Circadian phase typing in idiopathic generalized epilepsy: Dim light melatonin onset and patterns of melatonin secretion—Semicurve findings in adult patients Raffaele Manni a, ⁎, Roberto De Icco a , Riccardo Cremascoli a , Giulia Ferrera b , Francesca Furia c , Elena Zambrelli c , Maria Paola Canevini d , Michele Terzaghi a a Unit of Sleep Medicine and Epilepsy, C. Mondino National Neurological Institute, Pavia, Italy b Medical School, Insubria University, Varese, Italy c Epilepsy Center — Sleep Medicine Center, San Paolo Hospital, Milan, Italy d Department of Health Sciences, University of Milan, Milan, Italy abstract article info Article history: Received 8 March 2016 Revised 16 May 2016 Accepted 18 May 2016 Available online 23 June 2016 Objective/background: It has been debated in the literature whether patients with idiopathic generalized epilepsy (IGE) have a distinctive, evening-oriented chronotype. The few questionnaire-based studies that are available in the literature have conflicting results. The aim of our study was to define chronotype in patients with IGE by determining dim light melatonin onset (DLMO). Patients/methods: Twenty adults diagnosed with IGE (grand mal on awakening [GM] in 7 cases and juvenile myoclonic epilepsy in 13 cases) were investigated by means of a face-to-face semistructured sleep interview, Morningness–Eveningness Questionnaire (MEQ), Pittsburgh Sleep Quality Index (PSQI) questionnaire, and a melatonin salivary test with DLMO determination. Eighteen healthy subjects (HC) and 28 patients affected with cryptogenic focal epilepsy (FE) served as controls. Results: The mean MEQ score was significantly lower in patients with IGE than that in patients with FE (49.1 ± 5.9 versus 56.1 ± 8.7 P b 0.01) but not significantly lower than that in HC (49.1 ± 5.9 versus 49.3 ± 8.6). Midsleep on free days corrected for sleep duration did not differ significantly between the three subject groups (04:59 ± 01:21 h, 04:37 ± 01:17 h, 04:29 ± 00:52 h). The mean DLMO time in patients with IGE (22:13 ± 01:34 h) occurred 49 min later than that in HC (21.24 ± 1 h), and the melatonin surge within the 30-minute time interval after DLMO in patients with IGE was significantly lower than that in HC (1.51 ± 2.7 versus 3.8 ± 3.6 pg/mL P = 0.045). Conclusions: Subjective measures of chronotype do not indicate a definite evening-oriented chronotype in patients with IGE. However, the data concerning endogenous melatonin secretion indicate that patients with IGE tend to have a late circadian phase. Further studies are warranted in order to better define the late pattern of endogenous melatonin secretion in patients with IGE and to ascertain the role of this pattern in influencing behavioral chronotype in these subjects. © 2016 Published by Elsevier Inc. Keywords: Idiopathic generalized epilepsy Sleep Chronotype DLMO Epilepsy & Behavior 61 (2016) 132–137 Abbreviations: IGE, idiopathic generalized epilepsy; GM, grand mal on awakening; JME, juvenile myoclonic epilepsy; DLMO, dim light melatonin onset; MEQ, Morningness– Eveningness Questionnaire; PSQI, Pittsburgh Sleep Quality Index Questionnaire; HC, healthy subjects; FE, cryptogenic focal epilepsy; AEDs, antiepileptic drugs; MIDwd, midsleep on workdays; MIDf, midsleep on free days; MIDfc, midsleep on free days corrected for sleep duration; SJL, social jet lag; Post-DLMO measure, melatonin salivary concentration of the first post-DLMO melatonin sample; Post-DLMO surge, melatonin surge in the 30-minute time interval after DLMO occurrence; AUC, the under-the-curve area of the post-DLMO semicurve AUC; AUC 30 , the under-the-curve area specifically about the 30-minute time interval of melatonin secretion after DLMO occurrence AUC 30 ; SPSS, The Statistical Package for the Social Sciences; DSPS, delayed sleep phase syndrome. ⁎ Corresponding author at: C. Mondino National Neurological Institute, 27100 Pavia, Italy. E-mail addresses: raffaele.manni@mondino.it (R. Manni), rob.deicco@gmail.com (R. De Icco), cremaz@hotmail.it (R. Cremascoli), giulia.ferrera1@gmail.com (G. Ferrera), francesca.furia@asst-santipaolocarlo.it (F. Furia), elena.zambrelli@asst-santipaolocarlo.it (E. Zambrelli), maria.canevini@asst-santipaolocarlo.it (M.P. Canevini), michele.terzaghi@mondino.it (M. Terzaghi). http://dx.doi.org/10.1016/j.yebeh.2016.05.019 1525-5050/© 2016 Published by Elsevier Inc. Contents lists available at ScienceDirect Epilepsy & Behavior journal homepage: www.elsevier.com/locate/yebeh