Executive deficit in spinocerebellar ataxia type 2 is related to expanded CAG repeats: Evidence from antisaccadic eye movements

Spinocerebellar ataxia type 2: Measures of saccade changes improve power for clinical trials

“…In this article, we present the most extensive longitudinal study of saccadic eye movements in SCA2 patients to date and provide a much more advanced analysis of the disease progression than was possible with previous cross-sectional approaches. 14,[23][24][25][26] The more qualitative assessments of the clinical neurological picture of SCA2 patients showed a significant annual increase of SARA scores, which is consistent with the progressive nature of the SCA2 cerebellar syndrome and agrees with previous work demonstrating SARA to correlate with the disease duration and ataxia disease stage 23,34,35 and to increase over time in one longitudinal study. 36 This confirms the usefulness of this clinical scale to assess the progression of SCA2.…”

“…In this article, we present the most extensive longitudinal study of saccadic eye movements in SCA2 patients to date and provide a much more advanced analysis of the disease progression than was possible with previous cross‐sectional approaches …”

“…21,22 Saccade slowing has been characterized as a meaningful intermediate endophenotype of SCA2 23 and a sensitive prodromal biomarker, 14 whereas the increases of saccade latency and antisaccadic errors have been proposed as surrogate markers of cognitive decline. 24,25 In spite of this substantial research on the saccadic eye movements abnormalities in SCA2, 14,[23][24][25][26] there are scarce longitudinal data, a limiting factor in its usefulness during advances of age and disease and for the identification of suitable outcome parameters in clinical trials.…”

Modifications of resting state networks in spinocerebellar ataxia type 2

“…Conversely, the DMN alterations that we found in SCA2 patients may very well be in agreement with the preferential involvement of lobule IX in SCA2 (with uvula being the most significant GM cerebellar cluster detected when assessing regionally the atrophy in SCA2, with higher progression of atrophy over time, compared with normal subjects). A reduced FC within the DMN has been associated with a larger Stroop effect, which may be involved in the subtle deficits at Stroop test that have been found in this pathology …”

Eye Movement Abnormalities in Neurodegenerative Diseases

“…Saccade pathology in SCA2 is also characterized by abnormal prolongation of reflexive and voluntary latencies and increases of the antisaccade error rate. The later feature is also detected in prodromal stage and is significantly correlated with the mutation size [83][84][85].…”