5 The authors conclude that 48 hours of ambulatory EEG monitoring was sufficient for electro-clinical classification of 95% of patients in the cohort.
4 In a separate study, the same group reported the median latency to first IED was 316 min (IQR 70-772 min) in 180 patients with epilepsy. In a retrospective study of 324 outpatient ambulatory EEGs, Faulkner and colleagues identified 219 (68%) studies with positive data, 116 (36%) exhibiting interictal epileptiform discharges, 167 (52%) with events, and 105 (32%) studies that were normal. While inpatient video EEG monitoring is still considered to the gold standard, a far more cost-effective and quite effective approach to achieve the same ends is ambulatory EEG.Īmbulatory EEG can increase the yield of interictal epileptiform detection compared to routine EEG. 2,3 The obvious disadvantage of this approach is that it is prohibitively expensive in most cases. The main advantage of this approach is the ability to detect simultaneous seizure and convulsive activity and to rule out pseudoseizures and psychogenic nonepileptic seizures. 1 One approach to improve diagnosis is video EEG monitoring-patients are hospitalized in a specialized unit for up to a week where they undergo constant EEG monitoring and video surveillance. For example, interictal EEG abnormalities appear in just one in four adults presenting with their first unprovoked seizure. However, the diagnostic yield of this procedure is relatively low. We discuss the clinical indications for ambulatory EEG.Īmbulatory EEG is used to diagnose seizure disorderĪ routine EEG is an essential part of the workup for the first seizure. Just as cardiologists have adopted Holter monitoring into clinical practice, so too have neurologists turned to ambulatory EEG for certain diagnostic purposes. While these studies have their respective places in diagnostic medicine, they are limited in their ability to detect sporadic events such as paroxysmal atrial fibrillation in the former case, or a seizure event in the latter. A standard ECG captures 10 seconds of the heart’s electrical activity while a standard EEG captures perhaps 10 to 20 minutes of the brain’s electrical activity. Routine electroencephalography (EEG) suffers from the same problem as a standard 12 lead electrocardiogram (ECG): it is limited in time.