Diffusion tensor MRI alterations of subcortical deep gray matter in clinically isolated syndrome

Hippocampal microstructural damage correlates with memory impairment in clinically isolated syndrome suggestive of multiple sclerosis

“…Therefore either FA and MD measure different underlying histological substrate or, more likely, FA is less reliable than MD in grey matter which is in line with previous results [16,17]. Higher MD might correspond to a mixture of hippocampal demyelination, neuronal or synaptic loss together with inflammatory cells as described in post-mortem studies of MS brains [30].…”

“…Hippocampal FA was significantly decreased in the CIS group and even more in the MS group, in which a significant increase of hippocampal MD was also observed. In previous work assessing PwCIS, deep grey matter DTI changes were detected, while no hippocampal DTI changes were apparent [17]. However, the sensitivity to DTI changes in the hippocampus might have been hampered by partial voluming effects due to a larger voxel size (3.33mm x 3.33mm x 3.00mm) [17], compared with our 1.6mm 3 voxel size.…”

“…Diffusion tensor imaging (DTI) has been efficiently used to reveal widespread white matter damages from the stage of CIS [16] but less consistently within grey matter [17,18]. Specifically, there is no report of altered DTI within the hippocampus of persons with CIS and no strong imaging correlate of memory impairment at this stage.…”

Gray Matter Involvement in Radiologically Isolated Syndrome

“…Although these results were somewhat unexpected, they are indeed in line with previous research. Thus, although a large number of studies did not find decreased whole brain and cortical volumes in CIS patients, 36,37,39,43–45 all the studies published so far (with the exception of one publication) 10 have reported total brain and cortical atrophy in RIS patients, 3,6,8,9,12 thereby suggesting that, in contrast to CIS patients, decreased cortical volume in RIS patients is highly consistent. However, there are also several reasons that might partially explain these results: CIS patients had a lower median white matter lesion volume compared with RIS (albeit not significant); although there was no significant age difference among CIS and RIS groups in the present study, RIS patients were approximately 2 years older than those from the CIS group; nearly one-third of the CIS patients presented with spinal cord symptoms, which might led to lower average cortical thickness (the type of clinical picture at onset has been found to correlate with atrophy in the corresponding cortical areas) 46 ; in contrast with MS and CIS patients, the absence of a definable clinical event makes it impossible to establish the disease evolution among RIS patients and, thus, there is the possibility that RIS evolution have actually a much longer duration than expected.…”

Connectivity‐based parcellation of the thalamus in multiple sclerosis and its implications for cognitive impairment: A multicenter study

“…r Regional Thalamic Damage and Cognition in MS r r 2819 r (CIS) [Cappellani et al 2014a] has also been reported. Various factors might contribute to explain discrepancies among available studies, including not only clinical characteristics of patients studied, but also the technique applied to segment the thalamus.…”