Epilepsia, 49(9):1581–1585, 2008 doi: 10.1111/j.1528-1167.2008.01602.x FULL-LENGTH ORIGINAL RESEARCH The FLEP scale in diagnosing nocturnal frontal lobe epilepsy, NREM and REM parasomnias: Data from a tertiary sleep and epilepsy unit Raffaele Manni, Michele Terzaghi, and Alessandra Repetto Unit of Sleep Medicine and Epilepsy, Institute of Neurology “C. Mondino Foundation,” Pavia, Italy SUMMARY Purpose: To test the usefulness of the FLEP scale in diagnosing nocturnal frontal lobe epilepsy (NFLE), arousal parasomnias, and REM sleep behavior dis- order (RBD). Methods: The FLEP scale was applied to 71 sub- jects (60 male; 11 female; aged 54 ± 21) referred to an outpatient’s sleep and epilepsy unit for diag- nostic assessment of nocturnal motor-behavioral episodes, which turned to be arousal parasomnias (11 subjects), NFLE (14 subjects), or idiopathic RBD (46 subjects), based on the findings of in-lab full night video polysomnography with extended EEG montages. Results: The sensitivity of the scale as a diagnos- tic test for NFLE was 71.4%, the specificity 100%, the positive predictive value 100%, and the nega- tive predictive value 91.1%. The FLEP scale gave an incorrect diagnosis in 4/71 (5.6%) of the cases, namely NFLE patients with episodes of nocturnal wandering, and uncertain diagnostic indications in 22/71 subjects (30.9%). Conclusions: The FLEP scale shows high positive and negative predictive values in diagnosing NFLE versus arousal parasomnias and RBD. However, the scale is associated with a real risk of misdiagnosis in some patients and gives uncertain indications in about one-third of cases, mainly RBD. Our inves- tigation highlights the inadequacy of some of the items in the scale. The item investigating wander- ing, as presently formulated, may be unable to dis- tinguish nocturnal wandering from sleepwalking. The items about “recall” and “clustering” of the events throughout the night may increase the like- lihood of mistaking RBD for seizures. Further test- ing of the reliability of the FLEP scale items appears to be needed. KEY WORDS: FLEP, Arousal parasomnias, REM parasomnias, NFLE. Semeiological similarities, together with nonspecific surface electroencephalographic findings, make it difficult to distinguish nocturnal frontal lobe epilepsy (NFLE) from parasomnias. The differential diagnosis of NFLE is consid- ered challenging mainly with respect to arousal parasom- nias (sleepwalking, sleep terror, and confusional arousal) (Provini et al., 1999; Zucconi & Ferini-Strambi, 2000; Derry et al., 2006a). However, REM sleep behavior dis- order (RBD) episodes may also be misdiagnosed as NFLE (Schenck & Mahowald, 2002; Bazil, 2004). Comorbidity, Accepted March 4, 2008; Early View publication April 10, 2008. Address correspondence to Dr. Raffaele Manni, Unit of Sleep Medicine and Epilepsy, Institute of Neurology “C. Mondino Foundation,” Via Mondino 2, 27100 Pavia, Italy. E-mail: raffaele.manni@mondino.it Wiley Periodicals, Inc. C  2008 International League Against Epilepsy mainly of NFLE with arousal parasomnias (Bisulli et al., 2005), but also of RBD with epileptic seizures (Manni et al., 2006), may further complicate the clinical picture. Nocturnal video-polysomnography (V-PSG) which, un- til otherwise proven, remains the gold standard to achieve a definite diagnosis, is an expensive procedure and not uni- versally available. Many attempts have been made to identify distinc- tive clinical profiles of NFLE versus arousal parasomnias, through careful scrutiny of the reported symptoms (Provini et al., 1999; Derry et al., 2006a) and analysis of ictal video recordings (Vignatelli et al., 2007). However, no single, valid and reliable diagnostic procedure (with the exception of nocturnal V-PSG), or diagnostic algorithm, has been yet defined for these disorders. A new scale, the Frontal Lobe Epilepsy and Parasom- nias (FLEP) scale, was recently proposed as a tool for 1581