Predicting Response to vALIC Deep Brain Stimulation for Refractory Obsessive-Compulsive Disorder

Sex differences in clinical response to deep brain stimulation in resistant obsessive-compulsive disorder

INTRODUCTION

Deep brain stimulation (DBS) is an effective alternative to treat severe refractory obsessive-compulsive disorder (OCD), although little is known on factors predicting response. The objective of this study was to explore potential sex differences in the pattern of response to DBS in OCD patients.

METHODS

We conducted a prospective observational study in 25 patients with severe resistant OCD. Response to treatment was defined as a ≥35% reduction in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score. Logistic regression models were calculated to measure the likelihood of response at short and long-term follow-up by sex as measured by Y-BOCS score. Similar analyses were carried out to study changes in depressive symptomatology assessed with the Hamilton Depression Rating Scale (HDRS). Additionally, effect sizes were calculated to assess clinical significance.

RESULTS

We did not observe significant clinical differences between men and women prior to DBS implantation, nor in the response after one year of stimulation. At long-term follow-up, 76.9% of men could be considered responders to DBS versus only 33.3% of women. The final response odds ratio in men was 10.05 with significant confidence intervals (88.90-1.14). No other predictors of response were identified. The sex difference in Y-BOCS reduction was clinically significant, with an effect size of 3.2. The main limitation was the small sample size.

CONCLUSIONS

Our results suggest that gender could influence the long-term response to DBS in OCD, a finding that needs to be confirmed in new studies given the paucity of results on predictors of response to DBS.

Clinical outcomes of deep brain stimulation for obsessive-compulsive disorder: Insight as a predictor of symptom changes

AIM

Deep brain stimulation (DBS) is a safe and effective treatment option for people with refractory obsessive-compulsive disorder (OCD). Yet our understanding of predictors of response and prognostic factors remains rudimentary, and long-term comprehensive follow-ups are lacking. We aim to investigate the efficacy of DBS therapy for OCD patients, and predictors of clinical response.

METHODS

Eight OCD participants underwent DBS stimulation of the nucleus accumbens (NAc) in an open-label longitudinal trial, duration of follow-up varied between 9 months and 7 years. Post-operative care involved comprehensive fine tuning of stimulation parameters and adjunct multidisciplinary therapy.

RESULTS

Six participants achieved clinical response (35% improvement in obsessions and compulsions on the Yale Brown Obsessive Compulsive Scale (YBOCS)) within 6-9 weeks, response was maintained at last follow up. On average, the YBOCS improved by 45% at last follow up. Mixed linear modeling elucidated directionality of symptom changes: insight into symptoms strongly predicted (P = 0.008) changes in symptom severity during DBS therapy, likely driven by initial changes in depression and anxiety. Precise localization of DBS leads demonstrated that responders most often had their leads (and active contacts) placed dorsal compared to non-responders, relative to the Nac.

CONCLUSION

The clinical efficacy of DBS for OCD is demonstrated, and mediators of changes in symptoms are proposed. The symptom improvements within this cohort should be seen within the context of the adjunct psychological and biopsychosocial care that implemented a shared decision-making approach, with flexible iterative DBS programming. Further research should explore the utility of insight as a clinical correlate of response. The trial was prospectively registered with the ANZCTR (ACTRN12612001142820).

Poor Insight in Obsessive-Compulsive Disorder as a Multifaceted Phenomenon: Evidence From Brain Activation During Symptom Provocation

BACKGROUND

Poor insight in obsessive-compulsive disorder (OCD) is associated with higher symptom severity, more comorbidities, and worse response to treatment. This study aimed to elucidate underlying mechanisms of poor insight in OCD by exploring its neurobiological correlates.

METHODS

Using a symptom provocation task during functional magnetic resonance imaging, we compared brain activation of patients with poor insight (n = 19; 14 female, 5 male), good/fair insight (n = 63; 31 female, 32 male), and healthy control participants (n = 42; 22 female, 20 male) using a Bayesian region-of-interest and a general linear model whole-brain approach. Insight was assessed using the Overvalued Ideas Scale.

