Anterior Striatal Lesions are Associated with Aiming Neglect After Right Brain Stroke (P3.228)

Objective: To determine whether spatial-motor Aiming bias is predominant in neglect due to lesions affecting subcortical nuclei/white matter. Background: Spatial neglect after right stroke causes functional disability due to asymmetric perception and attention, but asymmetric spatial Aiming (failure to move or act leftward, or directional hypokinesia) can also increase the risk of falls, accidents and long-term skilled placement. Our research group reported that prism adaptation therapy, which specifically improves directional hypokinesia, is more effective in patients with frontal cortical lesions (Chen et al. 2014). However, many patients with spatial neglect have subcortical strokes, and we need to understand whether these brain lesions induce Aiming errors in humans, as they do in animals. Design/Methods: We retrospectively identified 16 brain images in consecutive right subcortical stroke patients (6 women, mean age 66.6, mean education 13.2) with spatial neglect on the Behavioral Inattention Test-conventional (mean 80.3). Clinical brain MRI or CT, mapped using MRIcron, were classified categorically. Results: 5 of 16 subjects had right Aiming bias (Garza et al., 2008). Overlap imaging revealed common lesion sites of the head of the caudate, putamen, internal capsule and periventricular white matter. Compared with 11 subjects who lacked right Aiming bias, subtraction analysis with minimum threshold of 3 subjects revealed lesions in caudate head, anterior putamen, and anterior limb of internal capsule. We identified more posterior subcortical lesions in subjects without Aiming bias. The rightward Aiming bias group tended to have larger stroke volume (43.13 CC, range 10.13 to 102.14 vs 16.64 CC, range 2.62 to 42.06, p value 0.056). Conclusions: These data support that subcortical lesions of the right hemisphere produce neglect. A subset of these patients, who had anterior, striatal lesions, demonstrated Aiming bias. Further research is required to confirm the association of striatal lesions and spatial Aiming bias in subcortical neglect. Study Supported by: NIH, NIDILRR, and the Kessler Foundation Disclosure: Dr. Thomas has nothing to disclose. Dr. Caulfield has nothing to disclose. Dr. Barrett has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with emedicine/WebMD.