Attentive and preattentive processing in narcolepsy as revealed by event-related potentials (ERPs)

Narcolepsy is a neurological disorder, characterised by excessive daytime s leepiness, sleep attacks, cataplexy and abnormal manifestations of rapid ey e movement sleep. Recent studies suggest that neuropsychological impairment s in narcolepsy may include memory and attention deficits due to a monoamin ergic or cholinergic transmitter dysfunction. To explore the nature of cogn itive problems, the P300 and mismatch negativity (MMN) event-related potent ials were investigated in narcoleptic patients and matched controls. Narcol eptics showed significantly increased P300 amplitudes relative to controls, especially at frontal recording sites. While control subjects exhibited ty pically larger MMN over the right than the left hemisphere, in particular a t frontal and central electrodes, narcoleptics did not show this asymmetry. These results are interpreted as possible alterations in cognitive preatte ntive and attentive processing associated with altered functioning of the p refrontal cortex in narcolepsy. NeuroReport 12:2807-2811 (C) 2001 Lippincot t Williams & Wilkins.