The aim was to determine the iron accumulation and  volumetric measurements of subcortical, brain stem and cerebellar deep gray matter structures in MS and healthy control subjects, and to investigate the correlation between iron accumulation and volumes.

Increased iron accumulation in subcortical gray matter is explained by the blood-brain barrier dysfunction, decreased iron clearance or dysfunction of iron transport proteins induced by inflammation and axonal degeneration.

Sixteen MS patients, 8 CIS and 17 control subjects were included in this study. Region of interest (ROI) analysis on T2* relaxation time maps was used to estimate T2* values for deep grey matter structures at high resolution MRI at 7 Tesla. All structures outlined bilaterally in visually observed sections that extended from caudal to rostral and iron measurements were performed by ROI.  

Statistically significant differences were identified for MS patients less than healthy controls in left red nucleus (p=0,006), left putamen (p=0,015), left remaining thalamus (p=0,032), right putamen (p=0,002) and splenium (p=0,010)  in T2* relaxation time. The sixteen MS patients and eight CIS patients showed significantly smaller volumes than the seventeen control patients (left red nucleus: 248,92 ± 44,08 vs 269,29 ± 28,86 (p=0,006), right red nucleus: 244,77 ± 44,35 vs 250,94 ± 29,47 (p=0,048), right putamen: 2934,75 ± 509,87 vs 3286,31 ± 363,60 (p=0,002) and splenium: 3281,70 ± 1009,98 vs 3657,52 ± 783,51 (p=0,01). There was no significant correlation between T2 star and volumes values in all structures analysed (p>0,05).

This study suggests the increased iron accumulation as indicated by decreased T2* relaxation times in red nucleus, splenium, putamen and thalamus in the early stage of MS. There were not a correlation between iron accumulation and the loss of volumes. These results can play a role in determining the course of the disease and deciding the treatment of the disease modifying therapy.