Diagnostic and localizing value of ictal SPECT in patients with nonconvulsive status epilepticus Ekrem Kutluay a, * , Jeannie Beattie b , Erasmo A. Passaro c , Jonathan C. Edwards a , Daniela Minecan a , Cassandra Milling a , Linda Selwa a , Ahmad Beydoun a a Department of Neurology, University of Michigan Health System, Ann Arbor, MI, USA b MINCEP Epilepsy Care, MN, USA c Bayfront Medical Center, St. Petersburg, FL, USA Received 21 September 2004; revised 29 November 2004; accepted 1 December 2004 Abstract In this study, we evaluate the diagnostic and localizing value of SPECT in three patients with nonconvulsive status epilepticus (NCSE). Our results indicate that ictal/subtraction ictal SPECT is a useful complementary noninvasive diagnostic test in patients with focal NCSE. This is especially the case when the EEG findings are inconclusive and for patients in whom surgical treatment is being considered. Ó 2004 Elsevier Inc. All rights reserved. Keywords: Single-photon emission computed tomography; Nonconvulsive status epilepticus; Epilepsy surgery 1. Introduction Gastaut defined status epilepticus (SE) as a ‘‘condi- tion characterized by an epileptic seizure that is so fre- quently repeated or so prolonged as to cause a fixed and lasting condition’’ [1]. Operationally, SE is defined as more than 30 minutes of continuous seizure activity or two or more sequential seizures without full recovery of consciousness between seizures [2]. SE is stratified into convulsive and nonconvulsive SE (NCSE). NCSE is defined as an epileptic state consisting of a prolonged alteration in mental status or behavior from baseline and accompanied by electrographic ictal activity [3]. Historically, NCSE has been divided into two major cat- egories: generalized NCSE (absence status) and focal NCSE. Although focal NCSE is most commonly of tem- poral origin, it can also emanate from the frontal, pari- etal, or occipital regions [4–6]. Convulsive SE is usually easily recognized clinically, whereas NCSE can be diagnostically challenging and is often unrecognized [3]. The subtle and variable clinical features of NCSE may change or evolve over time in individual patients, making NCSE difficult to recognize [3,7,8]. Electrographic evidence is necessary to confirm the diagnosis of NCSE, but ictal patterns are variable and at times equivocal [3]. For example, as focal NCSE progresses, discrete evolving electrographic seizures may no longer be seen, and a waxing and waning pat- tern of rhythmic activity can be observed instead [6,9]. In some cases periodic discharges can be seen, which could be either ictal or postictal [10]. Prompt recogni- tion is crucial, as NCSE can be associated with morbid- ity and mortality [11–13]. In some cases, additional studies may be needed to confirm the diagnosis, espe- cially when the EEG and neuroimaging findings are inconclusive. In this study, we evaluated the usefulness of ictal single-photon emission computed tomography (SPECT) as a confirmatory tool for the diagnosis of NCSE. In www.elsevier.com/locate/yebeh Epilepsy & Behavior 6 (2005) 212–217 1525-5050/$ - see front matter Ó 2004 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2004.12.001 * Corresponding author. Fax: +1 734 936 5520. E-mail address: ekutluay@umich.edu (E. Kutluay).