Annals of the New York Academy of Sciences
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Ann. N. Y. Acad. Sci. · Dec 2005
ReviewAmyotrophic lateral sclerosis and primary lateral sclerosis: The role of diffusion tensor imaging and other advanced MR-based techniques as objective upper motor neuron markers.
Amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease, is a motor neuron disease characterized by progressive degeneration of upper motor neuron (UMN) and lower motor neuron (LMN), while primary lateral sclerosis (PLS) is defined by pure UMN involvement. A reliable objective marker of UMN involvement is critical for the early diagnosis and monitoring of disease progression in patients with ALS and PLS. Diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), and magnetic resonance spectroscopy (MRS), which provide insight into the pathophysiological process of ALS and PLS, show great promise in this regard. Further investigation is needed to determine and to compare the utility of various neuroimaging markers.
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Functional magnetic resonance imaging (fMRI) of the perceptual, motor, and cognitive capacities in humans is of increasing importance for basic and clinical neurosciences. The explanatory power of current fMRI techniques could be greatly expanded, however, if the pattern of the neuronal connections between the active cortical areas could likewise be visualized. ⋯ Subsequently, diffusion tensor imaging (DTI) data from the same subjects were obtained, and the activation areas identified through fMRI were utilized as seeding points for 3D DTI fiber reconstruction algorithms. The methods developed in this study have the potential to lay a foundation for in vivo neuroanatomy and the ability for noninvasive longitudinal studies of brain development.
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Ann. N. Y. Acad. Sci. · Dec 2005
TLR1 and TLR6 polymorphisms are associated with susceptibility to invasive aspergillosis after allogeneic stem cell transplantation.
Toll-like receptors (TLRs) transmit signals in response to Aspergillus fumigatus conidia and hyphae. In this preliminary study, we examined the association between single nucleotide polymorphisms (SNPs) in TLR1, TLR4, and TLR6 genes and development of invasive aspergillosis (IA) in 127 allogeneic hematopoietic stem cell transplant recipients consisting of 22 patients with IA and 105 unaffected control subjects. ⋯ Analysis of recipient SNP data showed that the presence of TLR1 239G > C (Arg80 > Thr) or the presence of both TLR1 743A > G (Asn248 > Ser) and TLR6 745C > T (Ser249 > Pro) is associated with IA (odds ratio = 1.30, 95% confidence interval = 1.13 to 1.50; P < .001). Further analyses using a prospective cohort may enable us to identify TLR polymorphisms associated with the susceptibility to IA within a defined interval among immunocompromised patients.
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Ann. N. Y. Acad. Sci. · Dec 2005
Case ReportsEffects of prior exposure on music liking and recognition in patients with temporal lobe lesions.
Prior exposure to music typically increases liking. This manifestation of implicit memory can be dissociated from explicit memory recognition. To examine the contribution of the medial temporal lobe to musical preference and recognition, we tested patients with either left (LTL) or right (RTL) temporal lobe lesions as well as normal control (NC) participants using the procedure of Peretz et al. ⋯ In this case, the exposure effect on liking was also absent. However, repeated exposure to melodies was found to enhance both liking and recognition judgments. This remarkable sparing of memory observed through melody repetition suggests that extensive exposure may assist both implicit and explicit memory in the presence of global amnesia.
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The spinal cord is an important part of the nervous system and provides the connection of the brain with the periphery. It consists not only of a large number of longitudinal fibers, but also contains collateral fibers and a central gray matter structure, which are part of autonomous circuits. ⋯ This report summarizes the normal findings for ADC, diffusion anisotropy, and diffusion eigenvector directions in the spinal cord. Sagittal and axial diffusion-weighted images of the spinal cord were obtained with line scan diffusion imaging (LSDI) in adults, children, infants, and a spinal cord specimen.