Background Higher iron concentration in subcortical grey matter structures is documented in Huntington’s disease (HD) but the iron content on white matter (WM) is less well documented.

We previously investigated the iron level in the WM corpus callosum in HD reporting a lower iron level in posterior callosal subregion. Furthermore we explored the iron content in the callosal fibres, reporting a lower iron content in HD in few tracts, such as occipital (Occ), the superior parietal (PP), the orbital frontal (OF).

Aims To examine whether callosal tracts, who were different in iron content correlated with the main clinical scales (the Disease Burden index, the UHDRS I and the UHDRS II).

Methods Subjects groups included 25 HD patients, 25 presymptomatic HD (PreHD) subjects, 40 healthy controls. Tractography was performed for each region of the corpus callosum by manually drawing two regions of interest on each individuals fractional anisotropy colour map, then value were extracted from the Iron images coregistrered. To test for correlation among callosal and clinical data a Partial Correlation (covering for gender and age) was performed.

Results Results showed significantly correlation among the Occ callosal tract and all the clinical data.

The SP correlated with the UHDRSI and UHDRSII.

Conclusion We found that the lower is the iron content in the Occ and SP callosal fibres the worse are the symptoms. These results can be explained like a failure of the remyelination processes in the first stage of HD (“demyelination hypothesis”).