Lateral hypothalamic activity indicates hunger and satiety states in humans

Lateral hypothalamic area (LHA) local field potentials (LFPs) were recorded in a Prader–Willi patient undergoing deep brain stimulation (DBS) for obesity. During hunger, exposure to food-related cues induced an increase in beta/ low-gamma activity. In contrast, recordings during satiety were marked by prominent alpha rhythms. Based on these findings, we have delivered alphafrequency DBS prior to and during food intake. Despite reporting an early sensation of fullness, the patient continued to crave food. This suggests that the pattern of activity in LHA may indicate hunger/satiety states in humans but attest to the complexity of conducting neuromodulation studies in obesity

Tramadol versus meperidine in the treatment of shivering during spinal anesthesia in cesarean section

BACKGROUND: The aim of this study was to evaluate the efficacy and side effects of tramadol comparing with meperidine on post-spinal shivering in cesarean section.
 METHODS: In a prospective, controlled, randomized, double-blind clinical trial 73 ASA-I pregnant patients candidates of cesarean section under spinal anesthesia who had shivering postoperatively were selected and classified into two groups receiving tramadol or meperidine to control postoperative shivering. Spinal anesthesia was done by injection of epinephrinized 5% lidocaine at L3-L4 or L4-L5 segment. Pruritis, somnolence, dizziness, nausea, vomiting and the duration of shivering control were evaluated and recorded. All data were analyzed by using Fisher and Chi-square tests.
 RESULTS: There were no significant differences between two groups in age (P = 0.1) and weight (P = 0.8) of patients. There was no significant difference in response rate after injection of both drugs (P = 0.3). The time elapsed from treatment to ceased shivering was significantly less (P = 0.001) but frequency of somnolence (P = 0.001), nausea (P = 0.001) and vomiting (P = 0.005) were significantly more in tramadol group. Dizziness was significantly more common in meperidine group (P = 0.001) and pruritis was not seen in any group.
 CONCLUSION: Tramadol is more effective in controlling post-spinal shivering but results in more frequent nausea, vomiting and somnolence in comparison with meperidine.
 KEYWORDS: Shivering, meperidine, tramadol, spinal anesthesia, cesarean section

Preventive effect of paracetamol and dexamethasone on nausea, vomiting, and pain after laparoscopic cholecystectomy

Background: The currently used antiemetic drugs are not effective in all post-operative patients due to multifactorial origin of nausea and vomiting. Therefore, the present study was designed to evaluate the preventive effect of paracetamol on postoperative nausea and vomiting (PONV) in comparison with dexamethasone in patients undergoing elective laparoscopic cholecystectomy. Materials and Methods: in this double-blinded clinical trial 105 patients were selected using a random sampling method; they were American standards association (ASA) class I and II, 18-75 years and candidate for laparoscopic cholecystectomy; randomly assigned into three groups: Paracetamol, Dexamethasone, and control. They were anesthetized using the same method, using sodium thiopental, Fentanyl, Atracurium, and Lidocaine. Anesthesia was maintained with oxygen, Isoflurane and Morphine. They also received 6 mL/kg/h ringer lactate. Patients data were recorded and analyzed. Results: The mean severity of nausea and vomiting in the recovery room at minutes 30, 45, and 60 had a significant difference between the groups (p0.05). Conclusion: The severity of nausea and vomiting was low in the Paracetamol group and Paracetamol was more effective than Dexamethasone in terms of reducing the rate of nausea and vomiting. © 2017 Shahid Beheshti University of Medical Sciences, Anesthesiology Research Center. All rights reserved

Comparing the effect of local injection of combined morphine, triamcinolone and lidocaine and lidocaine injection on pain intensity after mastoidectomy-tympanoplasty; a triple-blind clinical trial

Introduction: Postoperative pain control is one of the patient's rights and the challenges of surgeons and anesthesiologists since about 20 of patients experience severe pain in the first 24 hours after surgery. Mastoidectomy and tympanoplasty are common surgeries in the head and neck area, in which profound and long-term analgesia is essential.Objectives: The present study investigated the effect of the combination of topical morphine, triamcinolone, and lidocaine compared to the control group.Patients and Methods: In the current clinical trial, 68 patients' candidates for mastoidectomy-tympanoplasty surgery were included and randomly divided into intervention and control groups. The variables of demographic, pain, hemodynamics, extubation time, and received opioids were measured.Results: The results of the current study indicated a significant reduction in the patient's pain scores in both groups (P = 0.001), while the patients of group 1 had significantly lower pain scores than group 2 after 8, 12, and 24 hours in the ward (P<0.05). Moreover, a significant reduction was observed in systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in all patients during surgery (P<0.001). However, in patients who received morphine, triamcinolone, and lidocaine (group 1), SBP and MAP were significantly lower than group 2 after 40, 80, 100, 120, 140, and 160 minutes during surgery (P<0.05).Conclusion: The present study indicated that the combination of morphine, triamcinolone, and lidocaine compared to the control group could lead to better pain control, further reduction of SBP and MAP, reduction of post-operative opioid use, and delay during the first opioid administration.Trial Registration: The trial protocol was approved by the Iranian Registry of Clinical Trials (identifier: IRCT20200825048515N39; https://irct.ir/trial/57931, ethical code; IR.MUI.MED.REC.1400.064)

Closed-Loop Interruption of Hippocampal Ripples through Fornix Stimulation in the Non-Human Primate

AbstractBackgroundHippocampal sharp-wave ripples (SWRs) arising from synchronous bursting in CA3 pyramidal cells and propagating to CA1 are thought to facilitate memory consolidation. Stimulation of the CA3 axon collaterals comprising the hippocampal commissure in rats interrupts sharp-wave ripples and leads to memory impairment. In primates, however, these commissural collaterals are limited. Other hippocampal fiber pathways, like the fornix, may be potential targets for modulating ongoing hippocampal activity, with the short latencies necessary to interrupt ripples.ObjectiveThe aim of this study is to determine the efficacy of closed-loop stimulation adjacent to the fornix for interrupting hippocampal ripples.MethodStimulating electrodes were implanted bilaterally alongside the fornix in the macaque, together with microelectrodes targeting the hippocampus for recording SWRs. We first verified that fornix stimulation reliably and selectively evoked a response in the hippocampus. We then implemented online detection and stimulation as hippocampal ripples occurred.ResultsThe closed-loop interruption method was effective in interrupting ripples as well as the associated hippocampal multi-unit activity, demonstrating the feasibility of ripple interruption using fornix stimulation in primates.ConclusionAnalogous to murine research, such an approach will likely be useful in understanding the role of SWRs in memory formation in macaques and other primates sharing these pathways, such as humans. More generally, closed-loop stimulation of the fornix may prove effective in interrogating hippocampal-dependent memory processes. Finally, this rapid, contingent-DBS approach may be a means for modifying pathological high-frequency events within the hippocampus, and potentially throughout the extended hippocampal circuit