Brain age prediction using combined deep convolutional neural network and multi-layer perceptron algorithms.

The clinical applications of brain age prediction have expanded, particularly in anticipating the onset and prognosis of various neurodegenerative diseases. In the current study, we proposed a deep learning algorithm that leverages brain structural imaging data and enhances prediction accuracy by integrating biological sex information. Our model for brain age prediction, built on deep neural networks, employed a dataset of 3004 healthy subjects aged 18 and above. The T1-weighted images were minimally preprocessed and analyzed using the convolutional neural network (CNN) algorithm. The categorical sex information was then incorporated using the multi-layer perceptron (MLP) algorithm. We trained and validated both a CNN-only algorithm (utilizing only brain structural imaging data), and a combined CNN-MLP algorithm (using both structural brain imaging data and sex information) for age prediction. By integrating sex information with T1-weighted imaging data, our proposed CNN-MLP algorithm outperformed not only the CNN-only algorithm but also established algorithms, such as brainageR, in prediction accuracy. Notably, this hybrid CNN-MLP algorithm effectively distinguished between mild cognitive impairment and Alzheimer's disease groups by identifying variances in brain age gaps between them, highlighting the algorithm's potential for clinical application. Overall, these results underscore the enhanced precision of the CNN-MLP algorithm in brain age prediction, achieved through the integration of sex information.

Cerebral cortical thinning in brain regions involved in emotional regulation relates to persistent symptoms in subjects with posttraumatic stress disorder.

A considerable proportion of individuals exposed to trauma experience chronic and persistent posttraumatic stress disorder (PTSD). However, the specific brain and clinical features that render trauma-exposed individuals more susceptible to enduring symptoms remain elusive. This study investigated 112 trauma-exposed participants who had been diagnosed with PTSD and 112 demographically-matched healthy controls. Trauma-exposed participants were classified into those with current PTSD (persistent PTSD, n = 78) and those without (remitted PTSD, n = 34). Cortical thickness analysis was performed to discern group-specific brain structural characteristics. Coping strategies and resilience levels, assessed as clinical attributes, were compared across the groups. The persistent PTSD group displayed cortical thinning in the superior frontal cortex (SFC), insula, superior temporal cortex, dorsolateral prefrontal cortex, superior parietal cortex, and precuneus, relative to the remitted PTSD and control groups. Cortical thinning in the SFC was associated with increased utilization of maladaptive coping strategies, while diminished thickness in the insula correlated with lower resilience levels among trauma-exposed individuals. These findings imply that cortical thinning in brain regions related to coping strategy and resilience plays a vital role in the persistence of PTSD symptoms.

Aberrant Resting-state Functional Connectivity in Complex Regional Pain Syndrome: A Network-based Statistics Analysis.

Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder. Pain catastrophizing, characterized by magnification, rumination, and helplessness, increases perceived pain intensity and mental distress in CRPS patients. As functional connectivity patterns in CRPS remain largely unknown, we aimed to investigate functional connectivity alterations in CRPS patients and their association with pain catastrophizing using a whole-brain analysis approach. Twenty-one patients with CRPS and 49 healthy controls were included in the study for clinical assessment and resting-state functional magnetic resonance imaging. Between-group differences in whole-brain functional connectivity were examined through a Network-based Statistics analysis. Associations between altered functional connectivity and the extent of pain catastrophizing were also assessed in CRPS patients. Relative to healthy controls, CRPS patients showed higher levels of functional connectivity in the bilateral somatosensory subnetworks (components 1~2), but lower functional connectivity within the prefronto-posterior cingulate (component 3), prefrontal (component 4), prefronto-parietal (component 5), and thalamo-anterior cingulate (component 6) subnetworks (p<0.05, family-wise error corrected). Higher levels of functional connectivity in components 1~2 (ß=0.45, p=0.04) and lower levels of functional connectivity in components 3~6 (ß=-0.49, p=0.047) were significantly correlated with higher levels of pain catastrophizing in CRPS patients. Higher functional connectivity in the somatosensory subnetworks implicating exaggerated pain perception and lower functional connectivity in the prefronto-parieto-cingulo-thalamic subnetworks indicating impaired cognitive-affective pain processing may underlie pain catastrophizing in CRPS.

Disturbed insular functional connectivity and its clinical implication in patients with complex regional pain syndrome.

