Volumetric MRI study of orbito-frontal cortex and thalamus in obsessive-compulsive personality disorder

Obsessive-Compulsive Disorder Comorbid with or without Obsessive-Compulsive Personality Disorder: Conceptual Implications, Clinical Correlates and Brain Morphometries

BACKGROUND

Obsessive-compulsive disorder (OCD) is often comorbid with obsessive-compulsive personality disorder (OCPD). The relationship between OCD and OCPD is complex, and the impact of comorbid OCPD on OCD remains underexplored, necessitating further research.. This study aims to investigate the clinical correlates and brain morphometries associated with comorbid OCPD in a large sample of unmedicated OCD patients.

METHODS

A total of 248 unmedicated patients diagnosed with OCD (45 comorbid with OCPD) were included in this study. All participants were assessed for OCD symptoms, OCPD traits, obsessive beliefs, depression and anxiety. Among them, 145 patients (23 comorbid with OCPD) volunteered to receive magnetic resonance imaging (MRI) brain scans.

RESULTS

Approximately 18% (45/248) of OCD patients were comorbid with OCPD. OCD comorbid with OCPD (OCD+OCPD) exhibited more severe OCD symptoms, obsessive beliefs, depression and anxiety than OCD comorbid without OCPD. Additionally, the severity of OCPD was positively correlated with OCD symptoms and obsessive beliefs. Furthermore, OCD+OCPD patients exhibited increased cortical complexity in the left superior parietal lobule and left precuneus, which mediated the relationship between OCPD and OCD symptoms only in OCD patients comorbid without OCPD.

CONCLUSIONS

The co-occurrence of OCPD may contribute to the heightened severity of psychopathological symptoms and associated brain morphological alterations in OCD patients, indicating distinct but interrelated constructs between these two disorders.

The neurobiology of misophonia and implications for novel, neuroscience-driven interventions

Decreased tolerance in response to specific every-day sounds (misophonia) is a serious, debilitating disorder that is gaining rapid recognition within the mental health community. Emerging research findings suggest that misophonia may have a unique neural signature. Specifically, when examining responses to misophonic trigger sounds, differences emerge at a physiological and neural level from potentially overlapping psychopathologies. While these findings are preliminary and in need of replication, they support the hypothesis that misophonia is a unique disorder. In this theoretical paper, we begin by reviewing the candidate networks that may be at play in this complex disorder (e.g., regulatory, sensory, and auditory). We then summarize current neuroimaging findings in misophonia and present areas of overlap and divergence from other mental health disorders that are hypothesized to co-occur with misophonia (e.g., obsessive compulsive disorder). Future studies needed to further our understanding of the neuroscience of misophonia will also be discussed. Next, we introduce the potential of neurostimulation as a tool to treat neural dysfunction in misophonia. We describe how neurostimulation research has led to novel interventions in psychiatric disorders, targeting regions that may also be relevant to misophonia. The paper is concluded by presenting several options for how neurostimulation interventions for misophonia could be crafted.

Advances in multimodal data fusion in neuroimaging: Overview, challenges, and novel orientation

Multimodal fusion in neuroimaging combines data from multiple imaging modalities to overcome the fundamental limitations of individual modalities. Neuroimaging fusion can achieve higher temporal and spatial resolution, enhance contrast, correct imaging distortions, and bridge physiological and cognitive information. In this study, we analyzed over 450 references from PubMed, Google Scholar, IEEE, ScienceDirect, Web of Science, and various sources published from 1978 to 2020. We provide a review that encompasses (1) an overview of current challenges in multimodal fusion (2) the current medical applications of fusion for specific neurological diseases, (3) strengths and limitations of available imaging modalities, (4) fundamental fusion rules, (5) fusion quality assessment methods, and (6) the applications of fusion for atlas-based segmentation and quantification. Overall, multimodal fusion shows significant benefits in clinical diagnosis and neuroscience research. Widespread education and further research amongst engineers, researchers and clinicians will benefit the field of multimodal neuroimaging.

Increased thalamic volume and decreased thalamo-precuneus functional connectivity are associated with smoking relapse

The thalamus, with the highest density of nicotinic acetylcholine receptor (nAChR) in the brain, plays a central role in thalamo-cortical circuits that are implicated in nicotine addiction. However, little is known about whether the thalamo-cortical circuits are potentially predictive of smoking relapse. In the current study, a total of 125 participants (84 treatment-seeking male smokers and 41 age-matched male nonsmokers) were recruited. Structural and functional magnetic resonance images (MRI) were acquired from all participants. After a 12-week smoking cessation treatment with varenicline, the smokers were then divided into relapsers (n = 54) and nonrelapsers (n = 30). Then, we compared thalamic volume and seed-based thalamo-cortical resting state functional connectivity (rsFC) prior to the cessation treatment among relapsers, nonrelapsers and nonsmokers to investigate the associations between thalamic structure/function and smoking relapse. Increased thalamic volume was detected in smokers relative to nonsmokers, and in relapsers relative to nonrelapsers, especially on the left side. Moreover, decreased left thalamo-precuneus rsFC was detected in relapsers relative to nonrelapsers. Additionally, a logistic regression analysis showed that the thalamic volume and thalamo-precuneus rsFC predicted smoking relapse with an accuracy of 75.7%. These novel findings indicate that increased thalamic volume and decreased thalamo-precuneus rsFC are associated with smoking relapse, and these thalamic measures may be used to predict treatment efficacy of nicotine addiction and serve as a potential biomarker for personalized medicine.

Pineal gland volumes are changed in patients with obsessive-compulsive personality disorder

OBJECTIVE

In the present study, taking into consideration our previous studies showing an association on the neuroanatomy of OCD and obsessive-compulsive personality disorders (OCPD), we also decided to examine pineal gland volumes in patients with obsessive-compulsive personality disorder and hypothesized that gland volumes would be found as altered in comparison with those of healthy subjects.

METHODS

Sixteen patients with OCPD and eighteen healthy control subjects underwent magnetic resonance imaging (MRI). We compared the volumes of pineal gland by using MRI between groups.

RESULTS

As compared to healthy control subjects, patients with OCPD had statistically significant smaller pineal gland volumes by using independent sample t test (87.34 ± 19.72 mm³ for patients with OCPD vs. 108.62 ± 22.56 mm³, with a statistically significantly difference of p < 0.01.When controlling for gender distribution, age and whole brain volumes in the General Linear Model, we saw that patients with OCPD had still statistically significant smaller pineal volumes compared to those of healthy control subjects.

CONCLUSION

Finally, the findings of the present study revealed that patients with OCPD had reduced pineal gland volumes compared to those of healthy control subjects, supporting the fact that OCPD might be included in the OCD spectrum disorders, since we have previously found same result in patients with OCPD.