Neurophysiology of cerebellar ataxias and gait disorders

Optimizing Rare Disease Gait Classification through Data Balancing and Generative AI: Insights from Hereditary Cerebellar Ataxia

“…Regarding the kinematic and spatiotemporal gait features, we found that pelvic rotation values have a positive impact on the classification of both classes. This supports the hypothesis of reduced pelvic mobility in response to chaotic upper trunk behavior and impaired trunk-lower limb coordination during gait [7,12,22,98].…”

“…We found no statistically significant differences between the sample distributions for all the gait features ( Table 4 , indicating that the ctGAN augmentation algorithm does not alter the statistical distribution of the investigated gait features. Secondly, we used a Shapley values-based strategy [ 94 ] to test the impact of each gait feature on the classification model in order to understand the most important gait variables in class identification and to ensure that the results were consistent with the known gait abnormalities of pwCA [ 7 ]. As shown in Figure 7 , the Shapley values, related to each gait feature for the two classes (i.e., pwCA and HS), showed that , HR, and pelvic rotation are the most impacting features on the classification model, in line with existing evidence.…”

“…Understanding and accurately identifying movement abnormalities in people with hereditary cerebellar ataxia (pwCA) is crucial for clinical management, prediction and monitoring of disease progression, and potential therapeutic interventions. In terms of spatiotemporal and kinematic parameters, increased step width, reduced ankle joint range of motion, increased gait variability, impaired foot positioning, abnormal lower limb muscle activation, and abnormal pelvic rotation have been observed to distinguish pwCA from normal gait patterns and other neurological gait disturbances [ 7 ]. Ataxic gait is also characterized by a loss of coordination between the upper and lower regions of the body, resulting in higher upper body oscillations and a lack of local trunk stability, causing the latter to generate perturbations while walking [ 7 , 8 , 9 , 10 , 11 , 12 ].…”

Local Dynamic Stability of Trunk During Gait is Responsive to Rehabilitation in Subjects with Primary Degenerative Cerebellar Ataxia

“…Due to the cerebellum's inability to process multisensory features and provide adequate computation and corrections to perturbations [1][2][3][4][5], subjects with degenerative cerebellar ataxia (swCA) exhibit poor joint coordination, abnormal intra-limb joint, and upper and lower body segment coupling during walking [5][6][7][8][9]. Ataxic gait is additionally characterized by incoordination between the upper and lower bodies, which results in increased upper body oscillations with a lack of local trunk stability, transforming the trunk into a generator of perturbations during walking.…”

SCAR32: Functional characterization and expansion of the clinical‐genetic spectrum

“…The term hereditary ataxia (HA) refers to a highly heterogeneous group of disorders phenotypically characterized by progressive damage to the cerebellum and/or its associated afferent tracts. 1 , 2 Collectively, these disorders have an estimated prevalence of 26/100,000 children. 3 Although more than 200 genes have been associated with different types of HA, many patients remain undiagnosed, particularly if they are simplex cases with a silent family history.…”