Drug-Resistant Epilepsy in Children with Juvenile Huntington's Disease: A Challenging Case and Brief Review

Abstract

Huntington's Disease (HD) is an autosomal dominant neurodegenerative disorder with a progressive decline in cognitive, motor, and psychological function. Chorea tends to be the most common associated movement disorder, although other variants of several abnormal movements are also seen. Adult-onset HD is the most common subtype. Juvenile Huntington's disease (JHD) accounts for 5%–10% of all HD cases and presents as a rapidly progressive disorder with a multitude of characteristics. We report on a 9-year-old male with JHD who presented with refractory epilepsy. His EEG findings, seizure type, and antiepileptic drug usage are discussed with a brief review of the currently available relevant literature. The currently reported case sheds light on antiepileptic drugs that proved effective in our patient and the importance of screening for JHD when a child presents with seizures that are difficult to control.

“Spazio Huntington”: Tracing the Early Motor, Cognitive and Behavioral Profiles of Kids with Proven Pediatric Huntington Disease and Expanded Mutations > 80 CAG Repeats

“…Among the peculiarities we highlight in our study, we describe and confirm the high occurrence of sleep disorders in affected young children, in line with previous reports on JOHD [14]. We also confirm the occurrence of seizures as a common feature in PHD [8,[31][32][33]. Furthermore, we report the occurrence of drooling, dysphagia, stereotypic movements and apraxia during the first phases of the disease, all features that may concur to worsen the disease severity and shorten the patients' life span, as described [8].…”

Juvenile Huntington’s disease masquerading as progressive myoclonus epilepsy

“…Although valproate is found to be the most effective drug, other commonly used antiseizure medications are phenytoin and carbamazepine, with clonazepam, ethosuximide, gabapentin, zonisamide, and lamotrigine being less commonly used [2] . In the report by Khair et al, the combination of oxcarbazepine, levetiracetam, and clobazam proved to be the most successful [13] .…”

“…EEG characteristics in JHD have been rarely described in the literature, with details pertaining to the progression in EEG over time largely absent. The reported EEG characteristics are from normal EEG to generalized spike- polyspike-and-wave discharges, focal or multifocal epileptform discharges, specifically bilateral parieto-occipital discharges and focal occipital discharges, 3-Hz spike-and-wave discharges as well as paroxysmal slowing [6] , [12] , [13] , [14] , [15] . In our patient, EEG was normal initially and subsequently showed background slowing with focal and generalized discharges with photosensitivity suggestive of PME.…”

Clinical Review of Juvenile Huntington’s Disease

“…Seizures are most often generalized tonic-clonic, myoclonic, or absence, and a child may have multiple seizure types [35,37]. Electroencephalogram (EEG) may show generalized, focal, or multifocal epileptiform discharges, commonly with a disorganized background and spike, poly-spike, and spike-andwave discharges [16,[40][41][42]. Over the course of the disease, the EEG may progress to diffuse slowing with resolution of epileptiform discharges [43,44].…”

“…Historically, carbamazepine and phenytoin were used, but they are now less favored due to their side-effect profile. Other antiseizure medications reported include levetiracetam, topiramate, clobazam, clonazepam, and lamotrigine [16,37,40,81,84,87]. While there is less data regarding these newer generation anti-seizure medications, it is reasonable to consider them for seizures that are not responsive to valproic acid.…”