Shared and distinct voxel-based lesion-symptom mappings for spasticity and impaired movement in the hemiparetic upper limb

Abstract

Hemiparesis and spasticity are common co-occurring manifestations of hemispheric stroke. The relationship between impaired precision and force in voluntary movement (hemiparesis) and the increment in muscle tone that stems from dysregulated activity of the stretch reflex (spasticity) is far from clear. Here we aimed to elucidate whether variation in lesion topography affects hemiparesis and spasticity in a similar or dis-similar manner. Voxel-based lesion-symptom mapping (VLSM) was used to assess the impact of lesion topography on (a) upper limb paresis, as reflected by the Fugl-Meyer Assessment scale for the upper limb and (b) elbow flexor spasticity, as reflected by the Tonic Stretch Reflex Threshold, in 41 patients with first-ever stroke. Hemiparesis and spasticity were affected by damage to peri-Sylvian cortical and subcortical regions and the putamen. Hemiparesis (but not spasticity) was affected by damage to the corticospinal tract at corona-radiata and capsular levels, and by damage to white-matter association tracts and additional regions in the temporal cortex and pallidum. VLSM conjunction analysis showed only a minor overlap of brain voxels where the existence of damage affected both hemiparesis and spasticity, suggesting that control of voluntary movement and regulation of muscle tone at rest involve largely separate parts of the motor network.

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.…”

Associating Functional Neural Connectivity and Specific Aspects of Sensorimotor Control in Chronic Stroke

“…The current results did not observe interhemispheric connectivity to be significantly associated with any of the grip measures. These findings may indicate how lesion location leads to functional deficits to somatosensation [ 77 , 78 ], motor performance [ 79 , 80 ], and subsequent recovery outcomes [ 81 ]. Heightened involvement or activity of the non-lesioned hemisphere relative to the lesioned hemisphere may indicate either the presence of compensatory mechanisms or bilateral drive needed to control paretic arm movement after stroke [ 82 , 83 , 84 , 85 ].…”

Regional homogeneity alterations in multifrequency bands in patients with basal ganglia stroke: A resting-state functional magnetic resonance imaging study

“…Our results showed that compared to the HCs, ReHo changed in the left putamen of the BGIS group in the conventional frequency band. Putamen as a nucleus of the BG was located near the motor never tracts of the brain ( Frenkel-Toledo et al, 2022 ). Damage to the corticospinal tract in the putamen would affect lower limb motor function of patients with stroke ( Frenkel-Toledo et al, 2021 ).…”