Stress Response Pattern of Heart Rate Variability in Patients with Functional Somatic Syndromes.

Functional somatic syndromes (FSSs) represent a clinically important group of disorders that are often stress-related. Their autonomic pathophysiology, including reduced heart rate variability (HRV), has been reported. However, the response pattern to mental stress and recovery in FSSs remains unclear. Thus, we aimed to clarify the pattern of autonomic stress response and recovery to mental arithmetic stress in patients with FSS compared to that in healthy controls. This cross-sectional study included 79 patients with FSS who visited the Department of Psychosomatic Medicine at a university hospital in Japan and 39 healthy controls. Following a mood questionnaire and obtaining epidemiologic information, HRV was measured during three periods (5 min each): relaxation baseline resting, stress (mental arithmetic task), and post-stress recovery period. The HRV analysis included inter-beat interval, low frequency power, and high frequency power. Compared to healthy controls, patients with FSS exhibited significantly higher scores on the mood questionnaire, prolonged duration of illness, and decreased functionality in daily activities. While the healthy control group showed a pronounced stress response pattern with a significant decrease in vagal HRV and recovery, the FSS group showed a "flat" vagal stress response pattern, and the HRV in the FSS group was lower at relaxation baseline, remained low during the stress, and did not change post stress. Patients with severe FSS exhibit an altered stress response pattern. Our results could provide significant clues for the diagnosis and treatment of such patients, as well as useful insights into the relationship between stress and illness.

Patients with postprandial distress syndrome experience problems with their interoceptive perceptual function to the gastric region, but their heartbeat perception is normal: a case control study.

BACKGROUND: Visceral hypersensitivity in functional dyspepsia can be localized or widespread, and there is no simple method of assessment. Measuring interoceptive accuracy at different sites provides an assessment of perceptual hypersensitivity to specific ecological phenomena. The purpose of this study was to characterize visceral hypersensitivity by comparing gastric sensory and cardiac perceptual tests in patients with postprandial distress syndrome and in healthy volunteers. METHODS: Sixteen patients with postprandial distress syndrome (age = 47.5 ± 17.4, all female) and 16 healthy volunteers (age = 43.3 ± 16.1, all female) participated in the study after a six-hour fast. Each participant answered questionnaires about physical and mental quality of life, depression and anxiety, tendency of alexithymia, and somatosensory amplification. After completing the questionnaire, the participants took the heartbeat tracking task and the five-minute water load test. We performed statistical analysis using the Mann-Whitney U test and Spearman's rank correlation coefficient. RESULTS: Subjects with postprandial distress syndrome had a lower drinking capacity than healthy volunteers (postprandial distress syndrome = 360.9 ± 170.0 mL, healthy volunteers = 644.1 ± 297 mL, P = 0.009), but there was no significant difference in the heartbeat perception score (postprandial distress syndrome = 0.599 ± 0.175, healthy volunteers = 0.623 ± 0.181, P = 0.647). There was a negative correlation (r = - 0.509, P < 0.05) between drinking capacity and the heartbeat perception score in healthy volunteers, but no correlation in postprandial distress syndrome (r = - 0.156, P = 0.564). Heartbeat perception score did not correlate with psychological measures. CONCLUSIONS: Compared with healthy volunteers, only the five-minute water load test values were reduced in patients with postprandial distress syndrome, and no difference was observed in the heartbeat tracking task. Combining the 5-minute water load test and the heart rate tracking task revealed a lost cardiac-gastric perceptual relationship in patients with postprandial distress syndrome that was not observed in healthy volunteers, suggesting that there is hypersensitivity in gastric interoceptive perceptual function. Performing sensory examinations at two different sites may be useful in clarifying whether visceral hypersensitivity is localized. TRIAL REGISTRATION: UMIN000057586. Registered11 March 2023(retrospectively registered).

Large rhabdoid meningioma presenting prominent hyperintensity in the optic nerve: An indicator of visual disturbance on constructive interference steady-state sequence?

