None listed
Conditions
Brief summary
Impairments in social relating are a core feature of autism spectrum disorder (ASD). Neuroimaging research suggest that this may be underpinned by abnormal activation with the right temporoparietal junction (rTPJ), which is a brain region that is important for social understanding (including recognising other's mental states and making social inferences). We have previously demonstrated that repetitive transcranial magnetic stimulation (rTMS) to another part of the "social brain" network, the dorsomedial prefrontal cortex (dmPFC), can improve social aspects of ASD. Our recent neuroimaging work, however, suggests that rTPJ is a more appropriate target than dmPFC. This study will involve theta burst stimulation (TBS), which is a newer form of rTMS that has several advantages over traditional rTMS protocols. TBS treatments are quick (3 minutes) and delivered at a low stimulation intensity (thereby reducing participant discomfort). Adolescents and young adults with ASD (n = 20) will completed a randomised, single-blind cross over study comparing TBS to the rTPJ with TBS to the dmPFC. Participants will be administered intermittent theta burst stimulation (iTBS), which can enhance brain activity and strengthen brain network connections. Participants will undergo various assessments before and after undergoing each of the TBS conditions, including magnetic resonance imaging, clinical interviews, and computerised experimental psychology tasks.
Interventions
iTBS is a form of repetitive transcranial magnetic stimulation (rTMS), which is a non-invasive brain stimulation technique. It involves the introduction of weak electrical current in the brain, which is achieved by delivering powerful but brief magnetic pulses to the scalp with a plastic-coated metallic coil.
The intervention will be delivered by a nurse who is highly experienced in the application of rTMS (minimum 2 years’ experience). iTBS will be administered at the Epworth Centre for Innova
iTBS is a form of repetitive transcranial magnetic stimulation (rTMS), which is a non-invasive brain stimulation technique. It involves the introduction of weak electrical current in the brain, which is achieved by delivering powerful but brief magnetic pulses to the scalp with a plastic-coated metallic coil. The intervention will be delivered by a nurse who is highly experienced in the application of rTMS (minimum 2 years’ experience). iTBS will be administered at the Epworth Centre for Innovation in Mental Health (ECIMH), Toorak Road, Camberwell. Each of the two arms of rTMS will be administered each consecutive weekday for a four-week period (e.g., 20 treatments in total for each of the two treatment arms, which will be six-months apart). One arm involves stimulation of right temporoparietal junction (rTPJ), while the other treatment arm involves stimulation of bilateral dorsomedial prefrontal cortex (dmPFC). The site of stimulation (i.e., where the coil will be positioned) will be determined by co-registering the participant’s head to their structural magnetic resonance imaging (MRI) brain scan, and determining the scalp positions that sit over the target brain regions (rTPJ and dmPFC). Each iTBS treatment will last for 3 minutes and 10 seconds. Including setup time, each iTBS treatment is expected to take approximately 10 minutes. TBS will be delivered at an intensity equivalent to 70% of the participant’s “resting motor threshold” (RMT), which is the minimum stimulator intensity required to produce a discernable hand-muscle response following a single TMS pulse delivered to the primary motor cortex. In terms of stimulation frequency, iTBS involves the administration of 3 TMS pulses at 50Hz, repeated 5 times per second, for 2 seconds, followed by an 8 second rest. This is repeated until a total of 600 pulses have been delivered. Treating nurses will use a standardised treatment form to monitor adherence (e.g., number of sessions attended, percentage of protocol delivered).
Sponsors
Deakin University
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
14 Years to 30 Years
Healthy volunteers
No
Inclusion criteria
- DSM-5 diagnosis of autism spectrum disorder (ASD), OR DSM-IV/DSM-IV-TR diagnosis of autistic disorder or Asperger's disorder - Formal IQ assessment indicating FSIQ 55 or higher - Social Responsiveness Scale (SRS) score in the clinical range (60 or above)
Exclusion criteria
STUDY EXCLUSION CRITERIA: - Seizure history - First degree relative with seizure disorder - History of serious head injury - Presence of ferromagnetic metal in the head outside the mouth - Presence of implanted medical device - Pregnant or lactating - Current substance use disorder - Neurological or psychiatric disorder other than common comorbid disorders (specifically, ADHD, depression, anxiety, OCD) - Professional driver or machine operator REQUIREMENTS FOR INDIVIDUAL iTBS TREATMENT SESSIONS: - Recreational drugs or alcohol within past 24 hours - Change in medication regime within past 4 weeks - Typical sleep pattern (within 20%) previous 24 hours
Outcome results
None listed