Neuropsychological outcome in refractory obsessive-compulsive disorder treated with anterior capsulotomy including repeated surgery

Evidence Accumulation and Neural Correlates of Uncertainty in Obsessive-Compulsive Disorder

BACKGROUND

Decision making is frequently associated with risk taking under uncertainty. Elevated intolerance of uncertainty is suggested to be a critical feature of obsessive-compulsive disorder (OCD). However, impairments of latent constructs of uncertainty processing and its neural correlates remain unclear in OCD.

METHODS

In 83 participants (24 OCD patients treated with capsulotomy, 28 OCD control participants, and 31 healthy control participants), we performed magnetic resonance imaging using a card gambling task in which participants made decisions whether to bet or not that the next card would be larger than the current one. A hierarchical drift diffusion model was used to dissociate speed and amount of evidence accumulated before a decisional threshold (i.e., betting or no betting) was reached.

RESULTS

High uncertainty was characterized by a smaller amount of evidence accumulation (lower thresholds), thus dissociating uncertainty from conflict tasks and highlighting the specificity of this task to test value-based uncertainty. OCD patients exhibited greater caution with poor performance and greater evidence accumulation overall along with slower speed of accumulation, particularly under low uncertainty. Bilateral dorsal anterior cingulate and anterior insula distinguished high- and low-uncertainty decision processes in healthy control participants but not in the OCD groups, indicating impairments in anticipation of differences in outcome variance and salience network activity. There were no behavioral or imaging differences relating to capsulotomy despite improvements in OCD symptoms.

CONCLUSIONS

Our findings highlight greater impairments particularly in more certain trials in the OCD groups along with impaired neural differentiation of high and low uncertainty and suggest uncertainty processing as a trait cognitive endophenotype rather than a state-specific factor.

Mechanisms underlying capsulotomy for refractory obsessive-compulsive disorder: neural correlates of negative affect processing overlap with deep brain stimulation targets

Ablative procedures such as anterior capsulotomy are potentially effective in refractory obsessive-compulsive disorder (OCD). Converging evidence suggests the ventral internal capsule white matter tracts traversing the rostral cingulate and ventrolateral prefrontal cortex and thalamus is the optimal target for clinical efficacy across multiple deep brain stimulation targets for OCD. Here we ask which prefrontal regions and underlying cognitive processes might be implicated in the effects of capsulotomy by using both task fMRI and neuropsychological tests assessing OCD-relevant cognitive mechanisms known to map across prefrontal regions connected to the tracts targeted in capsulotomy. We tested OCD patients at least 6 months post-capsulotomy (n = 27), OCD controls (n = 33) and healthy controls (n = 34). We used a modified aversive monetary incentive delay paradigm with negative imagery and a within session extinction trial. Post-capsulotomy OCD subjects showed improved OCD symptoms, disability and quality of life with no differences in mood or anxiety or cognitive task performance on executive, inhibition, memory and learning tasks. Task fMRI revealed post-capsulotomy decreases in the nucleus accumbens during negative anticipation, and in the left rostral cingulate and left inferior frontal cortex during negative feedback. Post-capsulotomy patients showed attenuated accumbens-rostral cingulate functional connectivity. Rostral cingulate activity mediated capsulotomy improvement on obsessions. These regions overlap with optimal white matter tracts observed across multiple stimulation targets for OCD and might provide insights into further optimizing neuromodulation approaches. Our findings also suggest that aversive processing theoretical mechanisms may link ablative, stimulation and psychological interventions.

Cognitive outcomes following functional neurosurgery in refractory OCD patients: a systematic review

Neurosurgery is a therapeutic option for patients with refractory obsessive-compulsive disorder who do not respond to previous treatments. Although its efficacy in reducing clinical symptomatology has been proven, few studies have analyzed its effects at the cognitive level. The aim of this systematic review was to describe the cognitive outcomes of functional neurosurgery in patients that went through capsulotomies or cingulotomies. PubMed, Medline, Scopus, PsycInfo, PsyArticles, and Web of Knowledge were searched for studies reporting cognitive outcomes in refractory obsessive-compulsive patients after capsulotomies and cingulotomies. The risk of bias was assessed with the Assessment Tool for Before-After (Pre-Post) Studies With No Control Group tool; 13 studies met inclusion criteria, including 205 refractory obsessive-compulsive disorder patients for both surgical procedures. Results showed a substantial number of studies that did report significant cognitive improvement after surgery, being this improvement specially related to memory and executive functions. The second-most frequent finding is the maintenance of cognitive performance (nor improvement or worsening). From a neuropsychological point of view, this outcome might be considered a success, given that it is accompanied by amelioration of obsessive-compulsive symptoms. Subtle cognitive adverse effects have also been reported. Neurosurgery procedures appear to be safe from a cognitive point of view. Methodological issues must be improved to draw clearer conclusions, but capsulotomies and cingulotomies constitute an effective alternative treatment for refractory obsessive-compulsive disorder patients.

