). DOI:10.1111/epi.12525 · 4.58 Impact Factor
  • Leeda Ahmadi, Elaine Wirrell
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    Daniel Kenney, Elaine Wirrell
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    ABSTRACT: Focal epilepsy accounts for approximately one-half to two-thirds of new-onset epilepsy in children. Etiologies are diverse, and range from benign epilepsy syndromes with normal neuroimaging and almost certain remission to focal malformations of cortical development or hippocampal sclerosis with intractable seizures persisting lifelong. Other important etiologies in children include pre-, peri-, or postnatal brain injury, low-grade neoplasms, vascular lesions, and neuroimmunological disorders. Cognitive, behavioral, and psychiatric comorbidities are commonly seen and must be addressed in addition to seizure control. Given the diverse nature of focal epilepsies in children and adolescents, investigations and treatments must be individualized. First-line therapy consists of prophylactic antiepileptic drugs; however, prognosis is poor after failure of two to three drugs for lack of efficacy. Refractory cases should be referred for an epilepsy surgery workup. Dietary treatments and neurostimulation may be considered in refractory cases who are not good candidates for surgery.
    Adolescent Health, Medicine and Therapeutics 01/2014; 5:49-65. DOI:10.2147/AHMT.S44316
  • Elaine Wirrell

Publication Stats

3k Citations
456.44 Total Impact Points


  • 2008–2015
    • Mayo Clinic - Rochester
      • • Department of Neurology
      • • Division of Child and Adolescent Neurology
      Рочестер, Minnesota, United States
  • 2014
    • Central Arkansas Veterans Healthcare System
      Washington, Washington, D.C., United States
  • 2001–2012
    • The University of Calgary
      • • Division of Neurology
      • • Department of Paediatrics
      • • Section of Paediatric Neurology
      • • Department of Clinical Neurosciences
      • • Faculty of Medicine
      Calgary, Alberta, Canada
  • 2006
    • University of Ottawa
      • Department of Pediatrics
      Ottawa, Ontario, Canada
  • 2005
    • University of Alberta
      Edmonton, Alberta, Canada
  • 1998–2002
    • University of Saskatchewan
      • • Department of Pediatrics
      • • Department of Medical Imaging
      Saskatoon, Saskatchewan, Canada
  • 1997–1998
    • Royal University Hospital
      Saskatoon, Saskatchewan, Canada
  • 1996
    • IWK Health Centre
      Halifax, Nova Scotia, Canada
  • 1993–1996
    • Dalhousie University
      • Department of Pediatrics
      Halifax, Nova Scotia, Canada