Consultant for Pediatricians.
No. 11
Differentiating Epileptic Seizures From Nonepileptic Spells
By DONALD OLSON, MD |
November 1, 2008
Stanford University
Dr Olson is associate professor of neurology and pediatrics at Stanford University School of Medicine in Stanford, Calif.
Ideally, a seizure event should be captured on EEG, but this is seldom practical in the outpatient laboratory. If the events are reasonably frequent, a long-term EEG that records the habitual attacks helps provide diagnostic certainty.38 Both inpatient and outpatient long-term EEG are feasible, and outpatient video recording during EEG is increasingly practical, but the inpatient setting provides much more control over video recording conditions. For seizures with altered consciousness, the EEG will almost always show some paroxysmal change, and most of the time an evolving rhythmic ictal discharge will be apparent if the seizures are epileptic. Exceptions include some frontal lobe seizures in which the epileptogenic cortex is distant from recording scalp electrodes, such as in the mesial frontal or the orbital frontal region. Even in such cases, a paroxysmal EEG change, such as slowing, will be evident, but prominent movement artifacts may obscure the EEG. Other exceptions include auras or simple partial seizures. Not enough of the cortex may be synchronized to allow recording of the rhythmic discharges from the scalp electrodes.39 Because it is important that children who are hospitalized for video EEG recordings have their habitual seizures, antiepileptic drugs often are tapered. For patients with mixed epileptic and nonepileptic events, drug tapering presents a problem because drug withdrawal may simply uncover the epileptic attacks that were pharmacologically controlled, although the patient may also experience nonepileptic spells. It is important to document the variety of attacks in question and make sure that the video EEG captures the habitual events and not anomalous seizures that are provoked solely by medication withdrawal. CLINICAL HIGHLIGHTS - The distinction between epileptic seizures and syncope can be particularly challenging. Transient loss of consciousness-particularly if accompanied by body stiffening-can suggest seizures, but positive motor signs are common in syncope.
- Conversion disorders can manifest as psychogenic nonepileptic seizures (PNES) in adults and children. A history of significant social stresses points to the possibility of PNES.
- Behavioral nonepileptic events such as inattention or daydreaming may be hard to distinguish from absence seizures unless there is a clear history of a lack of response to physical stimulation. An electroencephalogram (EEG) is helpful, because untreated persons with absence epilepsy will almost always have generalized spike wave discharges.
- An EEG performed in the first 24 hours after a presumed seizure will show epileptiform abnormalities 51% of the time. Repeated EEGs, sleep deprivation before the EEG, and sleep recorded during the EEG all increase the likelihood of recording epileptiform discharges.
1.Kerrigan JF, Ng YT, Chung S, Rekate HL. The hypothalamic hamartoma: a model of subcortical epileptogenesis and encephalopathy. Semin Pediatr Neurol. 2005;12:119-131.
2.Norden AD, Blumenfeld H. The role of subcortical structures in human epilepsy. Epilepsy Behav. 2002;3:219-231.
3.Hauser WA, Annegers JF, Rocca WA. Descriptive epidemiology of epilepsy: contributions of population- based studies from Rochester, Minnesota. Mayo Clin Proc. 1996;71:576-586.
4.ILAE classification of epilepsies: its applicability and practical value of different diagnostic categories. Osservatorio Regionale per L’Epilessia (OREp), Lombardy. Epilepsia. 1996;37:1051-1059.
5.Berg AT, Shinnar S. The risk of seizure recurrence following a first unprovoked seizure: a quantitative review. Neurology. 1991;41:965-972.
6.Holmes GL, Zhao Q. Choosing the correct antiepileptic drugs: from animal studies to the clinic. Pediatr Neurol. 2008;38:151-162.
7.Shinnar S, Berg AT, Moshe SL, Shinnar R. How long do new-onset seizures in children last? Ann Neurol. 2001;49:659-664.
8.Camfield C, Camfield P, Gordon K, Dooley J. Does the number of seizures before treatment influence ease of control or remission of childhood epilepsy? Not if the number is 10 or less. Neurology. 1996;46:41-44.
9.Provenzale JM, Barboriak DP, VanLandingham K, et al. Hippocampal MRI signal hyperintensity after febrile status epilepticus is predictive of subsequent mesial temporal sclerosis. AJR. 2008;190:976-983.
10.Bender RA, Baram TZ. Epileptogenesis in the developing brain: what can we learn from animal models? Epilepsia. 2007;48(suppl 5):2-6.
11.De Santis A, Sganzerla E, Spagnoli D, et al. Risk factors for late posttraumatic epilepsy. Acta Neurochir Suppl (Wien). 1992;55:64-67.
12.Willmore LJ. Posttraumatic epilepsy. Neurol Clin. 1992;10:869-878.
13.Moldavsky M, Stein D. Munchausen syndrome by proxy: two case reports and an update of the literature. Int J Psychiatry Med. 2003;33:411-423.
14.Willis T, Roper H, Rabb L. Lamotrigine poisoning presenting as seizures: a case of deliberate poisoning. Child Abuse Negl. 2007;31:85-88.
15.Di Rosa G, Spanò M, Pustorino G, et al. Alternating hemiplegia of childhood successfully treated with topiramate: 18 months of follow-up. Neurology. 2006;66:146.
16.Neville BG, Ninan M. The treatment and management of alternating hemiplegia of childhood. Dev Med Child Neurol. 2007;49:777-780.
17.Di Capua M, Fusco L, Ricci S, Vigevano F. Benign neonatal sleep myoclonus: clinical features and video-polygraphic recordings. Mov Disord. 1993;8:191-194.
18.Goraya JS, Virdi VS. Persistence of breathholding spells into late childhood. J Child Neurol. 2001;16:697-698.