Background: Rhabdoid meningiomas (RMs) are a rare type of malignant meningioma. Here, we report a case of intracranial RM presenting with visual disturbance and prominent hyperintensity in the optic nerve (ON). Case Description: A 20-year-old female presented with a 1-year history of headache. At presentation, her visual acuity (VA) was 20/50 on the right side and 20/40 on the left, with an intraocular pressure of 17 mmHg on both sides. Cerebral magnetic resonance imaging revealed a broad-based tumor in the right frontal convexity. It measured 82 mm × 65 mm × 70 mm in diameter, accompanied by cystic components, and was inhomogeneously enhanced. The intraorbital ONs demonstrated prominent intramedullary hyperintensity on the constructive interference steady-state sequence. Gross total tumor resection was performed and the pathology was consistent with RM. Immediately after surgery, her VA and IOP were 20/17 and 10 mmHg, respectively, with a remarkable resolution of the intramedullary hyperintensity. Conclusion: Prominent hyperintensity in the ON identified in patients with chronic intracranial hypertension may be an indicator of visual disturbance. It can rapidly resolve after resolution of intracranial hypertension with functional recovery.

[Re-Administration of Anti-EGFR Antibody Drugs for Unresectable Colorectal Cancer-Focusing on Tumor Markers].

The 2022 edition of the Guidelines for the Treatment of Colorectal Cancer described rechallenge therapy as a backward treatment for unresectable colorectal cancer, but currently, there is no evidence to support its benefit. We reviewed 6 cases of rechallenge therapy in which tumor marker trends could be followed in our department. Two cases had a rapid decline in tumor markers that was maintained for 7-8 months. In 3 cases, PR was also confirmed on imaging. In contrast, there was 1 case with no decrease in tumor markers at all. Our findings suggest that cases of wild-type RAS prior to rechallenge therapy and cases that are responsive to initial anti-EGFR antibody drugs may have been involved in the effect of rechallenge therapy.

Large arachnoid granulation protruding into the transverse sinus: A probable cause of intermittent otologic symptoms.

A 69-year-old woman suffered attacks of hearing disturbance and vertigo for seven years. Her otologic and ophthalmological examinations did not show any significant findings. Cerebral magnetic resonance imaging revealed a cystic mass in the left cerebellar convexity. Computed tomography demonstrated a contrast defect of the distal left transverse sinus. Magnetic resonance imaging revealed a cyst protruding into the transverse sinus, and enlarging in the supine. Cerebral angiography demonstrated a congestive venous flow in the left transverse sinus, at the upstream of the cyst. At rest, the venous sinus pressure was 13 cm H2O at the upstream of the cyst and 8 cm H2O at the downstream. When the patient held a breath, the upstream pressure increased to 37 cm H2O, while the maximal downstream pressure was 22 cm H2O. A large AG protruding into the cranial dural sinus may cause intermittent venous congestion and associated otologic symptoms. Movements accompanied by a transient decrease in cardiac venous return and changes in head position can attribute to an enlargement of such AG.

Development of the efficient preparation method for thermoresponsive elastin-like peptides using liquid-phase synthesis combined with fragment condensation strategy.

Elastin-like peptides (ELPs) are synthetic peptides that mimic the characteristic hydrophobic amino acid repeat sequences of elastin and exhibit temperature-dependent reversible self-assembly properties. ELPs are expected to be used as temperature-responsive biomolecular materials across diverse industrial and research fields, and there is a requirement for a straightforward method to mass-produce them. Previously, we demonstrated that phenylalanine-containing ELP analogs, namely, (FPGVG)n , can undergo coacervation with short chains (n = 5). The Fmoc solid-phase peptide synthesis method is one strategy used to synthesize these short ELPs. However, owing to its low reaction efficiency, an efficient method for preparing ELPs is required. In this study, efficient preparation of ELPs was investigated using a liquid-phase synthesis method with a hydrophobic benzyl alcohol support (HBA-tag). Because HBA-tags are highly hydrophobic, they can be easily precipitated by the addition of poor solvents and recovered by filtration. This property allows the method to combine the advantages of the simplicity of solid-phase methods and the high reaction efficiency of liquid-phase methods. By utilizing liquid-phase fragment condensation with HBA-tags, short ELPs were successfully obtained in high yield and purity. Finally, the temperature-dependent response of the ELPs generated through fragment condensation was assessed using turbidity measurements, which revealed a reversible phase transition. Consequently, the ELPs exhibited a reversible phase transition, indicating successful synthesis of ELPs via fragment preparation with tags. These findings provide evidence of the potential for mass production of ELPs using this approach.

