ABSTRACT

Electroencephalography (EEG) is one of the most vital tools in neurology practice. It is used for the diagnosis and differential diagnosis of several clinical conditions. One of them is syncope. In this study, it was planned that a retrospective evaluation of EEGs performed due to syncope in our laboratory and determine the rate of abnormal EEGs.

EEG recordings performed due to syncope were reviewed over a two-years period in this study. The EEG findings were classified as normal and abnormal. The abnormal EEG findings were classified into focal epileptiform discharge, generalized epileptiform discharge, focal slowing and generalized slowing subgroups and analyzed.

The results of 298 EEGs were analyzed, which involved 174 (58.3%) female and 124 (41.6%) male subjects, with a mean age of 38.84±17.83 (min-max: 17–90) years. Among subjects with syncope, 90.6% of the EEGs were normal and 9.4% showed abnormal findings. The most common abnormal finding was focal epileptiform discharge (5.03%). Generalized epileptiform discharge was observed in three (1%), focal slowing in seven (2.3%) and generalized slowing in two (0.6%) subjects. Among the EEG results with no abnormal findings, 38 (12.7%) had sleep-deprived EEG and six (2.1%) were found to have focal epileptiform discharge. A total of 113 (37.9%) subjects had electrocardiogram recording and results were normal.

The rate of abnormal findings in EEGs performed due to syncope is low. EEG may be helpful in some selected subjects with syncope referred to the laboratory with a good history and neurological examination. EEG may be repeated if necessary.

Keywords: Consciousness, EEG, epilepsy, epileptiform discharge, syncope