title: Low-resolution brain electromagnetic tomography (LORETA) identifies brain regions linked to psychometric performance under modafinil in narcolepsy.
abstract: Low-resolution brain electromagnetic tomography (LORETA) showed a functional deterioration of the fronto-temporo-parietal network of the right hemispheric vigilance system in narcolepsy and a therapeutic effect of modafinil. The aim of this study was to determine the effects of modafinil on cognitive and thymopsychic variables in patients with narcolepsy and investigate whether neurophysiological vigilance changes correlate with cognitive and subjective vigilance alterations at the behavioral level. In a double-blind, placebo-controlled crossover design, EEG-LORETA and psychometric data were obtained during midmorning hours in 15 narcoleptics before and after 3 weeks of placebo or 400 mg modafinil. Cognitive investigations included the Pauli Test and complex reaction time. Thymopsychic/psychophysiological evaluation comprised drive, mood, affectivity, wakefulness, depression, anxiety, the Symptom Checklist 90 and critical flicker frequency. The Multiple Sleep Latency Test (MSLT) and the Epworth Sleepiness Scale (ESS) were performed too. Cognitive performance (Pauli Test) was significantly better after modafinil than after placebo. Concerning reaction time and thymopsychic variables, no significant differences were observed. Correlation analyses revealed that a decrease in prefrontal delta, theta and alpha-1 power correlated with an improvement in cognitive performance. Moreover, drowsiness was positively correlated with theta power in parietal and medial prefrontal regions and beta-1 and beta-2 power in occipital regions. A less significant correlation was observed between midmorning EEG LORETA and the MSLT; between EEG LORETA and the ESS, the correlation was even weaker. In conclusion, modafinil did not influence thymopsychic variables in narcolepsy, but it significantly improved cognitive performance, which may be related to medial prefrontal activity processes identified by LORETA.
authors.affiliation: Department of Neurology, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Saletu
authors.forename: Peter
authors.initials: P
authors.lastname: Anderer
authors.forename: Heribert V
authors.initials: HV
authors.lastname: Semlitsch
authors.forename: Gerda Maria
authors.initials: GM
authors.lastname: Saletu-Zyhlarz
authors.forename: Magdalena
authors.initials: M
authors.lastname: Mandl
authors.forename: Josef
authors.initials: J
authors.lastname: Zeitlhofer
authors.forename: Bernd
authors.initials: B
authors.lastname: Saletu
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects; D001143:Arousal / Q000187:drug effects; D001559:Benzhydryl Compounds / Q000627:therapeutic use*; D001931:Brain Mapping; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004328:Drive; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D000077408:Modafinil; D009290:Narcolepsy / Q000188:drug therapy*; D009483:Neuropsychological Tests; D009778:Occipital Lobe / Q000187:drug effects; D017286:Polysomnography; D017397:Prefrontal Cortex / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D012815:Signal Processing, Computer-Assisted; D012984:Software; D014851:Wakefulness / Q000187:drug effects
chemical_list: D001559:Benzhydryl Compounds; D000697:Central Nervous System Stimulants; D000077408:Modafinil