Diagnostic Yield of Routine Electroencephalography With Concurrent Video Recording in Detecting Interictal Epileptiform Discharges in Relation to Reasons for Request: A Prospective Study of 1,080 Video-Electroencephalograms

Purpose: The aim of this study was to prospectively analyze the sensitivity and specificity of routine electroencephalography with concurrent video recording (vEEG) in relation to the reasons for requesting the test and to investigate when routine vEEG should be requested. Methods: We prospectively analyzed 1,080 consecutive vEEGs performed between April 2015 and April 2016. The requests for vEEG were classified as requests with a low suspicion of epilepsy (syncope, confusion or delirium, suspicion of psychogenic nonepileptic seizures, and paroxysmal focal neurological deficit) or requests with a high suspicion of epilepsy (first clinical seizure, suspected status epilepticus, follow-up study of a patient with epilepsy, and acute symptomatic seizures). Predominant vEEG findings (ictal and interictal epileptiform activities, diffuse, or focal slowing and triphasic waves) were analyzed, and sensitivity and specificity ​​values calculated. Results: The most common indication for vEEG was a follow-up study of patients with epilepsy (38%), followed by first clinical seizure (19.3%) and suspected status epilepticus (11%). The respective specificity and sensitivity values were 93% and 58% for 235 vEEGs performed in children/adolescents (≤18 years), 95% and 40% for 533 vEEGs performed in adults (>18 ≤ 65 years), and 93% and 39% for 312 vEEGs performed in older adults (>65 years). Twenty-four patients with false-positive paroxysms had a clinical diagnosis of confusional state or paroxysmal focal neurological deficit. Neurologists and neuropediatricians with experience in managing epilepsy had higher specificity values than general neurologists or physicians ( P = 0.012). Conclusions: In our series, vEEG abnormalities were mainly observed in patients with clinical findings highly suggestive of epilepsy. In confusional states, and paroxysmal focal neurological deficit vEEG could be indicated.