Clinical and anamnestic characteristics of patients with unilateral and bilateral epileptiform discharges of temporal localization

The prevalence of bilateral interictal epileptiform discharges (EDs) in focal temporal lobe epilepsy (FTLE) reaches up to 60%. Some authors classify unilateral and bilateral interictal discharges of temporal localization as neurophysiological phenotypes of FTLE, while others believe these are two groups of diseases differing in etiology, clinical manifestations, and treatment strategies.

Objective: to compare clinical and anamnestic data and magnetic resonance imaging (MRI) results of the brain in patients with unilateral and bilateral interictal EDs of temporal localization.

Material and methods. The study included 130 patients [78 (60%) men and 52 (40%) women aged 21 to 73 years (mean age – 41.7 years)], who underwent video EEG monitoring sessions lasting 10–24 hours (bilateral interictal EDs were recorded in 64 sessions, and EDs originating from one temporal region in 66 sessions). MRI using the HARNESS-MRI protocol for epilepsy was performed on a 3T scanner.

Results. The duration of FTLE in patients with unilateral EDs was 10.5 [5.0; 19.0] years, and in patients with bilateral EDs – 13.5 [5.0; 24.5] years (p=0.307). The onset of FTLE in the group with bilateral EDs occurred at the age of 27.0 [15.0; 38.0] years (in patients with unilateral EDs – 24.5 [14.0; 40.0] years; p=0.911). Unilateral EDs in the left temporal region predominated in 66.7% of patients, and in the right temporal region – in 33.3%. EDs originating from both temporal regions were characterized by the absence of interhemispheric differences (the left temporal region was dominant in 48.4% of patients, the right – in 51.6%).

Conclusion. The obtained results indicate that dividing patients with FTLE into separate groups with unilateral and bilateral EDs is not justified.

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