Cerebellar grey matter modifications in lower limb amputees not using prosthesis

Abstract

Plastic brain changes following peripheral deafferentation, in particular those following limb amputations, are well-documented, with significant reduction of grey matter (GM) in the sensory-motor cerebral areas representing the amputated limb. However, few studies have investigated the role played by the use of a prosthesis in these structural brain modifications. Here we hypothesized that using a functional prosthesis that allows individuals to perform actions may reduce grey matter reduction. We investigated the brain structural reorganization following lower limb amputation by using a Voxel Based Morphometry (VBM) analysis of structural magnetic resonance imaging (MRI) in 8 right-handed individuals with lower limb amputation (LLA) fitted with prostheses (LLAwp), compared to 6 LLA who had never used a prosthesis (LLAnp). 14 age-matched healthy controls were also enrolled (HC). We did not find any significant effect when comparing LLAwp and HC. However we found a decreased GM volume in the bilateral cerebellum in LLAnp compared with HC. These results suggest that prosthesis use prevents GM decrease in the cerebellum after lower limb amputation.

Figure 1

The red-to-yellow patches show, on axial slices, the t statistic of the comparisons between grey matter volume of HC and LLAnp for p < 0.05, corrected for multiple comparisons at the cluster level using false discovery rate and peak p < 0.001 uncorrected.

Figure 2

Scatter plots depict the correlation between prosthesis index and GM volume in cerebellar lobules VIII (A) and CrusII (B). Each triangle represents a participant of the LLA group.