Functional Connectivity within the Frontal–Striatal Network Differentiates Checkers from Washers of Obsessive-Compulsive Disorder

Background: Obsessive-compulsive disorder (OCD) is a psychiatric disorder with high clinical heterogeneity manifested by the presence of obsessions and/or compulsions. The classification of the symptom dimensional subtypes is helpful for further exploration of the pathophysiological mechanisms underlying the clinical heterogeneity of OCD. Washing and checking symptoms are the two major symptom subtypes in OCD, but the neural mechanisms of the different types of symptoms are not yet clearly understood. The purpose of this study was to compare regional and network functional alterations between washing and checking OCD based on resting-state functional magnetic resonance imaging (rs-fMRI). Methods: In total, 90 subjects were included, including 15 patients in the washing group, 30 patients in the checking group, and 45 healthy controls (HCs). Regional homogeneity (ReHo) was used to compare the differences in regional spontaneous neural activity among the three groups, and local indicators were analyzed by receiver operating characteristic (ROC) curves as imaging markers for the prediction of the clinical subtypes of OCD. Furthermore, differently activated local brain areas, as regions of interest (ROIs), were used to explore differences in altered brain functioning between washing and checking OCD symptoms based on a functional connectivity (FC) analysis. Results: Extensive abnormalities in spontaneous brain activity involving frontal, temporal, and occipital regions were observed in the patients compared to the HCs. The differences in local brain functioning between checking and washing OCD were mainly concentrated in the bilateral middle frontal gyrus, right supramarginal gyrus, right angular gyrus, and right inferior occipital gyrus. The ROC curve analysis revealed that the hyperactivation right middle frontal gyrus had a better discriminatory value for checking and washing OCD. Furthermore, the seed-based FC analysis revealed higher FC between the left medial superior frontal gyrus and right caudate nucleus compared to that in the healthy controls. Conclusions: These findings suggest that extensive local differences exist in intrinsic spontaneous activity among the checking group, washing group, and HCs. The neural basis of checking OCD may be related to dysfunction in the frontal–striatal network, which distinguishes OCD from washing OCD.

The prefrontal cortex and neurosurgical treatment for intractable OCD

Over the past two decades, circuit-based neurosurgical procedures have gained increasing acceptance as a safe and efficacious approach to the treatment of the intractable obsessive-compulsive disorder (OCD). Lesions and deep brain stimulation (DBS) of the longitudinal corticofugal white matter tracts connecting the prefrontal cortex with the striatum, thalamus, subthalamic nucleus (STN), and brainstem implicate orbitofrontal, medial prefrontal, frontopolar, and ventrolateral cortical networks in the symptoms underlying OCD. The highly parallel distributed nature of these networks may explain the relative lack of adverse effects observed following surgery. Additional pre-post studies of cognitive tasks in more surgical patients are needed to confirm the role of these networks in OCD and to define therapeutic responses to surgical intervention.

Treatment Outcomes of Gamma-Knife Radio Surgery in Refractory Obsessive-Compulsive Disorder

Background

Obsessive-compulsive disorder (OCD) is a common disease that has negative effects on functionality, and 10% of the patients do not respond to first-line treatments. Gamma-knife radiosurgery (GKRS) has been used in patients with treatment-resistant OCD, but the data on long-term outcomes are still unsatisfactory.

Methods

In this study, 12 patients who underwent GKRS between 2005 and 2020 were evaluated retrospectively. Anterior capsulotomy was performed using two 4-mm isocenters at the midputaminal point of the anterior limb of the internal capsule on each side with a maximum radiation dose of 140-180 Gy. Patients were followed up with the Yale-Brown Obsession and Compulsion Scale (Y-BOCS), Montgomery-Asberg Depression Rating Scale (MADRS), and Brief Psychiatric Rating Scale (BPRS) on the first, third, and sixth months.

Results

After the procedure, a 35% reduction was observed in the overall Y-BOCS scores, and full response rate was 50%. There was a 49.5% decrease in the MADRS scores and a 57.8% decrease in the BPRS.

Conclusion

GKRS is an effective and non-invasive procedure with favorable side effects in treatment-resistant OCD with selected patients.

Cognitive deficits and clinical symptoms in patients with treatment-refractory obsessive-compulsive disorder: The role of slowness in information processing

Patients with Obsessive-Compulsive Disorder (OCD) present neuropsychological deficits across different cognitive domains, especially in executive functioning and information processing speed. Some studies have even suggested that speed deficits may underlie poor neuropsychological performance. However, this hypothesis remains unanswered in both OCD general population and OCD refractory subgroup. In addition, it is not clear whether such deficits are secondary to the clinical symptoms or may constitute a primary deficit. The aim of this study was to explore the speed of processing hypothesis in treatment-refractory OCD patients, and to clarify to what extent slowness is related to psychopathological symptoms. Both clinical and neuropsychological examination was conducted to assess 39 OCD refractory patients candidates for neurosurgery and 39 healthy matched individuals. Principal component analysis revealed a three-component structure in the neuropsychological battery being used, including a speed of processing, working memory, and conflict monitoring components. Group comparisons revealed that OCD patients performed significantly worse than healthy individuals in speed measures, but no differences were found in executive tests not influenced by time. Correlation analyses revealed a lack of association between neuropsychological and clinical measures. The results suggest that treatment-refractory OCD patients exhibit a primary deficit in information processing speed independent of clinical symptoms.