Poster 3: Frequency of Epileptic Seizures in a Population of Juvenile Huntington's Disease Patients

Abstract

Background Epileptic seizures are a common feature of juvenile Huntington's disease (JHD), yet very little is known about the frequency of seizures, seizure type, electroencephalographic (EEG) characteristics, and response to anti-epileptic drugs (AEDs) in this subset of patients, much less about what correlates with increased seizure risk. Methods and Results Via retrospective chart review, we evaluated the frequency of seizures in our JHD population. Since inception, our clinic has seen 13 patients with genetically confirmed JHD. Incomplete medical records necessitated exclusion of three patients from our review. Of the 10 remaining patients, 5 (50%) were being treated for paroxysmal events presumed to be seizures. Semiology was variable and included staring spells, hypertonicity with vocalizations, generalized convulsions, and myoclonic events. EEG data were available for 4 patients. One had a normal EEG. Two had diffuse background slowing with no obvious epileptiform abnormalities. One had a background of 2.5–4 Hz delta slowing that was monomorphic at times; she also had nearly continuous, bilateral parietal-occipital 2.5–3.0 Hz spike and slow wave discharges and occasional spike wave discharges seen in a more generalized distribution. Discussion Although the focality of the spike and slow wave discharges is suggestive of localization-related epilepsy, the presence of more generalized spike wave discharges suggests symptomatic generalized epilepsy. AEDs used in these patients included valproic acid, lamotrigine, levetiracetam, and alprazolam. All were managed effectively with monotherapy, except the child with epileptiform abnormalities on her EEG; she experienced an increase in her seizure frequency on levetiracetam monotherapy. Lamotrigine monotherapy was ineffective, and she is now on a combination of valproic acid and lamotrigine in attempt to reduce her seizure frequency from her current rate of 3 events per week. Expanding our understanding of the mechanism and best treatment of seizures in JHD will require analysis of data from multiple HD centers.