Lowering barometric pressure induces neuronal activation in the superior vestibular nucleus in mice

Sex-related differences regarding headache triggered by low barometric pressure in Japan

PURPOSE

The prevalence of migraine headache is higher in women. Low barometric pressure is a factor in headache triggering, but sex-related differences have not been identified. The purpose of this study was to examine sex-related differences in headache triggered by low barometric pressure.

METHODS

Study subjects aged 20-49 years were randomly selected from a research company's (Macromill, Inc.) web panel. Those with chronic migraine or tension-type headache invited to complete a web-based self-administered questionnaire. Logistic regression analysis was performed with the objective variable as the Headache Impact Test-6 (HIT-6) high scores (56 or more) or headache triggered by low barometric pressure.

RESULTS

Participants were 332 women and 337 men in the headache population. HIT-6 high scores were associated with age at headache occurrence 20 years or younger (OR: odds ratio 1.85, 95% CI: confidence interval 1.15-2.99, p = 0.012) and headache triggered by low barometric pressure (OR 2.11, 95%CI 1.51-2.94, p < 0.001). Headache triggered by low barometric pressure was significantly associated with women (OR 2.92, 95%CI 2.12-4.02, p < 0.001).

CONCLUSIONS

Headache triggered by low barometric pressure were related to sex-related differences. It was suggested that a sex-specific treatment approach for headache triggering is needed.

Mapping of afferent and efferent connections of phenylethanolamine N-methyltransferase-expressing neurons in the nucleus tractus solitarii

OBJECTIVE

Phenylethanolamine N-methyltransferase (PNMT)-expressing neurons in the nucleus tractus solitarii (NTS) contribute to the regulation of autonomic functions. However, the neural circuits linking these neurons to other brain regions remain unclear. This study aims to investigate the connectivity mechanisms of the PNMT-expressing neurons in the NTS (NTSPNMT neurons).

METHODS

The methodologies employed in this study included a modified rabies virus-based retrograde neural tracing technique, conventional viral anterograde tracing, and immunohistochemical staining procedures.

RESULTS

A total of 43 upstream nuclei projecting to NTSPNMT neurons were identified, spanning several key brain regions including the medulla oblongata, pons, midbrain, cerebellum, diencephalon, and telencephalon. Notably, dense projections to the NTSPNMT neurons were observed from the central amygdaloid nucleus, paraventricular nucleus of the hypothalamus, area postrema, and the gigantocellular reticular nucleus. In contrast, the ventrolateral medulla, lateral parabrachial nucleus, and lateral hypothalamic area were identified as the primary destinations for axon terminals originating from NTSPNMT neurons. Additionally, reciprocal projections were evident among 21 nuclei, primarily situated within the medulla oblongata.

CONCLUSION

Our research findings demonstrate that NTSPNMT neurons form extensive connections with numerous nuclei, emphasizing their essential role in the homeostatic regulation of vital autonomic functions.

Whether Weather Matters with Migraine

PURPOSE OF REVIEW

Many patients with migraine report their attacks are triggered by various weather anomalies. Studies have shown mixed results regarding the association of migraine to weather changes. The purpose of the current review is to compile the most up-to-date research studies on how weather may affect migraine. In addition, we explore the association between weather and other inflammatory disease states as well as neurotransmitters.

RECENT FINDINGS

Migraine attacks can be related to weather variables such as barometric pressure, humidity, and wind. However, the results of recent studies are inconsistent; weathers' effect on migraine attacks is around 20%. However, very strong weather factors have a more significant effect on migraine attack variables. Many individuals identify weather as a migraine attack trigger, yet we see no causative relationship between weather and migraine patterns. The outcomes of studies indicate mixed results and reflect individual variation in how weather can impact migraine patterns. Similar relationships can be seen with other rheumatologic and pain conditions in general. Overall, the combination of weather plus other factors appears to be a more significant migraine trigger.