Fibrinogen-to-lymphocyte Ratio Predicts the Outcomes of Hypopharyngeal Squamous Cell Carcinoma Treated With Definitive Radiotherapy.

BACKGROUND/AIM: Previous studies have identified several inflammatory biomarkers that are useful as prognostic biomarkers for various cancer types. However, the fibrinogen-to-lymphocyte ratio (FLR) has not been addressed in head and neck squamous cell carcinoma. Here, we aimed to examine the value of pretreatment FLR as a prognostic marker in patients who received definitive radiotherapy for hypopharyngeal squamous cell carcinoma (HpSCC). PATIENTS AND METHODS: This retrospective study included 95 patients treated with definitive radiotherapy for HpSCC between 2013 and 2020. The prognostic factors for progression-free (PFS) and overall (OS) survival were identified. RESULTS: The optimal cut-off value of pretreatment FLR for discriminating PFS was 2.46. Based on this value, 57 and 38 patients were classified into groups with high and low FLR, respectively. A high FLR was significantly associated with advanced local disease and overall stage, and with the development of synchronous second primary cancer compared with a low FLR. The high FLR group had significantly lower PFS and OS rates than the low FLR group. Multivariate analysis showed that having a high pretreatment FLR was an independent prognostic factor for poorer PFS and OS [PFS: hazard ratio (HR)=2.14, 95% confidence interval (CI)=1.09-4.19, p=0.026; OS: HR=2.86, 95% CI=1.14-7.20, p=0.024]. CONCLUSION: The FLR has a clinical effect on PFS and OS in patients with HpSCC, suggesting that it has potential application as a prognostic factor for patients with HpSCC.

Effects of eating together online on autonomic nervous system functions: a randomized, open-label, controlled preliminary study among healthy volunteers.

BACKGROUND: Eating alone has been significantly associated with psychological distress. However, there is no research that evaluates the effects or relation of eating together online to autonomic nervous system functions. METHODS: This is a randomized, open-label, controlled, pilot study conducted among healthy volunteers. Participants were randomized into either an eating together online group or an eating-alone group. The effect of eating together on autonomic nervous functions was evaluated and compared with that of the control (eating alone). The primary endpoint was the change in the standard deviation of the normal-to-normal interval (SDNN) scores among heart rate variabilities (HRV) before and after eating. Physiological synchrony was investigated based on changes in the SDNN scores. RESULTS: A total of 31 women and 25 men (mean age, 36.6 [SD = 9.9] years) were included in the study. In the comparison between the aforementioned groups, two-way analysis of variance revealed interactions between time and group on SDNN scores. SDNN scores in the eating together online group increased in the first and second halves of eating time (F[1,216], P < 0.001 and F[1,216], P = 0.022). Moreover, high correlations were observed in the changes in each pair before and during the first half of eating time as well as before and during the second half of eating time (r = 0.642, P = 0.013 and r = 0.579, P = 0.030). These were statistically significantly higher than those in the eating-alone group (P = 0.005 and P = 0.040). CONCLUSIONS: The experience of eating together online increased HRV during eating. Variations in pairs were correlated and may have induced physiological synchrony. TRIAL REGISTRATION: The University Hospital Medical Information Network Clinical Trials Registry, UMIN000045161. Registered September 1, 2021. https://center6.umin.ac.jp/cgi-open-bin/icdr/ctr_view.cgi?recptno=R000051592 .

