Video and ambulatory EEG monitoring in the diagnosis of seizures and epilepsy
- Lawrence J Hirsch, MD
Lawrence J Hirsch, MD
- Professor of Neurology
- Yale University School of Medicine
- Division of Epilepsy and EEG
- Yale Comprehensive Epilepsy Center
- Hiba Arif Haider, MD
Hiba Arif Haider, MD
- Division of Epilepsy, Department of Neurology
- Emory University School of Medicine
- Atlanta, GA
- Jeremy Moeller, MD
Jeremy Moeller, MD
- Assistant Professor of Neurology
- Yale University School of Medicine
It can be difficult to make a diagnosis of epilepsy, and misdiagnosis is not rare . In most cases, a detailed history and a reliable account of the event by an eyewitness is sufficient to make a diagnosis, but this may not always be available. In addition, certain types of nonepileptic events can be difficult to distinguish from seizures, and certain types of seizures can be misdiagnosed as nonepileptic events .
An interictal electroencephalogram (EEG) can provide evidence that helps to confirm or refute the diagnosis of epilepsy, but has many limitations. The most helpful finding on EEG is interictal epileptiform discharges (IEDs), but this finding has imperfect sensitivity and specificity. For patients with recurrent events and nondiagnostic interictal EEG findings, or lack of response to treatment, EEG monitoring is often required to distinguish epileptic seizures from nonepileptic events (table 1). EEG monitoring can be done in the outpatient setting (ambulatory-EEG monitoring) or in the inpatient setting, with combined continuous video monitoring (video-EEG monitoring).
This topic discusses the use of EEG monitoring in the diagnosis of seizures and epilepsy. More detailed discussions of routine EEG, and the use of other diagnostic tests in the evaluation of patients with seizures and epilepsy are presented separately. The differential diagnosis of seizures is also presented separately. (See "Electroencephalography (EEG) in the diagnosis of seizures and epilepsy" and "Neuroimaging in the evaluation of seizures and epilepsy" and "Evaluation and management of the first seizure in adults" and "Nonepileptic paroxysmal disorders in adolescents and adults".)
Ambulatory-EEG (aEEG) monitoring allows prolonged EEG recording outside the hospital or clinic setting. The technology has evolved such that portable recordings of up to 36 channels, over several days are possible . Typically, computer software designed to detect electrographic seizures and interictal epileptiform discharges (IEDs) assists in interpretation. However, no program has high specificity and sensitivity, and prolonged segments of the study, ideally the entire study, should be reviewed in their entirety as resources allow. Patients and observers also have the opportunity to "tag" portions of the recording during clinical events using a push button device. Some systems have the added capability of simultaneous electrocardiogram, pulse oximetry, polysomnography, and/or video recording.
aEEG is less expensive than inpatient video-EEG monitoring, with costs that are 51 to 65 percent lower than a 24-hour inpatient admission for video-EEG monitoring [3,4]. However, inpatient video-EEG has several advantages that make it the gold standard test in differentiating epileptic from nonepileptic seizures. (See 'Video-EEG monitoring' below.)
Subscribers log in hereLiterature review current through: Jun 2017. | This topic last updated: Dec 11, 2015.References
- Kanner AM. Common errors made in the diagnosis and treatment of epilepsy. Semin Neurol 2008; 28:364.
- Cascino GD. Use of routine and video electroencephalography. Neurol Clin 2001; 19:271.
- Schomer DL. Ambulatory EEG telemetry: how good is it? J Clin Neurophysiol 2006; 23:294.
- Foley CM, Legido A, Miles DK, et al. Long-term computer-assisted outpatient electroencephalogram monitoring in children and adolescents. J Child Neurol 2000; 15:49.
- Liporace J, Tatum W 4th, Morris GL 3rd, French J. Clinical utility of sleep-deprived versus computer-assisted ambulatory 16-channel EEG in epilepsy patients: a multi-center study. Epilepsy Res 1998; 32:357.
- Walczak, T, Scheuer, M, Resor, S, Pedley, T. Prevalence and features of epilepsy without interictal epileptiform discharges. Neurology 1993; 43:287.
- Schachter SC, Ito M, Wannamaker BB, et al. Incidence of spikes and paroxysmal rhythmic events in overnight ambulatory computer-assisted EEGs of normal subjects: a multicenter study. J Clin Neurophysiol 1998; 15:251.
- Olson DM. Success of ambulatory EEG in children. J Clin Neurophysiol 2001; 18:158.
- Morris GL 3rd, Galezowska J, Leroy R, North R. The results of computer-assisted ambulatory 16-channel EEG. Electroencephalogr Clin Neurophysiol 1994; 91:229.
- Yogarajah M, Powell HW, Heaney D, et al. Long term monitoring in refractory epilepsy: the Gowers Unit experience. J Neurol Neurosurg Psychiatry 2009; 80:305.
- Lawley A, Evans S, Manfredonia F, Cavanna AE. The role of outpatient ambulatory electroencephalography in the diagnosis and management of adults with epilepsy or nonepileptic attack disorder: A systematic literature review. Epilepsy Behav 2015; 53:26.
