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IntroductionElite breath-hold divers (BHD) possess several oxygen conserving adaptations to endure long dives similar to diving mammals. During dives, Bottlenose Dolphins may increase the alveolar ventilation (VA) to perfusion (Q) ratio to increase alveolar oxygen delivery. We hypothesized that BHD possess similar adaptive mechanisms during apnea.Methods and resultsPulmonary blood volume (PBV) was determined by echocardiography, 15O-H2O PET/CT, and cardiac MRi, (n = 6) during and after maximum apneas. Pulmonary function was determined by body box spirometry and compared to matched controls. After 2 min of apnea, the PBV determined by echocardiography and 15O-H2O-PET/CT decreased by 26% and 41%, respectively. After 4 min of apnea, the PBV assessed by echocardiography and cardiac MRi decreased by 48% and 67%, respectively (n = 6). Fractional saturation (F)O2Hb determined by arterial blood-gas-analyses collected after warm-up and a 5-minute pool-apnea (n = 9) decreased by 43%. Compared to matched controls (n = 8), spirometry revealed a higher total and alveolar-lung-capacity in BHD (n = 9), but a lower diffusion-constant.ConclusionOur results contrast with previous studies, that demonstrated similar lung gas transfer in BHD and matched controls. We conclude that elite BHD 1) have a lower diffusion constant than matched controls, and 2) gradually decrease PBV during apnea and in turn increase VA/Q to increase alveolar oxygen delivery during maximum apnea. We suggest that BHD possess pulmonary adaptations similar to diving mammals to tolerate decreasing tissue oxygenation.New and noteworthyThis manuscript addresses novel knowledge on tolerance to hypoxia during diving, which is shared by elite breath-hold divers and adult diving mammals: Our study indicates that elite breath-hold divers gradually decrease pulmonary blood volume and in turn increase VA/Q, to increase alveolar oxygen delivery during maximum apnea to tolerate decreasing oxygen levels similar to the Bottlenose Dolphin.

IntroductionElite breath-hold divers (BHD) enduring apneas of more than 5 min are characterized by tolerance to arterial blood oxygen levels of 4.3 kPa and low oxygen-consumption in their hearts and skeletal muscles, similar to adult seals. Adult seals possess an adaptive higher hemoglobin-concentration and Bohr effect than pups, and when sedated, adult seals demonstrate a blood shift from the spleen towards the brain, lungs, and heart during apnea. We hypothesized these observations to be similar in human BHD. Therefore, we measured hemoglobin- and 2,3-biphosphoglycerate-concentrations in BHD (n = 11) and matched controls (n = 11) at rest, while myocardial mass, spleen and lower extremity volumes were assessed at rest and during apnea in BHD.Methods and resultsAfter 4 min of apnea, left ventricular myocardial mass (LVMM) determined by 15O-H2O-PET/CT (n = 6) and cardiac MRI (n = 6), was unaltered compared to rest. During maximum apnea (∼6 min), lower extremity volume assessed by DXA-scan revealed a ∼268 mL decrease, and spleen volume, assessed by ultrasonography, decreased ∼102 mL. Compared to age, BMI and VO2max matched controls (n = 11), BHD had similar spleen sizes and 2,3- biphosphoglycerate-concentrations, but higher total hemoglobin-concentrations.ConclusionOur results indicate: 1) Apnea training in BHD may increase hemoglobin concentration as an oxygen conserving adaptation similar to adult diving mammals. 2) The blood shift during dry apnea in BHD is 162% more from the lower extremities than from the spleen. 3) In contrast to the previous theory of the blood shift demonstrated in sedated adult seals, blood shift is not towards the heart during dry apnea in humans.

