Background Neuroimaging studies showed impairment of the basal ganglia and thalamus in preclinical stages of Huntington's disease (HD) characterised by progressive volume loss, microstructural impairment and microglial activation. Therefore, biomarkers sensitive to all of these changes are needed.

Aims We assessed the multimodal MRI as biomarker of the disease vulnerability and progression.

Methods 3D T1 weighted image MRI acquisition was performed on a 3T Siemens scanner. We evaluated the macrostructure, microstructure and iron content of five vulnerable subcortical structures (high risk: caudate, putamen and pallidus; and low risk: thalamus and accumbens) in comparison with medial temporal lobe structures (hippocampus and amygdala) relatively preserved in early stages of the disease. 17 presymptomatic, 14 symptomatic (stages I–II) and 31 age and gender matched control subjects were scanned using the same protocol.

Results Pre-HD subjects had a selective decrease of volume and microstructural changes in high risk structures (caudate, putamen and pallidus) and increased iron accumulation in all three nuclei (but only statistically significant in the globus pallidus). HD patients had lower volume than pre-HD in all high risk nuclei, higher microstructural impairment in the striatum but not significant differences in iron content. The lesion extended to low risk subcortical nuclei (thalamus and accumbens). Furthermore, volume and microstructure correlated with the clinical measures of progression of the disease.

Conclusions This study provides proof of in vivo selective striatal degeneration in presymptomatic stages of the disease. Different parameters of MRI acquisition provide complementary information that give clues to the understanding of the pathophysiology underlying HD and its progression.