The diagnosis of nocturnal frontal lobe epilepsy (NFLE) is mainly based on video-polysomnographic examination of nocturnal episodes. The clinical spectrum of nocturnal frontal lobe seizures (NFLS) includes one or all of the following semiological patterns: 1) paroxysmal arousals (PA: brief and sudden recurrent motor paroxysmal behaviour), 2) hypercinetic seizures (HS: motor attacks with complex dyskinetic features) 3) asymmetric bilateral tonic seizure (ATS: motor attacks with dystonic features), 4) epileptic nocturnal wanderings (ENW: stereotyped, prolonged ambulatory behaviour mimicking somnambulism). The aim of this study was to estimate the interobserver reliability (IR) of video-polysomnographic diagnosis in patients with suspected NFLS among sleep medicine experts, epileptologists and trainees in sleep medicine. Sixty-six patients referred to our sleep centre for suspected NFLS were included. All underwent nocturnal video-polysomnographic recording. Six doctors (3 experts and 3 trainees) independently classified each case as "NFLS ascertained" (according to the above specified subtypes: PA, HS, ATS, ENW) or "NFLS excluded". IR was calculated by means of Kappa statistics, and interpreted according to standard classification (0.0-0.20 = slight agreement; 0.21-0.40 = fair; 0.41-0.60 = moderate; 0.61-0.80 = substantial; 0.81-1.00 = almost perfect). The observed raw agreement on the diagnosis of NFLS ranged from 63% to 79% between each pair of raters; the IR ranged from "moderate" (kappa = 0.50) to "substantial" (kappa = 0.72). The major source of variance was the disagreement in distinguishing between PA and non-epileptic arousal episodes. There were no differences in the level of agreement between experts and trainees. Among sleep medicine/epileptologist experts and trainees, interobserver reliability of diagnosis of NFLS on the basis of videotaped observation of sleep motor phenomena is not satisfactory. One of the sources of variance is probably the interpretation of motor phenomena resembling simple arousals or PA. Explicit video-polysomnographic criteria for the classification of paroxysmal sleep motor phenomena are needed.
|Translated title of the contribution||Difficulties in the diagnosis of nocturnal frontal lobe seizures: A study on interobserver reliability of video recordings|
|Number of pages||2|
|Journal||Bollettino - Lega Italiana contro l'Epilessia|
|Publication status||Published - Jul 2006|
ASJC Scopus subject areas
- Clinical Neurology