title: SPECT in the Kleine-Levin Syndrome, a Possible Diagnostic and Prognostic Aid?
abstract: BACKGROUND
  Kleine-Levin syndrome (KLS) is a rare syndrome of periodic hypersomnia and behavioral and cognitive symptoms based on clinical criteria. In the setting of differential diagnosis of hypersomnia disorders, an objective diagnostic aid is desirable. A promising modality is single photon emission computed tomography (SPECT). As intraepisodal investigations are difficult to perform, an interepisodal investigation would be very helpful. Another aim of the study was to correlate SPECT findings to prognosis.
  
  
  METHODS
  Twenty-four KLS-patients were categorized as severe or non-severe based on clinical characteristics. The clinical characteristics were analyzed in relation to SPECT-examinations performed between hypersomnia periods (interepisodal) or after remission, as a clinical routine investigation.
  
  
  RESULTS
  Forty-eight percent of the KLS-patients have hypoperfusion in the temporal or fronto-temporal regions. In patients that have undergone remission, 56% show that pattern. There were no specific findings related to prognosis.
  
  
  CONCLUSIONS
  SPECT might be a diagnostic aid, in a setting of hypersomnia experience. With a sensitivity of 48%, interepisodal SPECT alone cannot be used for diagnosing KLS.
authors.affiliation: Division of Neurology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University , Linköping , Sweden ; Department of Neurology, County Council of Östergötland , Linköping , Sweden.
authors.forename: Patrick
authors.initials: P
authors.lastname: Vigren
authors.affiliation: Division of Radiological Sciences, Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linköping University , Linköping , Sweden ; Center of Medical Image Science and Visualization (CMIV), Linköping University , Linköping , Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Engström
authors.affiliation: Division of Neurology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University , Linköping , Sweden ; Division of Radiological Sciences, Department of Medical and Health Sciences (IMH), Faculty of Health Sciences, Linköping University , Linköping , Sweden.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Landtblom
keywords: Kleine–Levin syndrome; brain perfusion; single photon emission tomography; sleep; sleep disorders