Penetrating orbitocranial injury by shoji frame: A rare indoor accident in a Japanese style house.

Background: To the best of our knowledge, there are no reports of penetrating orbitocranial injury (POCI) caused by a shoji frame. Case Description: A 68-year-old man fell in his living room and was stuck headfirst by a shoji frame. At presentation, marked swelling was noted in the right upper eyelid, with the edge of the broken shoji frame exposed superficially. Computed tomography (CT) revealed a hypodense linear structure located in the upper lateral sector of the orbit, partially protruding into the middle cranial fossa. Contrast-enhanced CT revealed intact ophthalmic artery and superior ophthalmic vein. The patient was managed with frontotemporal craniotomy. The shoji frame was extracted by pushing out the extradurally located proximal edge from the cranial cavity and simultaneously pulling the distal edge from the stab wound in the upper eyelid. Postoperatively, the patient received intravenous antibiotic therapy for 18 days. Conclusion: POCI can be caused by shoji frames as a result of an indoor accident. The broken shoji frame is evidently delineated on CT, which can result in prompt extraction.

Possible association between minor head injury and intratumoral hemorrhage: A metastatic brain tumor from thyroid carcinoma.

A 78-year-old woman presented after a fall and injury in the left forehead. She had undergone surgery for papillary thyroid carcinoma 14 years prior and breast carcinoma 7 years prior. The patient had exhibited uneventful postoperative courses without relapse or metastasis. Anticoagulants or antiplatelet agents were not prescribed her. At presentation, the patient exhibited no focal neurological deficits. Computed tomography revealed a 19 × 20 mm hemorrhagic lesion in the right temporal lobe. On cerebral magnetic resonance imaging, the center of the lesion exhibited inhomogeneous intensity on both T1- and T2-weighted sequences with heterogeneous enhancement. In contrast, the perilesional hemorrhagic regions, appearing hyperintense on both T1- and T2-weighted sequences, showed temporary regression followed by marked enlargement over the subsequent 123 days. The patient underwent total tumor resection. The microscopic findings of the resected specimens were consistent with papillary thyroid carcinoma. Minor head injuries may trigger intratumoral hemorrhage in metastatic brain tumors. Metastasis should be assumed when patients with a history of thyroid carcinoma present with a solitary parenchymal lesion with the appearance of cerebral cavernous malformation, even if they have been disease free for a long period.

Anaplastic oligodendroglioma presenting with apoplectic intratumoral hemorrhage.

A 31-year-old woman presented with a headache and nausea. At presentation, her blood pressure was 114/71 mm Hg with left hemiparesis. Computed tomography revealed a large hyperdense mass in the right temporal lobe accompanied by intralesional calcifications and ventricular perforation. Spot signs were not identified, and cerebral angiography did not reveal any abnormal vasculature. The patient underwent emergency craniotomy assuming an intracerebral hemorrhage. Intraoperatively, grayish tumor tissue was found to intermingle with the clots. Microscopic findings of the tumor revealed neoplastic cells possessing perinuclear halo and cell atypia, and diffusely stained with glial fibrillary acidic protein, which were consistent with anaplastic oligodendrogliomas. However, genomic analyses of the tumor showed non-mutant isocitrate dehydrogenase 1 and telomerase reverse transcriptase, in addition to wild-type O6-methylguanine DNA-methyltransferase. These are equivalent to glioblastoma multiforme. Based on the results, we assumed that anaplastic oligodendrogliomas may develop apoplectic intratumoral hemorrhages that mimic intracerebral hemorrhage. Genomic exploration is recommended for such tumors, coupled with careful follow-up, owing to its potentially aggressive nature.

Effect of visual feedback during ultrasound-guided hydrodissection for myofascial pain syndrome: An exploratory, prospective, observational clinical trial on the expectations for treatment.

