Raphe Nuclei Echogenicity and Diameter of Third Ventricle in Schizophrenia Measured by Transcranial Sonography.

Introduction: Serotonergic system hyperactivity at 5-HT2A receptors on glutamate neurons in the cerebral cortex is one of the pathways that is theoretically linked to psychosis. In addition to neurotransmitter dysfunction, volumetric studies have revealed the loss of cortical gray matter and ventricular enlargement in patients with schizophrenia, although there is no case-control research on patients with schizophrenia to evaluate echogenicity of raphe nuclei (RN) or diameter of the third ventricle (DTV). To address these issues, the present study assessed midbrain RN, as the main source of brain serotonin, and DTV, as an index of atrophy, by transcranial sonography (TCS) in a group of patients with schizophrenia. Methods: Thirty patients with schizophrenia and 30 controls were assessed by TCS for RN echogenicity and DTV. TCS was done through a temporal bone window via a phased-array ultrasound using a 2.5 MHz transducer in a depth of 14-16 cm. RN echogenicity was assessed by a semi-quantitative visual scale and DTV was measured in the thalamic plane. Results: Twenty-three patients (76.5%) and 15 controls (50 %) showed hypoechogenicity of RN, which was marginally significant (P=0.06). DTV was on average larger in the experimental group (0.388 cm vs 0.234 cm, P<0.001). Conclusion: Increased DTV in patients with schizophrenia is consistent with previous neuroimaging findings. However, marginally lower echogenicity of midbrain RN on TCS in schizophrenia is a new finding that supports the serotonin hypothesis of schizophrenia. Highlights: 30 patients with schizophrenia and 30 controls were assessed by TCS for RN echogenicity and diameter of the third ventricle (DTV).23 patients (76.5%) and 15(50 %) controls showed hypoechogenicity of RN which was marginally significant (P=0.06)DTV was in average larger in the patient's group (0.388 cm vs 0.234 cm, P<0.001).Increased DTV in the patients with schizophrenia is consistent with previous neuroimaging findingsMarginally lower echogenicity of midbrain RN on TCS in schizophrenia is a new finding that supports the serotonin hypothesis of schizophrenia. Plain Language Summary: Schizophrenia is a disabling psychiatric disorder. Various neurotransmitters have a role in the pathophysiology of schizophrenia including Serotonin and dopamine. This study assessed the echogenicity of raphe nuclei (RN), as the main source of brain serotonin, and the diameter of the third ventricle (DTV), as an index of atrophy, by transcranial sonography (TCS) method in 30 patients with schizophrenia and 30 healthy controls. Based on the results, 23 patients (76.5%) and 15 controls (50%) showed decreased echogenicity of RN. There was a significant difference between the two groups in terms of the echogenicity of RN. Moreover, the DTV diameter was significantly larger in patients compared to controls.

Transcranial sonography in carriers of Gaucher disease.

Background: Glucocerebrosidase (GBA) mutation is the most common genetic risk factor in Parkinson's disease (PD). Transcranial sonography (TCS) shows increased substantia nigra (SN) echogenicity in both idiopathic and genetic forms of PD. The goal of this study was to compare maximal area of SN hyperechogenicity (aSNmax) and diameter of third ventricle (DTV) between GBA mutation carriers and healthy controls. Methods: Twenty-six carriers of GBA mutation and twenty-six healthy controls underwent TCS. The aSNmax and the DTV were measured. Mini-mental status examination (MMSE) and demographic data of the subjects were recorded, too. Results: Mean aSNmax in GBA mutation carriers was significantly higher (0.31 ± 0.06 cm2) than controls (0.16 ± 0.04 cm2). Moreover, DTV was significantly higher in GBA mutation carriers group (3.98 ± 0.90 vs 3.29 ± 0.56 cm). Conclusion: Increased SN echogenicity and increased third ventricle diameter in GBA mutation carriers may be caused by alterations in iron metabolism with reference to their genetic status.

Raphe nuclei echogenicity changes in obsessive-compulsive disorder.

Background: Dysregulation of serotonin system is hypothesized to play the main role in the etiology of obsessive-compulsive disorder (OCD). Transcranial sonography (TCS) is a helpful noninvasive and low-cost tool for the assessment of subcortical brain architectures, mainly basal nuclei, cerebellar central structures, and midbrain. In this study, an ultrasound assessment was performed for a sample of the patients with OCD and healthy control group to evaluate echogenicity of midbrain raphe nuclei (RN). Methods: A total of 35 patients with OCD and 35 healthy controls of similar age and sex entered the study. Semi-structured clinical interview was performed according to the DSM IV-TR criteria to verify OCD. Echogenicity of the midbrain RN was assessed by an experienced neurologist applying TCS. The echogenicity of the 2 groups was compared using chi- square test. SPSS software (version 18, PASW) was used for statistical analysis and p-value of less than 0.05 was considered significant. Results: In this study, 15 OCD patients (42.9%) and 11 (31.4%) controls showed decreased echogenicity of midbrain RN. Also, the results of the chi-square test showed that the midbrain RN echogenicity was not significantly lower in patients with OCD compared to the control group (p= 0.322). Conclusion: Although decreased midbrain RN echogenicity is a characteristic of patients with major depression, it was not shown in OCD patients in this study, which can be explained by the involvement of RN projections rather that RN serotoninergic neurons.