Goreisan regulates cerebral blood flow according to barometric pressure fluctuations in female C57BL/6J mice

Goreisan is a Kampo medicine used to treat headaches associated with climate change. Here, by using an implantable complementary metal-oxide-semiconductor (CMOS) device, we evaluated the effects of Goreisan and loxoprofen on cerebral blood flow (CBF) dynamics associated with barometric pressure fluctuations in freely moving mice. In the vehicle group, decreasing barometric pressure increased CBF that was prevented by Goreisan and loxoprofen. Notably, Goreisan, but not loxoprofen, reduced CBF after returning to atmospheric pressure. These results indicate that, unlike the mechanism of action of antipyretic analgesics, Goreisan normalizes CBF abnormalities associated with barometric pressure fluctuations by actively reducing CBF increase.

Pain and Weather associations - Action Mechanisms; Personalized profiling

It is a well-known hypothesis that weather can influence human health, including pain sensation. The primary meteorological factors are atmospheric pressure, wind, humidity, precipitation, and temperature, which vary from the climate and seasons, but the parameters of space weather (e.g., geomagnetic and cosmic ray activities) also may affect our body condition. Despite a significant number of experimental studies, reviews, and meta-analyses concerning the potential role of weather in pain sensitivity, the findings are heterogeneous and lack consensus. Therefore, rather than attempting a comprehensive analysis of the entire literature on the effects of weather on different pain types, this study highlights the potential action mechanisms of the meteorological factors, and the possible causes of the controversial results. The few data available about the individual evaluations are discussed in detail to reveal the significance of the personalized analysis of the possible relationships between the most available weather parameters and the pain scores. The use of special algorithms may enable the individual integration of different data for a precise outcome concerning the link between pain sensitivity and weather parameters. It is presumed that despite the high level of interindividual differences in response to meteorological parameters, the patients can be clustered in different groups based on their sensitivity to the weather parameters with a possible disparate treatment design. This information may help patients to control their daily activities and aid physicians to plan more valuable management for patients with pain states when the weather conditions change.

Meteoropathy: a review on the current state of knowledge

Meteoropathy is no longer considered a popular myth, but a new disease that significantly impacts daily life, particularly in individuals who experience mental illness, cardiovascular disorders, and respiratory conditions. However, there are very limited data on this condition. This study aimed to comprehensively review and analyze existing in vivo animal studies and human clinical trials investigating the effects of meteoropathy on health and its pharmacological treatment. A thorough literature search was conducted across databases such as PubMed and Scopus to gather relevant information. Our analysis primarily focused on the relationship between meteoropathy and mental health, including the influence on affective temperaments. Additionally, we explored various treatment approaches, emphasizing the combination of muscle exercises, pharmacological interventions, and naturopathy, which have shown promise in alleviating pain among individuals affected by meteoropathy. Future research in meteoropathy should shed light on synthesizing new pharmacological compounds.

The effects of weather on depressive symptoms in patients after cardiac surgery

Patients with cardiovascular disease have depression more often than the general population does. The aim of the study was to detect the associations between the psychological state and weather variables in patients who underwent coronary artery bypass grafting or valve surgery. The prospective study was performed during 2008-2012 in Kaunas, Lithuania. The psychological state of 233 patients was assessed by using the Symptom Checklist-90-Revised instrument. The assessment was carried out at 1.5 months, 1 year, and 2 years after the surgery. A sample of 531 measurements of psychological states was used. To investigate the relationships between psychological scores and daily weather variables, a mixed linear model was used adjusting for sex, the type of surgery, age, the marital status, the presence of arterial hypertension, diabetes, major depressive disorders, dysthymic disorders, agoraphobia, smoking before surgery, and myocardial infarction in the anamnesis. The mean somatisation score and air temperature on the second day prior to the survey were found to have a negative correlation in the multivariate model. Lower mean scores of anxiety and depression were linked to hotter days (air temperature >16.25°C on the second day) that did not occur in July or August. During colder days (air temperature <0.35°C), a higher mean score of anxiety and phobic anxiety was observed. A higher mean score of somatizations, depression, and anxiety was seen on the second day after the day with wind speed ≤2.85 kt and on the day after the day with relative humidity <66%. Both a decrease and an increase in daily atmospheric pressure were associated with a higher depression score. Our results confirm that among patients after open heart surgery, psychosomatic complaints are related to some weather changes. The obtained results can help to determine the complexity of weather patterns linked to poorer psychological health.

