1. Assessment of Inter-Hemispheric Imbalance Using Imaging and Noninvasive Brain Stimulation in Patients With Chronic Stroke 
David A. Cunningham, MS, Andre Machado, MD, PhD, Daniel Janini, Nicole Varnerin, BS, Corin Bonnett, BS, Guang Yue, PhD, Stephen Jones, MD, PhD, Mark Lowe, PhD, Erik Beall, PhD, Ken Sakaie, PhD, Ela B. Plow, PhD, PT 
Archives of Physical Medicine and Rehabilitation 
Volume 96, Issue 4, Pages S94-S103 (April 2015)
DOI: /j.apmr
Copyright © 2015 American Congress of Rehabilitation Medicine Terms and Conditions

2. Fig 1
Example of an iSP from the (A) contralesional to ipsilesional and (B) ipsilesional to contralesional hemispheres. The iSP ratio was the percentage decrease of electromyographic activity of the contralesional to ipsilesional hemisphere/percentage decrease of electromyographic activity of the ipsilesional to contralesional hemisphere. The iSP onset and offset were determined as the point where the electromyography went <1 SD of the prestimulus mean and returned back within 1 SD of the prestimulus mean. Even though the patients maintained a contraction at 50% of the maximum voluntary contraction, it is important to notice the difference between the electromyographic scale of the paretic hand (A) and nonparetic hand (B), where the paretic hand electromyography reached a maximum of approximately 50μV and the nonparetic hand reached a maximum of approximately 400μV. Despite the difference in electromyographic activity, the level of electromyography does not influence the degree of inhibition.51 Results are reported as an iSP ratio, which is defined as the contralesional to ipsilesional iSP/ipsilesional to contralesional iSP. The subject shown had an iSP ratio of .75.
Archives of Physical Medicine and Rehabilitation  , S94-S103DOI: ( /j.apmr )
Copyright © 2015 American Congress of Rehabilitation Medicine Terms and Conditions

3. Fig 2
Correlation between the fMRI laterality index and TMS. (A) There was a positive correlation between the ratio of the iSP and fMRI laterality index within the M1. (B and C) There was a significant positive correlation between the fMRI laterality index within the M1 and PMC and the total ipsilesional map area count with the TMS. Abbreviations: ISP, ipsilateral silent period; M1laterality, primary motor cortex laterality index; PMClaterality, premotor cortex laterality index.
Archives of Physical Medicine and Rehabilitation  , S94-S103DOI: ( /j.apmr )
Copyright © 2015 American Congress of Rehabilitation Medicine Terms and Conditions

4. Fig 3
Correlation between the DTI and TMS. There was a significant positive correlation between the FAasymmetry (FA asymmetry) of the corticospinal tracts originating from the M1 and the recruitment curve of the contralesional hemisphere discerned with TMS.
Archives of Physical Medicine and Rehabilitation  , S94-S103DOI: ( /j.apmr )
Copyright © 2015 American Congress of Rehabilitation Medicine Terms and Conditions

5. Fig 4
Relation between the clinical assessment scores (UEFM, MAL amount score) and neurophysiological and neuroimaging outcomes. (A) There was a negative correlation between the UEFM and M1 FA asymmetry. (B–D) there was a positive correlation between the MAL amount score and fMRI laterality index within the M1, PMC, and SMA. (E) fMRI-based images in 2 different patients. Subject 1 shows high fMRI laterality, signifying good ipsilesional hemisphere dominance during contraction of the paretic hand. Subject 2 shows low fMRI laterality, signifying weaker ipsilesional hemispheric dominance during contraction of the paretic hand. Their MAL amount scores were 2.3 and .66, respectively, signifying that the patient with higher laterality showed a higher MAL amount score. (F) DTI-based images in 2 different patients. Subject 3 shows poor M1 FA asymmetry, signifying weaker integrity of corticospinal tracts originating from the ipsilesional side. Subject 4 shows good M1 FA asymmetry, signifying similar integrity of tracts in both hemispheres. Their UEFM scores were 35 and 50, respectively, signifying that the patient with higher function showed favorable integrity on the ipsilesional side. Abbreviations: A, anterior; I, inferior; L, left; M1laterality, M1 laterality index; MALamount, MAL amount score; P, posterior; PMClaterality, PMC laterality index; R, right; S, superior; SMAlaterality, SMA laterality index.
Archives of Physical Medicine and Rehabilitation  , S94-S103DOI: ( /j.apmr )
Copyright © 2015 American Congress of Rehabilitation Medicine Terms and Conditions