Naomi Kameoka

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism in schizophrenia is associated with age at onset and symptoms

Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor that promotes several functions of neurons and modulates neurotransmissions. It has been reported that there are alterations of BDNF levels in schizophrenic brains and that BDNF gene expressional changes would be responsible for the etiology of schizophrenia. Recent studies have shown that a variation of BDNF gene (Val66Met polymorphism) affects the function of neurons, and is associated with several neurological and psychiatrical disorders. We investigated the relationship between BDNF Val66Met polymorphism and the onset age as well as levels of clinical symptoms in 159 of chronic schizophrenia in-patients diagnosed by DSM-IV. The mean onset ages were 27.5+/-9.5 for BDNF Val/Val, 25.5+/-7.4 for BDNF Val/Met and 22.9+/-6.0 for BDNF Met/Met and this polymorphism was significantly associated with age at onset (P=0.023). The mean Brief Psychiatric Rating Scale scores (BPRS) were significantly different among those three groups (P=0.003). No significant differences were demonstrated comparing the BDNF genotype distributions of positive and negative family history (P=0.21). Our investigation indicates that the BDNF gene Val66Met polymorphism is related to the onset age of schizophrenia and the levels of clinical symptoms that remain after long-term antipsychotic treatment.

Activation of the Prefrontal Cortex during the Wisconsin Card Sorting Test as Measured by Multichannel Near-Infrared Spectroscopy

Background:The Wisconsin Card Sorting Test (WCST) is a neuropsychological test to evaluate the function of the prefrontal cortex (PFC). However, inconsistent results have been reported concerning whether this task activates the PFC symmetrically or asymmetrically. Objectives:To investigate the brain activation in the PFC during the WCST, we examined blood oxygenation changes of healthy subjects by using multichannel near-infrared spectroscopy (NIRS). Methods:Subjects were 32 healthy volunteers, 18 males and 14 females. The WCST was administered using a computerized version, and the hemodynamic changes of the PFC during the WCST were measured by a 24-channel NIRS system.Results:A bilateral increase in oxygenated hemoglobin (oxyHb) was observed in the PFC in 20 subjects during the WCST. However, 5 subjects showed predominant activation on the left side and 3 subjects one on the right side. No oxyHb change was observed in 4 subjects, although they had good performances in the WCST. Conclusions:These results directly confirmed that the PFC was activated during the WCST in vivo by using the optical technique and suggested that the distribution of the activation in the PFC is different among healthy individuals.

1H-magnetic resonance spectroscopy study of glutamate-related abnormality in bipolar disorder

BACKGROUND Previous studies of patients with bipolar disorder (BD) using magnetic resonance spectroscopy (MRS) have shown neurophysiological abnormalities related to the glutamate (Glu)-glutamine (Gln) cycle, membrane turnover, and neuronal integrity, although the results were neither consistent nor conclusive. Recently it has been reported the Gln/Glu ratio is the most useful index, quantifying neuronal-glial interactions and the balance of glutamatergic metabolites In this MRS study, we elucidated the abnormalities of metabolites in a larger sample of patients with BD with a high-field MRI system. METHODS Sixty-two subjects (31 patients with BD and 31 healthy controls [HC]) underwent 3T proton MRS (1H-MRS) of the anterior cingulate cortex (ACC) and left basal ganglia (ltBG) using a stimulated echo acquisition mode (STEAM) sequence. RESULTS After verifying the data quality, 20 patients with BD and 23 age- and gender-matched HCs were compared using repeated-measures analysis of covariance (ANCOVA). Compared to the HC group, the BD group showed increased levels of Gln, creatine (Cr), N-acetyl aspartate (NAA), choline (Cho), and an increased ratio of Gln to Glu in the ACC, and increased Gln and Cho in the ltBG. These findings remained after the participants with BD were limited to only euthymic patients. After removing the influence of lithium (Li) and sodium valproate (VPA), we observed activated glutamatergic neurotransmission in the ACC but not in the ltBG. LIMITATIONS The present findings are cross-sectional and metabolites were measured in only two regions. CONCLUSIONS Our results support a wide range of metabolite changes in patients with BD involved in glutamatergic neurotransmission, membrane turnover, and neuronal integrity. Moreover, the elevation of Gln/Glu ratio suggested that hyperactivity of glutamatergic neurotransmission in the ACC is a disease marker for BD.

Psychiatric symptoms in a patient with isolated adrenocorticotropin deficiency: case report and literature review

We report a 59-year-old man with isolated adrenocorticotropin (ACTH) deficiency. The patient presented with sudden onset of delusions and hallucinations at the age of 54, which resolved gradually without treatment. Subsequently, the patient manifested stereotypy, wandering, hypobulia, and autistic symptoms, and was treated with antipsychotics for 1 year without any improvement. He suffered from neuroleptic malignant syndrome-like symptoms at the age of 59. A thorough endocrine assessment revealed isolated ACTH deficiency. After hydrocortisone supplementation, the physical and psychiatric symptoms improved dramatically. Clinicians should consider this rare disease when diagnosing patients with refractory psychiatric symptoms and unique physical symptoms of isolated ACTH deficiency.

Impaired social cognition in anorexia nervosa patients

Background The purpose of this study was to investigate the characteristics of social cognition in patients with anorexia nervosa (AN). Methods Eighteen female patients with AN (mean age =35.4±8.6 years) and 18 female healthy controls (HC) (mean age =32.8±9.4 years) participated in the study. Their social cognition was assessed with the Social Cognition Screening Questionnaire (SCSQ). Results The results showed that total score of the SCSQ and scores of theory of mind and metacognition were significantly lower in AN group than those in HC group. Moreover, significant differences in theory of mind, metacognition, and total score of the SCSQ remained when the effects of depression, anxiety, and starvation were eliminated statistically. Conclusion These results suggest that patients with AN may have difficulty inferring other people’s intention and also monitoring and evaluating their own cognitive activities. Therefore, these features may explain some aspects of the pathology of AN.

