In vivo microstructural white matter changes in early spinocerebellar ataxia 2

Abstract

Objective White matter (WM) integrity of Spinocerebellar ataxia 2 (SCA2) is poorly understood, more so in the early stages of SCA2. In this study, we evaluated the microstructural integrity of the WM tracts with an emphasis on the nature of in vivo pathological involvement in early SCA2. Materials and methods We evaluated the MRI images of 26 genetically proven SCA2 patients with disease duration <5 years and 24 age‐ and gender‐matched healthy controls using tract‐based spatial statistics (TBSS) to identify the WM tract changes and their clinico‐genetic correlates (age at onset, duration of disease, ataxia severity and CAG repeat length) using standard methodology. Results The mean age at onset and duration of disease were 28.7 ± 8.51 years and 3.5 ± 0.69 months, respectively. The mean CAG repeat length was 42.5 ± 4.6, and the ataxia severity score was 16.1 ± 4.9. Altered DTI scalars signifying degeneration was present in the bilateral anterior thalamic radiation (ATR), corticospinal tract (CST), inferior fronto‐occipital fasciculus (IFOF), superior and inferior longitudinal fasciculus (SLF and ILF), uncinate fasciculus (UF), cingulum, corpus callosum (CC), forceps major and forceps minor (corrected p < .05). DTI scalars representing demyelination was seen in the superior cerebellar peduncle (SCP) and cerebellar WM. There was a significant correlation of SARA score with axial diffusivity of the bilateral cingulum, ATR, CST, forceps minor, IFOF, ILF, SLF and SCP on the right side (corrected p < .05). Conclusion Extensive WM involvement is present in early SCA2. The DTI scalars indicate degeneration and demyelination and may have clinical implications.

Neuroradiological findings in GAA-FGF14ataxia (SCA27B): more than cerebellar atrophy

“…27 Our study is the first to describe the involvement of the SCPs and their decussation within the midbrain in subjects with GAA-FGF14 ataxia. While microstructural changes and reduced volume have been documented in SCA2 and Friedreich ataxia respectively, [31][32][33][34] a pattern of abnormal T2-hypersignal along the SCP like the one we observed in GAA-FGF14 ataxia subjects has been previously documented in some patients with POLR3-related spastic ataxia. 35,36 Co-existent SCP and vermian atrophy was present in 57% of our patients, and could suggest that the SCP abnormality is a reflection of reduced vermis-dentate connectivity secondary to vermian atrophy.…”

Management of essential tremor deep brain stimulation-induced side effects

“…This pathway connects efferent fibers from the deep cerebellar nuclei to the thalamus ( Elsen et al, 2013 ; Fine et al, 2014 ). Finally, a few genetic subtypes of ataxia have been associated with axonal loss in the uncinate fasciculus providing further evidence to support this notion ( Stezin et al, 2021 ).…”

A comprehensive review of iPS cell line-based disease modelling of the polyglutamine Spinocerebellar Ataxias 2 and 3: A focus on the research outcomes

“…Early SCA2 disease has also been recently characterized by white matter impairments, such as reduced axial diffusivity (AD) and fractional anisotropy (FA), and increased mean and radial diffusivities (MD and RD). These in-vivo modifications suggest the involvement of nerve damage, as white matter fibres enable the efficient transmission of information signals to neurons 49 . As the disease progressed, a broad range of symptoms began to appear.…”