BACKGROUND: Complex regional pain syndrome (CRPS) is characterized by continued amplification of pain intensity. Given the pivotal roles of the insula in the perception and interpretation of pain, we examined insular functional connectivity and its associations with clinical characteristics in patients with CRPS. METHODS: Twenty-one patients with CRPS and 49 healthy controls underwent resting-state functional magnetic resonance imaging. The seed-to-seed functional connectivity analysis was performed for the bilateral insulae and cognitive control regions including the dorsal anterior cingulate cortex (dACC) and bilateral dorsolateral prefrontal cortex (DLPFC) between the two groups. Correlations between altered functional connectivity and clinical characteristics were assessed in CRPS patients. RESULTS: CRPS patients exhibited lower functional connectivity within the bilateral anterior insulae, between the insular and cognitive control regions (the bilateral anterior/posterior insulae-dACC; the right posterior insula-left DLPFC), as compared with healthy controls at false discovery rate-corrected p < 0.05. In CRPS patients, pain severity was associated negatively with the left-right anterior insular functional connectivity (r = -0.49, p = 0.03), yet positively with the left anterior insula-dACC functional connectivity (r = 0.51, p = 0.02). CONCLUSIONS: CRPS patients showed lower functional connectivity both within the bilateral anterior insulae and between the insular and cognitive control regions. The current findings may suggest pivotal roles of the insula in dysfunctional pain processing of CRPS patients.

Complications and safety of the transplanted organ after upper extremity surgery in patients receiving immunosuppressant therapy after solid organ transplantation.

PURPOSE: The purpose of this study was to evaluate the complications and safety of transplanted organs after upper extremity surgery in patients taking immunosuppressants after solid organ transplantation (SOT). METHODS: Seventy-two transplant recipients underwent 99 upper extremity surgeries while on immunosuppressants after SOT at our institution between January 2009 and December 2018. We retrospectively reviewed the clinical data of these patients, including their demographic information and data related to the SOT and upper extremity surgery. RESULTS: Trigger/tendon release (n = 31, 31.3%) was the most frequently performed upper extremity surgery, followed by incision and drainage for an infection (n = 16, 16.2%). Post-operative complications occurred after ten upper extremity operative procedures (10.1%), among which uncontrolled infection after surgery for an infection (n = 4) was the most common. According to the Clavien-Dindo classification, the complications of three surgical procedures were grade I, three were grade II, and four were grade III, and all were treatable. The occurrence rate of the complications was not significantly different between emergent and elective surgery. All transplanted organ-specific indicators did not worsen significantly after emergent or elective upper extremity surgery. CONCLUSIONS: Since the function of the transplanted organ was well-preserved after emergent or elective upper extremity surgery, common upper extremity procedures do not seem to be a worrisome practice for SOT patients. However, when treating hand and upper extremity infections in SOT patients, surgeons should explain the possible need for multiple operations  and the high complication rate.

AGSM Proficiency and Depression Are Associated With Success of High-G Training in Trainee Pilots.

INTRODUCTION: High-gravity (G) training is used to educate trainee pilots about anti-G straining maneuvers (AGSM) in an environment similar to that of a real fighter aircraft, and to enhance their G tolerance. The success or failure of high-G training could be multifactorial, but most previous studies have only focused on the effect of pilots' physical condition.METHODS: A total of 138 male trainee pilots participated in this study. All trainee pilots had received AGSM training from experienced instructors and then underwent centrifuge high-G training. Participants completed questionnaire surveys about body size, lifestyle, self-reported AGSM proficiency, resilience (Connor-Davidson Resilience Scale, CD-RISC), and depression level (Center for Epidemiologic Studies Depression Scale, CES-D).RESULTS: Of the 138 subjects, 100 (72.5%) successfully completed high-G training without experiencing G-induced loss of consciousness (G-LOC) within two trials; these were allocated to the success group. The remaining 38 (27.5%) subjects who completed the training after three or more attempts, or who failed to complete the training at all, were allocated to the failure group. Multivariate analyses revealed that the success of centrifuge training was positively associated with age and self-reported AGSM proficiency, and negatively associated with depression level.DISCUSSION: The success of high-G training was significantly associated with self-reported AGSM proficiency and depression level. Instructors should emphasize the importance of AGSM proficiency and offer practice-based learning to trainee pilots. In addition, they should pay attention to not only trainee pilots' physical condition, but also their psychological status.Yun C, Oh S, Shin YH. AGSM proficiency and depression are associated with success of high-G training in trainee pilots. Aerosp Med Hum Perform. 2019; 90(7):613-617.