The severity of seizures and epileptiform activity index in the assessment of antiepileptic treatment efficacy in patients with generalized tonic-clonic awakening seizures

Objective: to evaluate the role of seizure severity and epileptiform activity index (IEA) assessment in newly-diagnosed idiopathic generalized epilepsy with generalized tonic-clonic awakening seizures (GTCS).
Material and methods. The study included 31 patients with newly-diagnosed generalized epilepsy with GTCS aged 14–52 years (mean age 25.06±9.3 years), which were divided into two groups depending on seizure severity: Group 1 (n=9, 29%) with <18 points, and Group 2 (n=22, 71%) with ≥18 points. Seizure severity was analysed by using National Hospital Seizure Severity Scale (NHS3). All patients underwent video-electroencephalography monitoring (8–24 hours) with IEA assessment at baseline and at 1, 3, 6 and 12 months after the beginning of treatment. Therapeutic efficacy was assessed using the criteria of seizure absence (medically induced remission), seizure rate decrease by >50% (responders), seizure rate decrease by <50% (insufficient efficacy), seizure rate increase and retention in treatment.
Results. Total EAI at baseline was significantly higher in patients from Group 2 (p=0.019). Despite markedly reduced EAI level in both groups, in Group 1 (less than 18 points by NHS3) EAI was significantly lower compared to Group 2 (≥18 points) at all subsequent visits: visit 2 (p=0.038), visit 3 (p=0.035), visit 4 (p=0.047), and visit 5 (p=0.022).
Conclusions. Assessing seizure severity may become an additional objective criterion while evaluating treatment efficacy.

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