J Psychiatry Neurosci 2015;40(6):378-386
Mariska Mantione, Msc; Dorien Nieman, PhD; Martijn Figee, MD, PhD; Pepijn van den Munckhof, MD, PhD; Rick Schuurman, MD, PhD; Damiaan Denys, MD, PhD
Background: Deep brain stimulation (DBS) is a promising treatment for treatment-refractory obsessive–compulsive disorder (OCD). However, the effects of DBS on cognitive functioning remain unclear. Therefore, we aimed to assess cognitive safety of DBS for treatment- refractory OCD and the association between clinical changes and cognitive functioning.
Methods: Patients with treatment-refractory OCD treated with DBS targeted at the nucleus accumbens (NAcc) were compared with a control group of 14 patients with treatment-refractory OCD treated with care as usual. We assessed cognitive functioning at baseline, 3 weeks postoperatively and following 8 months of DBS. We compared change in clinical symptoms with cognitive changes.
Results: There were 16 patients in the DBS group and 14 patients in the control group. Three weeks postoperatively, the DBS group showed a significantly reduced performance on measures of visual organization and verbal fluency and a trend toward reduced performance on measures of visual memory and abstract reasoning. Cognitive functioning was found to be stable on all other measures. After 8 months of DBS, reduced performances persisted, except for a significant improvement in verbal fluency. Cognitive functioning in all other domains remained unaffected. We found no correlation between improvement of clinical symptoms and cognitive changes.
Limitations: A limitation of this study was its relatively small sample size.
Conclusion: Deep brain stimulation targeted at the NAcc may be considered a safe method in terms of cognition because cognitive functioning was unaffected on most neuropsychological measures. Nevertheless, we observed some minor reduced performance on specific measures of executive functioning that were possibly associated with surgical intervention. Our results suggest that severity of OCD symptoms is independent of cognitive functioning.
Submitted Aug. 1, 2014; Revised Nov. 30, 2014; Accepted Jan. 5, 2015; Early-released June 23, 2015.
Affiliations: From the Department of Psychiatry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands ( Mantione, Nieman, Figee, Denys); the Department of Neurosurgery, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands (van den Munckhof, Schuurman); and the Netherlands Institute for Neuroscience, an institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands (Denys).
Funding: This study was part of the study on the clinical effects of DBS of the nucleus accumbens for treatment-refractory obsessive–compulsive disorder, supported by an unrestricted investigator initiated initiated research grant by Medtronic Inc., who provided the devices, and by the Netherlands organization for Scientific Research (NWO): ZON-MW VENI program (D.D. 916.66.095).
Competing interests: R. Schuurman acts as consultant to Medtronic on educational matters and received an unrestricted research grant from Medtronic. No other competing interests declared.
Contributors: All authors designed the study. M. Mantione and D. Denys acquired and analyzed the data and wrote the article, which all authors reviewed and approved for publication.
Correspondence to: M. Mantione, Academic Medical Center, University of Amsterdam, PA.0-162, PO Box 22660 — 1100 DD Amsterdam; firstname.lastname@example.org