Virtual brain modelling in cerebellar ataxic patients

Pediatric cerebellar ataxias (PCAs) are neurological disorders characterized by impairment in motor coordination. Surprisingly, within PCA, patients with Joubert syndrome may show postural motor behaviour comparable to that of healthy subjects, probably due to the non-progressive evolution of the pathology. Indeed, remaining brain areas could cope with a stable lesion by neural plasticity. To uncover the neural substrates involved in functional compensation, we simulated whole-brain dynamics starting from a multimodal dataset within “The Virtual Brain (TVB)” framework, including or excluding the cerebro-cerebellar connections. One subject affected by Joubert syndrome and two with slow-progressive ataxia underwent diffusion and resting state fMRI to create specific structural and experimental functional connectomes (expFC). Brain dynamics were simulated for 6 minutes. Preliminary data highlighted that Pearson correlation coefficients (prediction power) between expFC and simulated FC strongly decreased not only when cerebro-cerebellar connectivity was excluded from the generation of cerebral activity but also in slow-progressive patients. This result supports the hypothesis that in patients with non-progressive disorder, the cerebellum may create new neural pathways providing compensatory strategies in brain networks. Future studies are warranted to focus on specific neural candidates that could be involved in the functional compensation.