A study of novel bilateral thermal capsulotomy with focused ultrasound for treatment-refractory obsessive– compulsive disorder: 2-year follow-up

Background: Recently, a new thermal lesioning approach using magnetic resonance–guided focused ultrasound (MRgFUS) was introduced for the treatment of neurologic disorders. However, only 2 studies have used this approach for treatment-refractory obsessive– compulsive disorder (OCD), and follow-up was short-term. We investigated the efficacy and safety of bilateral thermal lesioning of the anterior limb of the internal capsule using MRgFUS in patients with treatment-refractory OCD and followed them for 2 years. Methods: Eleven patients with treatment-refractory OCD were included in the study. Clinical outcomes were evaluated using the Yale–Brown Obsessive Compulsive Scale, the Clinical Global Impression scale (including improvement and severity), the Hamilton Rating Scale for Depression (HAM-D) and the Hamilton Rating Scale for Anxiety (HAM-A) at 1 week and 1, 3, 6, 12 and 24 months following MRgFUS. Neuropsychological functioning, Global Assessment of Functioning and adverse events were also assessed. Results: After MRgFUS, Yale–Brown Obsessive Compulsive Scale scores decreased significantly across the 24-month follow-up period (mean ± standard deviation, 34.4 ± 2.3 at baseline v. 21.3 ± 6.2 at 24 months, p < 0.001). Scores on the Hamilton rating scales for depression and anxiety also significantly decreased from baseline to 24 months (HAM-D, 19.0 ± 5.3 v. 7.6 ± 5.3, p < 0.001; HAM-A, 22.4 ± 5.9 v. 7.9 ± 3.9, p < 0.001). Global Assessment of Functioning scores improved significantly (35.8 ± 4.9 at baseline v. 56.0 ± 10.3 at 24 months, p < 0.001) and Memory Quotient significantly improved, but other neuropsychological functions were unchanged. The side effects of MRgFUS included headache and vestibular symptoms, but these were mild and transient. Limitations: The main limitations of this study were the small sample size and the open-label design. Conclusion: Bilateral thermal lesioning of the anterior limb of the internal capsule using MRgFUS may improve obsessive–compulsive, depressive and anxiety symptoms in patients with treatment-refractory OCD, without serious adverse effects.