A theory inspired proposal for a novel medical treatment in autism. The cerebellar model of autism and the hypothesis of dorsal stream dysfunction: evidence from idiopathic and syndromic cases.

Abstract

The cerebellum figures prominently in the pathophysiology of idiopathic autism. Many syndromic comorbid cases and animal studies also highlight cerebellar involvement. The role of the cerebellum is implicated in cognitive and affective disorders. However, there remains a profound gap in understanding the route from genes, the effect of mutations on Purkinje cells and ultimately the behavioural phenotype. Given that conditions like autism are disorders of consciousness it is likely that progress will be made beyond the data generating enterprise, by improved theoretical models of the mind-body gap. A way forward is the proposal of consciousness as embodiment of a process of world discovery through motor efference copy. The cerebellum and basal ganglia are essential to a component theory of motor efference copy, providing a heuristic for understanding the structure of cortical dorsal and ventral stream pathways of a sensory modality. This then, further suggests that autism results from a selective dorsal stream dysfunction with all the attendant and hierarchical features that follow such a model and lead to both high level social and attentional deficits as well as lower level motor and restrictive interests. The paper aims to present evidence for dorsal stream dysfunction and how it may relate to a primary cerebellar pathology. The involvement of the cerebellum in most if not all syndromic cases of comorbid ASD is then presented. Finally, it is shown how such insights can be used to propose a general medical intervention based on the use of cerebellar rTMS across the disorder spectrum.