TMS Therapy for Autism

Autism in DSM5 is characterized as one of the so-called pervasive developmental disorders (PDD) which also includes Asperger’s disorder and other pervasive developmental disorders not hereto specified. These groups of disorders are collectively called autism spectrum disorders (ASD). ASDs are characterized by impairments in social skills, repetitive behavior, and the communicative use of verbal and nonverbal language.

Children with restricted and repetitive behavior share features such as intricacies of behavior and the inability to grasp concepts. ASD affects about 1 in 60 children, but there are currently no pharmaceutical treatments that can target the core networks implicated in ASD. Recent evidence shows that repetitive transcranial magnetic stimulation (rTMS) holds high potential to alleviate the main symptoms of individuals with ASD

How we use rTMS in ASDs

As in depression, the standard rTMS in ASD uses the site of treatment based upon fixed location relative to the motor cortex. For depression, it has been shown that differences in the clinical efficacy of different left dorsolateral prefrontal cortex (DLPFC) stimulation sites are related to differences in the connectivity of these sites to deeper limbic regions, especially the subgenual cingulate (sgACC).

Target sites in the left DLPFC with the best rTMS antidepressant efficacy showed the strongest anticorrelated resting-state functional connectivity (rsFC) with the sgACC. Since autism is a disorder of the association cortex, and in particular, a disorder of connectivity that primarily involves intra-hemispheric connectivity, for treating ASD a connectivity-based targeting strategy for TMS would be to identify optimal TMS target coordinates in the bilateral DLPFC. We—uniquely—have such capability.

Our prior experience suggests that in ASD with a predominance of social-cognitive malfunctions, our technology enables us to:

(i) measure changes in resting-state functional connectivity (rsFC) between nodes of involved networks, e.g., Theory of Mind (ToM) network of prefrontal cortex, orbitofrontal cortex, supplementary areas, anterior cingulate cortex, posterior cingulate, superior temporal cortex, superior/middle temporal gyrus and inferior parietal lobe regions, with the culprit deep nuclei regions, e.g., ventral anterior nucleus of the thalamus. Such comparisons yield correlations that mediate treatment response and,

(ii) we use a connectivity-based targeting approach applied at the single-subject level to identify optimized bilateral targets in the prefrontal cortex for TMS to individualize therapy. We, therefore, offer a novel, innovative approach with enhanced efficacy TMS guided by rsFC MRI.

This approach is fundamentally different from traditional approaches that target without looking into your brain or understanding differences in brain organization. Indeed, our approach stimulates the brain based on the individual brain’s rsFC pattern.

Our emphasis is on the network architecture of the human brain and as such we use rsFC MRI to construct the networks implicated in each disorder.

Concerning ASD, evidence such as the generalized dysfunction of the association cortex with sparing of primary sensory and motor cortex and white matter, combined with the absence of clinical signs of focal brain dysfunction, common in children with hypoxic-ischemic injury and cerebral palsy, such as visuospatial deficits, points to a distributed neural systems abnormality.