In this blog I would like to mention the latest publication from our group regarding transcranial magnetic stimulation (TMS) and autism spectrum disorders (ASD). The reported study took a fairly large population of high functioning ASD individuals (n=124) and divided them across 3 groups receiving either 6, 12, or 18 sessions of rTMS. A strength of the study was the large number of participating patients and of outcome measurements employed. Not surprisingly, the study argues that the best results were obtained with the largest number of sessions (n=18). This is part of a baby-step process of elucidating the best and safest protocol for TMS treatment in autistic children.
In the future, some of the questions that we would like to pursue are why do some patients have beneficial results and others don’t, predicting those who will experience beneficial results (e.g., gamma brainwave power at baseline), and examining whether we can obtain synergism by using TMS along with neurofeedback. Thus far we have had approximately 15 clinical trials using TMS in autism, all with positive results. We have treated approximately over 500 patients with only 2 drop outs and no major side effects (Note: In this number I am counting the control patients who went on to receive the therapy once the clinical trial was over). All of the patients have been treated for free in a research setting. Unfortunately, we have not had the backing necessary by the federal government to pursue a large scale project on TMS and get the intervention approved by the FDA. For those interested in reading more about TMS, in layman terms, please see the references listed below.
The abstract of the study reads as follows:
There is no accepted pathology to autism spectrum disorders (ASD) but research suggests the presence of an altered excitatory/inhibitory (E/I) bias in the cerebral cortex. Repetitive transcranial magnetic stimulation (rTMS) offers a non-invasive means of modulating the E/I cortical bias with little in terms of side effects. In this study, 124 high functioning ASD children (IQ > 80, <18 years of age) were recruited and assigned using randomization to either a waitlist group or one of three different number of weekly rTMS sessions (i.e., 6, 12, and 18). TMS consisted of trains of 1.0 Hz frequency pulses applied over the dorsolateral prefrontal cortex (DLPFC). The experimental task was a visual oddball with illusory Kanizsa figures. Behavioral response variables included reaction time and error rate along with such neurophysiological indices such as stimulus and response-locked event-related potentials (ERP). One hundred and twelve patients completed the assigned number of TMS sessions. Results showed significant changes from baseline to posttest period in the following measures: motor responses accuracy [lower percentage of committed errors, slower latency of commission errors and restored normative post-error reaction time slowing in both early and later-stage ERP indices, enhanced magnitude of error-related negativity (ERN), improved error monitoring and post-error correction functions]. In addition, screening surveys showed significant reductions in aberrant behavior ratings and in both repetitive and stereotypic behaviors. These differences increased with the total number of treatment sessions. Our results suggest that rTMS, particularly after 18 sessions, facilitates cognitive control, attention and target stimuli recognition by improving discrimination between task-relevant and task-irrelevant illusory figures in an oddball test. The noted improvement in executive functions of behavioral performance monitoring further suggests that TMS has the potential to target core features of ASD.
- Why use transcranial magnetic stimulation in autism?
- Translating TMS: From autism science to autism therapy
- The FDA and safety of rTMS in children
- Low frequency rTMS in children with autism
- The attached blog summarizes my conclusions regarding this therapy Thoughts on transcranial magnetic stimulation and autism