Isolated motor neglect following infarction of the posterior limb of the right internal capsule: a case study with diffusion tensor imaging-based tractography.

Motor neglect is an impairment in the ability to initiate movement not attributable to muscle weakness. The neural network of this syndrome is not precisely defined. We present the diffusion tensor imaging (DTI)-base tractography findings in an acute stroke patient presenting with isolated motor neglect following infarction in the posterior limb of the internal capsule within the anterior choroidal artery territory. A left-handed 17-year-old woman presented with an acute onset of motor neglect of her left arm. Motor tasks performed with the affected limb were awkward; however, the tasks could be accomplished with effort. Magnetic resonance imaging (MRI) including DTI of the brain were performed. DTI-based tractography extracted the fiber tracts originating from regions of interest placed on the ischemic lesion. MRI revealed an acute ischemic infarction at the posterior part of the posterior limb of the right internal capsule within the territory of the anterior choroidal artery. DTI-based tractography showed fiber tracts projecting from the lesion to the posterior part of the supplementary motor area and some fiber tracts projecting to posterior aspects of the thalamus. DTI-based tractography may be a useful tool for visualizing white matter pathways in vivo following an acute infarction. Our case study supports the notion that fiber tracts connecting the posterior part of the posterior limb of the internal capsule, supplementary motor area, and posterior aspect of the thalamus are key areas of a neural network involved in motor neglect syndrome.