Investigating the effects of weather on headache occurrence using a smartphone application and artificial intelligence: A retrospective observational cross-sectional study

OBJECTIVE

To investigate the relationship between weather and headache occurrence using big data from an electronic headache diary smartphone application with recent statistical and deep learning (DL)-based methods.

BACKGROUND

The relationship between weather and headache occurrence remains unknown.

METHODS

From a database of 1 million users, data from 4375 users with 336,951 hourly headache events and weather data from December 2020 to November 2021 were analyzed. We developed statistical and DL-based models to predict the number of hourly headache occurrences mainly from weather factors. Temporal validation was performed using data from December 2019 to November 2020. Apart from the user dataset used in this model development, the physician-diagnosed headache prevalence was gathered.

RESULTS

Of the 40,617 respondents, 15,127/40,617 (37.2%) users experienced physician-diagnosed migraine, and 2458/40,617 (6.1%) users had physician-diagnosed non-migraine headaches. The mean (standard deviation) age of the 4375 filtered users was 34 (11.2) years, and 89.2% were female (3902/4375). Lower barometric pressure (p < 0.001, gain = 3.9), higher humidity (p < 0.001, gain = 7.1), more rainfall (p < 0.001, gain = 3.1), a significant decrease in barometric pressure 6 h before (p < 0.001, gain = 11.7), higher barometric pressure at 6:00 a.m. on the day (p < 0.001, gain = 4.6), lower barometric pressure on the next day (p < 0.001, gain = 6.7), and raw time-series barometric type I (remaining low around headache attack, p < 0.001, gain = 10.1) and type II (decreasing around headache attack, p < 0.001, gain = 10.1) changes over 6 days, were significantly associated with headache occurrences in both the statistical and DL-based models. For temporal validation, the root mean squared error (RMSE) was 13.4, and the determination coefficient (R² ) was 52.9% for the statistical model. The RMSE was 10.2, and the R² was 53.7% for the DL-based model.

CONCLUSIONS

Using big data, we found that low barometric pressure, barometric pressure changes, higher humidity, and rainfall were associated with an increased number of headache occurrences.

Tympanostomy tube placement for pressure-sensitive vertigo

Objective

To evaluate tympanostomy tube placement in patients with pressure-sensitive vertigo.

Methods

Retrospective case series.

Results

Six patients with pressure-sensitive vertigo reported resolution of their vertigo and other vestibular symptoms after placement of the tympanostomy tubes. All recurrences of symptoms were due to either extrusion or plugging of the tubes. All patients fulfilled the criteria for vestibular migraine. None of the patients had superior canal dehiscence on imaging or precedent event that triggered the problem, and all had a negative fistula test.

Conclusion

Tympanostomy tube placement should be considered in selected patients with vertigo exacerbated by seemingly small changes in atmospheric pressure (e.g., just prior to thunderstorms, air travel, or travel to the mountains). By eliminating the capability of the tympanic membrane to sense changes in pressure with a tube, patients with pressure-induced vertigo (in the absence of perilymph fistula or superior canal dehiscence) may have relief of their symptoms.

Level of Evidence IV

To tolerate weather and to tolerate pain: two sides of the same coin? The Tromsø Study 7

ABSTRACT

It is a common belief that weather affects pain. Therefore, we hypothesized that weather can affect pain tolerance. This study used data from over 18,000 subjects aged 40 years or older from the general population, who participated in the Tromsø Study 7. They underwent a one-time assessment of cuff algometry pressure pain tolerance (PPT) and cold pain tolerance (CPT), tested with a cold pressor test. The results showed a clear seasonal variation in CPT. The rate of withdrawal in the cold pressor test was up to 75% higher in months in the warmer parts of the year compared with January 2016. There was no seasonal variation in PPT. The study not only found a nonrandom short-term variation in PPT but also indications of such a variation in CPT. The intrinsic timescale of this short-term variation in PPT was 5.1 days (95% % confidence interval 4.0-7.2), which is similar to the observed timescales of meteorological variables. Pressure pain tolerance and CPT correlated with meteorological variables, and these correlations changed over time. Finally, temperature and barometric pressure predicted future values of PPT. These findings suggest that weather has a causal and dynamic effect on pain tolerance, which supports the common belief that weather affects pain.

