Acute stimulation effect of the ventral capsule/ventral striatum in patients with refractory obsessive–compulsive disorder – a double-blinded trial

Hsin-Chi Tsai,1,2 Chun-Hung Chang,3,4 Jiann-I Pan,5 Hung-Jen Hsieh,6 Sheng-Tzung Tsai,7 Hsiang-Yi Hung,7 Shin-Yuan Chen1,71Institute of Medical Science, Tzu-Chi University, Hualien City, Taiwan; 2Department of Psychiatry, Tzu-Chi General Hospital, Hualien City, Taiwan; 3Department of Psychiatry, China Medical University and Hospital, Taichung, Taiwan; 4China Medical University, Taichung, Taiwan; 5Department of Medical Informatics, Tzu-Chi University, Hualien, Taiwan; 6Nuclear Medicine, Tzu Chi General Hospital, Hualien City, Taiwan; 7Department of Neurosurgery, Tzu-Chi General Hospital, Hualien City, TaiwanObjective: Deep-brain stimulation (DBS) for treating refractory obsessive–compulsive disorder (OCD) has shown positive results in small clinical trials. Ventral capsule/ventral striatum (VC/VS) is one of the promising targets; however, whether or not acute stimulation test can provide substantial information for chronic stimulation is not yet known. We evaluated postoperative test stimulation and examined the relationship of acute simulation-induced smile/laughter and 15-month clinical outcome.Methods: Four adult patients with refractory OCD were implanted with Model 3387 leads bilaterally in an area of VC/VS. Postoperative test stimulation was performed at least 2 weeks after surgery. We performed double-blinded postoperative test stimulation with different contact and voltage. The relationship of stimulation-induced smile/laughter and chronic response was examined.Results: Patients presented smile, laughter, euphoria, increased heart rate, increased blood pressure, smell, chest vibration, dizziness, nausea, heat, or increased sexual drive during acute stimulation. We found that the higher the percentage of smile/laughter (34.3%, 31.3%, 56.3%, and 12.5% for four cases), the greater the reduction in the Yale-Brown Obsessive Compulsive Scale (30.6%, 38.9%, 58.8%, and 7.7% respectively at 15-month DBS).Conclusion: This study showed that acute DBS of the VC/VS might cause mood change, cardiovascular, sensory, or motor effects. These effects were transient or habituated over six months. We suggest stimulation-induced smile/laughter may be a possible predictor for long-term DBS outcome. Larger studies, genetic studies, and imaging studies are needed to evaluate the effects of different parameters and possible predictors in the treatment of OCD.Keywords: deep-brain stimulation, DBS, OCD, VC/VS, nucleus accumbens, NAcc