Reliability of threshold determination using portable muscle oxygenation monitors during exercise testing: a systematic review and meta-analysis.

Over the last few years, portable Near-Infrared Spectroscopy (NIRS) technology has been suggested for determining metabolic/ventilator thresholds. This systematic review and meta-analysis aimed to assess the reliability of a portable muscle oxygenation monitor for determining thresholds during exercise testing. The proposed PICO question was: Is the exercise intensity of muscle oxygenation thresholds, using portable NIRS, reliable compared with lactate and ventilatory thresholds for exercise intensity determined in athletes? A search of Pubmed, Scopus and Web of Science was undertaken and the review was conducted following PRISMA guidelines. Fifteen articles were included. The domains which presented the highest biases were confounders (93% with moderate or high risk) and participant selection (100% with moderate or high risk). The intra-class correlation coefficient between exercise intensity of the first ventilatory or lactate threshold and the first muscle oxygenation threshold was 0.53 (obtained with data from only 3 studies), whereas the second threshold was 0.80. The present work shows that although a portable muscle oxygenation monitor has moderate to good reliability for determining the second ventilatory and lactate thresholds, further research is necessary to investigate the mathematical methods of detection, the capacity to detect the first threshold, the detection in multiple regions, and the effect of sex, performance level and adipose tissue in determining thresholds.

Acute effects of fatigue on internal and external load variables determining cyclists' power profile.

The aim of the present study was to determine whether fatigue affects internal and external load variables determining power profile in cyclists. Ten cyclists performed outdoor power profile tests (lasting 1-, 5 and 20-min) on two consecutive days, subject either to a fatigued condition or not. Fatigue was induced by undertaking an effort (10-min at 95% of average power output obtained in a 20-min effort followed by 1-min maximum effort) until the power output decreased by 20% compared to the 1-min power output. Fatigued condition decreased power output (p < 0.05, 1-min: 9.0 ± 3.8%; 5-min: 5.9 ± 2.5%; 20-min: 4.1 ± 1.9%) and cadence in all test durations, without differences in torque. Lactate decreased in longer efforts when a fatigue protocol had previously been conducted (e.g., 20-min: 8.6 ± 3.0 vs. 10.9 ± 2.7, p < 0.05). Regression models (r2 ≥ 0.95, p < 0.001) indicated that a lower variation in load variables of 20-min in fatigued condition compared with the non-fatigued state resulted in a lower decrease in critical power after the fatigue protocol. The results suggest that fatigued condition on power was more evident in shorter efforts and seemed to rely more on a decrease in cadence than on torque.

Acute physiological responses to a pyramidal exercise protocol and the associations with skin temperature variation in different body areas.

This study aimed to examine the skin temperature (Tsk) variations in five regions of interest (ROI) to assess whether possible disparities between the ROI's Tsk could be associated with specific acute physiological responses during cycling. Seventeen participants performed a pyramidal load protocol on a cycling ergometer. We synchronously measured Tsk in five ROI with three infrared cameras. We assessed internal load, sweat rate, and core temperature. Reported perceived exertion and calves' Tsk showed the highest correlation (r = -0.588; p < 0.01). Mixed regression models revealed that the heart rate and reported perceived exertion were inversely related to calves' Tsk. The exercise duration was directly associated with the nose tip and calf Tsk but inversely related to the forehead and forearm Tsk. The sweat rate was directly related to forehead and forearm Tsk. The association of Tsk with thermoregulatory or exercise load parameters depends on the ROI. The parallel observation of the face and calf Tsk could indicate simultaneously the observation of acute thermoregulatory needs and individual internal load. The separate Tsk analyses of individual ROI appear more suitable to examine specific physiological response than a mean Tsk of several ROI during cycling.

Chronic and Acute Effects on Skin Temperature from a Sport Consisting of Repetitive Impacts from Hitting a Ball with the Hands.