Repeated Atmospheric Pressure Alteration Effect on the Cochlea in Rats: Experimental Animal Study

OBJECTIVE: This study aimed to evaluate the effects of repeated pressure alterations on cochlear structures in rats in an attempt to understand indirectly the inner ear status of flight crew who are repeatedly exposed to pressure alterations.METHODS: There were 12 adult Wistar albino rats equally divided into 2 groups: Group 1 (controls) and Group 2 (study group). The animals in Group 2 were exposed to repeated pressure changes in a pressure cabin which is regulated by manometers. The animals in Group 1 were placed in the cabin without being exposed to pressure changes. Auditory brainstem response (ABR) testing was performed in all animals at the beginning and at the end of the study. After 12 wk the animals were sacrificed and their cochleas were investigated using scanning electron microscopy (SEM).RESULTS: In the study group, hearing decreases at 2 kHz, 4 kHz, 6 dB at 8 kHz, and 32 kHz were encountered at the end of 3 mo. On SEM evaluation of the control group, the outer hair cells (OHC) and stereocilia were normal throughout the cochlea. In the study group, there were irregularities in lateral surface connections and separations, collapse, and adhesions in the basal segment of the cochlea and partial loss of stereocilia throughout the cochlea.CONCLUSION: Repeated alterations in the atmospheric pressure can lead to damage in the inner ear with subtle or evident hearing loss. Frequent flyers like air workers may be at risk of inner ear damage, which may be considered an occupational health problem.Eroglu S, Dizdar HT, Cevizci R, Cengiz AB, Ogreden S, Bulut E, Ilgezdi S, Dilci A, Ustun S, Sirvanci S, Kaya OT, Bayazit D, Caki BO, Oktay MF, Bayazit Y. Repeated atmospheric pressure alteration effect on the cochlea in rats: experimental animal study. Aerosp Med Hum Perform. 2021; 92(7):550555.

Weather sensitivity associated with quality of life in patients with fibromyalgia

Background

Fibromyalgia is characterized by chronic widespread pain, and more than half of patients with fibromyalgia report that weather-related variables aggravate their symptoms. However, the differences in actual symptoms have not been measured between those with and without weather sensitivity. The present study aimed to investigate whether weather sensitivity associated with the minimal clinically important difference values of quality of life in patients with fibromyalgia, between those with and without weather sensitivity.

Methods

Sixty-four consecutive outpatients with fibromyalgia on their first visit to our tertiary center were included. Weather sensitivity was measured using self-perceived symptoms. Pain intensity was measured using the 0–10 Numerical Rating Scale (NRS). Quality of life was measured using the Euro Quality of life-5 Dimensions-3 level (EQ-5D-3L) scale. The variables were subjected to univariable and multivariable analysis using the EQ-5D-3L scale.

Results

The mean age of the patients was 50 years. Forty-eight patients (75%) were women. The mean EQ-5D-3L score was 0.55. Thirty-seven patients (58%) reported weather sensitivity. In univariable analysis, the welfare recipient, weather sensitivity, and NRS values were associated with EQ-5D-3L scale scores. In multivariable analysis, NRS value and weather sensitivity were independently associated with EQ-5D-3L scale scores. The NRS and EQ-5D-3L scale scores were significantly worse in those with weather sensitivity than those without weather sensitivity. The difference in NRS values was less than 1.5 points between groups. The differences in EQ-5D-3L scale scores were 0.16 points between groups.