RESULTS

Compared with patients with good/fair insight and healthy control participants, patients with OCD and poor insight showed widespread lower task-related activation in frontal areas (subgenual anterior cingulate cortex, ventromedial prefrontal cortex, dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, supplementary motor area, precentral gyrus), parietal areas (posterior parietal cortex, precuneus), and the middle temporal gyrus and insula. Results were not driven by interindividual differences in OCD symptom severity, medication usage, age of disorder onset, or state distress levels.

CONCLUSIONS

During symptom provocation, patients with OCD and poor insight show altered activation in brain circuits that are involved in emotional processing, sensory processing, and cognitive control. Future research should focus on longitudinal correlates of insight and/or use tasks that probe emotional and sensory processing and cognitive control.

Changes in insight throughout the natural four-year course of obsessive-compulsive disorder and its association with OCD severity and quality of life

Objective

Patients with obsessive-compulsive disorder (OCD) and poor insight show higher symptom severity, lower quality of life (QoL), and a reduced treatment response compared to patients with good insight. Little is known about changes in insight. This study explored the course of insight and its association with OCD severity and QoL among 253 patients with OCD participating in the prospective naturalistic Netherlands Obsessive Compulsive Disorder Association (NOCDA) Study.

Results

In 70% of the participants with available insight data, the level of insight changed during the four-year course. Insight was most variable in participants with poor insight. Improvement of insight scores was statistically significantly associated with improvement of Y-BOCS scores (r = 0.19), but not with changes in QoL scores. Change in insight in the first 2 years was not statistically significantly predictive of OCD severity or QoL at four-year follow-up.

Conclusion

These findings suggest that patients' levels of insight may change during the natural four-year course of OCD and that improvement in the level of insight have a positive association with improvement in OCD severity.

Tractography-based versus anatomical landmark-based targeting in vALIC deep brain stimulation for refractory obsessive-compulsive disorder

Deep brain stimulation (DBS) of the ventral anterior limb of the internal capsule (vALIC) is effective for refractory obsessive-compulsive disorder (OCD). Retrospective evaluation showed that stimulation closer to the supero-lateral branch of the medial forebrain bundle (slMFB), within the vALIC, was associated with better response to DBS. The present study is the first to compare outcomes of DBS targeted at the vALIC using anatomical landmarks and DBS with connectomic tractography-based targeting of the slMFB. We included 20 OCD-patients with anatomical landmark-based DBS of the vALIC that were propensity score matched to 20 patients with tractography-based targeting of electrodes in the slMFB. After one year, we compared severity of OCD, anxiety and depression symptoms, response rates, time to response, number of parameter adjustments, average current, medication usage and stimulation-related adverse effects. There was no difference in Y-BOCS decrease between patients with anatomical landmark-based and tractography-based DBS. Nine (45%) patients with anatomical landmark-based DBS and 13 (65%) patients with tractography-based DBS were responders (BF₁₀ = 1.24). The course of depression and anxiety symptoms, time to response, number of stimulation adjustments or medication usage did not differ between groups. Patients with tractography-based DBS experienced fewer stimulation-related adverse effects than patients with anatomical landmark-based DBS (38 vs 58 transient and 1 vs. 17 lasting adverse effects; BF₁₀ = 14.968). OCD symptoms in patients with anatomical landmark-based DBS of the vALIC and tractography-based DBS of the slMFB decrease equally, but patients with tractography-based DBS experience less adverse effects.

Efficacy and safety of deep brain stimulation for treatment-refractory anorexia nervosa: a systematic review and meta-analysis

BACKGROUND

Several pioneering studies investigated deep brain stimulation (DBS) in treatment-refractory anorexia nervosa (AN) patients, but overall effects remain yet unclear. Aim of this study was to obtain estimates of efficacy of DBS in AN-patients using meta-analysis.

METHODS

We searched three electronic databases until 1st of November 2021, using terms related to DBS and AN. We included trials that investigated the clinical effects of DBS in AN-patients. We obtained data including psychiatric comorbidities, medication use, DBS target, and study duration. Primary outcome was Body Mass Index (BMI), secondary outcome was quality of life, and the severity of psychiatric symptoms, including eating disorder, obsessive-compulsive, depressive, and anxiety symptoms. We assessed the risk of bias using the ROBINS-I tool.

