Diffusion tensor MR imaging evaluation of the corpus callosum of patients with multiple sclerosis

Abstract

-Objective: To evaluate the fractional anisotropy (FA) values of the normal-appearing white matter of the corpus callosum (CC) in patients with relapsing-remitting multiple sclerosis (MS). Method: Fifty-seven patients with diagnosis of relapsing-remitting MS and 47 age-and gender-matched controls were studied. A conventional MR imaging protocol and a DTI sequence were performed. One neuroradiologist placed the regions of interest (ROIs) in the FA maps in five different portions of the normal-apearing CC (rostrum, genu, anterior and posterior portion of the body and splenium) in all cases. The statistical analysis was performed with the Mann-Whitney U test and p<0.05 was considered statistically significant. Results: The FA values were lower in the MS patients compared with the controls (p<0.05) in the following CC regions: rostrum (0.720 vs 0.819), anterior body (0.698 vs 0.752), posterior body (0.711 vs 0.759) and splenium (0.720 vs 0.880). Conclusion: In this series, there was a robust decrease in the FA in all regions of the normal-appearing CC, being significant in the rostrum, body and splenium. This finding suggests that there is a subtle and diffuse abnormality in the CC, which could be probably related to myelin content loss, axonal damage and gliosis.Key WORDS: multiple sclerosis, diffusion tensor imaging, fractional anisotropy. avaliação do corpo caloso em pacientes com esclerose múltipla através de imagens de rM por tensor de difusãoResumo -Objetivo: Avaliar os valores da anisotropia fracionada (FA) da substância branca aparentemente normal do corpo caloso (CC) em pacientes com esclerose múltipla (eM) remitente recorrente. Método: 57 pacientes com diagnóstico de eM remitente recorrente e 47 controles pareados por sexo e idade foram estudados. O protocolo convencional de RM e imagens de tensor de difusão foram adquiridas. Um neurorradiologista posicionou as regiões de interesse nos mapas de FA em seis porções do CC aparentemente normal (rostro, joelho, anterior e posterior porções do corpo e esplênio) em todos os casos. A análise estatística foi realizada com o teste Mann-Whitney U e p<0,05 foi considerado estatisticamente significativo. Resultados: Os valores de FA foram menores nos pacientes com eM comparados com os controles (p<0,05) nas seguintes porções do CC: rostro (0,720 vs 0,819), corpo anterior (0,698 vs 0,752), corpo posterior (0,711 vs 0,759) e esplênio (0,720 vs 0,880). Conclusão: Na presente série houve redução robusta na FA em todas as regiões aparentemente normais do CC, sendo significativa no rostro, corpo e esplênio. este achado sugere que há alteração difusa no corpo caloso de pacientes com eM, provavelmente relacionada a perda da mielina, lesão axonal e gliose.PAlAvRAS-ChAve: esclerose múltipla, imagens de tensor de difusão, anisotropia fracionada.

Antigen-Specific Suppression of Experimental Autoimmune Encephalomyelitis by a Novel Bifunctional Peptide Inhibitor: Structure Optimization and Pharmacokinetics

“…Multiple sclerosis (MS), a demyelinating disease affecting the central nervous system, is characterized by inflammatory demyelinating foci in the brain white matter with variable axonal damage (Huizinga et al, 2008;Rueda et al, 2008). Although its etiology is still scarcely understood, the composition of plaques, immunogenetic background, responses to immunomodulation, and data from animal models suggest that MS is mediated by myelin-specific CD4 ϩ T cells (Lu, 2006;Sonobe et al, 2007;Elyaman et al, 2008;Sabatino et al, 2008).…”

Neuroimaging of corpus callosum in central nervous system demyelinating disorders

“…[29][30][31][32][33] Sigal et al [11] used DTI to investigate CC integrity in MS patients and age matched controls. In agreement with other studies, [15,26,28,31] MS patients had significant reduction in CC 's FA compared with control group in all subregion of CC, indicating axonal loss and dysfunction in callosal fibers. Most recent studies agree on the fact that in MS patients all MRI indices and parameters are altered pathologically especially in the CC structure.…”

Diffusion Tensor Group Tractography of the Corpus Callosum in Clinically Isolated Syndrome

“…Some authors observed FA decreases predominantly in the body of the CC, [6][7][8] with an insignificant trend in the splenium, 7,8 and no significant changes in the genu. 7 Therefore, some researchers reported that CC abnormalities might be a sensitive marker of MS. 9,10 CIS, suggestive of MS, as typically the earliest clinical expression of many patients with MS, 11 has received a great deal of attention from recent clinical research.…”

“…Abnormal CC integrity (reduced FA or increased MD) is also a common finding in MS using DTI. [4][5][6][7][8] Moreover, some DTI studies have found different change patterns in the subdivisions of the CC.…”

“…15,16,19 Moreover, the fiber distribution in the CC is known to be heterogeneous, [20][21][22] and there are different change patterns in the subdivisions of the CC in MS [6][7][8] ; therefore, we hypothesized that the patterns of CC abnormalities are also spatially heterogeneous in CIS. To show this heterogeneity, we parcellated the entire CC further into 3 subregions on the basis of known callosal anatomic projections, which are the genu, body, and splenium [23][24][25][26] ; then, we created their probability maps and used them to evaluate the diffusion indices inside these regions.…”