Expectations for treatment have a favorable effect on the subsequent course of pain and behavior in patients. It is not known whether receiving hydrodissection while patients view their ultrasound image with doctors (visual feedback) is associated with positive treatment expectations. This was an exploratory, prospective, observational clinical trial. We explored the possibility that visual feedback immediately after ultrasound-guided hydrodissection increases the expectations for treatment, which could be one of the related factors for pain reduction. Treatment expectations were set as mediators of pain using path analysis. The primary endpoint was the numerical rating scale to assess expectations for treatment immediately after hydrodissection, between with and without the visual feedback. During 2019 and 2020, 136 outpatients received ultrasound-guided hydrodissection for myofascial pain syndrome. Of these, 65 (47.8%) patients received visual feedback during ultrasound-guided hydrodissection. Compared with the non-visual feedback group, the visual feedback group had higher expectations for treatment immediately after hydrodissection, and their expectations were maintained at day 14 of treatment (p < 0.001). A numerical rating scale (NRS) to assess expectations for treatment was similar before hydrodissection and immediately after hydrodissection was 8.4 (standard deviations, 1.6) in the visual feedback and 5.9 (standard deviations, 2.6) in the visual feedback. The proportion of increased expectations immediately after hydrodissection was 90.8% (95% CI: 83.7-97.9) in visual feedback group and 38.0% (95% CI: 26.7-49.3) in non-visual feedback group (p < 0.001). In the visual feedback group, 67.7% of patients showed improvement in pain numerical rating scale score by 50% or more at day 14, whereas such improvement was observed in only 36.6% of the non-visual feedback group (p < 0.001). Based on path analysis, the visual feedback had the greatest influence on pain numerical rating scale reduction at 14 days, indirectly due to increased expectations for treatment as a mediator (ß = 0.434). However, the adjusted R 2 values, which is the overall fit of the model, was low at 0.298. Visual feedback during ultrasound-guided hydrodissection increases the expectations for treatment immediately after hydrodissection, which could be one of the related factors for pain reduction in patients with myofascial pain syndrome.

A Case Report of Primary Unresectable Hilar Cholangiocarcinoma Causing Colonic Obstruction Due to Peritoneal Dissemination.

Although surgical resection is the only available treatment to achieve long-term survival in biliary tract cancer, many cases are often identified at an advanced stage at the time of diagnosis. Radiotherapy may be an alternative option to prolong survival in cases with locally advanced unresectable disease. While there are some reports of long-term survival after radiotherapy for unresectable biliary tract cancer, it is rare that clinical symptoms are exhibited by peritoneal dissemination more than 8 years after radiotherapy and that resection can be performed. Our case was a 55-year-old female who had visited with a complaint of jaundice and was diagnosed with primary unresectable hilar cholangiocarcinoma. She received definitve chemoradiotherapy, and repeated receiving maintenance chemotherapy thereafter until clinical manifestation. During follow-up, she was diagnosed with stenosis of the sigmoid colon, which was attributed to peritoneal dissemination of cholangiocarcinoma. We herein report a rare case of primary unresectable hilar cholangiocarcinoma after chemoradiotherapy which was followed by chemotherapy that was controlled for more than 8 years but eventually caused colonic obstruction attributed to peritoneal dissemination.

π-Topology and ultrafast excited-state dynamics of remarkably photochemically stabilized pentacene derivatives with radical substituents.

Pentacene derivatives with both π-radical- and TIPS-substituents (1m and 1p) were synthesized and their photochemical properties and excited-state dynamics were evaluated. The pentacene-radical-linked systems 1m (1p) showed a remarkable improvement in photochemical stability, which was 187 (139) times higher than that of 6,13-bis(triisopropylsilylethynyl)pentacene. Transient absorption spectroscopy showed that this remarkable photostabilization is due to the ultrafast intersystem crossing induced by effective π-conjugation between the radical substituent and pentacene moiety. The relationship between π-topology and the photochemical stability is also discussed based on the excited-state dynamics.

