Abstracts

Rationale: Efficacy of antiepileptic drug (AED) therapy in patients with Unverricht-Lundborg Disease (ULD) may be measured by changes in the Unified Myoclonus Rating Scale (UMRS) scores before and after treatment. While patients may experience clinically meaningful improvements, the UMRS may fail to detect a significant difference. Furthermore, the UMRS is a skewed scale and may not reflect the severity of the disease accurately, especially during the later stage of the disease. Methods: In this study, mutual information and nonlinear interdependence measures were applied to electroencephalogram (EEG) recordings in an attempt to identify the effect of AED treatment on the coupling strength and directionality of information transport between different brain cortical regions. Four ULD subjects were included and two 1-hour EEG recordings were acquired for each; one shortly before and one after adding a new AED for a minimum of two months. All four subjects were siblings from the same parents and were close in age (48 ± 3 years) and duration of disease (~37.75 years). Results: Lower mutual information between different brain cortical regions were seen in less severe patients (P1