- Faulkner HJ, Arima H, Mohamed A. The utility of prolonged outpatient ambulatory EEG. Seizure 2012; 21:491.
- Blum DE, Eskola J, Bortz JJ, Fisher RS. Patient awareness of seizures. Neurology 1996; 47:260.
- Gotman J. Automatic seizure detection: improvements and evaluation. Electroencephalogr Clin Neurophysiol 1990; 76:317.
- Tatum WO 4th, Winters L, Gieron M, et al. Outpatient seizure identification: results of 502 patients using computer-assisted ambulatory EEG. J Clin Neurophysiol 2001; 18:14.
- Koepp MJ, Farrell F, Collins J, Smith S. The prognostic value of long-term ambulatory electroencephalography in antiepileptic drug reduction in adults with learning disability and epilepsy in long-term remission. Epilepsy Behav 2008; 13:474.
- Goodwin E, Kandler RH, Alix JJ. The value of home video with ambulatory EEG: a prospective service review. Seizure 2014; 23:480.
- Faulkner HJ, Arima H, Mohamed A. Latency to first interictal epileptiform discharge in epilepsy with outpatient ambulatory EEG. Clin Neurophysiol 2012; 123:1732.
- Worrell GA, Lagerlund TD, Buchhalter JR. Role and limitations of routine and ambulatory scalp electroencephalography in diagnosing and managing seizures. Mayo Clin Proc 2002; 77:991.
- Moien-Afshari F, Griebel R, Sadanand V, et al. Safety and yield of early cessation of AEDs in video-EEG telemetry and outcomes. Can J Neurol Sci 2009; 36:587.
- Friedman DE, Hirsch LJ. How long does it take to make an accurate diagnosis in an epilepsy monitoring unit? J Clin Neurophysiol 2009; 26:213.
- Moseley BD, Dewar S, Haneef Z, Stern JM. How long is long enough? The utility of prolonged inpatient video EEG monitoring. Epilepsy Res 2015; 109:9.
- Muniz J, Benbadis SR. Repeating video/EEG monitoring: why and with what results? Epilepsy Behav 2010; 18:472.
- Alving J, Beniczky S. Diagnostic usefulness and duration of the inpatient long-term video-EEG monitoring: findings in patients extensively investigated before the monitoring. Seizure 2009; 18:470.
- Guaranha MS, Garzon E, Buchpiguel CA, et al. Hyperventilation revisited: physiological effects and efficacy on focal seizure activation in the era of video-EEG monitoring. Epilepsia 2005; 46:69.
- Jonas J, Vignal JP, Baumann C, et al. Effect of hyperventilation on seizure activation: potentiation by antiepileptic drug tapering. J Neurol Neurosurg Psychiatry 2011; 82:928.
- Malow BA, Passaro E, Milling C, et al. Sleep deprivation does not affect seizure frequency during inpatient video-EEG monitoring. Neurology 2002; 59:1371.
- Marciani MG, Gotman J, Andermann F, Olivier A. Patterns of seizure activation after withdrawal of antiepileptic medication. Neurology 1985; 35:1537.
- Marks DA, Katz A, Scheyer R, Spencer SS. Clinical and electrographic effects of acute anticonvulsant withdrawal in epileptic patients. Neurology 1991; 41:508.
- Fisch BJ, So EL. Activation Methods. In: Current practice of Clinical Electroencephalography, Third, Ebersole JS, Pedley TA. (Eds), Lippincott Williams & Wilkins, Philadelphia 2003.
- Rizvi SA, Hernandez-Ronquillo L, Wu A, Téllez Zenteno JF. Is rapid withdrawal of anti-epileptic drug therapy during video EEG monitoring safe and efficacious? Epilepsy Res 2014; 108:755.
- Jehi L. Antiepileptic Drug Management in the Epilepsy Monitoring Unit: Any Standards? Epilepsy Curr 2016; 16:116.
- Millett CJ, Johnson AL, Thompson PJ, Fish DR. A study of the relationship between participation in common leisure activities and seizure occurrence. Acta Neurol Scand 2001; 103:300.
- Noe KH, Drazkowski JF. Safety of long-term video-electroencephalographic monitoring for evaluation of epilepsy. Mayo Clin Proc 2009; 84:495.
- Dobesberger J, Walser G, Unterberger I, et al. Video-EEG monitoring: safety and adverse events in 507 consecutive patients. Epilepsia 2011; 52:443.
- Arrington DK, Ng YT, Troester MM, et al. Utility and safety of prolonged video-EEG monitoring in a tertiary pediatric epilepsy monitoring unit. Epilepsy Behav 2013; 27:346.
- Ryvlin P, Nashef L, Lhatoo SD, et al. Incidence and mechanisms of cardiorespiratory arrests in epilepsy monitoring units (MORTEMUS): a retrospective study. Lancet Neurol 2013; 12:966.
