The objective assessment of the effects on cognition functioning among military personnel exposed to hypobaric-hypoxia: A pilot fMRI study.

OBJECTIVE: To identify regions of the brain affected during cognitive working memory during tasks to assess attention, planning and decision making among military aviation personnel who have chronic intermittent exposure to high altitude environment. METHOD: A case-control study was conducted in the Universiti Putra Malaysia among eight military personnel, four of whom had chronic intermittent exposure to high altitude training. They were divided into two groups, chronic intermittent exposure group (CE) (n=4) and a control group (n=4). They underwent a task-based functional magnetic resonance imaging (fMRI) that utilised spatial working memory task to objectively evaluate the neural activation in response to the Tower of London paradigm. Each correct answer was given a score of one and the maximum achievable score was 100%. RESULTS: A consecutive dichotomised group of CE (4/8) and control (4/8) of age-matched military aviation personnel with a mean age of 37.23±5.52 years; showed significant activation in the right middle frontal gyrus (MFG). This in turn was positively correlated with response accuracy. A significant difference in the response accuracy was noted among both the groups at p<0.05. CONCLUSION: At the minimum results of power analysis of this preliminary fMRI study, our group of aviation personnel who had chronic intermittent exposure to hypobaric hypoxic environment, did not have any significant decrease in cognitive function namely attention, decision-making and problem solving compared to controls during a working memory task.

18F-FDG PET/CT as a potential predictor of survival in patient with oesophageal cancer: a preliminary result.

AIMS: A study was undertaken to investigate the value of pretreatment PET-CT in predicting survival in patients with oesophageal cancer (OC). METHODS: Between June 2010 and December 2011, 18 consecutive OC patients median (61.00 ± 12.07 years) with median survival of 7.5 month had a pretreatment PET-CT scan. Staging of the disease was made in accordance to the American Joint Committee on Cancer staging system (7th edition) and grouped as stage I-IIA and stage IIB-IV. Maximum standardized uptake value (SUVmax), size of a primary tumour and the presence of fluorodeoxyglucose (FDG)-avid lymph nodes were evaluated for all patients. Survival was analysed using the Kaplan-Meier product limit method and Cox proportional hazards regression model. RESULTS: PET-CT stages I-IIA and IIB-IV had a 1-year survival of 50% and 25%, respectively. Patient with size of primary tumour (<4.5 cm) had significantly (p < 0.036) better survival than those with large size (>4.5 cm). Multivariate Cox regression analysis showed that SUVmax of >5.5 in the primary tumour [hazard ratio (HR) 23.017; 95% confidence interval, p = 0.038] and the presence of FDG-avid lymph node (HR 1.248; p = 0.028) were strongly predictive of poor overall survival on multivariate analysis. CONCLUSION: Pretreatment 18F-FDG PET-CT SUVmax of a primary tumour and the presence of FDG-avid lymph nodes independently predict survival in patients with oesophageal carcinoma which may potentially be used as surrogate markers for prognostic and therapeutic purposes.