Abstract Breath-hold divers (BHD) enduring apnea for more than 4 min are characterized by resistance to release of reactive oxygen species, reduced sensitivity to hypoxia, and low mitochondrial oxygen consumption in their skeletal muscles similar to northern elephant seals. The muscles and myocardium of harbor seals also exhibit metabolic adaptations including increased cardiac lactate-dehydrogenase-activity, exceeding their hypoxic limit. We hypothesized that the myocardium of BHD possesses similar adaptive mechanisms. During maximum apnea 15O-H2O-PET/CT (n = 6) revealed no myocardial perfusion deficits but increased myocardial blood flow (MBF). Cardiac MRI determined blood oxygen level dependence oxygenation (n = 8) after 4 min of apnea was unaltered compared to rest, whereas cine-MRI demonstrated increased left ventricular wall thickness (LVWT). Arterial blood gases were collected after warm-up and maximum apnea in a pool. At the end of the maximum pool apnea (5 min), arterial saturation decreased to 52%, and lactate decreased 20%. Our findings contrast with previous MR studies of BHD, that reported elevated cardiac troponins and decreased myocardial perfusion after 4 min of apnea. In conclusion, we demonstrated for the first time with 15O-H2O-PET/CT and MRI in elite BHD during maximum apnea, that MBF and LVWT increases while lactate decreases, indicating anaerobic/fat-based cardiac-metabolism similar to diving mammals.

Introduction: The cardiac electrical conduction system is very sensitive to hypoglycemia and hypoxia, and the consequence may be brady-arrythmias. Weddell seals endure brady-arrythmias during their dives when desaturating to 3.2 kPa and elite breath-hold-divers (BHD), who share metabolic and cardiovascular adaptions including bradycardia with diving mammals, endure similar desaturation during maximum apnea. We hypothesized that hypoxia causes brady-arrythmias during maximum apnea in elite BHD. Hence, this study aimed to define the arterial blood glucose (Glu), peripheral saturation (SAT), heart rhythm (HR), and mean arterial blood pressure (MAP) of elite BHD during maximum apneas.Methods: HR was monitored with Direct-Current-Pads/ECG-lead-II and MAP and Glu from a radial arterial-catheter in nine BHD performing an immersed and head-down maximal static pool apnea after three warm-up apneas. SAT was monitored with a sensor on the neck of the subjects. On a separate day, a 12-lead-ECG-monitored maximum static apnea was repeated dry (n = 6).Results: During pool apnea of maximum duration (385 ± 70 s), SAT decreased from 99.6 ± 0.5 to 58.5 ± 5.5% (∼PaO2 4.8 ± 1.5 kPa, P < 0.001), while Glu increased from 5.8 ± 0.2 to 6.2 ± 0.2 mmol/l (P = 0.009). MAP increased from 103 ± 4 to 155 ± 6 mm Hg (P < 0.005). HR decreased to 46 ± 10 from 86 ± 14 beats/minute (P < 0.001). HR and MAP were unchanged after 3–4 min of apnea. During dry apnea (378 ± 31 s), HR decreased from 55 ± 4 to 40 ± 3 beats/minute (P = 0.031). Atrioventricular dissociation and junctional rhythm were observed both during pool and dry apneas.Conclusion: Our findings contrast with previous studies concluding that Glu decreases during apnea diving. We conclude during maximum apnea in elite BHD that (1) the diving reflex is maximized after 3–4 min, (2) increasing Glu may indicate lactate metabolism in accordance with our previous results, and (3) extreme hypoxia rather than hypoglycemia causes brady-arrythmias in elite BHD similar to diving mammals.

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Refixation saccades with normal gain value occur more frequently with increasing age. The phenomenon has also been observed in different vestibular disorders. In this case, we present a young male with normal gain value and refixation saccades tested with the video head impulse test (vHIT) the day after his cochlear implantation. One month after surgery, refixation saccades were no longer present. This suggests that refixation saccades can occur as a result of temporary pathology such as surgery. Refixation saccades with normal gain values might reflect a partial deficit in the vestibulo-ocular reflex. However, this partial deficit is in conflict with the current way of interpreting vHIT results in which the vestibular function is classified as either normal or pathological based only on the gain value. Refixation saccades, which are evident signs of vestibulopathy, are not considered in the evaluation. A new way of interpreting the vHIT based on the saccades must be considered. [ABSTRACT FROM AUTHOR]

Symptoms of Eustachian tube dysfunction are frequent and multiple. Therefore, clear definitions and diagnostic criteria are important in order to achieve appropriate patient flow. So far, there has been a lack of consensus on this subject, but the proposed definitions and diagnostic criteria in this review may aid to achieve this. Tubomanometry is a diagnostic tool to evaluate Eustachian tube function, and balloon dilation of the Eustachian tube can be a helpful treatment in patients with Eustachian tube dysfunction.

