1. The study explored the relationship between absolute beta power and regional cerebral metabolic rate of glucose (rCMRglc) during REM sleep in subjects with primary insomnia. 2. No significant positive correlations were found between beta power and rCMRglc in brain regions involved in arousal. Significant negative correlations were found in the left cingulate gyrus, right temporal regions, and left fusiform gyrus. 3. The findings suggest that higher beta power, indicating greater arousal, is associated with lower rCMRglc in key brain regions during REM sleep in primary insomnia. Larger studies are needed to replicate these preliminary results.

2. The Relationship Add Title
Click to between Absolute
Beta Power and rCMRglc in Primary
Insomnia during REM sleep
Click to Add Speaker Information
Jennifer Alman1, David Cashmere2, Jean Miewald2, Eric
Nofzinger, M.D.2, Daniel Buysse, M.D.2, and Anne Germain,
Ph.D.2
Washington & Jefferson College
1
Department of Psychiatry, University of Pittsburgh School of Medicine
2

3. Conflict of Interest Disclosures
Speaker:
X 1. I do not have any potential conflicts of interest to disclose, OR
2. I wish to disclose the following potential conflicts of interest:
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3. The material presented in this lecture has no relationship with any of these potential conflicts,
OR
4. This talk presents material that is related to one or more of these potential conflicts, and the
following objective references are provided as support for this lecture:
1.
2.
3.

4. Background
• Increased beta power has been shown in
primary insomnia (PI) during NREM sleep.
 e.g., Merica and Gaillard, 1998
• PI is a disorder characterized by hyperarousal.
• REM sleep is a state of hyperarousal,
especially in limbic regions.
• The neurobiological correlates of beta power
in PI during REM sleep have not been
investigated.

5. Study Aim
• Explore relationship between absolute
beta power and rCMRglc during REM
in PI.
• Hypothesis: Positive correlation
between beta power and rCMRglc in:
– Occipital gyrus
– Anterior cingulate cortex
– Gyrus rectus and posterior medial
orbitofrontal cortex

6. Participants
• 10 PI subjects
• Mean age: 37.86 ± 9.38 years
• 7 women, 3 men
• All subjects were free of medication,
comorbid psychiatric, other sleep and
medical disorders.

7. Procedures
• 3 nights spent in the lab.
– Night 1: Sleep apnea screening
– Night 2: Baseline
– Night 3: PET sleep study
• Whole-night REM sleep beta (16-32Hz)
power estimates obtained from Night 2
from artifact-free 4-second epochs,
averaged across all REM sleep periods.

8. PET
Lab Room
EEG
EMG
EOG
saline
[radiotracer]

9. PET Data Analysis
• Correlation analyses were conducted
to determine the relationships
between beta activity and rCMRglc
during REM sleep.
• Reported results are corrected for
multiple comparisons (p < .05).

10. Results
• No significant positive correlation
between beta activity and rCMRglc.
• Trends observed for:
– Gyrus rectus *
– Middle temporal gyrus
– Middle frontal gyrus
– Dorsal/anterior cingulate gyrus *
– Parieto-occipital sulcus

11. Results
• Significant negative correlations were found
between beta activity and rCMRglc during REM
sleep in 3 brain regions.
Coordinates K Corrected p-
values
-10, 48, 10 3219 0.03
52, -66, 14 10431 0.001
-34, -44.-20 3034 0.04

12. Results: Region 1
• Significant Areas:
– Left cingulate gyrus
Cingulate Gyrus
Frontal
Gyri
– Inferior and middle
9
frontal gyri 8
7
6
5
4
3
2
1
0
Continuous Voxels: 3219
Coordinates: -10, 48, 10
Z=3.36, p=0.03

13. Results: Region 2
Superior Parietal Lobule
• Significant Areas:
-14.1, -64.3, 31.8
-16.4, -51.8, 5.2
– Right temporal gyri
Temporal Gyri
ParrahippocampalGyrus/
Hippocampus
– Parahippocampal gyrus
and hippocampus
-16.4, -51.8, 5.2
9
8
7
6
5
– Superior parietal lobule 4
3
2
1
0
Continuous Voxels: 10431
Coordinates: 52, -66, 14
Z=4.15, p<.001

14. Results: Region 3
Fusiform gyrus
• Significant Areas:
-35.2, -57.2, -10.4
34, -44.-20
– Left fusiform gyrus
– Temporal gyri
Temporal Gyri
9
8
-35.2, -57.2, -10.4
7
6
5
4
3
2
1
0
Continuous Voxels: 3034 Coordinates:
-34, -44.-20
Z=4.38, p=.04

15. Conclusions
• No areas reached
statistical significance for
positive correlations
between beta activity and
rCMRglc at corrected
level of significance.
• PI decreased whole-night
beta activity was
associated with increased
rCMRglc during REM
sleep.

16. Limitations
• Whole-night absolute beta power used was
from Night 2.
– Repeat with beta activity during uptake period
• Beta power was the only measure used to
indicate arousal.
– Assess correlations with other measures of
arousal:
• Peripheral arousal with heart rate variability
• Cognitive/dream content
• Indices of somatic arousal
» Perlis et al., 2001

17. Discussion
• No areas reached statistical significance for positive
correlations between beta activity and rCMRglc at
corrected level of significance.
• Differences across studies may result from a difference
between NREM vs. REM sleep.
• The small sample sizes warrant caution when
interpreting these preliminary results.

18. Discussion
• We observed a negative correlation between beta activity
and rCMRglc during REM sleep.
• This pattern may not be specific to central arousal in PI
during REM sleep:
– Frontal, parieto-occipital, and temporal regions are part of a
perceptual/sensory integration and information processing
network also involved dreaming.
– Maquet et al., 1996
– Beta activity orchestrates activity across these brain regions
during wakefulness, and is decreased during REM sleep.
– Pérez-Garci et al., 2001
• The observed pattern may reflect disturbed REM sleep
mentation in PI.
– Perlis et al., 2001

19. Future Directions
1. Replication in larger samples.
2. Focus on beta activity during FDG uptake period.
3. Exploration and comparison of the relationships
between beta activity and rCMRglc during REM and
NREM sleep.
4. Contrast these relationships across healthy
sleepers, subjects with PI or insomnia comorbid with
other disorders such as PTSD and depression.
5. Obtain dream reports from subjects undergoing
sleep neuroimaging studies.

20. Acknowledgements
• Gina Pietrone
• Research participants
• N-CTRC staff
US Department of Defense (PT073961-W81XWH-07-PTSD-IIRA)
National Institutes of Health (MH053035; MH024652; MH66227;
RR024153)