Enhanced Visual Cortex Activation in People With Narcolepsy Type 1 During Active Sleep Resistance: An fMRI-EEG Study

Frontiers in Neuroscience, vol. 16, pp. 904820

Abstract

The brain activation patterns related to sleep resistance remain to be discovered in health and disease. The maintenance of wakefulness test (MWT) is an objective neuropsychological assessment often used to assess an individual's ability to resist sleep. It is frequently used in narcolepsy type 1, a disorder characterized by impaired sleep-wake control and the inability to resist daytime sleep. We investigated the neural correlates of active sleep resistance in 12 drug-free people with narcolepsy type 1 and 12 healthy controls. Simultaneous fMRI-EEG measurements were recorded during five cycles of two alternating conditions of active sleep resistance and waking rest. Cleaned EEG signals were used to verify wakefulness and task adherence. Pooling both subject groups, significantly higher fMRI activation when actively resisting sleep was seen in the brainstem, superior cerebellum, bilateral thalamus and visual cortices. In controls the activation clusters were generally smaller compared to patients and no significant activation was seen in the brainstem. Formal comparison between groups only found a significantly higher left primary visual cortex activation in patients during active sleep resistance. The active sleep resistance paradigm is a feasible fMRI task to study sleep resistance and induces evident arousal- and visual-related activity. Significantly higher left primary visual cortical activation in patients could be caused by an enhanced need of visual focus to resist sleep, or reflecting a more rapid descent in their level of alertness when resting.

Authors 5

1. Jari K. Gool corresponding Aachen Department of Neurology, Leiden University Medical Centre

   Leiden University · Leiden University Medical Center · Amsterdam Neuroscience · Stichting Epilepsie Instellingen Nederland · Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam Neuroscience, Mood, Anxiety, Psychosis, Sleep & Stress Program, Amsterdam, Netherlands

   Anatomy & Neurosciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands

   Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands

   Sleep-Wake Centre, Stichting Epilepsie Instellingen Netherland (SEIN), Heemstede, Netherlands

2. Rolf Fronczek Aachen Department of Neurology, Leiden University Medical Centre

   Leiden University · Leiden University Medical Center · Stichting Epilepsie Instellingen Nederland

   Affiliation as printed

   Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands

   Sleep-Wake Centre, Stichting Epilepsie Instellingen Netherland (SEIN), Heemstede, Netherlands

3. Johan N. van der Meer

   University of Amsterdam

   Affiliation as printed

   Department of Radiology and Nuclear Medicine, University of Amsterdam, Amsterdam, Netherlands

4. Ysbrand D. van der Werf

   Amsterdam Neuroscience · Vrije Universiteit Amsterdam

   Affiliation as printed

   Amsterdam Neuroscience, Mood, Anxiety, Psychosis, Sleep & Stress Program, Amsterdam, Netherlands

   Anatomy & Neurosciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands

5. Gert Jan Lammers Aachen Department of Neurology, Leiden University Medical Centre

   Leiden University · Leiden University Medical Center · Stichting Epilepsie Instellingen Nederland

   Affiliation as printed

   Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands

   Sleep-Wake Centre, Stichting Epilepsie Instellingen Netherland (SEIN), Heemstede, Netherlands