Introduction: Fine-needle aspiration (FNA) is a cornerstone in diagnosing thyroid nodules. For decades, Danish FNA has been categorised into the groups: "FNA not performed", "Inadequate", "Cystic", "Inconclusive", "Benign", "Suspicious", "Malignant" and "Information missing". Internationally, The Bethesda Classification System (TBCS) is increasingly accepted, especially owing to a detailed specification of FNA suspicious for malignancy. The Danish "Suspicious" group is very broad and includes atypia, follicular neoplasia and FNA suspicious of other malignancies. The purpose of this study was to apply TBCS to the Danish "Suspicious" FNA group and to estimate the frequency of malignancy in the individual Bethesda groups (BG)., Methods: This descriptive study is based on a prospective cohort from the THYKIR database. It includes 479 patients with a "Suspicious" FNA and surgical treatment in The Region of Southern Denmark from 2001 to 2013. Based on pathology records, FNA was classified according to the TBCS. Malignancy was determined by the histological diagnosis from the THYKIR database., Results: The Danish "Suspicious" group was allocated to the BG I, II, III, IV, V and VI with a malignancy risk of 36.4%, 13.3%, 17.2%, 16.1%, 55.3% and 88.2%, respectively., Conclusions: The Danish "Suspicious" group contains a broad spectrum of BG with varying malignancy risk. The results indicate a need for standardisation of the Danish FNA classification. A national introduction of the TBCS might secure an international and comparable standard., Funding: none., Trial Registration: not relevant., (Articles published in the Danish Medical Journal are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.)

This is a case report of a 30-year-old female, who presented to the emergency department with headache, nausea and neck pain after five days of otitis media. After lumbar puncture, CT and MRI the patient was treated for meningitis with initial improvement in the clinical state. After four days she developed contralateral neurological symptoms, and after five days she had a seizure. MR-venography showed thrombosis of the lateral dural sinus with venous cerebral infarction. The treatment of intravenously administered antibiotics, mastoidectomy and anticoagulation is discussed and compared with other cases in the literature.

Introduction: Fine-needle aspiration biopsy (FNAB) is the cornerstone of thyroid nodule evaluation. In most cases, FNAB can discriminate between benign and malignant disease. In other cases, it is only indicative of malignancy and the results are considered "suspicious". In Denmark, thyroid FNAB results are categorised into six groups: "inadequate", "cystic", "inconclusive", "benign", "suspicious" and "malignant". The risk of malignancy in the Danish "suspicious" group is of interest for patients as well as doctors participating in the diagnosis and treatment. The Danish Thyroid Surgery Database (THYKIR) registers preoperative thyroid FNAB and final histology. The aim of this study was to assess the malignancy risk among patients with a suspicious thyroid FNAB according to the Danish criteria and to identify possible predictors of malignant histology., Methods: A prospective cohort counting 483 patients with a "suspicious" thyroid FNAB who had been treated surgically in The Region of Southern Denmark in the 2001-2013 period was retrieved from the THYKIR database., Results: The risk of malignancy in the Danish thyroid FNAB "suspicious" group is 22%. Serum thyroid-stimulating hormone outside the normal range and vocal cord palsy may be patient-related predictors of malignancy., Conclusion: Awaiting the introduction of reliable tools for preoperative evaluation, the current practice with histo-logical clarification of the "suspicious" thyroid FNAB seems justified., Funding: none., Trial Registration: not relevant.

Loss of vestibular function is a common side effect to cochlear implant (CI) surgery. We present a patient who experienced balance problems and showed a reduced vestibulo-ocular reflex (VOR) gain (0.47 ± 0.10) combined with saccades in the horizontal semicircular canals demonstrated by the video head impulse test the day after CI surgery. One month after the operation VOR gain was normal (0.95 ± 0.05) and neither balance problems nor saccades occurred. Our findings indicate that vestibular dysfunction after CI surgery can be reversible, and VOR gain can return to normal.

