Lesion Localization of Poststroke Lateropulsion

Abstract

Background and Purpose: Hemispheric stroke studies associating lateropulsion (pusher syndrome) with the location of brain lesions have had mixed results from small, unmatched samples. This study was designed to determine whether lateropulsion localizes to specific brain regions across patients with stroke using a case-control design. Methods: Fifty patients with lateropulsion following stroke were matched with 50 stroke patients without lateropulsion using age, time since onset of stroke, admission motor Functional Independence Measure (FIM) score, lesion side and gender. The primary analysis included multivariate lesion symptom mapping using sparse canonical correlations to identify regions most associated with lateropulsion as assessed with the Burke Lateropulsion Scale. Secondary analyses included evaluating paired comparisons for lesion volume, degree of motor impairment, motor and cognitive FIM scores. Results: The lesion symptom mapping analysis of all lesions mapped onto a common hemisphere produced an overall significant model (P < 5 × 10 −5) with a regional peak at the

Is Lateropulsion Really Related with a Specific Lesion of the Brain?

“…Previous studies suggested that disruption of networks in the right hemisphere could impair vertical postural control and lead to lateropulsion [ 5 ]. The postcentral gyrus and surrounding white matter, and the postcentral gyrus and Brodmann area 40 in the inferior parietal lobe, were reportedly associated with lateropulsion [ 3 , 7 , 27 ]. Damage to the inferior frontal gyrus and precentral gyrus was previously reported to be associated with lateropulsion [ 3 , 27 , 28 ].…”

“…The postcentral gyrus and surrounding white matter, and the postcentral gyrus and Brodmann area 40 in the inferior parietal lobe, were reportedly associated with lateropulsion [ 3 , 7 , 27 ]. Damage to the inferior frontal gyrus and precentral gyrus was previously reported to be associated with lateropulsion [ 3 , 27 , 28 ]. The insula may play a role in vestibular function [ 29 ], and damage in this area might disrupt the vestibulospinal system and induce lateropulsion.…”

“…Lateropulsion (pusher syndrome) is a postural bias toward the weak side [ 1 , 2 ] accompanied by resistance to postural correction back to a vertical upright position after stroke [ 3 , 4 , 5 ]. Patients with pusher syndrome are able to consciously perceive body orientation, and are capable of spontaneous postural adjustment of the non-paretic leg in the roll plane [ 6 ].…”

“…In addition, thalamoparietal projections have a functional role in the processing of somasthetic graviceptive information [ 5 ]. Research has also shown that the inferior parietal lobe plays a role in lateropulsion [ 3 ]. Other reports have demonstrated that injury to the insular cortex, postcentral gyrus and posterior thalamus might be associated with lateropulsion [ 7 ].…”

Fractional Anisotropy of Thalamic Nuclei Is Associated With Verticality Misperception After Extra-Thalamic Stroke

“…The structural biology of verticality perception is incompletely understood; however, studies of voxel-based lesion-behavior mapping and neuronal network-based mathematical modeling (5–7), have shown a clear involvement of posterior nuclei of the thalamus. What remains unclear is whether degeneration of the thalamic nuclei is a common feature when primary lesions are outside thalamus, and whether symptom-lesion association is confined to specific posterior nuclei of the thalamus.…”