Valencian handball consists in hitting the ball with the hands and it may contribute to injury development on the hands. This study aimed to analyze skin temperature asymmetries and recovery after a cold stress test (CST) in professional players of Valencian handball before and after a competition. Thirteen professional athletes and a control group of ten physically active participants were measured. For both groups, infrared images were taken at the baseline condition; later they underwent a thermal stress test (pressing for 2 min with the palm of the hand on a metal plate) and then recovery images were taken. In athletes, the images were also taken after their competition. Athletes at baseline condition presented lower temperatures (p < 0.05) in the dominant hand compared with the non-dominant hand. There were asymmetries in all regions after their match (p < 0.05). After CST, a higher recovery rate was found after the game. The regions with the most significant differences in variation, asymmetries and recovery patterns were the index, middle and ring fingers, and the palm of the dominant hand. Taking into account that lower temperatures and the absence of temperature variation may be the consequence of a vascular adaptation, thermography could be used as a method to prevent injuries in athletes from Valencian handball.

Potential Association Between Acute Colonic Pseudo-Obstruction (Ogilvie Syndrome) and Oral Nimodipine: Report of Two Cases.

Nimodipine is a calcium channel blocker used for the management of patients with aneurysmal subarachnoid hemorrhage. Oral nimodipine has been rarely implicated in the development of acute colonic pseudo-obstruction (Ogilvie syndrome) in patients treated for aneurysmal subarachnoid hemorrhage. Nimodipine inhibits the transmembrane influx of calcium ions which are essential for the excitation-contraction coupling process of smooth muscle cells. We thought this mechanism of action could predispose patients to develop Ogilvie syndrome. This report aimed to examine the existing literature concerning the potential association between Ogilvie syndrome and nimodipine in patients with aneurysmal subarachnoid hemorrhage. All published cases of aneurysmal subarachnoid hemorrhage associated with Ogilvie syndrome were reviewed. We presented two female patients with aneurysmal subarachnoid hemorrhage produced after a ruptured anterior communicating artery aneurysm who received oral nimodipine and developed Ogilvie syndrome. The patients developed Ogilvie syndrome four to six days after receiving oral nimodipine. These two cases may further support the potential association of Ogilvie syndrome with the use of oral nimodipine during the treatment of patients with aneurysmal subarachnoid hemorrhage.

Skin temperature measurement in individuals with spinal cord injury during and after exercise: Systematic review.

BACKGROUND: Athletes with spinal cord injury (SCI) have difficulties in maintaining thermal homeostasis during exercise due to their lower sweat capacity and skin vasodilation. Skin temperature (Tsk) assessment, as opposed to core temperature, has become more widely accepted due to its non-invasive nature. The aims of this systematic review was to collate research studies that measured Tsk of individuals with SCI during or after exercise, study their Tsk response, taking into account the method employed, the environmental and exercise conditions, and to identify the different cooling strategies and their effect during exercise. METHODS: Pubmed, Web of Science and Scopus databases were searched to identify the articles published since year 2000. Two reviewers working independently extracted data and assessed the quality of the articles included. If they disagreed, a third reviewer was consulted. ROBINS-I scale was used to assess the quality of the articles, and the review has been conducted in agreement with PRISMA guidelines. RESULTS: Twenty studies were included in this review. 84% of them presented moderate, serious or critical risk of bias. The entire of the studies assessed Tsk during exercise, but only seven studies measured it during rest or after exercise. Eighteen studies used contact thermometry to assess Tsk and the two remaining studies employed non-contact techniques. Seven studies were conducted in warm conditions (>31.5°C) and the remaining studies in moderate conditions (10°C to 26.6°C). According to cooling strategies, ice vests and water spray are effective in reducing Tsk and decreasing the risk of heat stroke. CONCLUSIONS: The 90% of the studies applied contact thermometry and due to their effect in the data assessed, it is necessary more research into the SCI population using infrared thermography due to its differences in characteristics, methodology, and applications. The methodological differences among studies make difficult to perform a meta-analysis.

