Author response: Alterations of functional connectivity of the motor cortex in Fabry disease: An RS-fMRI study

We thank Sechi et al. for the comments on our article.1 We agree that investigating the relationship between functional changes and disease course is a core issue for defining the role of functional imaging in both pathophysiology and clinical studies in Fabry disease (FD). The findings of Ortu et al.2 help define the role of the functional connectivity (FC) alterations in patients. Indeed, in their study,2 motor cortex hyperexcitability partly subsided when enzyme replacement therapy was started (although the small number of patients and the incomplete reversal of transcranial magnetic stimulation findings, possibly related to insufficient follow-up, does not allow for firm conclusions due to its complete reversibility). On the contrary, we found that resting-state–fMRI alterations were present in successfully treated patients, mitigating against the hypothesis that these changes may reflect reversible FD features.1 While our view is that "a direct relationship between motor cortex hyperexcitability...and present FC changes remains speculative,"1 longitudinal studies with suitable sample sizes assessing both FC and motor cortex excitability are needed. Only this approach will demonstrate if FC changes are related to a residual, nonreversible hyperexcitability, or if different neural circuit alterations are probed by the 2 techniques.

Source: Neurology - October 23, 2017 Category: Neurology Authors: Cocozza, S., Pisani, A., Brunetti, A., Quarantelli, M., Tedeschi, E. Tags: WRITECLICK & amp;reg; EDITOR ' S CHOICE Source Type: research