Lesion Topography Impact on Shoulder Abduction and Finger Extension Following Left and Right Hemispheric Stroke

Abstract

The existence of shoulder abduction and finger extension movement capacity shortly after stroke onset is an important prognostic factor, indicating favorable functional outcomes for the hemiparetic upper limb (HUL). Here, we asked whether variation in lesion topography affects these two movements similarly or distinctly and whether lesion impact is similar or distinct for left and right hemisphere damage. Shoulder abduction and finger extension movements were examined in 77 chronic post-stroke patients using relevant items of the Fugl-Meyer test. Lesion effects were analyzed separately for left and right hemispheric damage patient groups, using voxel-based lesion-symptom mapping. In the left hemispheric damage group, shoulder abduction and finger extension were affected only by damage to the corticospinal tract in its passage through the corona radiata. In contrast, following the right hemispheric damage, these two movements were affected not only by corticospinal tract damage but also by damage to white matter association tracts, the putamen, and the insular cortex. In both groups, voxel clusters have been found where damage affected shoulder abduction and also finger extension, along with voxels where damage affected only one of the two movements. The capacity to execute shoulder abduction and finger extension movements following stroke is affected significantly by damage to shared and distinct voxels in the corticospinal tract in left-hemispheric damage patients and by damage to shared and distinct voxels in a larger array of cortical and subcortical regions in right hemispheric damage patients.

Direction-dependent neural control of finger dexterity in humans

“…Family-wise error rate (FWER) was controlled using the false discovery rate (FDR) method 80 with p-value < 0.05. Due to the relatively small sample size, we also reported voxels that did not survive these corrections, but instead survived a more lenient criterion of p < 0.01, similarly to previous reports [14][15][16][17][18]70 . To explore the extent of anatomical overlap between brain voxels implicated in finger-individuation and strength in each direction (flexion, extension), we employed VLSM conjunction analysis contrasting brain voxels that were selectively associated with either flexion or extension, and brain voxels without such direction selectivity (i.e., voxels in which the existence of damage affected performance in both flexion and extension).…”

“…We therefore report here for the extension analysis voxels that survived a lenient criterion of p < 0.01 (corresponding to minimal z-score of 2.32). For a similar approach see 14,[16][17][18] . The cluster peak z-score (z = 3.26) was situated within M1-CST (8% of the cluster; MNI coordinates: -28 -16 48), while its periphery also overlapped with SLF-II (30%), M1 (19%), CRP (14%), and PM-CST (5%).…”

“…VLSM conjunction analysis 14,17,18 (Fig. 4A; Table 3) was done to explore which brain structures were specifically associated with finger-individuation in one direction but not the other, as well as brain structures associated with finger-individuation in both directions.…”

Stroke Lesion Impact on Lower Limb Function

“…The study was approved by the Ethics Review Board of the Loewenstein Rehabilitation Medical Center (approval number LOE-004-14). The current cohort included subjects who participated also in our recently published study ( Frenkel-Toledo et al, 2020 ), but only those who met the aforementioned inclusion criteria. All participants were informed about the protocol and gave their written informed consent prior to inclusion in the study.…”

Association of Acute Infarct Topography With Development of Cerebral Palsy and Neurologic Impairment in Neonates With Stroke

“…It enables more precise investigation of the relationship between stroke outcomes and infarct topography by reducing the influence of other lesion characteristics known to correlate with outcome, such as lesion volume. This technique has been increasingly used in adult arterial ischemic stroke to map stroke lesions underlying outcomes including somatosensory, 9 upper limb motor, [10][11][12] and language deficits, 13 and to determine regions of higher importance in determining overall functional outcomes. The application of VLSM in pediatric AIS has so far been limited, with one longitudinal Spanish study of NAIS, correlating brain regions associated with motor, cognitive, and language outcomes, 14 and another cross-sectional French study of children with a history of previous NAIS, correlating brain regions remote from the site of infarction with contralateral hand function.…”