Spectroscopic abnormalities in the pregenual anterior cingulate cortex in obsessive-compulsive disorder using proton magnetic resonance spectroscopy: a controlled study

BACKGROUND

The main aim of the present study is to determine the role of metabolites observed using proton magnetic resonance spectroscopy (1H-MRS) in obsessive-compulsive disorder (OCD). As the literature describing biochemical changes in OCD yields conflicting results, we focused on accurate metabolite quantification of total N-acetyl aspartate (tNAA), total creatine (tCr), total choline-containing compounds (tCh), and myo-inositol (mI) in the anterior cingulate cortex (ACC) to capture the small metabolic changes between OCD patients and controls and between OCD patients with and without medication.

METHODS

In total 46 patients with OCD and 46 healthy controls (HC) matched for age and sex were included in the study. The severity of symptoms in the OCD was evaluated on the day of magnetic resonance imaging (MRI) using the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Subjects underwent 1H-MRS from the pregenual ACC (pgACC) region to calculate concentrations of tNAA, tCr, tCho, and mI. Twenty-eight OCD and 28 HC subjects were included in the statistical analysis. We compared differences between groups for all selected metabolites and in OCD patients we analyzed the relationship between metabolite levels and symptom severity, medication status, age, and the duration of illness.

RESULTS

Significant decreases in tCr (U = 253.00, p = 0.022) and mI (U = 197.00, p = 0.001) in the pgACC were observed in the OCD group. No statistically significant differences were found in tNAA and tCho levels; however, tCho revealed a trend towards lower concentrations in OCD patients (U = 278.00, p = 0.062). Metabolic concentrations showed no significant correlations with the age and duration of illness. The correlation statistics found a significant negative correlation between tCr levels and YBOCS compulsions subscale (cor = -0.380, p = 0.046). tCho and YBOCS compulsions subscale showed a trend towards a negative correlation (cor = -0.351, p = 0.067). Analysis of subgroups with or without medication showed no differences.

CONCLUSIONS

Patients with OCD present metabolic disruption in the pgACC. The decrease in tCr shows an important relationship with OCD symptomatology. tCr as a marker of cerebral bioenergetics may also be considered as a biomarker of the severity of compulsions. The study failed to prove that metabolic changes correlate with the medication status or the duration of illness. It seems that a disruption in the balance between these metabolites and their transmission may play a role in the pathophysiology of OCD.

Glutamatergic abnormalities in the pregenual anterior cingulate cortex in obsessive-compulsive disorder using magnetic resonance spectroscopy: A controlled study

In this study, we utilized proton magnetic resonance spectroscopy (MRS) to understand the role of glutamate (Glu), glutamine (Gln), and gamma-aminobutyric acid (GABA) of OCD patients in the pregenual anterior cingulate cortex (pgACC). In total, 54 patients with OCD and 54 healthy controls (HC) matched for age and sex were included in the study. They underwent MRS in the pgACC region to calculate the concentrations of Glu, Gln, GABA, and Glu + Gln (Glx). After quality control of the MRS data, 21 OCD and 21 HC were statistically analyzed. The severity of symptoms were evaluated using the Yale-Brown Obsessive-Compulsive Scale (YBOCS). In the statistical analysis, we compared differences between groups for the metabolites; in the OCD we analyzed the correlations with symptom severity, medication status, age, and duration of illness. A significant decrease in Glx, in Glu, and in Gln in the pgACC were observed in the OCD compared to HC. The correlation statistics showed a significant positive correlation between Glu levels and the YBOCS compulsions subscale. The results indicate that patients with OCD present a disturbance in glutamatergic metabolism in the pgACC. The results also demonstrate that these changes correlate with the severity of compulsions.

