title: Circadian phase typing in idiopathic generalized epilepsy: Dim light melatonin onset and patterns of melatonin secretion-Semicurve findings in adult patients.
abstract: 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).
  
  
  
  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.
  
  
  
  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<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±01:21h, 04:37±01:17h, 04:29±00:52h). The mean DLMO time in patients with IGE (22:13±01:34h) occurred 49min later than that in HC (21.24±1h), 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±3.6pg/mL P=0.045).
  
  
  
  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.
authors.affiliation: Unit of Sleep Medicine and Epilepsy, C. Mondino National Neurological Institute, Pavia, Italy. Electronic address: raffaele.manni@mondino.it.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Manni
authors.affiliation: Unit of Sleep Medicine and Epilepsy, C. Mondino National Neurological Institute, Pavia, Italy. Electronic address: rob.deicco@gmail.com.
authors.forename: Roberto
authors.initials: R
authors.lastname: De Icco
authors.affiliation: Unit of Sleep Medicine and Epilepsy, C. Mondino National Neurological Institute, Pavia, Italy. Electronic address: cremaz@hotmail.it.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Cremascoli
authors.affiliation: Medical School, Insubria University, Varese, Italy. Electronic address: giulia.ferrera1@gmail.com.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ferrera
authors.affiliation: Epilepsy Center - Sleep Medicine Center, San Paolo Hospital, Milan, Italy. Electronic address: francesca.furia@asst-santipaolocarlo.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Furia
authors.affiliation: Epilepsy Center - Sleep Medicine Center, San Paolo Hospital, Milan, Italy. Electronic address: elena.zambrelli@asst-santipaolocarlo.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Zambrelli
authors.affiliation: Department of Health Sciences, University of Milan, Milan, Italy. Electronic address: maria.canevini@asst-santipaolocarlo.it.
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Canevini
authors.affiliation: Unit of Sleep Medicine and Epilepsy, C. Mondino National Neurological Institute, Pavia, Italy. Electronic address: michele.terzaghi@mondino.it.
authors.forename: Michele
authors.initials: M
authors.lastname: Terzaghi
mesh_terms: D000293:Adolescent; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D004829:Epilepsy, Generalized / Q000145:classification / Q000378:metabolism* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D008875:Middle Aged; D012890:Sleep / Q000502:physiology*; D055815:Young Adult
chemical_list: D008550:Melatonin
keywords: Chronotype; DLMO; Idiopathic generalized epilepsy; Sleep