Fig. 3. Anatomical considerations of circuits associated with improvements of tremor and axial symptoms.

As opposed to the other figures, tracts in this figure are not thresholded at significance after FDR correction but include a broader set of tracts to appreciate the broader distribution of symptoms across streamlines (lower threshold). A Tremor tracts included projections from the cerebellar nuclei to thalamus as well as the cortical projections from primary motor cortex to STN, matching current pathophysiological models of tremor³². B Tracts associated with axial symptoms included a brainstem connection to the pedunculopontine nucleus region. C Segregating axial symptoms into gait vs. all other (axial) items revealed that this connection was driven by gait (and not by other axial symptoms). D Comparison to the projection site with a matching slice from a histological atlas published by Coulombe and colleagues at z = +5.08 mm (panel adapted under the Creative Commons Attribution (CC-BY) license from Coulombe et al., 2021 Frontiers in Neuroanatomy⁷⁵). A = Anterior, L = Lateral, P = Posterior.