Histamine intolerance and anxiety disorders: pilot cross-sectional study of histamine intolerance prevalence in cohort of patients with anxiety disorders

Introduction

Histamine intolerance (HI) is a disorder associated with an impairment of ability to metabolize ingested histamine. The incidence of HI in general population is 1-3%. Clinical manifestation of HI contains nonspecific predominantly gastrointestinal, but also extraintestinal symptoms. HI could be primary with genetic predisposition, or secondary with lower activity of diaminooxidase (DAO) without positive genetic screening.

Objectives

This study aims to evaluate the prevalence of HI by patients with anxiety disorders. HI can imitate anxiety symptoms, therefore we predict higher prevalence HI in patients with anxiety disorders than in general population.

Methods

It is observational cross-sectional study on cohort of anxious patients for detecting the prevalence of HI. Patients were screened by scale for histamine intolerance questionnaire. Patients with positive questionnaire were examined for serum DAO and genetically examined.

Results

113 patients fulfilled the HI questionnaire. From this cohort 35.4% (40 subjects) were positive at screening. Biomarkers of HI were screened only in case of positivity in this questionnaire. Table No. 1: Results of our study from cohort with positive screening, 35.4 % (40 subjects).

		Genetic predisposition
		positivity in risk allele	negativity in risk allele	altogether
Serum level of DAO	positive screening (DAO<10 U/ml)	5 (4.4%)primary-genetically determined HI	5 (4.4%)secondary HI	10
	negative screening (DAO≥10 U/ml)	14 (12.4%)	16 (14.2%)	30
	altogether	19	21

Conclusions

This pilot study shows that the prevalence of HI could be higher in group of patients with anxiety disorders than in general population. For further confirmation other studies with control group and larger cohort should be done.

Disclosure

No significant relationships.

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Associated factors of REM sleep without atonia in younger (≤ 50 years) hospitalized psychiatric patients

BACKGROUND

Isolated REM sleep without atonia (RSWA) as a main polysomnograhic feature of REM sleep behaviour disorder (RBD) is thought to be a prodromal or subclinical state of the disease. RSWA/RBD occurence in psychiatric population is much more frequent than in general population but its associated factors are still not known.

METHODS

We invited 88 psychiatry in-patients to undervent video-polysomnography. The visual scoring was focused on RSWA in submentales and flexores digitales superficiales muscles. This parametr was subsequently correlated mainly with age/gender, their medication and mental status.

RESULTS

The RWSA was mostly still in normal range despite the fact, that selected psychiatry patients (≤ 50 years) were taking several classes of psychoactive medication. 3,6% had convincingly RBD, although 35.7% reported rare lifetime occurence of dream-enacting behaviour and 62.8% sporadic nightmares. We found correlation between RSWA and SNRI medication class (p = 0.015), specifically venlafaxine (p = 0.029) as well as quetiapine (p = 0.030). Another significant associated factors were current anxiety (p < 0.001) and depressive symptoms (p = 0.05), but we found no relation between RSWA and given diagnosis.

CONLUCIONS

Isolated RSWA in younger psychiatry patients might be a result of multiple factors, including medication and current mental status but these factors are in most cases not sufficient to manifest RBD.

Epidemiology and Risk Factors of Bipolar Disorder and Schizophrenia in the Conceptualization of the Disease Spectrum

Both disorders are worldwide, lifelong, and recurrent illnesses with periods of exacerbation and partial or full remissions. Lifetime prevalence of schizophrenia and bipolar disorder type I is around 1%. Women and men are affected at proximately equal rates and the typical age of onset is similar. Both disorders also share risk factors showing evidence for impaired prenatal development, such as birth seasonality, abnormal dermatoglyphs and higher incidence of perinatal complications. However, there is evidence for differences in prevalence in geographical isolates, in presence of minor physical abnormalities and possibly also in influence of psychosocial factors, urbanicity and use of cannabis. However, based only on similar epidemiological parameters, it is not possible to assume any degree of continuity between bipolar disorder and schizophrenia. The main evidence for partially shared pathophysiology is given by genetic studies.