19.Lombroso CT, Lerman P. Breathholding spells (cyanotic and pallid infantile syncope). Pediatrics. 1967;39:563-581.
20.Daoud AS, Batieha A, al-Sheyyab M, et al. Effectiveness of iron therapy on breath-holding spells. J Pediatr.1997;130:547-550.
21.Nanayakkara CS, Paton JY. Sandifer syndrome: an overlooked diagnosis? Dev Med Child Neurol. 1985;27:816-819.
22.Somjit S, Lee Y, Berkovic SF, Harvey AS. Sandifer syndrome misdiagnosed as refractory partial seizures in an adult. Epileptic Disord. 2004;6:49-50.
23.Benton TJ, Narayanan D. Differentiating seizure and convulsive syncope: the importance of history taking. Postgrad Med. 2008;120:50-53.
24.McKeon A, Vaughan C, Delanty N. Seizure versus syncope. Lancet Neurol. 2006;5:171-180.
25.Strzelczyk A, Bauer S, Knake S, et al. Ictal asystole in temporal lobe epilepsy before and after pacemaker implantation. Epileptic Disord. 2008;10:39-44.
26.Chung SS, Gerber P, Kirlin KA. Ictal eye closure is a reliable indicator for psychogenic nonepileptic seizures. Neurology. 2006;66:1730-1731.
27.Peguero E, Abou-Khalil B, Fakhoury T, Mathews G. Self-injury and incontinence in psychogenic seizures. Epilepsia. 1995;36:586-591.
28.Olson DM, Howard N, Shaw RJ. Hypnosisprovoked nonepileptic events in children. Epilepsy Behav. 2008;12:456-459.
29.Barry JJ, Atzman O, Morrell MJ. Discriminating between epileptic and nonepileptic events: the utility of hypnotic seizure induction. Epilepsia. 2000;41:81-84.
30.Selwa LM, Geyer J, Nikakhtar N, et al. Nonepileptic seizure outcome varies by type of spell and duration of illness. Epilepsia. 2000;41:1330-1334.
31.Lüders HO. Paroxysmal choreoathetosis. Eur Neurol. 1996;36(suppl 1):20-23.
32.Goldsmith IL, Zupanc ML, Buchhalter JR. Long-term seizure outcome in 74 patients with Lennox-Gastaut syndrome: effects of incorporating MRI head imaging in defining the cryptogenic sub-- group. Epilepsia. 2000;41:395-399.
33.Castillo EM, Butler IJ, Baumgartner JE, et al. When epilepsy interferes with word comprehension: findings in Landau-Kleffner syndrome. J Child Neurol. 2008;23:97-101.
34.Trevathan E. Seizures and epilepsy among children with language regression and autistic spectrum disorders. J Child Neurol. 2004;19(suppl 1):S49-S57.
35.Nickels K, Wirrell E. Electrical status epilepticus in sleep. Semin Pediatr Neurol. 2008;15:50-60.
36.King MA, Newton MR, Jackson GD, et al. Epileptology of the first-seizure presentation: a clinical, electroencephalographic, and magnetic resonance imaging study of 300 consecutive patients. Lancet. 1998;352:1007-1011.
37.Ellingson RJ, Wilken K, Bennett DR. Efficacy of sleep deprivation as an activation procedure in epilepsy patients. J Clin Neurophysiol. 1984;1:83-101.
38.Olson DM. Success of ambulatory EEG in children. J Clin Neurophysiol. 2001;18:158-161.
39.Devinsky O, Sato S, Kufta CV, et al. Electroencephalographic studies of simple partial seizures with subdural electrode recordings. Neurology. 1989;39:527-533.
40.Rosenow F, Wyllie E, Kotagal P, et al. Staring spells in children: descriptive features distinguishing epileptic and nonepileptic events. J Pediatr. 1998;133: 660-663.
41.Pachatz C, Fusco L, Vigevano F. Benign myoclonus of early infancy. Epileptic Disord. 1999;1:57-61.
42.Wulff CH, Ostergaard JR, Storm K. Epileptic fits or infantile masturbation? Seizure. 1992;1:199-201.
43.Panayiotopoulos CP. Elementary visual hallucinations, blindness, and headache in idiopathic occipital epilepsy: differentiation from migraine. J Neurol Neurosurg Psychiatry. 1999;66:536-540.
44.Haut SR, Bigal ME, Lipton RB. Chronic disorders with episodic manifestations: focus on epilepsy and migraine. Lancet Neurol. 2006;5:148-157.
45.Hart YM, Andermann F. Migraine aura, seizures, and temporal lobe epilepsy. Adv Neurol. 1999;81:145-152.
46.Lombroso CT. Pavor nocturnus of proven epileptic origin. Epilepsia. 2000;41:1221-1226.
47.Brower MC, Price BH. Epilepsy and violence: when is the brain to blame? Epilepsy Behav. 2000;1: 145-149.
48.Fleisher DR, Gornowicz B, Adams K, et al. Cyclic vomiting syndrome in 41 adults: the illness, the patients, and problems of management. BMC Med. 2005;21:20.
49.Shuper A, Goldberg-Stern H. Ictus emeticus(ictal vomiting). Pediatr Neurol. 2004;31:283-286.
50.Panayiotopoulos CP. Benign childhood epileptic syndromes with occipital spikes: new classification proposed by the International League Against Epilepsy. J Child Neurol. 2000;15:548-552.
51.Marcelli V, Piazza F, Pisani F, Marciano E. Neuro-otological features of benign paroxysmal vertigo and benign paroxysmal positioning vertigo in children: a follow-up study. Brain Dev. 2006;28:80-84.
52.Salvinelli F, Firrisi L, Casale M, et al. Benign paroxysmal positional vertigo: diagnosis and treatment. Clin Ter. 2004;155:395-400.
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