- Labiner DM, Bagic AI, Herman ST, et al. Essential services, personnel, and facilities in specialized epilepsy centers--revised 2010 guidelines. Epilepsia 2010; 51:2322.
- Pati S, Kumaraswamy VM, Deep A, et al. Characteristics of falls in the epilepsy monitoring unit: a retrospective study. Epilepsy Behav 2013; 29:1.
- Surges R, Strzelczyk A, Scott CA, et al. Postictal generalized electroencephalographic suppression is associated with generalized seizures. Epilepsy Behav 2011; 21:271.
- Cuthill FM, Espie CA. Sensitivity and specificity of procedures for the differential diagnosis of epileptic and non-epileptic seizures: a systematic review. Seizure 2005; 14:293.
- Nordli DR Jr. Usefulness of video-EEG monitoring. Epilepsia 2006; 47 Suppl 1:26.
- Binnie CD, Rowan AJ, Overweg J, et al. Telemetric EEG and video monitoring in epilepsy. Neurology 1981; 31:298.
- Smolowitz JL, Hopkins SC, Perrine T, et al. Diagnostic utility of an epilepsy monitoring unit. Am J Med Qual 2007; 22:117.
- Scheepers B, Clough P, Pickles C. The misdiagnosis of epilepsy: findings of a population study. Seizure 1998; 7:403.
- Eirís-Puñal J, Rodríguez-Núñez A, Fernández-Martínez N, et al. Usefulness of the head-upright tilt test for distinguishing syncope and epilepsy in children. Epilepsia 2001; 42:709.
- Oto M, Russell AJ, McGonigal A, Duncan R. Misdiagnosis of epilepsy in patients prescribed anticonvulsant drugs for other reasons. BMJ 2003; 326:326.
- Zaidi A, Clough P, Cooper P, et al. Misdiagnosis of epilepsy: many seizure-like attacks have a cardiovascular cause. J Am Coll Cardiol 2000; 36:181.
- LaFrance WC Jr, Benbadis SR. Differentiating frontal lobe epilepsy from psychogenic nonepileptic seizures. Neurol Clin 2011; 29:149.
- Devinsky O, Kelley K, Porter RJ, Theodore WH. Clinical and electroencephalographic features of simple partial seizures. Neurology 1988; 38:1347.
- Tao JX, Baldwin M, Ray A, et al. The impact of cerebral source area and synchrony on recording scalp electroencephalography ictal patterns. Epilepsia 2007; 48:2167.
- Verma A, Radtke R. EEG of partial seizures. J Clin Neurophysiol 2006; 23:333.
- Benbadis SR, LaFrance WC Jr, Papandonatos GD, et al. Interrater reliability of EEG-video monitoring. Neurology 2009; 73:843.
- Dreifuss FE. Role of intensive monitoring in classification. Adv Neurol 1987; 46:13.
- Sutula TP, Sackellares JC, Miller JQ, Dreifuss FE. Intensive monitoring in refractory epilepsy. Neurology 1981; 31:243.
- Benbadis SR, O'Neill E, Tatum WO, Heriaud L. Outcome of prolonged video-EEG monitoring at a typical referral epilepsy center. Epilepsia 2004; 45:1150.
- Asano E, Pawlak C, Shah A, et al. The diagnostic value of initial video-EEG monitoring in children--review of 1000 cases. Epilepsy Res 2005; 66:129.
- Cascino GD. Video-EEG monitoring in adults. Epilepsia 2002; 43 Suppl 3:80.
- Boylan LS, Labovitz DL, Jackson SC, et al. Auras are frequent in idiopathic generalized epilepsy. Neurology 2006; 67:343.
- Heo JH, Kim DW, Lee SY, et al. Reliability of semiology description. Neurologist 2008; 14:7.
- Hirfanoglu T, Serdaroglu A, Cansu A, et al. Semiological seizure classification: before and after video-EEG monitoring of seizures. Pediatr Neurol 2007; 36:231.
- Eisenman LN, Attarian H, Fessler AJ, et al. Self-reported seizure frequency and time to first event in the seizure monitoring unit. Epilepsia 2005; 46:664.
- Hoppe C, Poepel A, Elger CE. Epilepsy: accuracy of patient seizure counts. Arch Neurol 2007; 64:1595.
- Cambier DM, Cascino GD, So EL, Marsh WR. Video-EEG monitoring in patients with hippocampal atrophy. Acta Neurol Scand 2001; 103:231.
- Porter RJ, Sato S, Long RL. Video recording. Electroencephalogr Clin Neurophysiol Suppl 1985; 37:73.
- Quesney LF, Gloor P. Localization of epileptic foci. Electroencephalogr Clin Neurophysiol Suppl 1985; 37:165.
- AMBULATORY-EEG MONITORING
- Interictal epileptiform discharge (IED) detection
- Ictal recording
- Duration of recording
- VIDEO-EEG MONITORING
- Advantages of video-EEG
- Duration of recording
- Provocative techniques
- - Differential diagnosis
- - Seizure classification
- - Seizure quantification
- - Epilepsy surgery planning
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS