Obsessive-compulsive disorder in chronic epilepsy

Abnormal patterns of sleep and waking behaviors are accompanied by neocortical oscillation disturbances in an Ank3 mouse model of epilepsy-bipolar disorder comorbidity

ANK3 is a leading bipolar disorder (BD) candidate gene in humans and provides a unique opportunity for studying epilepsy-BD comorbidity. Previous studies showed that deletion of Ank3-1b, a BD-associated variant of Ank3 in mice leads to increased firing threshold and diminished action potential dynamic range of parvalbumin (PV) interneurons and absence epilepsy, thus providing a biological mechanism linking epilepsy and BD. To explore the behavioral overlap of these disorders, we characterized behavioral patterns of Ank3-1b KO mice during overnight home-cage activity and examined network activity during these behaviors using paired video and EEG recordings. Since PV interneurons contribute to the generation of high-frequency gamma oscillations, we anticipated changes in the power of neocortical EEG signals in the gamma frequency range (> 25 Hz) during behavioral states related to human BD symptoms, including abnormal sleep, hyperactivity, and repetitive behaviors. Ank3-1b KO mice exhibited an overall increase in slow gamma (~25-45 Hz) power compared to controls, and slow gamma power correlated with seizure phenotype severity across behaviors. During sleep, increased slow gamma power correlated with decreased time spent in the rapid eye movement (REM) stage of sleep. Seizures were more common during REM sleep compared to non-REM (NREM) sleep. We also found that Ank3-1b KO mice were hyperactive and exhibited a repetitive behavior phenotype that co-occurred with increased slow gamma power. Our results identify a novel EEG biomarker associating Ank3 genetic variation with BD and epilepsy and suggest modulation of gamma oscillations as a potential therapeutic target.

Factors related to the severity of obsessive-compulsive symptoms and their impact on suicide risk in epileptic patients

OBJECTIVE

To explore relevant factors for the severity of obsessive-compulsive symptoms (OCSs) in adult epileptic patients and investigate whether the severity of OCSs is a mediator in the relationship between depressive/anxiety symptoms and suicide risk in epileptic patients.

METHODS

This was a cross-sectional study from a hospital in Northeast China. Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Neurological Disorders Depression Inventory for Epilepsy (NDDIE), Generalized Anxiety Disorder (GAD-7), and Nurses' Global Assessment of Suicide Risk (NGASR) were used to assess the severity of OCSs, depressive symptoms, anxiety symptoms, and suicide risk in epileptic patients, respectively. The independent factors of the severity of OCSs and their mediating effects in the relationship between depressive/anxiety symptoms and suicide risk were evaluated by regression analyses and mediator models, respectively.

RESULTS

NDDIE scores (β = 0.404, p < 0.001), GAD-7 scores (β = 0.247, p = 0.009), and polytherapy (β = 0.119, p = 0.032) were the independent factors of Y-BOCS scores. The Y-BOCS scores partially mediated the relationship between GAD-7 scores and NGASR scores (standardized coefficients of indirect effect = 0.109, Bootstrap 95% CI = 0.024 to 0.214). Still, they did not mediate the relationship between NDDIE scores and NGASR scores (standardized coefficients of indirect effect = 0.062, Bootstrap 95% CI = -0.024 to 0.169).

CONCLUSIONS

Depressive symptoms, anxiety symptoms, and polytherapy are independently associated with the severity of OCSs in epileptic patients. Depressive and anxiety symptoms mediate the effect of the severity of OCSs on suicide risk in epileptic patients completely.

Early-life seizures alter habit behavior formation and fronto-striatal circuit dynamics

Obsessive compulsive disorder (OCD) can occur comorbidly with epilepsy; both are complex, disruptive disorders that lower quality of life. Both OCD and epilepsy are disorders of hyperexcitable circuits, but it is unclear whether common circuit pathology may underlie the co-occurrence of these two neuropsychiatric disorders. Here, we induced early-life seizures (ELS) in rats to examine habit formation as a model for compulsive behaviors. Compulsive, repetitive behaviors in OCD utilize the same circuitry as habit formation. We hypothesized that rats with ELS could be more susceptible to habit formation than littermate controls, and that altered behavior would correspond to altered signaling in fronto-striatal circuits that underlie decision-making and action initiation. Here, we show instead that rats with ELS were significantly less likely to form habit behaviors compared with control rats. This behavioral difference corresponded with significant alterations to temporal coordination within and between brain regions that underpin the action to habit transition: 1) phase coherence between the lateral orbitofrontal cortex and dorsomedial striatum (DMS) and 2) theta-gamma coupling within DMS. Finally, we used cortical electrical stimulation as a model of transcranial magnetic stimulation (TMS) to show that temporal coordination of fronto-striatal circuits in control and ELS rats are differentially susceptible to potentiating and suppressive stimulation, suggesting that altered underlying circuit physiology may lead to altered response to therapeutic interventions such as TMS.

Plasticity-Related Activity in the Hippocampus, Anterior Cingulate, Orbitofrontal, and Prefrontal Cortex Following a Repeated Treatment with D2/D3 Agonist Quinpirole

Quinpirole (QNP) sensitization is a well-established model of stereotypical checking relevant to obsessive-compulsive disorder. Previously, we found that QNP-treated rats display deficits in hippocampus-dependent tasks. The present study explores the expression of immediate early genes (IEG) during QNP-induced stereotypical checking in the hippocampus, anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and medial prefrontal cortex (mPFC). Adult male rats were injected with QNP (0.5 mg/mL/kg; n = 15) or saline (n = 14) daily for 10 days and exposed to an arena enriched with two objects. Visits to the objects and the corners of the arena were recorded. QNP-treated rats developed an idiosyncratic pattern of visits that persisted across experimental days. On day 11, rats were exposed to the arena twice for 5 min and sacrificed. The expression of IEGs Arc and Homer1a was determined using cellular compartment analysis of temporal activity by fluorescence in situ hybridization. IEG-positive nuclei were counted in the CA1 area of the hippocampus, ACC, OFC, and mPFC. We found significantly fewer IEG-positive nuclei in the CA1 in QNP-treated rats compared to controls. The overlap between IEG expressing neurons was comparable between the groups. We did not observe significant differences in IEG expression between QNP treated and control rats in ACC, OFC, and mPFC. In conclusion, treatment of rats with quinpirole decreases plasticity-related activity in the hippocampus during stereotypical checking.

Differences in obsessive-compulsive symptom dimensions between patients with epilepsy with obsessive-compulsive symptoms and patients with OCD

Clinical correlates of obsessive-compulsive symptoms (OCS) were evaluated in 100 adult consecutive outpatients with epilepsy, using the Obsessive-Compulsive Inventory (OCI-R), Beck Depression Inventory (BDI), Dissociative Experiences Scale (DES-II), and the Schizotypal Personality Questionnaire (SPQ). Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) was applied to determine the types and severity of OCS to the 45 patients with epilepsy who were over 21 points on the OCI-R scale and 30 patients who were with diagnosed obsessive-compulsive disorder (OCD) among the patients in the psychiatry outpatient clinic, as a control group. As a result, it was found that patients with epilepsy with OCS tend to have more symmetry/exactness obsessions and compulsions, whereas patients with OCD had significantly more contamination/cleaning and aggressiveness obsessions and compulsions. In addition, OCS was found to be significantly higher in temporal lobe epilepsy (TLE) and extratemporal epilepsy than generalized epilepsy. However, OCS were correlated with depression, dissociation, and schizotypy in patients with epilepsy, while only depression was predictive when regression analysis was performed for OCS. This study is the first study to compare patients with OCD with patients with epilepsy in terms of the nature of OCS and first identified the differences in OCS dimensions between patients with epilepsy with OCS and patients with OCD.

Factors associated with obsessive-compulsive symptoms in people with epilepsy

PURPOSE

Obsessive-compulsive disorder (OCD) is a common but underrecognized psychiatric condition comorbid with epilepsy. We thus investigated clinical factors associated with obsessive-compulsive symptoms (OCS) in adults with epilepsy.

METHODS

This was a cross-sectional multicenter study in Republic of Korea. Obsessive-compulsive symptoms were assessed using the Obsessive-Compulsive Inventory-Revised (OCI-R). Clinical factors that were assessed included age, sex, seizure-related variables, and the number and use of antiepileptic drugs (AEDs) prescribed. Data were analyzed by stepwise linear regression and adjusted according to anxiety and depressive symptoms as assessed by Hospital Anxiety Depression Scale (HADS).

RESULTS

The study population comprised 221 adults with epilepsy (42.1% male, 39.7 ± 11.9 years of age). The mean OCI-R score was 18.0 (standard deviation, 12.7), and an OCI-R score of ≥21 was obtained for 40.3% of the study sample. On a stepwise linear regression analysis, epilepsy severity, temporal lobe seizures, the use of topiramate, and the use of lamotrigine were identified as independent factors associated with OCI-R score after adjusting for anxiety according to the HADS. All factors except topiramate usage were positively associated with OCS. The total explained variance was 37.3%.

CONCLUSIONS

Obsessive-compulsive symptoms are common in persons with epilepsy and are associated with severe epilepsy, temporal lobe seizures, and the use of topiramate and lamotrigine. Specifically, the use of lamotrigine may aggravate OCS, whereas the use of topiramate may have beneficial effects on OCS.

Epilepsy Surgery in 2019 : A Time to Change

Epilepsy has been known to humankind since antiquity. The surgical treatment of epilepsy began in the early days of neurosurgery and has developed greatly. Many surgical procedures have stood the test of time. However, clinicians treating epilepsy patients are now witnessing a huge tide of change. In 2017, the classification system for seizure and epilepsy types was revised nearly 36 years after the previous scheme was released. The actual difference between these systems may not be large, but there have been many conceptual changes, and clinicians must bid farewell to old terminology. Paradigms in drug discovery are changing, and novel antiseizure drugs have been introduced for clinical use. In particular, drugs that target genetic changes harbor greater therapeutic potential than previous screening-based compounds. The concept of focal epilepsy has been challenged, and now epilepsy is regarded as a network disorder. With this novel concept, stereotactic electroencephalography (SEEG) is becoming increasingly popular for the evaluation of dysfunctioning neuronal networks. Minimally invasive ablative therapies using SEEG electrodes and neuromodulatory therapies such as deep brain stimulation and vagus nerve stimulation are widely applied to remedy dysfunctional epilepsy networks. The use of responsive neurostimulation is currently off-label in children with intractable epilepsy.

Fantastic confabulation in right frontal lobe epilepsy

Background

Interictal behavioral symptoms in frontal lobe epilepsy (FLE) are variable and often difficult to discriminate from other localization-related epilepsies.

Methods and results

We report two female patients with right FLE who exhibited fantastic confabulations. One of the patients had a 14-year history of hypermotor seizures, and the other had a 10-year history of dyscognitive seizures with automatism. Their fantastic confabulations arose in the context of moderate-to-severe cognitive impairment and of a variety of behavioral abnormalities, including emotional withdrawal and compulsive behaviors.

Conclusion

Fantastic confabulations are rare but may be a relatively specific behavioral marker for FLE-associated psychosis.

Electrical stimulation in the bed nucleus of the stria terminalis alleviates severe obsessive-compulsive disorder

In 1998, we proposed deep brain stimulation as a last-resort treatment option for patients suffering from severe, treatment-resistant obsessive-compulsive disorder (OCD). Here, 24 OCD patients were included in a long-term follow-up study to evaluate the effects of electrical stimulation in the anterior limbs of the internal capsule (ALIC) and bed nucleus of the stria terminalis (BST). We find that electrical stimulation in the ALIC/BST area is safe and significantly decreases obsessions, compulsions, and associated anxiety and depressive symptoms, and improves global functioning in a blinded crossover trial (n=17), after 4 years (n=18), and at last follow-up (up to 171 months, n=24). Moreover, our data indicate that BST may be a better stimulation target compared with ALIC to alleviate OCD symptoms. We conclude that electrical stimulation in BST is a promising therapeutic option for otherwise treatment-resistant OCD patients.

The crossroads of anxiety: distinct neurophysiological maps for different symptomatic groups

BACKGROUND

Despite the devastating impact of anxiety disorders (ADs) worldwide, long-lasting debates on causes and remedies have not solved the clinician's puzzle: who should be treated and how? Psychiatric classifications conceptualize ADs as distinct entities, with strong support from neuroscience fields. Yet, comorbidity and pharmacological response suggest a single "serotonin dysfunction" dimension. Whether AD is one or several disorders goes beyond academic quarrels, and the distinction has therapeutic relevance. Addressing the underlying dysfunctions should improve treatment response. By its own nature, neurophysiology can be the best tool to address dysfunctional processes.

PURPOSE

To search for neurophysiological dysfunctions and differences among panic disorder (PD), agoraphobia-social-specific phobia, obsessive-compulsive disorder (OCD) and generalized anxiety disorder.

METHODS

A sample population of 192 unmedicated patients and 30 aged-matched controls partook in this study. Hypothesis-related neurophysiological variables were combined into ten independent factors: 1) dysrhythmic patterns, 2) delta, 3) theta, 4) alpha, 5) beta (whole-head absolute power z-scores), 6) event-related potential (ERP) combined latency, 7) ERP combined amplitude (z-scores), 8) magnitude, 9) site, and 10) site of hyperactive networks. Combining single variables into representative factors was necessary because, as in all real-life phenomena, the complexity of interactive processes cannot be addressed through single variables and the multiplicity of potentially implicated variables would demand an extremely large sample size for statistical analysis.

RESULTS

The nonparametric analysis correctly classified 81% of the sample. Dysrhythmic patterns, decreased delta, and increased beta differentiated AD from controls. Shorter ERP latencies were found in several individual patients, mostly from the OCD group. Hyperactivities were found at the right frontorbital-striatal network in OCD and at the panic circuit in PD.

CONCLUSIONS

Our findings support diffuse cortical instability in AD in general, with individual differences in information processing deficits and regional hyperactivities in OCD and PD. Study limitations and the rationale behind the variable selection and combination strategy will be discussed before addressing the therapeutic implications of our findings.

Environmental effects on compulsive tail chasing in dogs

Obsessive Compulsive Disorder (OCD) is a neuropsychiatric disorder observed both in humans and animals. Examples of Canine Compulsive Disorder (CD) include excessive tail chasing (TC), light/shadow chasing and flank sucking. We performed a questionnaire survey to investigate the characteristics of compulsive (TC) and its possible associations with environmental correlates and personality in a pet population of 368 dogs from four dog breeds. We observed an early onset of TC at 3–6 months of age and a large variation in TC frequency in all breeds, with an overrepresentation of milder cases. Almost half of the TC dogs showed lowered responsiveness during bouts and displayed also other types of compulsions more often than the controls. Interestingly, dogs that received dietary supplements, especially vitamins and minerals, expressed less TC compared to dogs that did not receive any supplements. Neutered females had less TC, suggesting an influence of ovarian hormones on TC. Tail chasers were shyer and had separated earlier from their mothers than the controls. Finally, our genetic study did not find an association between TC and CDH2, a locus previously associated with the canine flank sucking compulsion. In conclusion, the early-onset and the variable nature of the repetitive behaviour, which is affected by environmental factors such as micronutrients, neutering and maternal care, share several similar components between canine and human compulsions and supports canine TC as a model for human OCD.

Structural brain MR imaging changes associated with obsessive-compulsive disorder in patients with multiple sclerosis

BACKGROUND AND PURPOSE

Psychiatric symptoms occur in approximately 30% of patients with MS. Such symptoms include OCD, which may interfere heavily with the patient's daily life. We hypothesized that the widespread involvement of both GM and WM, which characterizes MS, may be responsible for the occurrence of OCD when specific brain structures are affected. The aim of this study was to evaluate the relationship between GM and WM tissue damage and OCD in patients with MS.

MATERIALS AND METHODS

We evaluated 16 patients with relapsing-remitting MS who had been diagnosed with OCD on the basis of the Diagnostic and Statistical Manual of Mental Disorders (4th edition) and 15 age- and sex-matched patients with relapsing-remitting MS with no psychiatric disorders as a CG. The MR study (1.5T) included 3D T1-weighted fast-field echo sequences, DTI (32 directions), and conventional MRI. Images were processed using SPM5, FSL, and Jim 5.0 software to evaluate VBM, TBSS, and global and regional LV, respectively.

RESULTS

The VBM analysis revealed a set of clusters of reduced GM volume in the OCD group, compared with the CG, located in the right inferior and middle temporal gyri and in the inferior frontal gyrus. TBSS did not detect any differences in the FA values between the 2 groups; global and regional LV values also did not differ significantly between the 2 groups.

CONCLUSIONS

Our study suggests that OCD in MS may be caused by damage in the right frontotemporal cortex.