Dysfunctional information processing during an auditory event-related potential task in individuals with Internet gaming disorder.

Internet gaming disorder (IGD) leading to serious impairments in cognitive, psychological and social functions has gradually been increasing. However, very few studies conducted to date have addressed issues related to the event-related potential (ERP) patterns in IGD. Identifying the neurobiological characteristics of IGD is important to elucidate the pathophysiology of this condition. P300 is a useful ERP component for investigating electrophysiological features of the brain. The aims of the present study were to investigate differences between patients with IGD and healthy controls (HCs), with regard to the P300 component of the ERP during an auditory oddball task, and to examine the relationship of this component to the severity of IGD symptoms in identifying the relevant neurophysiological features of IGD. Twenty-six patients diagnosed with IGD and 23 age-, sex-, education- and intelligence quotient-matched HCs participated in this study. During an auditory oddball task, participants had to respond to the rare, deviant tones presented in a sequence of frequent, standard tones. The IGD group exhibited a significant reduction in response to deviant tones compared with the HC group in the P300 amplitudes at the midline centro-parietal electrode regions. We also found a negative correlation between the severity of IGD and P300 amplitudes. The reduced amplitude of the P300 component in an auditory oddball task may reflect dysfunction in auditory information processing and cognitive capabilities in IGD. These findings suggest that reduced P300 amplitudes may be candidate neurobiological marker for IGD.

Functional neuroanatomical correlates of the executive clock drawing task (CLOX) performance in Alzheimer's disease: a FDG-PET study.

The executive clock drawing task (CLOX) is one of the widely used clock drawing tests (CDTs) and is composed of CLOX1, an unprompted CDT, and CLOX2, a simple copying CDT. Although it is conceptually believed that CLOX1 is sensitive to both executive function and constructional ability while CLOX2 reflects only constructional ability, there are still lack of studies on the functional neuroanatomical substrates of CLOX1 and 2 performances. This study aimed to identify the functional brain correlates of CLOX1 and 2 performances in patients with Alzheimer's disease (AD). CLOX was administered to 139 AD patients and 50 normal controls, and regional cerebral glucose metabolism (rCMglc) was measured by (18)F-fluoro-2-deoxy-glucose positron emission tomography. Correlations between CLOX scores and rCMglc were examined on a voxel-by-voxel basis in AD patients. For the overall AD group, significant positive correlations between CLOX1 and rCMglc were found in the bilateral temporo-parietal and left middle frontal regions, while CLOX2 was correlated with rCMglc of the bilateral temporo-parietal regions. Additional subgroup analysis showed that CLOX1 was associated with the left temporal metabolism in less severe AD, and with the right temporo-parietal metabolism in more severe AD. In contrast, CLOX2 was correlated with rCMglc of the diffuse right fronto-temporo-parietal regions in more severe AD, but not with any rCMglc in less severe AD. This is the first neuroimaging study on the functional neuroanatomical correlates of CLOX performances in AD. Given the relationships between specific cognitive performances and regional brain functions, the findings probably support the notion that CLOX1 demands not merely visuospatial functions but also executive control, while CLOX2 depends mainly on visuospatial ability. Our results also indicate that each CLOX performance depends on very different functional brain regions according to AD clinical stages.

Submuscular periareolar approach to augmentation mammoplasty in Korean women.

Augmentation mammoplasty can be approached by various methods according to the type of implant and implantation site depending on the status of the patient or surgeon's preference. The advantage for submuscular placement is based on problems associated with subglandular placement, especially capsular contracture and sensory changes in the nipple, and interference with the interpretation of mammograms is avoided. There are fewer complications such as hematoma, infection, and extrusion of the implant with submuscular dissection and relatively avascular, minimal sensory changes in the nipple compared with subglandular approach. The submuscular periareolar approach to augmentation mammoplasty was first described in the 1970s. This approach provides easy access to both the subglandular and subpectoral planes. It also provides a central point of access for creation of the implant pocket, which allows for easier and more accurate dissection in all diameters. The resultant periareolar scar is usually minimal with less injury to breast parenchyme and eventual biopsy or mastectomy incision to be performed through or around the areola. During the period of March 1999 to January 2000, 19 cases of who received submuscular periareolar augmentation mammoplasty under general anesthesia resulted in favorable scars with accurate access to pocket margin, easier dissection, and less bleeding compared with submuscular transaxillary augmentation mammoplasty. In our experience with the submuscular periareolar approach to breast augmentation it was highly versatile, safe, and less painful; postoperative hematoma incidence was greatly reduced and breast tissue injury was minimized.