Purpose: To clarify the electroclinical characteristics of epileptic seizures in patients with juvenile type dentatorubral-pallidoluysian atrophy (DRPLA).
Methods: Seventeen patients with juvenile type DRPLA confirmed by genetic analysis were studied retrospectively. The clinical records of all 17 patients and the ictal video electroencephalography (EEG) recordings from 12 of the 17 patients were reviewed.
Results: Electroclinical studies in 12 patients identified 11 habitual seizures in 6 patients as partial seizures on ictal video EEG recordings. Clinical manifestations composed mainly of versions of the head and loss of consciousness. These partial seizures were persistently recorded throughout the clinical course. Brief generalized seizures (atypical absence and myoclonic seizure) were observed in 6 of 12 patients at the early stage. In contrast, generalized tonic-clonic seizures (GTCS) were recorded in four advanced stage patients who were almost bedridden. Semiological studies in 17 patients showed that the prevalence of partial seizures was significantly higher in patients with younger epilepsy onset (below 10 years of age; chi(2) test, p < 0.05) and that the age of epilepsy onset was significantly lower in patients with partial seizures than in those without partial seizures (Mann-Whitney U test, p = 0.02). However, the number of CAG repeats and age at clinical onset were not significantly different between two groups.
Discussion: Partial seizure is one of the common epileptic features in juvenile type DRPLA, especially in patients with younger epilepsy onset. Seizure types may be affected in an age-dependent manner and change evolutionally during progression of the clinical stage.