EEG Value in Recurrent Stereotypical Events of Transient Neurological Dysfunction

An electroencephalogram (EEG) is frequently used in the evaluation of recurrent and stereotypical events of transient neurological dysfunction (TND), which may be clinically similar to epileptic seizures.

To assess whether the EEG findings prompted a change of diagnosis or treatment of TND.

A retrospective review of the inpatient computerized medical information management system and the EEG laboratory computerized database for adult inpatients who had a standard or sleep-deprived EEG following TND during a 3-year period (2019-2021).

One hundred forty-five patients with TND, aged 63.4 ± 17.2 (range: 18-97), had a standard (135) (93.1%) or a sleep-deprived (10) (6.9%) EEG. Interictal epileptiform discharges (IEDs) were recorded in six (4.1%) patients. Antiseizure medications (ASMs) were initiated in 17 (11.7%) patients, and 10 (6.9%) had a discharge diagnosis of epilepsy. Patients with IEDs on the EEG were more likely to be diagnosed with epilepsy (p = 0.025) and to initiate ASM treatment (p = 0.011). The EEG led to a diagnosis change in one (0.7%) patient and to ASM initiation in three (2.1%) patients.

The diagnostic yield of EEG and its impact on diagnosis and treatment in patients with recurrent stereotypical events of TND were low. Further research is warranted on the effect of structured history on the use of inpatient EEG and its diagnostic yield in patients with TND.