Bariatric surgery for hypothalamic obesity in craniopharyngioma patients: a retrospective, matched case-control study

Context: Craniopharyngioma is a sellar tumor associated with high rates of pituitary deficiencies (similar to 98%) and hypothalamic obesity (similar to 50%).Objective: This work aims to determine the efficacy regarding long-term weight loss after bariatric surgery in obese craniopharyngioma patients with hypothalamic dysfunction.Methods: This retrospective, case-control, multicenter, international study included obese craniopharyngioma patients (N=16; of whom 12 are women) with a history of bariatric surgery (12 Roux-en-Y gastric bypass, 4 sleeve gastrectomy; median age 21 years [range, 15-52 years], median follow-up 5.2 years [range, 2.0-11.3 years]) and age/sex/surgery/body mass index-matched obese controls (N=155). Weight loss and obesity-related comorbidities up to 5 years after bariatric surgery were compared and changes in hormonal replacement therapy evaluated.Results: Mean weight loss at 5-year follow-up was 22.0% (95% CI, 16.1%-27.8%) in patients vs 29.5% (95% CI, 28.0%-30.9%) in controls (P=.02), which was less after Roux-en-Y gastric bypass (22.7% [16.9%-28.5%] vs 32.0% [30.4%-33.6%]; P=.003) but at a similar level after sleeve gastrectomy (21.7% [-1.8% to 45.2%] vs 21.8% [18.2%-25.5%]; P=.96). No major changes in endocrine replacement therapy were observed after surgery. One patient died (unknown cause). One patient had long-term absorptive problems.Conclusion: Obese patients with craniopharyngioma had a substantial mean weight loss of 22% at 5-year follow-up after bariatric surgery, independent of type of bariatric surgery procedure. Weight loss was lower than in obese controls after Roux-en-Y gastric bypass. Bariatric surgery appears to be effective and relatively safe in the treatment of obese craniopharyngioma patients.Development and application of statistical models for medical scientific researc

Center of mass, spin supplementary conditions, and the momentum of spinning particles

We discuss the problem of defining the center of mass in general relativity and the so-called spin supplementary condition. The different spin conditions in the literature, their physical significance, and the momentum-velocity relation for each of them are analyzed in depth. The reason for the non-parallelism between the velocity and the momentum, and the concept of "hidden momentum", are dissected. It is argued that the different solutions allowed by the different spin conditions are equally valid descriptions for the motion of a given test body, and their equivalence is shown to dipole order in curved spacetime. These different descriptions are compared in simple examples.Comment: 45 pages, 7 figures. Some minor improvements, typos fixed, signs in some expressions corrected. Matches the published version. Published as part of the book "Equations of Motion in Relativistic Gravity", D. Puetzfeld et al. (eds.), Fundamental Theories of Physics 179, Springer, 201