Non-invasive brain surgery safe and effective in treating OCD and depression
A non-invasive surgery focusing ultrasound waves deep into the brain has been shown to be a safe and effective treatment for obsessive-compulsive disorder (OCD), as well as major depressive disorder (MDD).
“The results of our clinical trial provide evidence to suggest that MR-guided focused ultrasound is a safe therapy at long-term particularly for the treatment of obsessive-compulsive disorder (OCD), but also major depressive disorder (MDD),” says Dr. Clement Hamani, lead author of the study and senior scientist at Sunnybrook Research Institute.
Focused ultrasound (FUS) is a non-invasive therapy that uses intersecting beams of ultrasound guided by real-time imaging to treat tissue deep in the body, or in this case, guided into the brain using magnetic-resonance imaging (MRI) – also described as “MR-guided”.
“In these patients with severe, chronic and treatment-resistant OCD and depression, this therapy led to gradual and sustained improvements over 12-24 months; providing a possible option for others facing these debilitating symptoms, when conventional therapies haven’t worked,” adds Dr. Hamani, also a full professor in neurosurgery at University of Toronto.
Published online in the journal Biological Psychiatry, this Phase I single-centre study evaluated 27 patients in whom the clinicians were able to successfully create a lesion – a burn in the area of the brain that cause these symptoms.
At one year after treatment, 47 per cent of the patients with OCD were considered to be treatment responders, showing a significant reduction in anxiety and OCD scores. In the MDD group, 25 per cent responded to treatment. No serious side effects were reported, and neuropsychological testing showed no negative cognitive effects.
In 2012, Sunnybrook researchers conducted the first Canadian clinical trial applying this “scalpel-free” surgery technique in the treatment of essential tremor, a debilitating nervous system (neurological) disorder that causes involuntary and rhythmic shaking. Four years later, the therapy was determined to be effective and safe, receiving approval from Health Canada and the FDA for the management of refractory essential tremor.
In 2017, the Sunnybrook researchers turned their attention to other conditions of the brain as they started enrolling patients with treatment-resistant OCD and MDD into this study recently published.
“Over the past 12 years, the application of MR-guided focused ultrasound to produce surgical lesions in the brain has transformed the way we look at brain surgery – without the need for cutting into the scalp and skull,” says Dr. Nir Lipsman, senior author of the study, a neurosurgeon, and Chief of the Hurvitz Brain Sciences Program at Sunnybrook.
The study investigators say the results are encouraging and future studies will examine the optimal volume and precise location for the therapy to target.
“In addition to being a less invasive form of neurosurgery, we are increasingly working towards personalizing the right treatments for the right patients,” adds Dr. Lipsman, who also holds the Harquail Chair in Neuromodulation, at Sunnybrook and the University of Toronto.
The ability to focus ultrasound energy non-invasively, through the human skull was largely pioneered by scientists at Sunnybrook. This work created a spring-board for the development of new therapeutic applications, by enabling surgeons and scientists safe and precise access to deeper brain structures, without opening the skull. Sunnybrook has become a global leader in FUS research and clinical trials, and is the only Canadian site designated as a Focused Ultrasound Centre of Excellence by the Focused Ultrasound Foundation.
This project was supported by funds from the Midas Touch Foundation, Harquail Centre for Neuromodulation, and the Focused Ultrasound Foundation.
