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Objective A number of studies provide supporting evidence for changes in synchronization during anesthetic-induced unconsciousness. This study investigates how anesthetic administration affects the widespread patterns of phase synchrony. Methods The recently introduced method of Spatial Analytic Phase Difference (SAPD) was used to measure changes in synchrony in the electroencephalogram (EEG) activity of 29 patients undergoing routine surgery. Analysis was performed over 9 frequency bands: (i) δ (1.5–3.5 Hz); (ii) θ (3.5–7.5 Hz); (iii) α 1 (8–10 Hz); (iv) α 2 (10.5–12 Hz); (v) β 1 (12.5–18 Hz); (vi) β 2 (18.5–21 Hz); (vii) β 3 (21.5–30 Hz); (viii) γ 1 (30.5–40 Hz); and (ix) γ 2 (60–80 Hz). Results Anesthesia was characterized by (a) large and localized synchrony increases in mid-frequency bands (8–12 Hz), (b) smaller and widespread synchrony increases in higher frequency bands (30.5–40 Hz, 60–80 Hz), and (c) both increase and decrease of synchrony in low frequency bands (1.5–7.5 Hz). Conclusions This study supports anesthetic-induced changes in synchrony, with the inducement of persistent and reversible widespread γ synchrony being most prominent. Significance Our findings have implications in the study of consciousness, support existing literature in the field and contribute towards the theoretical understanding of the mechanisms behind loss of consciousness. Future investigations could result in a synchrony-based measure for monitoring the level of hypnosis of patients during surgery. [ABSTRACT FROM AUTHOR]

Background Anaesthetic agents may disrupt consciousness by inhibiting long-range synchronization of brain activity. In the current study, the patterns of widespread and spatially localized synchrony during anaesthesia are investigated using a measure called global field synchrony (GFS). Methods The EEG obtained during routine surgery in 29 patients was analysed with GFS over the following frequency bands: δ (1.5–3.5 Hz), θ (3.5–7.5 Hz), α1 (8–10 Hz), α2 (10.5–12 Hz), β1 (12.5–18 Hz), β2 (18.5–21 Hz), β3 (21.5–30 Hz), γ1 (30.5–40 Hz), and γ2 (60–80 Hz). In addition, localized GFS estimations over aggregate brain areas were performed. GFS was estimated over 2 s non-overlapping windows. The differences in GFS values between ‘wakefulness’ and ‘anaesthesia’ were assessed with the two-sided Wilcoxon rank-sum tests (α=0.05). Results Anaesthetic administration caused significant GFS changes in all frequency ranges and electrode combinations studied: (i) widespread synchrony increased in the α2 and β1 ranges and decreased in all other ranges, with the exception of α1 and β2, where no specific pattern was identified; and (ii) localized synchrony decreased in all areas in the δ and γ2 ranges, while location-specific changes were observed in the remaining frequency ranges. The most consistent findings were statistically significant decreases over all areas in the γ2 range, with GFS decrease over the central–right temporal being the most consistent change. Conclusions Significant frequency- and location-dependent changes in GFS were induced by anaesthetic administration, with more robust changes identified in the γ range. GFS can act as an aid for further and more detailed analysis regarding the particular combinations of frequency ranges and spatial locations that are most informative for the study of anaesthetic-induced unconsciousness. [ABSTRACT FROM AUTHOR]

A case of a squamous carcinoma arising in a “True” tracheal bronchus is described. The presentation and management of this case is discussed. [ABSTRACT FROM AUTHOR]

Abstract: INTRODUCTION: Right Atrial masses may represent tumors or thrombi of the heart and are potentially fatal if left untreated. PRESENTATION OF CASE: A 45-year-old woman with a previous history of breast cancer who was found to have a right atrial mass diagnosed as a tumor by Echocardiography and Computed Tomography which ultimately proved to be a giant organized thrombus at surgery. DISCUSSION: Metastatic tumors of the heart are 20 times more common than primary tumors and malignancies that often involve the heart include breast, lung, lymphoma, melanoma and sarcomas. Myxomas remain the most common cause of atrial tumors and are classically described arising on the left but a significant amount do occur on the right side. Presenting features with masses in the right atrium are similar to patients with tricuspid stenosis which may present with tiredeness, swelling of the feet, hepatomegaly and ascites. The clinical presentation and history may be of help in the diagnosis especially if the patient has a confirmed tumour. CONCLUSION: Despite our current state of the art equipment these “masses” still pose a diagnostic challenge in distinguishing between solid thrombus and tumour as to determine the appropriate therapeutic approach. Surgical removal of Giant Atrial Thrombi appears to be the procedure of Choice. [Copyright &y& Elsevier]