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Objective: To quantify the effects of traumatic brain injury on integrity of thalamocortical projection fibers and to evaluate whether damage to these fibers accounts for impairments in executive function in chronic traumatic brain injury.Methods: High-resolution (voxel size: 0.78 mm ϫ 0.78 mm ϫ 3 mm 3 ) diffusion tensor MRI of the thalamus was conducted on 24 patients with a history of single, closed-head traumatic brain injury (TBI) (12 each of mild TBI and moderate to severe TBI) and 12 age-and education-matched controls. Detailed neuropsychological testing with an emphasis on executive function was also conducted. Fractional anisotropy was extracted from 12 regions of interest in cortical and corpus callosum structures and 7 subcortical regions of interest (anterior, ventral anterior, ventral lateral, dorsomedial, ventral posterior lateral, ventral posterior medial, and pulvinar thalamic nuclei). Results:Relative to controls, patients with a history of brain injury showed reductions in fractional anisotropy in both the anterior and posterior corona radiata, forceps major, the body of the corpus callosum, and fibers identified from seed voxels in the anterior and ventral anterior thalamic nuclei. Fractional anisotropy from cortico-cortico and corpus callosum regions of interest did not account for significant variance in neuropsychological function. However, fractional anisotropy from the thalamic seed voxels did account for variance in executive function, attention, and memory. Conclusions:The data provide preliminary evidence that traumatic brain injury and resulting diffuse axonal injury results in damage to the thalamic projection fibers and is of clinical relevance to cognition. Neurology ® 2010;74:558 -564 GLOSSARY ACR ϭ anterior corona radiata; AN ϭ anterior thalamic nucleus; bCC ϭ body of the corpus callosum; CST ϭ cortical-spinal tract; DAI ϭ diffuse axonal injury; DM ϭ dorsomedial nucleus; DTI ϭ diffusion tensor imaging; FA ϭ fractional anisotropy; fMaj ϭ forceps major; fMin ϭ forceps minor; FOV ϭ field of view; FSE ϭ fast spin echo; gCC ϭ genu of the corpus callosum; IC ϭ internal capsule; IFOF ϭ inferior frontal occipital fasciculus; LOC ϭ loss of consciousness; miTBI ϭ mild TBI; msTBI ϭ moderate to severe TBI; NEX ϭ number of excitations; PCR ϭ posterior corona radiata; PTA ϭ posttraumatic amnesia; PU ϭ pulvinar; ROI ϭ region of interest; sCC ϭ splenium of the corpus callosum; SLF ϭ superior longitudinal fasciculus; SS ϭ sagittal stratum; TBI ϭ traumatic brain injury; TE ϭ echo time; TR ϭ repetition time; VA ϭ ventral anterior thalamic nucleus; VL ϭ ventral lateral thalamic nucleus; VPL ϭ ventral posterior lateral nucleus; VPM ϭ ventral posterior medial nucleus. Traumatic brain injury (TBI) is a serious public health problem with a high incidence 1-3 which can result in structural damage to the cerebrum including contusions, edema, and diffuse axonal injury (DAI).4 DAI has been demonstrated in all stages and severities [5][6][7] and is often the only significant pathology in milder injury...

SUMMARY Fourteen right-handed patients with right hemispheric strokes were examined for disorders of affective language in order to further define the clinical-anatomical correlates of the aprosodias. A bedside evaluation strategy and CT scan mappings were utilised to make these comparisons. There were six patients with motor aprosodia, one with global aprosodia, two with conduction aprosodia, one with sensory aprosodia, one with transcortical sensory aprosodia, one with pure affective deafness and two with normal examinations of affect. Functional-anatomical correlations were consistent with those predicted previously. Recovery of affective language function in selected cases was characterised by improvements in affective-prosodic repetition and/or evolution into other aprosodic subtypes. Our results lend further support to the hypothesis that the organisation of affective language in the right hemisphere mirrors that of propositional language in the left hemisphere.Because the left hemisphere plays a major role in the neural processes governing the production and comprehension of propositional language, it has been designated as the "dominant" hemisphere. The

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