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Cortisol dysregulation has been proposed to be involved in depression. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation associated with major depressive disorder (MDD) was previously reported to be higher in the elderly. Furthermore, insulin resistance and the prevalence of type 2 diabetes are known to increase with aging. The aim of the present study was to determine whether a relationship existed between plasma cortisol levels following the dexamethasone/corticotrophin-releasing hormone (DEX/CRH) test and insulin resistance evaluated by the homeostasis model assessment of insulin resistance (HOMA-R) in elderly MDD subjects. Fifteen unmedicated MDD inpatients and 17 age- and sex-matched healthy controls participated in this study. After overnight fasting, blood samples were collected to measure plasma glucose and insulin concentrations, estimate HOMA-R, and perform the DEX/CRH test to evaluate HPA axis function. The value of the area under the time curve of plasma cortisol concentrations (CortAUC) and peak cortisol values (Cortpeak) following the administration of DEX/CRH both correlated with HOMA-R in MDD group. In contrast, neither CortAUC nor Cortpeak correlated with HOMA-R in controls. This is the first study to directly demonstrate the relationship between HPA axis dysregulation assessed with the DEX/CRH test and the index of insulin resistance estimated as HOMA-R in elderly MDD patients.

Social cognition is an important determinant of functional impairment in schizophrenia, but its relationship with the prefrontal functional abnormalities associated with the condition is still unclear. The present study aimed to explore the relationship between social cognition and prefrontal function in patients with schizophrenia using 52-channel near-infrared spectroscopy (NIRS). Twenty-six patients with schizophrenia and 26 age-, gender-, and intelligence quotient-matched healthy controls (HCs) participated in the study. Hemodynamic responses in the prefrontal and superior temporal cortical regions were assessed during a working memory task using NIRS. Social cognition was assessed using the Social Cognition Screening Questionnaire (SCSQ). The observed hemodynamic responses were significantly reduced in the lateral prefrontal cortex (PFC), the frontopolar cortex, and temporal regions in subjects with schizophrenia compared to HCs. Additionally, lateral PFC hemodynamic responses assessed during the working memory task demonstrated a strong positive correlation with the SCSQ theory of mind (ToM) subscale score even after controlling for working memory performance. These results suggest that ToM integrity is closely related to lateral PFC functional abnormalities found in patients with schizophrenia. In addition, this study provides evidence to suggest that NIRS could be used to identify biomarkers of social cognition function in subjects with schizophrenia.

Our new finding on magnetic resonance imaging (MRI) of Machado-Joseph disease (MJD) patients indicates degeneration of the lenticular fasciculus (LF), a major outflow of the internal segment of the globus pallidus (GPi). We examined the clinical, radiological, and autopsy findings of one MJD patient and then retrospectively reviewed the MRI images of another 15 patients looking for a similar abnormal signal intensity. The significance of the clinicoradiological correlation of the MRI finding was confirmed by examining the MRI images of 130 control subjects. In the autopsy case, abnormal linear high intensity areas were observed along the bilateral medial margins of the internal segments of the GPi on T2 weighted, FLAIR, and proton density images, but not on T1 weighted images. Pathologically, this abnormal signal intensity was consistent with degeneration of the LF. The same finding was also observed in the other 15 patients. In two patients the finding was only unilaterally observed. No control subject showed this MRI finding. In MJD patients, abnormal linear high intensity areas indicating LF degeneration are usually observed along the medial margin of the GPi on T2 weighted, FLAIR, and proton density sequences. To our knowledge, this MRI finding has not previously been described.T he lenticular fasciculus (LF), which is a major outflow of the internal segment of the globus pallidus (GPi), is severely degenerated [1][2][3] in Machado-Joseph disease (MJD), which is one of the most prevalent familial cerebellar degenerative diseases in Japan. 4 We found in MJD patients that abnormal linear high intensity is observed on T2 weighted magnetic resonance imaging (MRI) along the medial margin of the internal segment of the GPi. This study was carried out to confirm that this MRI finding indicates LF degeneration. An autopsied case of MJD was clinicopathologically examined and then MRI images of other MJD cases were reviewed. The clinicoradiological relationship was examined and the significance of the MRI finding confirmed by examining MRI images of control subjects. METHODSPatients and control subjects There were 16 MJD patients (table 1). The diagnosis of MJD was made based on clinical presentation, positive family history for autosomal dominant cerebellar degeneration, and DNA analysis. The control subjects consisted of 130 consecutive patients (aged between 12 and 77 years old; mean age 51.7 years), who presented at our hospital during 2003 because of headache or dizziness, but showed no neurological abnormality other than exaggerated deep tendon reflexes. Molecular analysis of the MJD1 geneMolecular analysis of the MJD1 gene was performed as described by Kawaguchi and colleagues. 5MRI examination MRI examinations were performed using two different systems. A 1.0 T system (SMT-100X, Shimadzu, Kyoto, Japan) was used until April 2000, and a 1.5 T system (Magnetom Symphony, Siemens, Munich, Germany) thereafter. Standard brain examinations were carried out using T1 and T2 sequences with contiguous 10 mm thick slices. ...

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