Neuroimaging in Stroke Recovery: A Position Paper from the First International Workshop on Neuroimaging and Stroke Recovery

Baron, Jean-Claude*Black, Sandra E.Butler, Andrew J.Carey, JamesChollet, FrancoisCohen, Leonardo G.*Corbetta, MaurizioCramer, Steven C.*Dobkin, Bruce H.*Frackowiak, RichardHeiss, W.D.Johansen-Berg, Heidi*Krakauer, John W.Lazar, Ronald M.Lennihan, Laura L.Loubinoux, Isabelle*Marshall, Randolph S.*Matthews, PaulMohr, J.P.Nelles, GereonPascual-Leone, AlvaroPomeroy, ValerieRijntjes, MichelRossini, Paolo MariaRothwell, John C.Seitz, Rudiger J.Small, Steven L.Sunderland, AlanWard, N.S.*Weiller, CorneliusWise, Richard J.S.IntroductionThe First International Workshop on Neuroimagingand Stroke Recovery was convened in February, 2004 inNew York City. The purpose of the workshop was to de-scribe the state of the field with regard to technical andanalytical methods, to discuss the use of complementaryimaging modalities, and to assess the current potential toapply functional neuroimaging to the development of ratio-nal treatment strategies for enhanced stroke recovery.Presented herein is a summary statement of topics dis-cussed at the workshop. These included (i) the clinical rel-evance of functional imaging changes after stroke for themotor and language systems; (ii) the technical challengesfaced in moving towards establishing functional neuro-imaging as a clinically useful tool; (iii) the contributions ofneurophysiological probes such as transcranial magnet-ic stimulation (TMS) to improve understanding of themechanisms underlying brain reorganization after stroke;and (iv) the potential role of neuroimaging in the assess-ment and development of rational pharmacological andbehavioral therapies.Clinical RelevanceFunctional recovery commonly occurs in survivingstroke patients in the weeks and months following theinjury. There is evidence from animal models that cere-bral reorganization underlies at least some of this recov-ery and it is hoped that an understanding of the neuro-physiological processes underlying this reorganization inthe human brain will lead to a rational approach to thetreatment of impairment. In animal models, focal braindamage triggers a number of changes at the molecular, cel-lular, and systems level, some of which alter the potentialfor cerebral reorganization and consequent functionalrecovery. Although the same techniques are not availableto study the working human brain, functional brain imag-ing has provided insights into how the human brainresponds to focal injury.