Conclusions

Weather sensitivity was significantly associated with quality of life in patients with fibromyalgia. There was an association with weather sensitivity and the minimal clinically important difference values of quality of life in patients with fibromyalgia. The presence of weather sensitivity could have a key role in the quality of life in patients with fibromyalgia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-021-00185-4.

Migraine Triggers: An Overview of the Pharmacology, Biochemistry, Atmospherics, and Their Effects on Neural Networks

We define a migraine trigger to be an endogenous agent or agency such as the menses or an exogenous agent or agency such as red wine or a drop in barometric pressure, and their ability to reduce the threshold of a migraine attack in those predisposed to migraine. This definition excludes agents with idiosyncratic mechanisms that may trigger a migrainous (migraine-like) headache in non-migraineurs such as benign cough headaches or headaches due to altitude-sickness. We also assume as axiomatic that migraine has as its basis the activation of the trigeminovascular pathway (TVP) and the key role of serotonin and the calcitonin gene-related peptide (CGRP). The network activation of the visual/auditory association cortices and the rostrodorsal pons (locus ceruleus and raphe nucleus) are also accepted as key features of activation of the TVP. In addition, we outline the role of the superior salivatory nucleus-sphenopalatine ganglion-greater superficial petrosal nerve (SSN-SPG-GSPN) arc in migraine activation.

We also explore how olfactory afferents intermingle with trigeminal nerve collaterals in the glomeruli of the olfactory bulb thus allowing volatile molecules to activate the TVP and induce a migraine. The classification of migraine triggers is complex, as there is a wide panorama of inciting agents, including atmospheric conditions, a wide-ranging variety of foods and beverages, endogenous hormonal influences, synthetic alkaloids and dyes, and volatile molecules (odorants). We will explore the high-frequency migraine-provoking agents in each category. There are exciting and intriguing hypotheses regarding the role of atmospheric chemistry when the barometric pressure drops; the role of hot, dry desert winds and lightning discharges in the generation of cations and the turnover of serotonin in the nervous system. We will explore the effects of a drop in barometric pressure on the vestibular nuclei and the modulation of sympathetically mediated pain. The role of volatile odorants and their activation of the transient receptor potential ankyrin-1 (TRPA-1) receptor will be outlined. We will streamline the highly complex role of estrogen fluctuation in the precipitation of migraine headaches, its pharmacodynamic effects, and the role of the sexually dimorphic nucleus of the preoptic area (SDN-POA) of the hypothalamus. We will also adumbrate the protean effects of alcohol and its congeners and the role of stress and sleep disturbances in the allostatic load model of salience network-pain perception.

Craniofacial sensations induced by transient changes of barometric pressure in healthy subjects – A crossover pilot study

Background:

Changes in atmospheric pressure are suggested to trigger headaches. This pilot study was made to determine craniofacial sensations accompanying short phases of changing barometric pressure.

Methods:

In a crossover design, 15 adult healthy subjects were exposed in a climate chamber to 8 min phases of barometric pressure lowering by 0, 20 and 40 hPa. The subjects rated their sensations of ear pressure, head compression and the occurrence of headache every minute on a visual analogue scale (VAS, range 0–10). Pulse rate was recorded as a parameter for autonomic functions.

Results:

Nearly all subjects experienced ear pressure and half of them compression of their head at variable degrees. These sensations started in most subjects during the phase of lowering barometric pressure and increased to an average rating of about 3 VAS when returning to ambient atmospheric pressure. Heart rate slightly decreased during this phase. Three subjects reported mild to moderate headache for various durations within these phases.

Conclusions:

Changes in barometric pressure can be associated with sensations of ear pressure and head compression and may trigger headaches. The generation of these sensations is discussed with regard to convergent trigeminal innervation of the ear, the paranasal sinuses and the cranial meninges.

Personality profiles and meteoropathy intensity: A comparative study between young and older adults

OBJECTIVES

This study's main aims were to investigate the Big Five personality trait heterogeneity of study participants in two age groups and to examine whether these traits' heterogeneity can explain possible individual differences in meteoropathy intensity.

