Objective. The objective of the proposed study is to investigate the spatio-temporal characteristics of brain activity during sleep. A number of recent fMRI (Ogawa, lee et al. 1990) studies have shown that in absence of external stimuli, the brain continues to show spatial patterns of activity that resemble the networks that activate during sensory and cognitive task (Biswal, Yetkin et al. 1995; Greicius, Krasnow et al. 2003; Greicius, Srivastava et al. 2004; Salvador, Suckling et al. 2005). This phenomenon greatly affects the interpretation of neuroimaging studies based on PET and fMRI, since these rely on differential imaging in which activity during a task is contrasting against activity during rest. In addition, resting state activity in itself potentially contains unique information on the large scale organization of neuronal networks and reveals information about functional abnormalities related to disease processes.

Study Population. To avoid confounding factors related to disease, subjects for this study will be recruited from the normal adult population. In addition, subjects will be screened for sleep behavior, and subjects with abnormal sleep behavior will be excluded.

Design. The study is design to facilitate MRI detection of cerebral metabolic differences between the sleep and awake states. Wakefulness and sleep, and the various stages will be classified in accordance with the EEG criteria, consistent with the guidlines of Rechtsshaffen and Kales (Rechtschaffen, 1968). For this purpose, we will optimize the methodology for the concurrent acquisition of EEG and fMRI signals. Using concurrent EEG and state-of-the-art MRI, we plan to establish the precise spatial distribution of changes in brain activity that are associated with changes in the sleep/wake state and the various stages of sleep, specifically early sleep (stage 1 and 2). Secondly, we plan to investigate whether changes in regional brain metabolism as measured by MRI correlates with transitory EEG phenomena during sleep, including fluctuations in band-specific power, sleep spindles, and K-complexes.

Outcome Measure. As an outcome of this study, an atlas of activity clusters in normal subjects will be established, both during waking conditions, as well as during several sleep stages. Further outcomes will be spatial patterns of covariance with EEG band-specific power, spindles, and K-complexes. These data will serve as a baseline for comparison with activity patterns in patients.

Further Study Details: 

Expected Total Enrollment:  100

Objective. The objective of the proposed study is to investigate the spatio-temporal characteristics of brain activity during sleep. A number of recent fMRI (Ogawa, lee et al. 1990) studies have shown that in absence of external stimuli, the brain continues to show spatial patterns of activity that resemble the networks that activate during sensory and cognitive task (Biswal, Yetkin et al. 1995; Greicius, Krasnow et al. 2003; Greicius, Srivastava et al. 2004; Salvador, Suckling et al. 2005). This phenomenon greatly affects the interpretation of neuroimaging studies based on PET and fMRI, since these rely on differential imaging in which activity during a task is contrasting against activity during rest. In addition, resting state activity in itself potentially contains unique information on the large scale organization of neuronal networks and reveals information about functional abnormalities related to disease processes.

Study Population. To avoid confounding factors related to disease, subjects for this study will be recruited from the normal adult population. In addition, subjects will be screened for sleep behavior, and subjects with abnormal sleep behavior will be excluded.

Design. The study is design to facilitate MRI detection of cerebral metabolic differences between the sleep and awake states. Wakefulness and sleep, and the various stages will be classified in accordance with the EEG criteria, consistent with the guidlines of Rechtsshaffen and Kales (Rechtschaffen, 1968). For this purpose, we will optimize the methodology for the concurrent acquisition of EEG and fMRI signals. Using concurrent EEG and state-of-the-art MRI, we plan to establish the precise spatial distribution of changes in brain activity that are associated with changes in the sleep/wake state and the various stages of sleep, specifically early sleep (stage 1 and 2). Secondly, we plan to investigate whether changes in regional brain metabolism as measured by MRI correlates with transitory EEG phenomena during sleep, including fluctuations in band-specific power, sleep spindles, and K-complexes.

Outcome Measure. As an outcome of this study, an atlas of activity clusters in normal subjects will be established, both during waking conditions, as well as during several sleep stages. Further outcomes will be spatial patterns of covariance with EEG band-specific power, spindles, and K-complexes. These data will serve as a baseline for comparison with activity patterns in patients.

Genders Eligible for Study:  Both

Criteria

INCLUSION CRITERIA:

Any neurologically and psychiatrically normal, male or female, healthy volunteer between 18 and 65 years old is in principle eligible for the study. Subjects must be capable of understanding the procedure and requirements of this study. Subjects must be willing to sign an informed consent document.

EXCLUSION CRITERIA:

A subject will be excluded if he/she has a contraindication to MR scanning such as the following: pregnancy, aneurysm clip; implanted neural stimulator: implanted cardiac pacemaker or auto-difibrillator; cochlear implant; known absent acoustic reflex; ocular foreign body (e.g. metal shavings or insulin pump) and any pre-existing eye conditions. Subjects who underwent brain surgery, eho have a neurological lesion, a psychiatric history or a migraine will also be excluded from this study. To minimize potential confounds, subjects with abnormal sleep/wake patterns will be excluded. They should report no sleep problems or shift work, and no use of medications, drugs, or tobacco. Subjects will be in good health as assessed by medical history, interview and physical exam.

Subjects will be asked to:

Refrain from alcohol and caffeinated products for 1 day prior to the study;

Maintain their habitual bed times and wake-up times for 1 week prior to thestudy. A wrist-worn activity monitor (Actigraph, Precision Control Design, INC., Fort Walton Beach, FL) may be used to confirm compliance with the latter instruction.

Exclusion criterions include:

Sleep disorder (reported or detected);

Psychopathology, personal or first-degree relative of diagnosed significant. Particularly mood or psychotic disorders, because they are likely to place the subject at risk for an adverse consequence related to the extended wakefulness portion of the study);

Seizures or head injury with loss of consciousness greater than 5 minutes;

Substance dependence (diagnosable);

Smoking tobaccco or psychotropic mecications (currently);

Caffeine consumption of 300 mg or2 ounces of alcohol on a regular daily consumption;

Cardiac, respiratory, or other medical condition that may affect cerebral metabolism.

Please refer to this study by ClinicalTrials.gov identifier  NCT00117221

Maryland
      National Institute of Neurological Disorders and Stroke (NINDS), 9000 Rockville Pike,  Bethesda,  Maryland,  20892,  United States; Recruiting

Study ID Numbers:  050179; 05-N-0179
Record last reviewed:  June 20, 2005
Last Updated:  July 2, 2005
Record first received:  July 2, 2005
ClinicalTrials.gov Identifier:  NCT00117221
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2005-07-05