One of the most distinguished neurosurgeons in South Korea and the Asian Pacific region, Jin Woo Chang, MD, PhD achieved an extraordinary first this month by using focused ultrasound to treat a patient with Obsessive Compulsive Disorder (OCD), an anxiety disorder that afflicts between one and three percent of the teen-through-adult population.
“This is an extremely important milestone in the evolution of focused ultrasound,” observes Focused Ultrasound Foundation Chairman Neal Kassell, MD. “It is the first step in developing a noninvasive alternative to surgery for certain patients disabled by OCD. If this study and subsequent trials confirm the safety and efficacy of focused ultrasound in treating OCD, it may be possible to improve the quality of life for large numbers of desperately ill patients and may lead to new treatments for depression and other psychiatric conditions.”
OCD is characterized by recurring, intrusive thoughts and/or repetitive behaviors. Although the exact cause of OCD remains unknown, neurological scans indicate that the condition alters the brain’s activity patterns and circuitry functioning.
Chang, who is Professor and Chairman of the Department of Neurosurgery and Director of the Brain Research Institute at Yonsei University Medical Center in Seoul, South Korea, performed the treatment as part of a 15-patient clinical trial evaluating InSightec’s ExAblate Neuro system. He has been treating OCD patients since 1998 by using radiofrequency (RF) to make lesions in areas of the brain. During the past year, he has used focused ultrasound to perform brain lesioning in a clinical trial involving essential tremor patients and theorizes that the investigational technology may be as effective as RF in treating patients with OCD.
Focused ultrasound may offer some advantages compared to RF. “Noninvasive, focused ultrasound is not associated with infection, blood clots or physical damage to the brain that can result from passes of the electrode en route to the target during RF ablation,” says Kassell.
Expanding the treatment envelope
aluating the safety and efficacy of focused ultrasound as an OCD therapy, Chang plans to treat areas of the brain that are conventional targets for lesioning – the anterior cingulate cortex, the anterior limb of the internal capsule and the sub caudate nucleus. “For the first five patients, I will make bilateral lesions on the anterior limb of the internal capsule, and I will try other targets later,” he says. According to Chang, the anterior limb of the internal capsule is a well-known target for treating OCD with RF ablation and Deep Brain Stimulation (DBS).
Describing what happened during the first patient treatment, Chang says, “I could increase the temperature above 55° C to make a lesion on this area. Immediately after the treatment, we found a significant signal change on the MRI of this area.”
Until now,targeting the internal capsulewas considered to be beyond the reach of transcranial focused ultrasound. “Dr. Chang and his team havepushed the clinical treatment envelope a huge step forward. Their work may lead toadditional new clinical targets in the future,” remarks Eyal Zadicario, Vice President of Research and Development and Director of Neuro Programs for InSightec, Ltd.
Chang’s first study patient is reported to be fine with no noticeable complications, although it may take several months for the full effect of focused ultrasound lesioning to be realized. “OCD symptoms do not stop immediately after surgery, even with DBS and other conventional lesioning techniques,” he notes.
Because OCD symptoms are often behavioral and habitual in nature, they require time to change.
“I learned a lot from this first treatment,” Chang says. “There are many things that we need to think about, including how to modify the procedure to get an optimal result for patients with OCD.”
The second OCD study treatment is scheduled for March 2013. Optimistic about what lies ahead, Chang observes, “I believe that OCD and depression will become the next common surgical candidates for our functional neurosurgeons in the near future.”
According to Zadicario, “Doing anything for the first time in the world is never easy. It requires an innovative spirit, great dedication and, most of all, collaboration between many teams in sharing the risk of failure as well as the satisfaction of success.”
He cautions, “There is still a long road ahead of us, even on this specific target. It will require a lot of effort to analyze and improve until we reach a robust treatment result. We will keep pushing the technology to help as many patients and clinical conditions as we can. After all, isn’t that what pioneering is all about?”