[Combined epilepsy with generalized and focal seizures]

Area of Science:

• Neurology
• Epileptology
• Clinical Neuroscience

Background:

• Combined epilepsy, characterized by both generalized and focal seizures, is an underreported epilepsy classification.
• Existing literature on combined epilepsy is limited, necessitating further investigation into its characteristics.

Purpose of the Study:

• To conduct a comprehensive literature review on combined epilepsy.
• To analyze and report on the individual and group-level characteristics of 31 patients with combined epilepsy.
• To investigate epidemiological, clinical, and genetic factors associated with combined epilepsy.

Main Methods:

• Systematic review of existing literature on combined epilepsy.
• Retrospective analysis of 31 patients diagnosed with combined epilepsy.
• Characterization of patient data including seizure types, timing, family history, and electro-clinical phenotype.
• Statistical comparison with generalized and focal epilepsy cohorts using Fisher's exact test, Kruskal-Wallis, and Dunn tests.

Main Results:

• Combined epilepsy was found in 1.56% of classifiable epilepsy patients, with a higher prevalence in females (67.7%).
• Distinct associations were observed between seizure interval (short vs. long) and the presence of other cerebral abnormalities.
• Combined epilepsy patients showed a greater proportion of positive family history and more atypical absence seizures compared to generalized and focal epilepsy groups.

Conclusions:

• The study provides clinically relevant evidence on combined epilepsy, supporting prior findings and introducing novel subgroup analyses.
• Dissecting combined epilepsy into "long interval" and "short interval" subgroups revealed distinct pathogenetic and clinical correlates.
• Dissemination of case reports and group-level analyses can enhance medical community awareness and understanding of combined epilepsy.