Non-Invasive Deep Brain Stimulation: The Promise of Transcranial Focused Ultrasound with Dr. Samuel Pichardo - #46

Non-Invasive Deep Brain Stimulation: The Promise of Transcranial Focused Ultrasound with Dr. Samuel PichardoIn this episode, Dr. Michael Passmore sits down with Dr. Samuel Pichardo, biomedical engineer and researcher at the University of Calgary and the Hotchkiss Brain Institute, to explore one of the most exciting frontiers in neuromodulation: transcranial focused ultrasound stimulation (TUS/tFUS).Dr. Pichardo's lab is at the cutting edge of ultrasound neuromodulation — investigating how low-intensity pulsed ultrasound can precisely target deep brain structures non-invasively, with lasting effects on neural activity.What We Cover:What is transcranial focused ultrasound (TUS)? How it differs from TMS and tDCS, and why its ability to penetrate to deep brain structures makes it uniquely powerfulThe physics of neuromodulation: How pulsed ultrasound bursts at low frequencies (e.g., ~250 kHz) can produce neuromodulatory effects lasting 30–60 minutes after a single session — and why the underlying mechanism is still an active area of researchPulse repetition frequency (PRF): Key findings from Dr. Pichardo's lab comparing 10 Hz, 100 Hz, and 1000 Hz PRF — and why 100 Hz produced the strongest and most sustained inhibitory effectThe skull barrier: Why lower ultrasound frequencies are used to overcome skull attenuation, and the challenges this creates for precision targetingPilot clinical study — essential tremor and Parkinson's disease: Targeting the ventral intermediate nucleus (VIM) of the thalamus non-invasively, and what the results showed: significant tremor reduction in essential tremor patients, and a promising but less robust trend in Parkinson's patientsThe multi-focus targeting strategy: How Dr. Pichardo's team addressed the precision-vs.-accuracy tradeoff using phased array transducers to enlarge the treatment envelopeBabelBrain: The open-source, cross-platform (Mac, Windows, Linux) software tool developed by Dr. Pichardo's lab that integrates MRI/CT imaging data to model acoustic intensity, thermal effects, and safety parameters — a turnkey solution for TUS researchers worldwideThe future of the field: Which neuropsychiatric conditions are most likely to benefit first — including refractory depression, OCD, PTSD, and addiction — and why Dr. Pichardo believes depression may become the "poster child" indication for TUS in the next few yearsNomenclature: Why the field still hasn't settled on a consistent acronym (TUS, tFUS, LIFU, FUS) — and why that's okayKey Takeaways:Focused ultrasound can reach deep brain targets non-invasively with millimeter precision — something no other non-invasive technology can currently matchThe neuromodulatory effects are real, reproducible, and growing in clinical promise, but replication studies and sham-controlled trials are still essentialBabelBrain is freely available as an open-source tool for research labs worldwideThe field is at an inflection point, with rapid growth in FDA applications and commercial investmentLinks & Resources:Dr. Pichardo's lab at the University of Calgary / Hotchkiss Brain Institute https://www.neurofus.ca/BabelBrain (open-source TUS planning software) https://proteusmrighifu.github.io/BabelBrain/Pulse repetition frequency study (PRF paper from the Pichardo lab) https://pubmed.ncbi.nlm.nih.gov/38621645/VIM thalamic TUS pilot study (essential tremor & Parkinson's) https://pubmed.ncbi.nlm.nih.gov/8109299/Focused Ultrasound Neuromodulation Symposium, Paris (July) https://www.itrusst.com/fun26The Neurostimulation Podcast is hosted by Dr. Michael Passmore, clinical associate professor in the Department of Psychiatry at the University of British Columbia. The content shared is for educational purposes only and is not intended as medical advice. Always consult your healthcare provider regarding your specific health needs.If you enjoyed this episode, please like, subscribe, and share with anyone who might find it valuable. Drop your questions and comments below — and tune in next time for another journey into the cutting edge of neuroscience and clinical neurostimulation.