Visuospatial Memory Improvement after Gamma Ventral Capsulotomy in Treatment Refractory Obsessive-Compulsive Disorder Patients

Abstract

Gamma ventral capsulotomy (GVC) radiosurgery is intended to minimize side effects while maintaining the efficacy of traditional thermocoagulation techniques for the treatment of refractory obsessive-compulsive disorder (OCD). Neuropsychological outcomes are not clear based on previous studies and, therefore, we investigated the effects of GVC on cognitive and motor performance. A double-blind, randomized controlled trial (RCT) was conducted with 16 refractory OCD patients allocated to active treatment (n=8) and sham (n=8) groups. A comprehensive neuropsychological evaluation including intellectual functioning, attention, verbal and visuospatial learning and memory, visuospatial perception, inhibitory control, cognitive flexibility, and motor functioning was applied at baseline and one year after the procedure. Secondary analysis included all operated patients: eight from the active group, four from the sham group who were submitted to surgery after blind was broken, and five patients from a previous open pilot study (n=5), totaling 17 patients. In the RCT, visuospatial memory (VSM) performance significantly improved in the active group after GVC (p=0.008), and remained stable in the sham group. Considering all patients operated, there was no decline in cognitive or motor functioning after one year of follow-up. Our initial results after 1 year of follow-up suggests that GVC not only is a safe procedure in terms of neuropsychological functioning but in fact may actually improve certain neuropsychological domains, particularly VSM performance, in treatment refractory OCD patients.

Trial registration: ClinicalTrials.gov NCT01004302.

Figures

Figure 1

Groups, neuropsychological assessment time points and study design. Groups and neuropsychological assessments time points, showing the two comparisons: (a) RCT within and between-groups comparisons: blue boxes represent ATa and ST groups, evaluated before and 12 months after the procedure; (b) Within-group comparisons for all operated patients: blue boxes represent ATa, ATb and pilot study groups; ATa, randomized active treatment group; ATb, open active treatment group (four patients initially from the ST group, operated after blind was broken); BVMT-R, Brief Visuospatial Memory Test-Revised; NS, nonsignificant; RCT, randomized clinical trial; ST, randomized sham treatment group. A full color version of this figure is available at the Neuropsychopharmacology journal online.

Figure 2

Interaction effects of four visuospatial memory tests (NP-MANOVA). Statistically significant differences of within-group comparisons for the ATa group (green): *p-value=0.016/**p-value=0.008. The error bars represent the 95% confidence interval; ATa, randomized Active Treatment group (green); BVMT-R, Brief Visuospatial Memory Test-Revised; ROCF, Rey–Osterrieth complex figure; ST, sham treatment group (blue). A full color version of this figure is available at the Neuropsychopharmacology journal online.