The diagnostic accuracy of routine electroencephalography after a first unprovoked seizure

Abstract

The clinical utility of routine electroencephalography (EEG) after a first unprovoked seizure remains uncertain. Its diagnostic accuracy in identifying adults and children with new onset epilepsy was examined. A systematic review and meta-analysis of studies examining individuals who underwent routine EEG after a first unprovoked seizure and were followed for seizure recurrence for at least 1 year was performed. A 'positive' test was defined by the presence of epileptiform discharges (ED). Pooled sensitivity and specificity estimates were calculated using a bivariate random effects regression model. In all, 3096 records were reviewed, from which 15 studies were extracted with a total of 1799 participants. Amongst adult studies, the sensitivity and specificity (95% confidence interval) of routine EEG were 17.3% (7.9, 33.8) and 94.7% (73.7, 99.1), respectively. Amongst child studies, the pooled sensitivity and specificity were 57.8% (49.7, 65.6) and 69.6% (57.5, 79.5), respectively. Based upon our positive likelihood ratios, and assuming a pre-test probability of 50%, an adult with ED on routine EEG after a first unprovoked seizure has a 77% probability of having a second seizure, whilst a child with similar findings has a 66% probability. Further studies are required to examine the impact of patient characteristics and EEG features on the diagnostic accuracy of routine EEG for new onset epilepsy.

Electroencephalography after a single unprovoked seizure

“…In the same systematic review, when considering studies involving children, routine EEG after a single unprovoked seizure was found to have a sensitivity and specificity for seizure recurrence of 57.8% and 69.6% respectively. This corresponded to a post-test probability of developing recurrent seizures of 66% when epileptiform abnormalities were observed and 38% when absent [11]. This is in keeping with previous findings in general pediatric populations (e.g., [4]).…”

“…A previous meta-analysis showed a post-test probability of epilepsy in 49.5% of those with epileptiform abnormalities on EEG and 27.4% in those without [2]. It was felt that the difference might have been related to the addition of more recent studies and the strict eligibility criteria for study inclusion [11]. Nevertheless, in both systematic reviews, the presence of epileptiform discharges on EEG in the context of a single unprovoked seizure was predictive of the development of recurrent seizures.…”

“…The presence of any EEG abnormality (an epileptiform abnormality and/or focal slowing of background rhythms) predicted seizure recurrence (e.g., [9,10]), although the presence of epileptiform discharges was thought to offer more predictive ability. A systematic review and meta-analysis of 15 studies examining the diagnostic accuracy of routine EEG after a single unprovoked seizure demonstrated, in adults, a sensitivity and specificity of interictal epileptiform discharge for seizure recurrence of 17.3% and 94.7% respectively [11]. This corresponded to a 77% post-test probability of recurrent seizures when epileptiform discharges were seen and a 47% post-test probability of recurrent seizures when not.…”

Diagnostic Accuracy of the Ambulatory EEG vs. Routine EEG for First Single Unprovoked Seizures and Seizure Recurrence: The DX-Seizure Study

“…If abnormalities on the routine EEG are found, such as focal spikes and generalized spike waves, the risk of seizure recurrence increases two times. However, the routine EEG has its limitations as its accuracy to detect abnormalities after a FSUS has a sensitivity of 17% and specificity of 95% (7). Previous studies have shown that some factors affect the accuracy of recording abnormalities in the routine EEG in FSUS, such as early recording (up to 72 h) relative to the index event (8,9).…”

Advances and insights into neurological practice 2016−17

“…Epilepsy likewise represents another neurological disorder with significant societal and economic consequences, as well as medical [177][178][179][180][181][182][183][184][185][186][187][188][189][190]. Treatments for epilepsy have been available for many years; a recent study on the long term prognosis of epilepsy found 59% of patients were seizure free, with a progressive increase in remission over time [184].…”