Abstract Archives of the RSNA, 2008


SSQ15-07

Functional MRI of Rehabilitation in Chronic Stroke Using a Novel MR-Compatible, Hand-induced, Robotic Device

Scientific Papers

Presented on December 4, 2008
Presented as part of SSQ15:

Neuroradiology (Brain: Functional Imaging/Cortical Activation)

Participants

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

PURPOSE

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).

METHOD AND MATERIALS

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). 

RESULTS

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.

CONCLUSION

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

CLINICAL RELEVANCE/APPLICATION

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

Cite This Abstract

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