title: Long-term follow-up of cognitive functions in patients with continuous spike-waves during sleep (CSWS).
abstract: Continuous spike-waves during sleep (CSWS) are associated with several cognitive, neurological, and psychiatric disorders, which sometimes persist after CSWS disappearance. The purpose of this retrospective study was to investigate the correlation between general (clinical and instrumental) and neuropsychological findings in CSWS, to identify variables that predispose patients to a poorer long-term neuropsychological outcome. Patients with spikes and waves during sleep with a frequency ≥25/min (spikes and waves frequency index - SWFI) were enrolled. There were patients presenting abnormal EEG activity corresponding to the classic CSWS and patients with paroxysmal abnormalities during sleep <85% with SWFI ≥25/min that was defined as excessive spike-waves during sleep (ESWS). Clinical and instrumental features and neuropsychological findings during and after the spike and wave active phase period were considered. A statistical analysis was performed utilizing the Spearman correlation test and multivariate analysis. The study included 61 patients; the mean follow-up (i.e., the period between SWFI ≥25 first recording and last observation) was 7years and 4months. The SWFI correlated inversely with full and performance IQ during CSWS/ESWS. Longer-lasting SWFI ≥25 was related to worse results in verbal IQ and performance IQ after CSWS/ESWS disappearance. Other variables may influence the neuropsychological outcome, like age at SWFI ≥25 first recording, perinatal distress, pathologic neurologic examination, and antiepileptic drug resistance. This confirms that CSWS/ESWS are a complex pathology and that many variables contribute to its outcome. The SWFI value above all during CSWS/ESWS and long-lasting SWFI ≥25 after CSWS/ESWS disappearance are the most significant indexes that appear mostly to determine cognitive evolution. This finding underscores the importance of EEG recordings during sleep in children with a developmental disorder, even if seizures are not reported, as well as the importance of using therapy with an early efficacy.
authors.affiliation: Child Neurology and Psychiatry Unit, Azienda Ospedaliero-Universitaria Policlinico S. Orsola-Malpighi of Bologna and Department of Medical and Surgical Sciences, University of Bologna, Via Massarenti 9, Bologna, Italy. Electronic address: lucia.maltoni@studio.unibo.it.
authors.forename: Lucia
authors.initials: L
authors.lastname: Maltoni
authors.affiliation: Child Neurology and Psychiatry Unit, IRCCS Institute of Neurological Sciences of Bologna and Department of Biomedical and Neuromotor Sciences, University of Bologna, Ospedale Bellaria, Padiglione G, Via Altura 3, Bologna, Italy. Electronic address: annio.posar@unibo.it.
authors.forename: Annio
authors.initials: A
authors.lastname: Posar
authors.affiliation: Child Neurology and Psychiatry Unit, Azienda Ospedaliero-Universitaria Policlinico S. Orsola-Malpighi of Bologna and Department of Medical and Surgical Sciences, University of Bologna, Via Massarenti 9, Bologna, Italy. Electronic address: antonia.parmeggiani@unibo.it.
authors.forename: Antonia
authors.initials: A
authors.lastname: Parmeggiani
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000293:Adolescent; D002648:Child; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D004569:Electroencephalography / Q000379:methods / Q000639:trends*; D004827:Epilepsy / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011247:Pregnancy; D012189:Retrospective Studies; D012890:Sleep / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
keywords: CSWS; Childhood; Cognitive functions; Epilepsy; Neuropsychology; Outcome