Malignant peripheral nerve sheath tumour transformation of histological benign vestibular schwannoma after stereotactic radiosurgery in patients without neurofibromatosis.

Stereotactic radiosurgery (SRS) poses a minimal but important risk for tumour transformation, typically occurring 8-10 years after the treatment. Malignant peripheral nerve sheath tumour (MPNST) is the most common tumour arising from a vestibular schwannoma treated with SRS, with only 14 cases previously reported. We present the fifteenth case and describe its evolution and clinical course. A 56-year-old man without a history of neurofibromatosis was diagnosed 9 years prior with a vestibular schwannoma. SRS to the residual tumour was given 3 months later. During the current hospitalisation, he was reoperated where histology confirmed a MPNST. All 15 MPNST cases were analysed, showing a 77% female predominance presenting a malignant transformation at a mean age of 51. The diagnosis was made at a mean time of 74 months after SRS. The mean survival time after diagnosis was 16 months. MPNST arising from benign vestibular schwannoma after SRS treatment is an uncommon but devastating complication.

Obstructive Hydrocephalus and Chemical Meningitis Secondary to a Ruptured Spinal Epidermoid Cyst.

BACKGROUND: Epidermoid cysts of the spinal cord may rupture, resulting in keratin dissemination in the subarachnoid space, in the ventricles, and along the central canal of the spinal cord causing meningitis, myelopathic changes, or hydrocephalus. CASE DESCRIPTION: A 53-year-old woman with no past medical history presented with a 2-week history of headache located in the occipital region associated with neck pain. Brain magnetic resonance imaging demonstrated multiple fat droplets scattered throughout the subarachnoid and intraventricular spaces with significant edema of the right posterior temporoparietal lobes with trapping of the right temporal horn of the lateral ventricle and atrium. An intracranial lesion could not be observed in the study. The spinal region was suspected as the possible culprit, and spinal imaging showed a large cystic lesion at the level of the conus medullaris. The patient underwent neuronavigation endoscopic exploration of the right lateral ventricle with flushing of the keratin particles followed by a posterior lumbar decompression with resection of the epidermoid cyst. Pathology was consistent with an epidermoid cyst. Successful recovery with improvement in symptoms was quickly observed. CONCLUSIONS: When an epidermoid cyst is suspected but no intracranial lesion is found, the intraspinal area should be studied. Rupture of a spinal epidermoid cyst may cause meningitis and inflammation producing obstructive hydrocephalus. We present this rare entity and describe the diagnostic and surgical techniques used.

Asthma and insulin resistance in obese children and adolescents.

BACKGROUND: Obese children and adolescents have an increased risk for asthma. A few studies have evaluated the association of insulin resistance and asthma in obese pediatric populations. We examined whether there was a relationship between high degrees of insulin resistance and the presence of asthma in obese children and adolescents. METHODS: A total of 153 patients aged 4-15 years with at or above the 95th percentile BMI for age were prospectively recruited. Assessments included diagnosis of asthma, skin prick test reactivity to common environmental aeroallergens, and HOMA estimated insulin resistance, with the median (2.22) used as a cutoff value to categorize insulin resistance. RESULTS: There were 56 (36.6%) asthmatic and 97 (63.4%) non-asthmatic patients. HOMA values were significantly associated with positive skin tests (p = 0.008) and allergic asthma diagnosis (p = 0.016). Baseline insulin value was significantly associated with the risk of presenting asthma with positive skin testing (odds ratio 1.084, p = 0.037). Differences in age, BMI, and waist circumference were found between the groups of HOMA-IR <2.22 and ≥2.22. Waist circumference (WC) was significantly associated with FVC (p = 0.0001) and FEV1 (p < 0.0003); the greater the WC, the lower FVC and FEV1 values. CONCLUSIONS: Insulin resistance is a risk for allergic asthma in obese children and adolescents. Waist circumference was related to CVF and FEV1 impairment.