METHOD

The sample was comprised of 758 participants divided into two age groups: 378 young adults (18-30 years old) and 380 older adults (60+ years old). The participants filled out online or paper versions of the METEO-Q questionnaire and the Ten Item Personality Inventory (TIPI).

RESULTS

A latent profile analysis of the completed inventories showed various personality profiles differ in meteoropathy intensity. However, personality's differentiating effect on meteoropathy was observed only among the young adult group.

CONCLUSIONS

Our study's results indicate that there is no one personality trait pattern that fits all individuals regarding sensitivity to weather changes. This issue is especially visible when considering age differences.

Environmental cue affects the hearing-related behaviors of Drosophila melanogaster by targeting the redox pathways

Environmental cues like noise, pressure, and circadian rhythm can affect the hearing ability of human beings. Nevertheless, the complex physiology of the human being does not allow us to understand how these factors can affect hearing and hearing-related behaviors. Conversely, these effects can be easily checked using the hearing organ of Drosophila melanogaster, the Johnston organ. In the current study, the Drosophila was exposed to challenging environments like noise, low pressure, and altered circadian rhythm. The hearing organ of larvae, as well as adults, was analyzed for hearing-related defects. In the third instar larva, the cell deaths were detected in the antenna imaginal disc, the precursor of Johnston's organ. Elevated levels of reactive oxygen species and antioxidant enzymes were also detected in the adult antennae of environmentally challenged flies. The ultrastructure of the antennae suggests the presence of abundant mitochondria in the scolopidia of control. Fewer amounts of mitochondria are found in the environmentally challenged adult antennae. In adults, various hearing-related behaviors were analyzed as a readout of functionality of the hearing organ. Analysis of climbing, aggressive, and courtship behaviors suggests abnormal behavior in environmentally challenged flies than the control. The current study suggests that the environmental cues can alter hearing-related behaviors in Drosophila. The methods used in this study can be used to monitor the environmental pollution or to study the effect of alteration of noise, pressure, and circadian rhythm on hearing-related behaviors taking Drosophila melanogaster as a model organism. Graphical abstract.

Examination of pain relief effect of Goreisan for glossodynia

BACKGROUND

Pain in glossodynia may be severe; it may prevent patients from working, interfere with daily life activities, and necessitate a patient's visit to a medical institution for consultation and treatment. The pain may be described as persistent and burning (tingling, tingling) or stinging. Patients may complain of dry mouth (dryness), which is thought to cause inflammation of the tongue and gingival mucous membranes and increased pain. Medications are prescribed based on the symptoms of glossodynia, and the therapeutic effect is confirmed. However, each drug has side effects, for example, pain may reduce, but drowsiness and dizziness may occur; further, there is always a tendency of drowsiness.On the other hand, Goreisan, a Chinese herbal medicine, has already been used by physicians to treat pain in the oral and maxillofacial regions resulting from rapid changes in air pressure. However, the lack of high-quality clinical research has been of concern, and a randomized clinical trial to investigate the efficacy and safety of Goreisan for treatment of pain in glossodynia is warranted.

METHODS/DESIGN

This multicenter, randomized, controlled study will involve patients treated for glossodynia-related pain. In the experimental group, Goreisan will be taken for 12 weeks in combination with conventional treatment. Participants in the control group will not take any Kampo medicine; only the standard treatment will be taken. Subsequently, the degree of pain will be assessed, and saliva tests of all the patients on their first visit will be performed. Goreisan will be taken at a dose of 7.5 g/d (minute 3) for 12 consecutive weeks. Twelve weeks later, the degree of pain of each patient will be assessed.

DISCUSSION

The purpose of this study is to investigate the efficacy of Goreisan for pain reduction in patients undergoing treatment for glossodynia-related pain. If pain in glossodynia patients can be reduced by the administration of Goreisan, its candidacy as an alternative treatment for pain in glossodynia can be further supported by more reliable research.

TRIAL REGISTRATION

The study was registered in the jRCTs071200017. URL https://jrct.niph.go.jp/latest-detail/jRCTs071200017.

