Absence seizures with evolution into generalized tonic-clonic activity: clinical and EEG features

Area of Science:

• Neurology
• Epileptology
• Clinical Neuroscience

Background:

• Idiopathic generalized epilepsy (IGE) encompasses various seizure types.
• Absence seizures and generalized tonic-clonic (GTC) seizures are common in IGE.
• Understanding seizure evolution is critical for accurate diagnosis and management.

Purpose of the Study:

• To describe the clinical and electrographic characteristics of absence seizures that progress to GTC activity.
• To identify features distinguishing this evolving seizure pattern in patients with IGE.
• To contribute to the classification of epilepsy seizure types.

Main Methods:

• Video-electroencephalography (EEG) monitoring was performed on six patients with refractory epilepsy.
• Seizure semiology, ictal, and interictal EEG data were analyzed post-antiseizure drug withdrawal.
• Clinical data and treatment responses were reviewed.

Main Results:

• All six patients were women, with a mean age of 27 years and seizure onset at 12 years.
• Absence seizures evolved into GTC activity, characterized by generalized spike-and-wave discharges on EEG.
• Divalproex monotherapy resulted in seizure freedom for five patients; one experienced a breakthrough GTC seizure.

Conclusions:

• Absence seizures can transform into GTC seizures, a pattern that warrants inclusion in seizure classifications.
• Distinguishing this evolution from secondary generalized seizures is vital for appropriate therapeutic strategies.
• This specific seizure evolution requires recognition for optimal patient management in IGE.