Qiaozhen Chen

PET imaging reveals brain functional changes in internet gaming disorder

BackgroundInternet gaming disorder is an increasing problem worldwide, resulting in critical academic, social, and occupational impairment. However, the neurobiological mechanism of internet gaming disorder remains unknown. The aim of this study is to assess brain dopamine D2 (D2)/Serotonin 2A (5-HT2A) receptor function and glucose metabolism in the same subjects by positron emission tomography (PET) imaging approach, and investigate whether the correlation exists between D2 receptor and glucose metabolism.MethodsTwelve drug-naive adult males who met criteria for internet gaming disorder and 14 matched controls were studied with PET and 11C-N-methylspiperone (11C-NMSP) to assess the availability of D2/5-HT2A receptors and with 18F-fluoro-D-glucose (18F-FDG) to assess regional brain glucose metabolism, a marker of brain function. 11C-NMSP and 18F-FDG PET imaging data were acquired in the same individuals under both resting and internet gaming task states.ResultsIn internet gaming disorder subjects, a significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems. Dysregulation of D2 receptors was observed in the striatum, and was correlated to years of overuse. A low level of D2 receptors in the striatum was significantly associated with decreased glucose metabolism in the orbitofrontal cortex.ConclusionsFor the first time, we report the evidence that D2 receptor level is significantly associated with glucose metabolism in the same individuals with internet gaming disorder, which indicates that D2/5-HT2A receptor-mediated dysregulation of the orbitofrontal cortex could underlie a mechanism for loss of control and compulsive behavior in internet gaming disorder subjects.

Alexithymia and Personality Disorder Functioning Styles in Paranoid Schizophrenia

Objectives: Personality disorder functioning styles might contribute to the inconclusive findings about alexithymic features in schizophrenia. We therefore studied the relationship between alexithymia and personality styles in paranoid schizophrenia. Methods: We administered the Chinese versions of the Toronto Alexithymia Scale (TAS-20), the Parker Personality Measure (PERM), the Positive and Negative Syndrome Scale as well as the Hamilton Anxiety and Depression Scales to 60 paranoid schizophrenia patients and 60 healthy control subjects. Results: Patients scored significantly higher on the Positive and Negative Syndrome Scale, TAS ‘difficulty identifying feelings’ and ‘difficulty describing feelings’, Hamilton Depression Scale and most PERM scales. In healthy subjects, difficulty identifying feelings predicted the PERM ‘dependent’ style, and the Hamilton Anxiety Scale predicted difficulty identifying feelings and difficulty describing feelings. In patients, difficulty identifying feelings nonspecifically predicted all the PERM scales; by contrast, the PERM ‘antisocial’ style predicted difficulty identifying feelings, the ‘avoidant’ style predicted difficulty describing feelings, and the ‘histrionic’ and ‘paranoid (–)’ styles predicted ‘externally oriented thinking’. Conclusions: Personality disorder functioning styles – instead of anxiety, depression, psychotic symptoms or disease duration – were specifically associated with alexithymia scales in our patients, which sheds light on a cognitive-personological substrate in paranoid schizophrenia on the one hand, and calls for a longitudinal design to discover how premorbid or postacute residual personality styles contribute to the sluggish disorder on the other.

Molecular imaging in patients with mood disorders: a review of PET findings

Mood disorders are chronic, recurrent psychiatric disorders with high morbidity rates that cause severe disability. Researchers have used molecular imaging extensively in studies of mood disorders. In this article, we concisely and selectively review the major findings of positron emission tomography studies of patients with mood disorders. Specifically, we describe findings from cerebral blood flow, cerebral glucose/oxygen metabolism, and radioligand studies in both cross-sectional and longitudinal investigations. Patients with mood disorders have mood-correlated regional metabolism changes and molecular abnormalities in several neurotransmitter systems. Although the findings of these studies are not completely consistent and confounding factors, including drug effects and specific methodology, should be strictly controlled, these results reveal the pathophysiology of mood disorders and aid the development of novel treatment approaches for mood disorders. Future positron emission tomography research will benefit greatly from the development of better radioligands to simultaneously identify multiple neurotransmitter systems in the specific brain region and the integration of more detecting methods in specifying the neurobiological predictors of treatment response in patients with mood disorders. Understanding the molecular mechanisms in underlying mood disorders will result in aetiological diagnosis and individualization of treatment of these disorders.

Effect of stripe order on the vortex phase transition in La1.44Nd0.4Sr0.16CuO4 films

The vortex phase transition in La1.44Nd0.4Sr0.16CuO4 epitaxial films with different thicknesses under a compressive strain were studied systematically by measuring the current?voltage (IV) characteristics in magnetic fields perpendicular to the CuO2 planes. For a strongly compressed thin film, in which the static stripe order is destroyed, the IV curves show a good three-dimensional (3D) vortex glass (VG) scaling collapse in various magnetic fields, indicating a 3D VG phase transition. By applying the standard scaling procedure to the data of a strain-released thick film with static stripe order, neither a 3D nor a quasi-2D VG model works well. Further investigation shows that, in order to achieve a good scaling collapse, the Kosterlitz?Thouless correlation length should be used for the isothermals above Tg. The scaling of isothermals below Tg can also be optimized if the VG correlation length and adjusted static critical exponent ? are used with D = 2 only, indicating that a quasi-2D VG phase might exist. Our findings reveal that the nature of the vortex phase transition is completely altered in the presence of the stripe order.