RESULTS

Four studies were included for meta-analysis, with a total of 56 patients with treatment-refractory AN. Follow-up ranged from 6-24 months. Random effects meta-analysis showed a significant increase in BMI following DBS, with a large effect size (Hedges's g = 1 ∙ 13; 95% CI = 0 ∙ 80 to 1 ∙ 46; Z-value = 6 ∙ 75; P < 0 ∙ 001), without heterogeneity (I²= 0 ∙ 00, P = 0 ∙ 901). Random effects meta-analysis also showed a significant increase in quality of life (Hedges's g = 0 ∙ 86; 95% CI = 0 ∙ 44 to 1 ∙ 28; Z-value = 4 ∙ 01, P < 0 ∙ 001). Furthermore, DBS decreased the severity of psychiatric symptoms (Hedges's g = 0 ∙ 89; 95% CI = 0 ∙ 57 to 1 ∙ 21; Z-value = 5 ∙ 47; P < 0 ∙ 001, I²= 4 ∙ 29, P = 0 ∙ 371).

DISCUSSION

In this first meta-analysis, DBS showed statistically large beneficial effects on weight restoration, quality of life, and reduction of psychiatric symptoms in patients with treatment-refractory AN. These outcomes call for more extensive naturalistic studies to determine the clinical relevance for functional recovery. This study is preregistered in PROSPERO,CRD42022295712.

A Systematic Review of Treatment Outcome Predictors in Deep Brain Stimulation for Refractory Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a chronic and debilitating mental disorder. Deep brain stimulation (DBS) is a promising approach for refractory OCD patients. Research aiming at treatment outcome prediction is vital to provide optimized treatments for different patients. The primary purpose of this systematic review was to collect and synthesize studies on outcome prediction of OCD patients with DBS implantations in recent years. This systematic review (PROSPERO registration number: CRD42022335585) followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-analysis) guidelines. The search was conducted using three different databases with the following search terms related to OCD and DBS. We identified a total of 3814 articles, and 17 studies were included in our review. A specific tract confirmed by magnetic resonance imaging (MRI) was predictable for DBS outcome regardless of implant targets, but inconsistencies still exist. Current studies showed various ways of successful treatment prediction. However, considering the heterogeneous results, we hope that future studies will use larger cohorts and more precise approaches for predictors and establish more personalized ways of DBS surgeries.

Neural Processing Dysfunctions During Fear Learning but Not Reward-Related Processing Characterize Depressed Individuals With High Levels of Repetitive Negative Thinking

BACKGROUND

Repetitive negative thinking (RNT) is a symptom dimension of depression that is associated with a poorer prognosis in terms of higher recurrence, treatment resistance, residual symptoms, and disability. This investigation examined whether RNT is associated with aberrant reward processing and fear learning.

METHODS

Very high RNT (VH-RNT) (n = 60) and high RNT (H-RNT) (n = 60) propensity-matched individuals with depression (age, sex, race/ethnicity, income/employment, body mass index, depressive and anxiety symptom severity) participated in this study along with matched healthy comparison volunteers (n = 30). This propensity-matched sample was selected from the larger Tulsa 1000 study. Participants performed two functional magnetic resonance imaging tasks: the monetary incentive delay task probing reward processing and the fear conditioning task probing aversive learning and extinction.

RESULTS

Both VH-RNT and H-RNT groups showed lower neural activity than healthy comparison subjects in reward circuitry, including the inferior frontal gyrus (VH-RNT: β = -1.24, H-RNT: β = -1.28) and the cerebellum (VH-RNT: β = -0.93, H-RNT: β = -1.14). However, individuals with VH-RNT exhibited lower activation than those with H-RNT in central autonomic network components during fear conditioning (β = -0.84) and continued conditioned responses during early extinction in the postcentral cortex (β = 0.71).

CONCLUSIONS

VH-RNT showed aberrant processing in fear conditioning during both learning and extinction phases compared with H-RNT. These findings demonstrate that dysfunctions of negative valence associated with RNT may be domain specific, which should be taken into account for identifying potential specific targets of intervention.