Risk factors for refeeding hypophosphatemia in Japanese inpatients with anorexia nervosa.

OBJECTIVE Refeeding in patients with anorexia nervosa (AN) is associated with a risk of refeeding syndrome, which is a disruption in metabolism with a variety of features including hypophosphatemia. We evaluated the risk factors for refeeding hypophosphatemia (RH) during nutritional replenishment in Japanese patients with AN. METHODS We retrospectively examined clinical data for 99 female inpatients (mean age 30.9 ± 10.7 years; range, 9 - 56 years). RESULTS RH (phosphate < 2.3 mg/dL) occurred within 4.8 ± 3.7 days of hospital admission and was still observed at 28 days after admission in 21 of the 99 cases (21.2%). Oral or intravenous phosphate was given to some patients to treat or prevent RH. Patients with RH had a significantly lower body mass index, were older, and had higher blood urea nitrogen than those without RH. Severe complications associated with RH were recorded in only one patient who showed convulsions and disturbed consciousness at Day 3 when her serum phosphate level was 1.6 mg/dL. CONCLUSIONS The significant risk factors for RH that we identified were lower body mass index, older age, and higher blood urea nitrogen at admission. No significant difference in total energy intake was seen between the RH and no RH groups, suggesting that RH may not be entirely correlated with energy intake. Precisely predicting and preventing RH is difficult, even in patients with AN who are given phosphate for prophylaxis. Thus, serum phosphate levels should be monitored for more than 5 days after admission.

Influence of cognitive function on quality of life in anorexia nervosa patients

The purpose of this study was to elucidate determinants of quality of life (QOL) in anorexia nervosa (AN) patients.

Relationship between social and cognitive functions in people with schizophrenia

Purpose The purpose of the present study was to examine clinical factors related to social function in people with schizophrenia. Patients and methods The participants were 55 stabilized outpatients with schizophrenia. Their mean age was 39.36 (SD =10.65) years. Social function was assessed using the Quality of Life Scale (QLS). Cognitive function was evaluated with the Measurement and Treatment Research to Improve Cognition in Schizophrenia Consensus Cognitive Battery (MCCB). Clinical symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS), the Calgary Depression Scale for Schizophrenia, and the Drug-Induced Extrapyramidal Symptoms Scale. Results Neither the MCCB cognitive domain score nor composite score was correlated with the QLS scores. However, of the 10 MCCB subtests, the Trail Making Test Part A and the Brief Assessment of Cognition in Schizophrenia-Symbol Coding (BACS-SC) scores were positively correlated with the QLS scores. Among clinical variables, especially the PANSS negative syndrome scale score had a strong negative correlation with the QLS scores. Stepwise regression analyses showed that the PANSS negative syndrome scale score was an independent predictor of the QLS scores, and although the BACS-SC score predicted the QLS common objects and activities subscale score, the association was not so strong compared to the PANSS negative syndrome scale score. Conclusion These results indicate that speed of processing evaluated by BACS-SC could predict some aspect of social function but negative symptoms have a much stronger impact on global social function in people with schizophrenia.

Structural equation modeling approach between salience network dysfunction, depressed mood, and subjective quality of life in schizophrenia: an ICA resting-state fMRI study

Purpose Quality of life (QOL) is an important clinical outcome for patients with schizophrenia, and recent studies have focused on subjective QOL. We evaluated the causal relationship between psychosocial aspect of subjective QOL, symptoms, cognitive functions, and salience network (SN) dysfunction in schizophrenia using structural equation modeling (SEM). Patients and methods We performed a cross-sectional study of 21 patients with symptomatically stabilized schizophrenia and 21 age-, sex-, and education level-matched healthy controls who underwent resting-state functional magnetic resonance imaging. We evaluated SN dysfunction in schizophrenia using independent component analysis (ICA). We rated participant psychopathology using the Positive and Negative Syndrome Scale (PANSS), the Brief Assessment of Cognition in Schizophrenia (BACS), and the Calgary Depression Scale for Schizophrenia (CDSS). We rated psychosocial aspect of subjective QOL using the Schizophrenia Quality of Life Scale (SQLS) psychosocial subscale. We applied SEM to examine the relationships between SN dysfunction, PANSS positive and negative scores, CDSS total scores, BACS composite scores, and SQLS psychosocial subscale scores. Results In second-level analysis after group ICA, patient group had significant lower right pallidum functional connectivity (FC) within the SN than the controls did (Montreal Neurological Institute [MNI] [x y z] = [22 −2 −6]) (p = 0.027, family-wise error [FWE] corrected). In SEM, we obtained a good fit for an SEM model in which SN dysfunction causes depressed mood, which in turn determines psychosocial aspect of subjective QOL (chi-squared p = 0.9, root mean square error of approximation (RMSEA) < 0.001, comparative fit index [CFI] = 1.00, and standardized root mean square residual [SRMR]= 0.020). Conclusion We found a continuous process by which SN dysfunction causes depressed moods that determine psychosocial aspect of subjective QOL in schizophrenia. This is the first report that offers a unified explanation of functional neuroimaging, symptoms, and outcomes. Future studies combining neuroimaging techniques and clinical assessments would elucidate schizophrenia’s pathogenesis.