Scientific Report 2003-2004 - Cleveland Clinic Lerner Research ...

NEURAL CONTROLGuang H. Yue, Ph.D.THE YUELABORATORYPROJECT STAFFJing-Zhi Liu, Ph.D.,Wlodzimierz (Vlodek)Siemionow, Ph.D.SENIOR RESEARCH ENGINEERSYin Fang, Ph.D.Vinoth K. Ranganathan, M.S.RESEARCH TECHNOLOGISTJohn Boros, M.S.GRADUATE STUDENTSHaibin Huang, M.S.Beth Lewandowski, B.S.Zuyao Shan, M.S.Bin Yao, M.S.Luduan Zhang, M.S.COLLABORATORSRobert W. Brown, Ph.D. 1Leonard H. Calabrese, D.O. 2Peter J. Evans, M.D., Ph.D. 3Joan E. Fox, Ph.D. 4Mark L. Latash, Ph.D. 5Zong-Ming Li, Ph.D. 6Steven I. Reger, Ph.D. 7Vinod Sahgal, M.D. 7Maria Siemionow, Ph.D., M.D. 81Case Western Reserve Univ.,Cleveland, OH2Dept. of Rheumatic andImmunologic Disease, CCF3Dept. of Orthopaedic Surgery,CCF4Dept. of Molecular Cardiology,CCF5Pennsylvania State Univ.,University Park, PA6Univ. of Pittsburgh, Pittsburgh,PA7Dept. of Physical Medicine andRehabilitation, CCF8Dept. of Plastic and ReconstructiveSurgery, CCFMechanisms of control of humanvoluntary movements have been studiedextensively over the past severaldecades. Although much has been revealedregarding control strategies in the peripheralneuromuscular system, little is known concerning(1) how the brain, the center of any neuromuscularoperation, controls a voluntary motoraction, and (2) how the central nervous system(CNS), including the brain, adapts to variousacute and chronic perturbations, such as fatigue,immobilization, training, aging, microgravity,injury or disease. A better understanding ofthese questions will lead to more effectivetreatment of movement-disorders. Ourlaboratory focuses on investigating issues relatedto these questions.Cortical control of finger movementsHow the brain controls our fingers is oftremendous interest to many disciplines. We areconducting a number of projects to investigatethis question. One project involves studyingforce-sharing patterns among individual fingers,using healthy subjects and different groups ofpatients, while brain signals are recorded.Another study attempts to improve hand/fingerfunction in older adults through training whilemonitoring brain adaptability.Plasticity of neural command for maximalvoluntary contraction (MVC)Is the command from brain to muscle forMVC fixed? If the answer is yes, then musclestrength enhancements can only be achieved byenlarging muscle mass and/or improving musclecoordination; if no, then muscle strength can beimproved by increasing neural commands fromthe brain through training the neuromuscularsystem or even the neural system alone. Thispossibility (training the neural system to improvemuscle strength) has great potential in neuromus-The Department of Biomedical EngineeringMovement Disorder Treatment Optionsto be Expanded with Insight into NeuralControl of Motor Actioncular rehabilitation because it provides opportunitiesfor improving motor function (strength) inpatients who cannot perform forceful musclecontraction training. Our data show that significantstrength gain can be achieved by training theCNS alone.Neural mechanisms of muscle fatigueIncreased fatigability occurs in every patientwith muscle weakness, regardless of whether theweakness is due to a central or peripheral neurologicaldisorder. The underlying mechanisms arenot well understood, and there is a need inneurology and rehabilitation to study fatigabilitysystematically. The behavior of the peripheralneuromuscular system during muscle fatigue hasbeen studied extensively, but the role of the CNSin muscle fatigue is largely unknown. We believethat without a good understanding of mechanismsof fatigue in health, an assessment of mechanismscontributing to increased fatigability in neurologicaldisorders is difficult. Our goal is to determinethe mechanisms underlying increased fatigability inpatients with neurological disorders.Neural mechanisms underlying motorfunctionrecovery in stroke patientsMotor-function recovery after stroke is aprocess of re-learning lost motor skills. Althoughnumerous studies have been performed involvingmotor performance in stroke patients, little isknown about the neural mechanisms that mediatethe re-acquisition of motor skills. This projectuses functional magnetic resonance imaging andmovement-related cortical potential techniques todetermine brain-function mechanisms underlyingmotor-function recovery by examining the patternof brain activation at various stages of therecovery process. This information is importantfor designing rehabilitative treatments and forreducing health care costs by stopping unnecessarytreatment at the earliest appropriate stage.Yue, G.H., Liu, J.Z., Siemionow, V., Ranganathan, V.K., Ng, T.C., and V. Sahgal (2000) Brain activationduring human finger extension and flexion movements. Brain Res. 856:291-300.Liu, J.Z., Dai, T.H., Elster, T.H., Sahgal, V., Brown, R.W., and G.H. Yue (2000) Simultaneous measurementof human joint force, surface electromyograms, and functional MRI-measured brain activation. J.Neurosci. Methods 101:49-57.Dai, T.H., Liu, J.Z., Sahgal, V., Brown, R.W., and G.H. Yue (2001) Relationship between muscle outputand functional MRI-measured brain activation. Exp. Brain Res. 140:290-300.Fang, Y., Siemionow, V., Sahgal, V., Xiong, F., and G.H. Yue (2001) Greater movement-related corticalpotential during eccentric verses concentric muscle contractions. J. Neurophysiol. 86:1764-1772.Liu, J.Z., Dai, T.H., Sahgal, V., Brown, R.W., and G.H. Yue (2002) Nonlinear cortical modulation ofmuscle fatigue: a functional MRI study. Brain Res. 957:320-329.32