Introduction: The objective of this study was to evaluate patients' satisfaction with bone-anchored hearing aids (BAHA)., Methods: This study was retrospective and based on a postal questionnaire. The study sample consisted of patients undergoing surgery at Odense University Hospital in the 1992-2013-period. The questionnaire was a combination of Satisfaction with Amplification in Daily Life questions from the Hearing Aid Research Lab at the University of Memphis and questions used in a previous Danish study. We also used data from each patient's medical records. All information was collected in a database., Results: The response rate was 80% and the user percentage 88. The majority of the patients used their BAHA seven days a week and most of the day. 88% reported that it was in their best interest that they had received a BAHA. 80% of the respondents were able to communicate better using their BAHA in one-on-one conversations., Conclusion: BAHA is helpful in one-on-one conversations in quiet surroundings. Sound quality in group situations seems to be the main problem associated with BAHA. However, this study showed that BAHA is an effective hearing aid that is associated with a high degree of satisfaction., Funding: not relevant., Trial Registration: not relevant.

Abscesses of the tongue are rare and potentially life-threatening because of risk of airway obstruction. It is most often preceded by trauma. In this paper we present an otherwise healthy patient with an abscess in the tongue eleven days after a trauma involving the presence of an insect believed to be a spider in the mouth. The symptoms were oedema, redness and pain of the tongue. A computed tomography was used as a diagnostic tool. The abscess was successfully treated with incision and antibiotics. Abscess should be considered as a differential diagnosis in patients presenting with a swollen tongue.

We present a case in which a patient infected with human immunodeficiency virus (HIV) developed a sensorineural hearing loss and tinnitus due to inner-ear syphilis affection. The patient had normal otomicroscopy, tympanometry, ear, nose & throat examination, caloric test and intracranial magnetic resonance imagining. Relevant serological blood samples and lumbal puncture indicated syphilis in its secondary stage or the early latent phase. Audiometry demonstrated a considerable improvement and tinnitus decreased after ten days of treatment with antibiotics and prednisone.

Introduction: The purpose of this study was to assess the results after primary otosclerosis surgery at Odense University Hospital., Material and Methods: The study was based on information collected from a database and from patient records. A total of 154 primary stapedotomies (138 patients) were performed using small-fenester-technique in the period 1996-2005. Five experienced ear surgeons performed the operations. The surgeons were still in the learning phase with regard to otosclerosis surgery., Results: A significant improvement was found regarding the air-conduction pure tone average (PTA) (52.8 dB to 31.4 dB), the bone conduction PTA (25.2 dB to 23,1 dB), air-bone gap (27.6 dB to 8.3 dB), and the speech reception threshold (44.8 dB to 22.5 dB). One operation (0.6%) resulted in severe sensory-neural hearing loss, while other types of complications were seen after 7,2% of the operations. After thirteen operations (8.4%), reoperation was subsequently needed., Conclusion: Patients undergoing primary otosclerosis surgery gained a significant hearing improvement. The results of this survey matched those of larger international and Danish studies. Experienced ear surgeons can perform stapedotomy with good results without having initial experience in otosclerosis surgery.

Introduction: Our aim was to assess the effect of cochlear implant (CI) surgery on the mental quality of life in totally deaf adults using a generic type of questionnaire., Materials and Methods: The survey comprised 40 adult CI users who answered a standard and a retrospective version of the Short Form 36 questionnaire (SF-36). In the questionnaires, specific questions focused on four dimensions of the mental quality of life: vitality, social functioning, and emotional and mental health., Results: Due to qualitative and quantitative deficiencies, the emotional scale was omitted. A statistically significant improvement in the quality of life (p<05) was demonstrated in the three remaining subscales between pre-implant and post-implant scores. The greatest improvement was observed in the social functioning subscale. Pre-implant mean scores on all three subscales of the SF-36 were markedly below the mean scores of the equivalent subscales of the Danish population, whereas the post-implant mean scores in two out of three cases were above the mean scores of the Danish population., Discussion: CI was shown to have a statistically significant positive impact on the quality of life of adult deaf patients. This is in accordance with other published studies.