Positive Effect of Impairment-Oriented Training on N-Acetylaspartate Levels of Ipsilesional Motor Cortex in Subcortical Stroke: A Case Study
- *Corresponding Author:
- Carmen M. Cirstea
Department of Physical Medicine & Rehabilitation
University of Missouri, One Hospital Drive
DC046.00, Columbia, MO 65212, USA
E-mail: [email protected]
Received Date: December 11, 2015 Accepted Date: January 29, 2016 Published Date: February 01, 2016
Citation: Ahmed AB, Cirstea CM (2016) Positive Effect of Impairment-Oriented Training on N-Acetylaspartate Levels of Ipsilesional Motor Cortex in Subcortical Stroke: A Case Study. Int J Phys Med Rehabil 4:325. doi: 10.4172/2329-9096.1000325
Copyright: © 2016 Ahmed AB, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background and Purpose: We investigated the effects of an intensive impairment-oriented training on neuronal state (assessed by proton MR spectroscopy, 1H-MRS) of the spared motor and premotor cortices in the injured (ipsilesional) hemisphere and clinical impairment in a patient with chronic subcortical stroke. Methods: One survivor of a single ischemic stroke located outside of the motor and premotor cortices (assessed on T1-weighted MRI) was studied at six months after stroke. We used functional MRI-guided 1H-MRS to quantify the levels of N-acetylaspartate (NAA - a putative neuronal marker) in the hand representation within ipsilesional primary motor cortex (M1), dorsal premotor cortex (dPM) and supplementary motor area (SMA), and Fugl-Meyer (normal=66 points) test to assess the arm motor impairment immediately before and after a motor training paradigm. Training comprised intensive variable practice (1080 repetitions over 12 day-period) of a reach-to-grasp task with the impaired hand while focusing the learner’s attention on an altered movement component, i.e., decreased elbow extension. Results: At baseline, the patient was severely impaired (Fugl-Meyer score=25 points) and exhibited lower level of NAA in all areas (M1, 9.2 mM vs. 11.6 ± 2.0 mM in healthy controls; dPM, 8.9 mM vs. 12.2 ± 1.9 mM; SMA, 7.4 mM vs. 11.0 ± 2.3 mM). After training, the patient improved clinically (by 6 points) and displayed higher levels of NAA across all areas (by 0.6-3.3 mM). Conclusions: Our data demonstrated that the radiologically normal-appearing ipsilesional motor and premotor areas have the resources to boost behavioral output in response to an intervention. We hope that these data will act as a starting point for further research to test the potential of 1H-MRS measures to provide a biomarker of neuroplasticity in response to restorative therapies in chronic stroke.