SLEEP 2011 Abstract Supplement

A. Basic Science X. Dreaming
0261
PARAPLEGICS WALK IN THEIR DREAMS
Saurat M, Agbakou M, Arnulf I
Sleep Disorders Unit and Inserm U975, Pitié-Salpêtrière University
Hospital, Paris, France
Introduction: Mental activity during sleep can replay and consolidate
recently-acquired skills, or activate innate programs. To fuel the discussion
of this field, we studied the occurrence of walking within dreams of
subjects with congenital and acquired paraplegia.
Methods: The dreams of 15 subjects with paraplegia (10 with spinal
cord injury and 5 with congenital paraplegia) and 15 healthy, able-bodied
volunteers were prospectively collected at home via dream diaries
over a 6-week period. Sets of dream reports were manually searched for
the terms that referenced the experience of walking or moving voluntarily
the legs (walking dreams), with a double blind scoring. In addition,
dream contents were classified using Hall and Van de Castle categories.
The subjects completed questionnaires of sleep quality, depression, anxiety,
and post-traumatic stress disorder. They underwent verbal memory
tests.
Results: We collected 207 dreams from paraplegics and 208 from controls
(29,369 words). In 9/10 subjects with spinal cord injury and 5/5
subjects with congenital paraplegia, there were walking dreams, composed
of feelings of walking (40%), running or fleeing (7.5%), dancing
(7%), standing up (5%), bicycling (5%), and practicing sports (skiing,
playing basketball, swimming or climbing). Paraplegics experienced
walking dreams (38.2%) just as often as controls (28.7%), but they reported
twice as many clauses about walking than controls. There was no
correlation between the frequency of walking dreams and the duration
of paraplegia.
Conclusion: Subjects who had never walked or stopped walking 4 to
64 years prior to this study still experience walking in their dreams, suggesting
that a cerebral walking program, either genetic or developed via
mirror neurons (neurons activated when observing others performing an
action) is activated to replay walking during sleep.
0262
ETIOLOGY OF NIGHTMARES: ENVIRONMENTAL AND
GENETIC CORRELATES
Sandman NE 1,3 , Ollila H 1 , Kronholm E 2 , Partonen T 1 , Männistö S 1 ,
Salomaa V 1 , Perola M 1 , Valli KJ 3 , Paunio T 1,4
1
National Institute for Health and Welfare, Helsinki, Finland, 2 National
Institute for Health and Welfare, Turku, Finland, 3 Department of
Behavioural Sciences and Philosophy, University of Turku, Turku,
Finland, 4 Department of Psychiatry, Helsinki University Hospital,
Helsinki, Finland
Introduction: Previous studies have suggested several environmental
factors that affect nightmares, and the variance in tendency to experience
nightmares has been shown to have a heritable component of 40-
50%. However, systematic analysis of environmental factors is scarce
and to our knowledge, the genetic correlates of nightmares have not
been studied. In the present study, we investigated various environmental
and genetic factors affecting self-reported nightmare frequency in
adult population.
Methods: Data from three nationwide Finnish cross-sectional surveys
(Finrisk) from years 1997, 2002, and 2007 will be used (N= 25 436, ages
25-74). For investigation of environmental correlates for nightmares, the
data includes information on a variety of topics related to health and life
style, such as sociodemographic background, physical and psychological
health, and environmental stress. For identification of genetic risk
factors for nightmares, data from 550 000 genome-wide distributed single
nucleotide polymorphisms (SNPs) from 2000 subjects will be correlated
with the self-reported frequency of nightmares. Results will be
replicated in an independent population-based sample of twins.
Results: Preliminary analysis on environmental correlates revealed
several statistically highly significant associations between nightmares
and items related to factors such as anxiety, depression, life dissatisfaction,
work related stress, as well as other sleep disturbances (p for
all < 0.0001). Preliminary genetic analysis identified associations with
nightmare frequency and SNPs at vicinity of genes expressed in central
nervous system (p < 10E-6).
Conclusion: A number of health-related, environmental and genetic
factors were shown to associate significantly to frequency of nightmares
in a population-based sample of 25 436 adults. This data will be used
as a template for additional analysis on modelling the effect of environmental,
health related and genetic factors on frequency of nightmares.
Support (If Any): Sigrid Juselius foundation (to Dr Tiina Paunio) International
Association for the Study of Dreams & Dream Science Foundation
(to PhD student Nils Sandman) Academy of Finland (SA141005)
(To Dr Satu Männistö)
SLEEP, Volume 34, Abstract Supplement, 2011
A92