Eus JW Van Someren (Sleep & Cognition, Netherlands Institute for Neuroscience and VU University & Medical Center, Amsterdam, The Netherlands)

The Bernstein Center Freiburg

Bernstein Seminar

Eus JW Van Someren

Dept. Sleep & Cognition, Netherlands Institute for Neuroscience &
Institute of the Royal Netherlands Academy of Arts and Sciences &
VU University Amsterdam

 

Lying awake of insomnia:
imaging causes and consequences

Abstract:
With a prevalence of 4-11%, insomnia is the most common health complaint and has serious consequences. While it is the major risk factor for psychiatric disorders, our understanding of underlying genetics and brain mechanisms is limited. We argued that heterogeneity of underlying causes may have impeded progress and that definition of (endo)phenotypes is required. We commenced to do so using web-based survey and performance assessments as well as brain imaging tools including magnetic resonance imaging (MRI) and transcranial magnetic stimulation (TMS). While some deviations recover after therapy, e.g. attenuated prefrontal blood oxygenation level dependent (BOLD) activation during word fluency, others don’t and may represent heritable traits. Using TMS, we found an abnormal intracortical excitability that did not recover after treatment. Voxel based morphometry (VBM) showed the vulnerability to lie awake is associated with a lower volume of gray matter in the orbitofrontal cortex. Concertedly, the brain imaging results in part support current models of insomnia but also provide new avenues to explore for a better understanding of mechanisms of vulnerability and possibilities for treatment. Our next challenge will be to obtain 264-channel high-density sleep EEG to analyse spatiotemporal connectivity patterns in with the aim to understand why insomiacs with severe, so-called, ‘sleep state misperception’ report having been awake and conscious even if woken up from deep sleep. We now look for volunteers for extensive web-based characterization of different phenotypes of good and poor sleepers (www.sleepregistry.eu).

1. Van Someren EJW et al (2009) Frontiers in Neuroscience 3:436
2. Van Der Werf YD et al (2010) Biol Psychiatry 68:950-955
3. Altena E et al (2010) Biol Psychiatry 67:182-185
4. Altena E et al (2008) J Sleep Res 17:335-343
5. Altena E et al (2008) Sleep 31:1271-1276

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