The yield and clinical utility of outpatient short-term video-electroencephalographic monitoring: a five-year retrospective study.

Outpatient short-term video-electroencephalographic monitoring (OVEM) is recognized as a useful tool in the diagnosis of epilepsy and other paroxysmal disorders. The aim of this retrospective study was to determine the diagnostic yield of OVEM. We analyzed 175 OVEM records of adults (111 females and 64 males) referred over a period of 5 years. The mean length of recording was 3.8 h. The highest yield was found in psychogenic nonepileptic seizures (PNES) (37.1%), followed by interictal epileptiform discharges (17.2%), and epileptic seizures (6.9%). The provisional diagnosis was epilepsy in 77.7% and PNES in 22.3% before the test. Outpatient short-term video-electroencephalographic monitoring changed the pre-test diagnosis in 30.9% of patients. Outpatient short-term video-electroencephalographic monitoring is a useful diagnostic test for PNES. It has a higher yield for PNES than epilepsy. Crown