Purpose: To assess the long-term evolution of Unverricht-Lundborg disease (ULD), especially concerning myoclonus, seizures, and EEG characteristics.
Methods: We retrospectively evaluated 20 patients (six women, 14 men; mean age, 37.9 years; range, 26-53 years) with ULD who had been closely followed up since the onset of the disease (mean age, 12.3 years; range, 6-17 years) for an average of 25.6 years (range, 13-41 years). ULD was confirmed by genetic tests in all. We used simplified myoclonus and seizure rating scales.
Results: The geographic origin of the patients was Northern Africa in nine, France in two, Italy in six, and mixed European in three. Three patients were severely handicapped, six led fully autonomous lives, and 11 required various degrees of social support. Myoclonus progressed only during the first 5 years of disease. Major seizures occurred in 19. Three patients had a single seizure, and eight became seizure free, whereas six had rare seizures, and two had frequent attacks. Overall, seizures became much less frequent after 10 years of evolution. EEG changes abated during follow-up: background activity remained stable or improved, spontaneous discharges disappeared, and photoparoxysmal responses were abolished in all patients but two.
Conclusions: This study shows that ULD progresses only over a limited period and stabilizes thereafter. This self-limited progression may be the consequence of age-related apoptosis of selected neuronal populations.