Affective Temperaments and Meteoropathy Among Women: A Cross-sectional Study

The main goal of the study was to assess the relationship between affective temperaments and meteoropathy among women and examine meteorosensitivity as a mediator in this relationship. The issue of affective temperaments and meteoropathy has not been considered in the literature. The sample consisted of 450 Caucasian women gathered via the online recruitment platform. The participants’ ages ranged from 18 to 70 years (M = 30.01; SD = 9.10). The Polish version of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire was used to assess affective temperaments (depressive, cyclothymic, hyperthymic, irritable and anxious). Meteorosensitivity and meteoropathy were assessed using the Polish adaptation of the METEO-Q questionnaire. A large positive correlation was found between meteorosensitivity and meteoropathy. Medium positive correlations were found between meteorosensitivity/meteoropathy and cyclothymic and anxious temperaments. Small positive correlations were revealed between depressive and irritable temperaments and both meteorosensitivity and meteoropathy scales. No correlation was found between hyperthymic temperament and meteorosensitivity/meteoropathy. Mediation analyses indicated cyclothymic and anxious temperaments affected meteoropathy both directly and indirectly through meteorosensitivity as a mediator. The most severe meteoropathy symptoms in the studied sample were asthenia, an indefinite feeling of malaise and irritability. The results suggest affective temperaments may be related to meteoropathy symptoms in women.

Titanium-Nitride Coating Does Not Result in a Better Clinical Outcome Compared to Conventional Cobalt-Chromium Total Knee Arthroplasty after a Long-Term Follow-Up: A Propensity Score Matching Analysis

Background: The impact of titanium nitride (TiN) coating on implant components is controversial. TiN coating is proposed as having superior biomechanical properties compared to conventional cobalt-chromium (CoCr) alloy. This study compared long-term clinical data as well as meteoro-sensitivity in patients who underwent total knee arthroplasty (TKA), with either CoCr alloy or TiN coating. Methods: In this retrospective observational study, the clinically approved cemented “low contact stress” (LCS) TKA with conventional CoCr coating, was compared to un-cemented TiN-coated “advanced coated system” (ACS) TKA. Propensity score matching identified comparable patients based on their characteristics in a one-to-one ratio using the nearest-neighbor method. The final cohort comprised 260 knees in each cohort, with a mean follow-up of 10.1 ± 1.0 years for ACS patients and 14.9 ± 3.0 years for the LCS group. Physical examinations, meteoro-sensitivity, and knee scoring were assessed. Results: The clinical and functional Knee Society Score (KSS) (82.6 vs. 70.8; p < 0.001 and 61.9 vs. 71.1; p = 0.011), the postoperative Visual Analogue Scale (VAS) (2.9 vs. 1.4; p = 0.002), and the postoperative Tegner Score (2.6 vs. 2.2; p = 0.001) showed significant intergroup differences. The postoperative Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) was similar (79.9 vs. 81.3; p = 0.453) between groups. Meteoro-sensitivity of the artificial joint was significantly more prevalent in the ACS patient cohort (56% vs. 23%; p < 0.001). Conclusion: This study suggests that TiN coating does not provide improved clinical outcomes in this patient cohort after a long-term follow-up. Interestingly, sensitivity to weather changes were more correlated with un-cemented ACS implants.

Brain diseases in changing climate

Climate change is one of the biggest and most urgent challenges for the 21st century. Rising average temperatures and ocean levels, altered precipitation patterns and increased occurrence of extreme weather events affect not only the global landscape and ecosystem, but also human health. Multiple environmental factors influence the onset and severity of human diseases and changing climate may have a great impact on these factors. Climate shifts disrupt the quantity and quality of water, increase environmental pollution, change the distribution of pathogens and severely impacts food production - all of which are important regarding public health. This paper focuses on brain health and provides an overview of climate change impacts on risk factors specific to brain diseases and disorders. We also discuss emerging hazards in brain health due to mitigation and adaptation strategies in response to climate changes.