Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) which affects nearly one million people worldwide, leading to a progressive decline of motor and sensory functions, and permanent disability. High b‐value diffusion‐weighted MR images (b of up to 14000 s/mm²) were acquired from the brains of controls and MS patients. These diffusion MR images, in which signal decay is not monoexponential, were analyzed using the q‐space approach that emphasizes the diffusion characteristics of the slow‐diffusing component. From this analysis, displacement and probability maps were constructed. The computed q‐space analyzed MR images that were compared with conventional T₁, T₂ (fluid attenuated inversion recovery (FLAIR)), and diffusion tensor imaging (DTI) images were found to be sensitive to the pathophysiological state of white matter. The indices used to construct this q‐space analyzed MR maps, provided a pronounced differentiation between normal tissue and tissues classified as MS plaques by the FLAIR images. More importantly, a pronounced differentiation was also observed between tissues classified by the FLAIR MR images as normal‐appearing white matter (NAWM) in the MS brains, which are known to be abnormal, and the respective control tissues. The potential diagnostic capacity of high b‐value diffusion q‐space analyzed MR images is discussed, and experimental data that explains the consequences of using the q‐space approach once the short pulse gradient approximation is violated are presented. Magn Reson Med 47:115–126, 2002.

Background: Interactive video gaming has become ubiquitous in the practice of rehabilitation. The Nintendo Wii is one such system. Interactive gaming can promote intensive task-based therapy in a manner that is motivating for the user. Widespread enthusiasm for consoles and their games prompted us to analyze the games for their rehabilitation elements related to improving balance and mobility for individuals poststroke. Purpose: The purpose of this article is to provide a game analysis for clinical application and evaluation of the game elements for research on interactive video gaming. Methods: Using a team of game players and raters, 5 tables (1 for the Wii Sports and 4 for the Wii Fit) were developed and validated. The tables consist of 3 categories: game description, impairments targeted (strength, endurance, balance, and coordination), and feedback provided (knowledge of performance [KP] and knowledge of results [KR]). Two domain content experts established face validity. Construct validity was performed by 2 therapist-raters who had more than 15 years’ clinical experience and postgraduate training in motor learning. Observations about the games including the fidelity of the interfaces, the nature of the feedback, and some of the challenges to adapting the games for rehabilitation are presented. Results: An 80% agreement between raters set as the criterion for establishing the construct validity was met for feedback evaluation. There was 100% agreement on impairment ratings. Games provide a greater amount of KR compared with KP. Conclusion: Given the preponderance of KR, therapists will need to monitor motor performance. Adaptation of interactive video consoles for rehabilitation requires careful evaluation of the games’ attributes using relevant rehabilitation construits.

Object. The role of functional magnetic resonance (fMR) imaging has become increasingly important in the presurgical mapping of gray matter. Neurosurgical interventions often involve fiber bundles that connect critical functional areas. Recently, diffusion-tensor (DT) imaging has enabled the visualization of fiber bundle direction and integrity, thus providing the ability to delineate clearly white matter from gray matter tissue. The main objective of this study was to improve the presurgical assessment of critical functionality in the vicinity of brain lesions by combining DT and fMR imaging methodologies. Methods. Twenty patients with various space-occupying brain lesions underwent imaging for presurgical evaluation of motor and/or somatosensory functions. The authors focus on five patients with diverse space-occupying brain lesions. Diffusion tensor—based fiber tracking and fMR imaging activation maps were superimposed in three dimensions to visualize pyramidal tracts corresponding to motor and somatosensory regional activation. Conclusions. The combination of DT and fMR imaging for presurgical functional brain mapping provides valuable information that cannot be extracted using either method alone. The validity and sensitivity of noninvasive functional mapping for surgical guidance could be improved by considering results obtained with both methods. Furthermore, the use of three-dimensional visualization seems crucial and unique for viewing and understanding the complicated spatial relationship among the lesion, gray matter activation, and white matter fiber bundles.

Background. Off-the-shelf activity-promoting video games (AVGs) are proposed as a tool for promoting regular physical activity among individuals poststroke. Objective. To characterize the energy expenditure (EE), exercise intensity, and energy metabolism of individuals poststroke, while playing AVGs in different positions, from different consoles, and to compare the performance with comfortable walking and with able-bodied individuals. Methods. Eleven poststroke and 8 able-bodied participants played in standing Wii-Boxing Xbox-Boxing, Wii-Run and Penguin, and also Wii-Boxing in sitting. EE (expressed as metabolic equivalents [METs]); exercise intensity (expressed as %predicted maximal heart rate [HR]), rate of perceived exertion (RPE), and respiratory exchange ratio (RER) were used to characterize the games. Results. Participants’ poststroke EE ranged from 1.81 ± 0.74 to 3.46 ± 1.3 METs and was lower compared with able-bodied participants for Xbox-Boxing ( P = .001), Wii-Boxing in standing ( P = .01), Run ( P < .001), and Penguin ( P = .001). Participants’ poststroke exercise intensity ranged from 49.8 ± 9.3 to 64.7 ± 9.3 %predicted maximal HR and was lower compared with able-bodied participants for Xbox-Boxing ( P = .007) and Run ( P = .005). For participants poststroke, EE of walking at a comfortable did not differ from boxing games in standing or Run. For able-bodied participants only, the EE for Xbox-Boxing was higher than Wii-Boxing (6.5 ± 2.6 vs 4.4 ± 1.1, P = .02). EE was higher in standing versus sitting for poststroke ( P = .04) and able-bodied ( P = .03) participants. There were no significant group differences for RPEs. RER of playing in sitting approached anaerobic metabolism. Conclusions. Playing upper extremity (ie, Boxing) or mobility (ie, Run) AVGs in standing resulted in moderate EE and intensity for participants poststroke. EE was lower for poststroke than for able-bodied participants.