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We conclude that GES is more effective in improving long-term GI symptoms and costs, and decreasing use of healthcare resources than intensive medical therapy, in this sample of patients with the symptoms of GP followed for 3 years. Certain patients with GP form a high-risk group in terms of costs, quality of life, morbidity and mortality.

Gastric electrical stimulation (GES) is effective to improve symptoms of nausea and vomiting in most patients, but very little is known about the effect of varying stimulation parameters. We analysed stimulation parameters in a pilot study of 22 patients (12 idiopathic, four diabetic and four postsurgical) with drug-refractory gastroparesis who did not respond optimally to initial settings. Patients underwent high-frequency/low energy GES using identical initial stimulation parameters: 5 mA of current, 330 micros pulse width, 14 Hz for 0.1 s on and 5.0 s off. Due to lack on optimal response, 22 patients underwent alteration of an algorithm using stimulation parameters. At follow-up (mean of 4.3 years) a dose-response relationship for charge, power and energy were compared with baseline for the whole group and for each diagnostic subgroup by anova data are reported as mean +/- SE. Based on the mean of individual dose-response curves, differences in data are charge, current per pulse and energy per pulse were noted for the whole group at follow up vs baseline. The subgroup of patients with postsurgical gastroparesis required the most energy using the algorithm. In conclusion, an algorithmic approach to identify optimal stimulation parameters in GES for individual patients is associated with symptom improvement. Also, certain subgroups appear to have different energy parameters. Based on this preliminary data, the use of an algorithm for some patients with GES is feasible and may have potential for clinical application. A randomized-controlled trial of different stimulation parameters for GES seems warranted.

A microelectrode technique has been developed to enable the study of stress-generated potentials (SGP) in bone to a spatial resolution of 5 micrometers. The technique has been used to measure the electrical potentials as a function of bone micromorphology in four-point bending. Electric fields ranging from 30 to 10(3) times greater than is measured by conventional macroscopic methods have been discovered at the Haversian canals for human and bovine cortical bone. The amplitude and direction of the electric field in the osteons depend specifically upon the amplitude and the sign (i.e., compression or tension) of the stress. The implications of this finding with regard to the origin of SGP and their possible physiological significance are considered.

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GES improves exocrine pancreatic release, effects autonomic control, and improves GI symptoms, suggesting a possible role for GES in the treatment of pancreatic insufficiency associated with gastroparesis.

GES with appropriate parameters inhibits gastric motility, and the effects are reproducible. The GES method optimized to inhibit gastric motility reduces food intake in healthy dogs and may have a therapeutic potential for treating obesity.

. Gastric electrical stimulation parameter dependently alters ventral medial hypothalamic activity and feeding in obese rats. Am J Physiol Gastrointest Liver Physiol 301: G912-G918, 2011. First published August 18, 2011 doi:10.1152/ajpgi.00487.2010.-Gastric electrical stimulation (GES) has been used to treat obesity with unclear mechanisms and limited parameter ranges. This study explores effects of GES parameters on ventral medial hypothalamic (VMH) activity, feeding, and body weight in diet-induced obese (DIO) rats. For experiment 1, discharge rates were recorded in 39 gastric distension-responsive (GD-R) neurons in 12 DIO rats. Basal rates were compared with rates under GES using varied pulse amplitudes, widths, frequencies, and train-on times. For experiment 2, a crossover experiment in 16 DIO rats measured food intake and weight effects of GES pulse width, the parameter with the steepest neuronal response gradient in experiment 1. Treatments were sham and 0.5-, 2.0-, and 5.0-ms pulse GES. In experiment 1, 11 of 13 GES parameter sets tested produced significantly (P Ͻ 0.05) altered discharge rates of GD-R neurons. Increases in pulse amplitude (P Ͻ 0.05) and width (P Ͻ 0.0001) produced significant upward linear trends in response over the range tested, with the trend being strongest for pulse width. In experiment 2, over 4 days of 0.5-, 2.0-, and 5.0-ms GES treatment, food intake was 9.6% (P Ͻ 0.05), 21.0% (P Ͻ 0.0001), and 47.3% (P Ͻ 0.0001) lower than under sham-GES, whereas body weight changes were 0.7 (P ϭ 0.48), 2.2 (P Ͻ 0.05), and 3.5 (P Ͻ 0.002) percentage points lower, respectively. We concluded that GES pulse width increases had the largest effect on VMH neuronal activity, and these effects were paralleled by pulse width-dependent reductions in food intake and body weight. Lengthening pulse width beyond the range used in prior clinical studies may be critical to making GES a viable obesity treatment. ventromedial hypothalamus; gastric distension; food intake; obesity THE PREVALENCE OF OBESITY is rising worldwide, and the majority of adults in the United States and many developed countries are overweight or obese. It is estimated that 1.6 billion adults worldwide are overweight [body mass index (BMI) Ͼ 25] and 400 million are obese (BMI Ͼ 30) (1). Obesity and its comorbidities have been estimated to claim over 400,000 lives and cost over $100 billion annually in the US alone (11). Obesity is associated with higher rates of disability and all-cause mortality, and the obese have increased incidences of type 2 diabetes, cardiovascular disease, musculoskeletal disorders, sleep apnea, fatty liver disease, and certain cancers.Conventional obesity treatments fall into three categories: behavioral treatments focused on diet and exercise, pharmacotherapy, and surgical treatments. Although many patients achieve weight loss through behavioral treatments, only a small minority succeed in maintaining their losses. Similarly, Food and Drug Administration-approved antiobesity drugs have demonstrated only short-term...