18F-FDG PET Study Reveals Brain Functional Changes During Attention in Rats

Attentional impairments are seen in many clinical syndromes, including attention deficit hyperactivity disorder, schizophrenia, and Alzheimer disease. Understanding the mechanism of attention can be helpful for the diagnosis and treatment of these diseases. The aim of this study was to assess brain glucose metabolic changes in a rat model of attention. Methods: Small-animal PET studies were performed at 4 stages. Statistical parametric mapping was used for image analysis. Results: Increased 18F-FDG uptake was found in the lateral hypothalamic area and left accumbens nucleus in the learning condition. Under the attentive condition, increased 18F-FDG uptake was observed in the right retrosplenial cortex but 18F-FDG uptake was decreased in the right medial geniculate nucleus. 18F-FDG uptake change in the right retrosplenial cortex was negatively correlated with correct latency of behavior performance. Conclusion: 18F-FDG small-animal PET imaging provided novel findings on attention-related glucose metabolic changes, which were significantly correlated with the behavior performance in this rat model.

Frightening Music Triggers Rapid Changes in Brain Monoamine Receptors: A Pilot PET Study

Frightening music can rapidly arouse emotions in listeners that mimic those from actual life-threatening experiences. However, studies of the underlying mechanism for perceiving danger created by music are limited. Methods: We investigated monoamine receptor changes induced by frightening music using 11C-N-methyl-spiperone (11C-NMSP) PET. Ten healthy male volunteers were included, and their psychophysiologic changes were evaluated. Results: Compared with the baseline condition, listening to frightening music caused a significant decrease in 11C-NMSP in the right and left caudate nuclei, right limbic region, and right paralimbic region; a particularly significant decrease in the right anterior cingulate cortex; but an increase in the right frontal occipital and left temporal lobes of the cerebral cortex. Conclusion: Transient fright triggers rapid changes in monoamine receptors, which decrease in the limbic and paralimbic regions but increase in the cerebral cortex.

Fluoxetine-responsive depression in a Chinese cerebrotendinous xanthomatosis

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive, lipid storage disorder which is extremely rare in the Chinese population. It is characterized by progressive neurologic dysfunction and enlargement of tendon xanthomas, and is often accompanied with neuropsychiatric symptoms. Few reports are available regarding depression and antidepressant medication in CTX patients. Here, we report a Chinese case of CTX associated with fluoxetine-responsive major depression.

Adult asymptomatic case of Dandy–Walker syndrome associated with bipolar disorder

