Introduction. The differentiation between the clinical and electroencephalographic changes in nonconvulsive status epilepticus (NCSE) and those in sporadic Creutzfeldt-Jakob disease (sCJD) is a crucial question.
Case report. A 77-year old woman was admitted because of fluctuating behavioural chancaseges, adynamia and apraxia since several months for diagnostic. The diagnosis of sCJD was suggested. Subsequently, she had a generalized tonic clonic seizure (GTCS) and the EEG revealed periodic lateralized epileptiform discharges and NCSE was considered.
Discussion. The presented case illustrates the dilemma in the differential diagnosis of sCJD and (symptomatic) NCSE in the light of the recently published new Salzburg consensus criteria and unified EEG terminology. Concerning these criteria, the patient showed after an initial generalized seizure and substantial clinical improvement after administration of antiepileptic drugs, persisting epileptic discharges and only subtle clinical ictal phenomena during the EEG patterns with typical spatiotemporal evolution as a correlate of a symptomatic NCSE. During the further course of the disease in the presented patient the picture changed into an encephalopathic pattern.
Conclusion. EEG criteria for the diagnosis of NCSE are complex. In our case the EEG resembled the pattern of NCSE in the postictal phase of a GTCS according to a classification of NCSE in use at this time. After initial responsiveness to antiepileptic medication the patient lost responsiveness to therapy displaying the typical encephalopathic EEG findings in sCJD. These findings may support the hypothesis of initial NCSE and transformation into prion protein induced encephalopathic EEG and demonstrated clinical usefulness of the Salzburg consensus criteria for NCSE.
Bagic A., Boudreau E.A., Greenfield J., Sato S.:Electro-clinical evolution of refractory non-convulsive status epilepticus caused by west nile virus encephalitis. Epileptic. Disord., 2007, 9: 98–103.
Bauer G., Trinka E.:Non convulsive status epilepticus and coma. Epilepsia, 2010, 51: 177–190.
Beniczky S., Hirsch L.J., Kaplan P.W., Pressler R., Bauer G., Aurlien H. et al.:Unified EEG terminology and criteria for nonconvulsive status epilepticus. Epilepsia, 2013, 54, (Suppl. 6): 28–29.
Espay A.J., Kumar V., Sarpel G.:Anti-Hu-associated paraneoplastic limbic encephalitis presenting as rapidly progressive nonconvulsive status epilepticus. J. Neurol. Sci., 2006, 246: 149–152.
Feshchenko V.A., Veselis R.A., Reinsel R.A.:Comparison of the EEG effects of midazolam, thiopental, and propofol: the role of underlying oscillatory systems. Neuropsychobiol., 1997, 35: 211–220.
Hirsch L.J., LaRoche S.M., Gaspard N., Gerard E., Svoronos A., Herman S.T. et al.:American Clinical Neurophysiology Society’s Standardized Critical Care EEG Terminology: 2012 version. J. Clin. Neurophysiol., 2013, 30: 1–27.
Kaplan P.W.:EEG criteria for nonconvulsive status eilepticus. Epilepsia, 2007, 48: 39–41.
Kim H., Ryu H., Kang J.K.:Anti-NMDA receptor antibody encephalitis presenting with unilateral non-convulsive status epilepticus in a male patient. J. Epilepsy Res., 2015, 5: 17–19.
Lancman M.E., Marks S., Mahmood K., Lansen T.:Atypical triphasic waves associated with the use of phenobarbital. Electroenceph. Clin. Neurophysiol., 1997, 102: 175–177.
Lapergue B., Demeret S., Denys V., Laplanche J.L., Galanaud D., Verny M. et al.:Sporadic Creutzfeldt-Jakob disease mimicking nonconvulsive status epilepticus. Neurology, 2010, 74: 1995–1999.
Leitinger M., Beniczky S., Rohracher A., Gardella E., Kalss G., Qerama E. et al.:Salzburg consensus criteria for non-convulsive status epilepticus – approach to clinical application. Epilep. Behav., 2015, 49: 158–163.
Rösche J., Rantsch K., Walter U., Wittstock M., Benecke R.:Elektroenzephalographische Befunde bei unterschiedlichen Formen des Status epielpticus – Assoziation mit einzelnen Syndromen und prognostische Bedeutung. Klin. Neurophysiol., 2015, 46: 123–127.
Shorvon S.:What is nonconvulsive status epilepticus – and what are its subtypes? Epilepsia, 2007, 48: 35–38.
Snodgrass S.M., Tsuburaya K., Ajmone-Marsan C.:Clinical significance of periodic lateralized epileptiform discharges: relationship with status epilepticus. J. Clin. Neurophysiol., 1989, 6: 159–172.
Sutter R., Kaplan P.W.:Electroencephalographic criteria for nonconvulsive status epilepticus: Synopsis and comprehensive survey. Epilepsia, 2012, 53, (Suppl. 3): 1–51.
Taskiran A., Tezer F.I., Saygi S.:Epilepsia partialis continua as the presenting symptom in probable sporadic Creutzfeldt-Jakob disease. Epileptic Disord., 2011, 13: 82–87.
Traub R.D., Pedley T.A.:Virus-induced electrotonic coupling: hypothesis on the mechanism of periodic EEG discharges in Creutzfeldt-Jakob disease. Ann. Neurol., 1981, 10: 405–410.
Trinka E., Cook H., Hesdorffer D., Rossetti A.O., Scheffer I.E., Shinnar S. et al.:A definition and classification of status epilepticus – Report of the ILAE task force on classification of status epilepticus. Epilepsia, 2015, 56: 1515–1523.