Medical Imaging for Understanding Sleep Regulation - PowerPoint Presentation

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Medical Imaging for Understanding Sleep Regulation

SESAPS October 2011Slide2

Research Team

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Linda Larson-Prior

Washington Univ.

Zang-Hee

Cho

Gachon

University

Seong

K.

Mun

Kenneth H. Wong

Alpay

ÖzcanSlide3

Why should we study sleep?

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Fundamentals of SleepA

reversible

state of disengagement from the conscious world.

Characterized by specific physiological and neurological changes.

A fundamental rhythm of the brain affected by internal clocks and external signals.Essential to human life (applies to other animals as well).

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Hypnogram a.k.a. Sleep Record

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http://science.education.nih.gov/supplements/nih3/sleep/guide/info-sleep.htm

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SLOW WAVE SLEEPSlide7

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REM SLEEPSlide8

1. Sleep-related disorders

Insomnia (~30-35% of USA population)

REM Behavior

Disorder (RBD)

Periodic Limb Movement DisordersRestless Leg SyndromeNarcolepsy

Obstructive Sleep ApneaLinks to Parkinson’s Disorder and other neurodegenerative diseases

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Clinical RBD Example

“One vivid example involved a man who held his wife's head in a headlock while moving his legs as if running while both were attempting to sleep in bed, then exclaimed, “I'm

gonna

make that touchdown!” and then attempted to forcefully throw her head down toward the foot of the bed. When awakened, he recalled a dream in which he was running for a touchdown, and he spiked the “football” in the end zone. His wife knew precisely what he had been dreaming about.”

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Boeve

BF, Silber MH,

Ferman

TJ, et al. REM sleep behavior disorder and degenerative dementia: an association likely reflecting Lewy body disease. Neurology

1998;51:363–370.Slide10

2. Drug Development Opportunities

Significant world market (~3.4B, 2.5B US)

Some major drugs coming off patent (

Ambien

in 2007, Lunesta in 2014)

Drugs are more effective and targeted now, but side effects still problematicSleep-promoting drugs warn that you must have a full night (8+ hrs) available for sleep, but this is often ignored.Long term consequences have not been studied.

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Sleep pharmaceuticals

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3. Why do we sleep so much?

"If sleep doesn't serve an absolutely vital function, it is the biggest mistake evolution ever made”

Alan

Rechtschaffen

, PhD

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gurumia.com

bestof.longislandpress.comSlide13

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http://writteninc.blogspot.com/2009_05_01_archive.html

http://

howdoistayawake.comSlide14

So…how do we study sleep?

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Principal ToolsElectroencephalography (EEG)

Brain electrical activity; defines sleep state

Magnetic Resonance Imaging (MRI)

Brain Structure

Positron Emission Tomography (PET)Brain Biochemistry

Functional MRI (fMRI)Brain “Activation”

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EEG

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“10-20” electrode locations

from Wikimedia Commons

High density EEG sensor net

from Electrical Geodesics, Inc.

Mindflex

Duel

TMSlide17

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Proton density

Tissue Composition

Pulse Sequence

MRI contrast

based on:Slide18

March 2010

Courtesy of Z.H. Cho,

Gachon

University, South Korea

High resolution MRI

opens new

windows for scientific discovery

1.5 T

7.0 TSlide19

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1.5 T Image

7T ImageSlide20

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fMRI is based on changes in cerebral blood flow

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Oxyhemoglobin

(diamagnetic)

Deoxyhemoglobin

(paramagnetic)

= BOLD Signal

B

lood

O

xygen Level

DependenceSlide24

fMRI examples

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Visual Signal

Motor ActivitySlide25

Functional Connectivity

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Larson-Prior et al, 2011Slide26

SummarySleep is a compelling scientific and medical area of inquiry.

Numerous technologies (designed and improved using physics) can help us to understand more about neuroscience.

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Thanks to…Neuroscience Research Institute,

Gachon

University, South Korea

U.S. Army Cooperative Agreement W81XWH-11-2-0187

Michael P. Brazaitis, MD, U.S. Army Grants Officer’s Representative (GOR)

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Questions?

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