To the Editor: Dandy–Walker syndrome is a rare congenital brain developmental malformation (1) that on structural imaging is typically characterised by hypoplasia of the cerebellar vermis and dilatation of the fourth ventricle with a posterior fossa cyst. It invariably results in hydrocephalus and clinically, symptoms are usually observed during the prenatal period or in early infancy. Dandy–Walker syndrome can also occur in association with other brain or systemic malformations, such as corpus callosum agenesis, aqueductal stenosis, syringomyelia, neurocutaneous melanosis andmalformations of the heart, face, kidney, limbs, fingers and toes. Recently, Papazisis et al. (2) reported a case of a young man with early onset schizophrenia comorbid with obsessive– compulsive disorder and aDandy–Walker variant.However, to date, Dandy–Walker syndrome has not been described in association with bipolar disorder, and therefore we briefly report a case of asymptomatic of Dandy–Walker syndrome in the context of bipolar II disorder. A 40-year-old man, admitted to hospital because of a severe depressive episode, developed after 1 month of antidepressant treatment with venlafaxine, hyperactive and elated mood that earn him the diagnosis of bipolar II disorder and led to the prescription of a mood stabiliser. On admission, his mental status examination revealed psychomotor retardation and depressed mood, but no delusional ideas or hallucinations. His manner was friendly and cooperative and he remained insightful. His main clinical complaints were anhedonia, insomnia and anorexia. A complete physical and neurological examination was unremarkable. Exploration of the patient’s developmental history did not reveal anything unusual and there was no history of familial psychiatric illness. After providing informed consent, he agreed to blood tests that assessed liver, renal and glandula thyreoidea function and gonadal hormone levels; an electrocardiogram; an echocardiograph; an abdominal ultrasound and a 3D magnetic resonance imaging (MRI) scan. He was prescribed lithium, seroquel and sertraline and after 2-week treatment underwent neuropsychological assessment that included the Wechsler Adult Intelligence Scale-Chinese Revised and Wechsler Memory Scale Revised in China (WMS-RC). After careful examination, no significant abnormalities were detected except adiposis hepatica, chronic cholecystitis and gallstones. The patient’s brain function was within the average range with full-scale IQ scores 98 and 101 scores for WMS-RC. Interestingly, the MRI scan of the patient showed hypoplasia of the cerebellar vermis, dilatation of the fourth ventricle and enlargement of the rest of the ventricular system with hydrocephalus (Fig. 1A–C). These findings showed that the patient had Dandy–Walker syndrome. To our knowledge, this is the first recorded case of bipolar disorder in an adultmanwithDandy–Walker syndrome. Clinically it is characterised by mental retardation, cerebellar ataxia and symptoms of hydrocephalus. Symptoms, which often occur in early infancy, include slow motor development and rapid increase in head circumference with abnormal bulging at the back of the skull. In older children, symptoms of increased intracranial pressure such as vomiting, irritability, convulsions and signs of cerebellar dysfunction such as unsteadiness, lack of muscle coordination or jerky movements of the eyes may occur. There may also be problems with the nerves that control the eyes, face and neck as well as abnormal breathing patterns. This patient is considered to have adult asymptomatic Dandy–Walker syndrome, as none of the aforementioned symptoms were experienced. Adult asymptomatic presentation of Dandy–Walker syndrome is extremely rare. Investigation suggested that preservation of the cortical cytoarchitecture as well as the paucity of additional neurodevelopmental changes may explain the absence of clinical expression (3). Judging from the patients’ symptoms, the comorbidity of Dandy–Walker syndrome and bipolar disorder is likely to be coincidental. However, evidence for the involvement of cerebellar abnormalities in the pathophysiology of bipolar disorder may suggest a direct causal relationship. The cerebellum plays an important role in cognition and psychiatric disorders (4) and, several morphometry neuroimaging studies have identified significantly smaller vermal subregion volume in bipolar disorder subjects, especially those that have experienced multiple episodes (5–6). Moreover, Lauterbach (7) reported that cerebellar lesions may induce mania and diminished cerebellar outputs may result in abnormal neuronal oscillation in bipolar disorders, especially in rapidcycling bipolar disorder. In addition, some brain metabolites such as N-acetylaspartate (NAA) and creatine (Cr) have been found to be approximately 8% lower for children with a mood disorder than healthy children within the cerebellar vermis (8). In sum, cerebellar abnormalities may be a risk factor for bipolar disorder, while recurrent episodes perhaps aggravate cerebellar atrophy. Clearly, further examination of this brain region is needed along with heightened awareness of this potential significance in the pathophysiology of mood.

Neural correlates of the popular music phenomenon: evidence from functional MRI and PET imaging

PurposeMusic can induce different emotions. However, its neural mechanism remains unknown. The aim of this study was to use functional magnetic resonance imaging (fMRI) and position emission tomography (PET) imaging for mapping of neural changes under the most popular music in healthy volunteers.MethodsBlood-oxygen-level-dependent (BOLD) fMRI and monoamine receptor PET imaging with 11C-N-methylspiperone (11C-NMSP) were conducted under the popular music Gangnam Style and light music A Comme Amour in healthy subjects. PET and fMRI images were analyzed by using the Statistical Parametric Mapping software (SPM).ResultsSignificantly increased fMRI BOLD signals were found in the bilateral superior temporal cortices, left cerebellum, left putamen and right thalamus cortex. Monoamine receptor availability was increased significantly in the left superior temporal gyrus and left putamen, but decreased in the bilateral superior occipital cortices under the Gangnam Style compared with the light music condition. Significant positive correlation was found between 11C-NMSP binding and fMRI BOLD signals in the left temporal cortex. Furthermore, increased 11C-NMSP binding in the left putamen was positively correlated with the mood arousal level score under the Gangnam Style condition.ConclusionPopular music Gangnam Style can arouse pleasure experience and strong emotional response. The left putamen is positively correlated with the mood arousal level score under the Gangnam Style condition. Our results revealed characteristic patterns of brain activity associated with Gangnam Style, and may also provide more general insights into the music-induced emotional processing.

Primary central nervous system lymphoma mimicking recurrent depressive disorder: A case report

Primary central nervous system lymphoma (PCNSL) is a rare subtype of extranodal non-Hodgkin lymphoma, which is limited to the central nervous system. Few studies are available reporting psychiatric symptoms as the initial and dominant presentation of PCNSL. The current study reports the case of a PCNSL patient with a history of major depressive disorder and coexisting rheumatoid arthritis (treated with methotrexate), who initially presented with recurrent depressive disorder that showed no response to antidepressant drug therapy. Magnetic resonance imaging revealed multiple mass lesions in the brain, and pathological examination of the biopsy confirmed the diagnosis of diffuse large B cell lymphoma of the central nervous system. The present case demonstrated that PCNSL may affect mood in the early stages of the disease and thus, clinicians must be aware of this manifestation in patients with depressive disorder co-existing with immunosuppressive conditions, as early detection and appropriate treatment are important prognostic factors for PCNSL.