Epilepsy and prion diseases: A narrative review

Epileptic seizures have been described as one feature of prion diseases, but are an unusual clinical presentation. The aim of this narrative Review was to summarize current knowledge of epileptic seizures in the various forms of prion diseases, from a clinical perspective. Examination of the published literature identified no systematic studies; the evidence base is largely anecdotal, consisting mainly of case studies and small case series. Hence, uncertainty prevails as to seizure frequency, semiology, treatment, and pathogenesis in prion diseases. Seizures probably occur in around 10% of sporadic cases but less frequently in iatrogenic and familial forms, with the possible exception of the E200K mutation. The literature suggests a predominance of focal motor and nonconvulsive status epilepticus. Electroencephalographic accompaniments include periodic lateralized or generalized periodic epileptiform discharges (PLEDs, GPEDs), sometimes predating the more typical periodic sharp wave complexes. There are no convincing accounts of successful antiepileptic drug therapy. The underlying mechanisms of epileptogenesis in prion diseases may include loss of cellular prion protein function (PrPc) and aggregation of abnormally folded prion protein (PrPSc). The need for systematic studies and clinical trials to expand the evidence base surrounding epilepsy and prion diseases is evident. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

Epileptic seizures are described as a feature of prion diseases, but systematic studies are lacking, leading to uncertainty about seizure frequency, semiology, treatment, and pathogenesis. Anecdotal evidence suggests seizures occur in around 10% of sporadic cases, with a predominance of focal motor and nonconvulsive status epilepticus, but there are no convincing accounts of successful antiepileptic drug therapy. Further research, including systematic studies and clinical trials, is needed to expand the evidence base surrounding epilepsy and prion diseases.