Neuroimaging of vacuolar tauopathy: Response to letter

Dear Editor,

We thank Kobayashi and colleagues for their thoughtful letter and for sharing their valuable longitudinal radiologic–pathologic observations in a case of vacuolar tauopathy (VT) due to valosin-containing protein (VCP) p.Asp395Gly.¹ Their case shows ribbon-like cortical hyperintensity on diffusion-weighted imaging (DWI) with later emergence of fluid-attenuated inversion recovery (FLAIR) changes—an evolution they note parallels patterns described in Creutzfeldt–Jakob disease (CJD)—thereby providing helpful time course context. Indeed, one of the cases we described (Case 5) underwent a brain biopsy, in part to rule out prion disease.²

In our series of cases, VT was associated with occipital cortical diffusion abnormalities, and this signal correlated with the presence of neocortical microvacuolization across three autopsy-confirmed cases.²

Interestingly, Kobayashi and colleagues highlighted the variability in the timing of DWI and FLAIR changes.¹ In our series, DWI changes were often detected early, including at the initial presentation, whereas in their case, DWI changes appeared 3 years after the initial visit, with FLAIR changes occurring later.

We note that there is significant technical variability across all of the neuroradiologic assessments for these VT cases where more standardized, longitudinal imaging would be helpful. We appreciate the contribution by Kobayashi et al.; their time series strengthens the association of cortical ribboning as a characteristic imaging signature of VT.

E.B.L. received consulting fees from Eli Lilly, unrelated to this study. I.M.N. served on a scientific advisory board for Eisai, unrelated to this study. All other authors declare no conflicts of interest. Author disclosures are available in the Supporting Information.