Improve our understanding of the processes that lead to specific
sleep disorders in children and adults. The following disorders
are included in this summary due to both their prevalence and
their impact on afflicted patients:
initiating or maintaining sleep): This should include the development
of animal models of insomnia, the study of specific insomnia
phenotypes and the application of neurophysiologic, neurochemical,
neuroanatomic and functional neuroimaging approaches to the
study of insomnia in humans. Understanding why women are at
higher risk for insomnia should be a goal as well. Finally,
genetic, genomic and proteomic studies are also needed.
Restless Legs Syndrome
(RLS) and Periodic Limb Movement Disorder (PLMD): Studies should
address the role of altered central dopaminergic mechanisms
and abnormal iron metabolism in their pathogenesis. Further
development, refinement and validation of animal models of RLS
and PLMD are also needed. The use of neuropathologic techniques
in the evaluation of brains and spinal cords of affected patients
are likely to be useful as well.
breathing (sleep apnea) and disorders of ventilatory control:
These studies should address the processes that control both
upper airway patency and ventilation itself with a particular
focus on the influence of sleep on these biologic processes.
The neural connections, neuromodulators and molecular events
mediating these state-dependent processes affecting respiration
during sleep need to be studied.
leading to hypersomnolence: The neural mechanisms leading to
hypersomnolence in conditions such as narcolepsy or primary
central nervous system hypersomnolence need to be investigated,
and the focus these studies should be how the neurobiologic
causes of hypersomnolence differ from or resemble the effects
of sleep loss.
An assessment of
normal human sleep phenotypes and the normal range of variation
in this phenotype in adults and children (including racial and
ethnic differences) is needed, not only to establish normative
standards but also to serve as a model for recommended sleep
behaviors. This assessment should include sleep duration, sleep
stage distribution, sleep timing, sleep disruption, sleep quality,
and other variables by which sleep and sleepiness can be quantitatively
Once normal sleep
phenotypes are defined, the associated genotypes should be fully
Abnormal sleep phenotypes
should subsequently be recognizable and genotyping of these
individuals should then be pursued to define the genetic underpinning
of abnormal sleep or altered circadian rhythm profiles. The
impact of single nucleotide polymorphisms (SNPs) on normal sleep
phenotypes should be testable as well.
The phenotype of
patients with specific sleep disorders should be carefully defined
in order to set the stage for subsequent genetic testing.
Methods to define
normal and abnormal phenotypes through questionnaires or simple
non-invasive testing should be a goal. Population surveillance
and assessment of associated morbidities will then be possible
on a large scale.