Cerebellar Neuromodulation in Autism Spectrum Disorders and Social Cognition: Insights from Animal and Human Studies.

Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by social atypicalities and repetitive behaviors. Growing evidence suggests that alterations in brain networks may contribute to ASD symptoms. The cerebellum, with its widespread connections to the cortex, has emerged as a potential key player in ASD. Non-invasive neuromodulation techniques, such as transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) offer a promising avenue for modulating brain activity and potentially alleviating ASD symptoms. In addition, preclinical studies in rodents further emphasize the therapeutic effect of cerebellar stimulation to target autism-related symptoms. This article reviews both clinical and preclinical studies aiming to modulate cerebellar circuits to improve symptoms of ASD. We found ten relevant studies assessing the effect of cerebellar neuromodulation in human and preclinical models. Posterior cerebellar tDCS represented the most frequent neuromodulation method and suggested that cerebellar tDCS can lead to improvements in symptoms of ASD and restore cerebellar connectivity in individuals with ASD. In neurotypical participants, there is evidence that cerebellar tDCS can enhance social cognitive abilities. These results are in line with preclinical studies, suggesting that chemogenetic stimulation can modulate cerebellar circuits involved in ASD and improve related behaviors. Further research is needed to establish standardized protocols, assess long-term effects, and investigate the underlying mechanisms of cerebellar stimulation. We examine research questions that need to be addressed before launching large scale randomized clinical trials.