A. Aria Tzika PhD, Presenter: Nothing to Disclose

Dionyssios Mintzopoulos PhD, Abstract Co-Author: Nothing to Disclose

Azadeh Khanicheh MS, Abstract Co-Author: Nothing to Disclose

Bruce R. Rosen MD, PhD, Abstract Co-Author: Nothing to Disclose

Loukas G. Astrakas PhD, Abstract Co-Author: Nothing to Disclose

Michael Moskowitz MD, Abstract Co-Author: Nothing to Disclose

To monitor brain activation after chronic stroke by combining functional magnetic resonance imaging (fMRI) with a novel MR-compatible hand-induced robotic device (MR_CHIROD).

We evaluated 60 fMRI datasets at 3T from five right-hand-dominant patients (mean age: 65 years) with first-ever left-sided stroke ≥6 months prior and mild to moderate hemiparesis affecting the right hand. Patients trained the paretic hand at approximately 75% of maximum strength with an exercise ball for 1 hour/day, 3 days/week for 4 weeks. MR neuroimaging exams were performed before, during (A), upon completion of training (B), and after a non-training period (C) to assess permanence of effects. We acquired fMRI data using a block design paradigm and parallel imaging (GeneRalized Autocalibrating Partially Parallel Acquisitions, GRAPPA; TR/TE=3000ms/30ms, 1.56 mm×1.56 mm×3 mm) while the participant used the MR_CHIROD. During the action period, subjects continuously squeezed and released the MR_CHIROD at 0.5 Hz. Volunteers performed the paradigm at 45%, 60%, and 75% of maximum dynamic grip strength and could fully squeeze the device at all levels. Clusters of statistically significant voxels (P<0.05, corrected) were further selected for BOLD ≥ 2.0%. This 2.0% threshold served as a filter, selecting regions of interest without enforcing their boundaries a priori. Comparisons between effort levels were done using t-test (two-tailed, P<0.05). 

Training significantly increased the number of activated voxels in the cortex as function of maximum effort. At 45% effort, A (mean number of activated voxels ± SD, 35 ± 15) differed from B (236 ± 32), P = 0.0022, and from C (246 ± 30), P = 0.0016. At the 60% effort, A (116 ± 31) differed significantly from B (271 ± 33), P < 0.05, and from C (271 ± 26), P < 0.05. At the 75% effort, A (180 ± 22) differed significantly from B (295 ± 38), P < 0.05, and from C (246 ± 20 voxels) P < 0.05.

Online fMRI using MR_CHIROD suggested that training-induced functional cortical plasticity persists even in chronic stroke patients indicating permanence of rehabilitation.

Persisting cortical plasticity persists even in chronic stroke patients indicated permanence of rehabilitation, which is remarkable since training is generally effective only in a narrow window aft

Tzika, A, Mintzopoulos, D, Khanicheh, A, Rosen, B, Astrakas, L, Moskowitz, M, Functional MRI of Rehabilitation in Chronic Stroke Using a Novel MR-Compatible, Hand-induced, Robotic Device.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6012708.html