Prevalence of Myofascial Pain Syndrome and Efficacy of Trigger Point Injection in Patients with Incurable Cancer: A Multicenter, Prospective Observational Study (MyCar Study).

OBJECTIVE: Myofascial pain syndrome (MPS) is caused by overload or disuse of skeletal muscles. Patients with cancer are often forced to restrict their movement or posture for several reasons. The study was conducted to investigate the prevalence and risks of MPS in patients with incurable cancer. The efficacy of trigger point injection (TPI) was also explored. METHODS: This was a multicenter, prospective observational study. Patients with incurable cancer who started receiving specialist palliative care were enrolled. We investigated the MPS in this population and accompanying risk factors for restricting body movement. Pre- and post-TPI pain was also evaluated using a Numerical Rating Scale (NRS) in patients who received TPI. The primary outcome was the prevalence of MPS. RESULTS: A total of 101 patients were enrolled from five institutions in Japan. Most of the patients (n = 94, 93.1%) had distant metastases, and half of the patients (50, 49.5%) received anticancer treatment. Thirty-nine (38.6%) patients had MPS lesions at 83 sites. Multivariate analysis revealed that the significant risk factor for MPS was poor Performance Status (PS) (odds ratio 3.26; 95% confidence interval [CI] 1.18-9.02, P = .023). We performed TPI for 40 out of 83 MPS lesions. Mean NRS for MPS before TPI was 7.95, which improved to 4.30 after TPI (P < .001). CONCLUSIONS: MPS was common in patients with incurable cancer and the risk factor identified in this study was poor performance status. TPI could be a treatment option.

[A Case of Ascending Colon Cancer with Skull Metastasis].

A 55-year-old woman became aware of a tumor on the left side of the head in July, 2020 and was referred to our hospital in September because of its rapid growth. A head CT showed a neoplastic lesion of the skull. A CT from the neck to the pelvis revealed an ascending colon tumor and multiple lesions in the liver, which was suspected as metastasis. A colonoscopy also showed a type 2 like lesion in the ascending colon, and a biopsy showed adenocarcinoma. A pedunculated polyp had been pointed out in the ascending colon at another hospital four years previously, and the pathological result was an adenoma, but endoscopic mucosal resection was not performed. It is considered that the adenoma became advanced colon cancer with metastasis through the mechanism of multistage carcinogenesis. Metastatic lesions of the ascending colon cancer was suspected with regard to the skull lesion. In addition to the rapid growth, surgical removal was desirable from the viewpoint of cosmetology, and surgery was performed in November. The postoperative pathological diagnosis was a metastatic skull tumor derived from ascending colon cancer. The diagnosis was Stage IVb according to the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma (9th Edition). Although chemotherapy was started after surgery, the metastatic liver cancer increased rapidly and the patient passed away in April, 2021.

Aurophilic Interactions in Multi-Radical Species: Electronic-Spin and Redox Properties of Bis- and Tris-[(Nitronyl Nitroxide)-Gold(I)] Complexes with Phosphine-Ligand Scaffolds.

Multinuclear AuI complexes with two or three nitronyl nitroxide-2-ide radical anion and phosphine-ligand scaffolds, (NN-Au)2 -1 o, (NN-Au)2 -1 m, and (NN-Au)2 -1 p, have been synthesized to investigate the influence of AuI -AuI (aurophilic) interactions on the properties of multispin molecular systems. The desired complexes were successfully prepared in moderate yields in a one-pot synthesis from the corresponding phosphine ligand, AuI source, parent NN, and sodium hydroxide. Among the prepared complexes, (NN-Au)2 -1 o, in which an aurophilic interaction was clearly observed by crystal structure analysis, showed characteristic spin-spin interactions, electrochemical properties, and solvatochromic behavior. The results from theoretical calculations also suggested that the differences in properties between complex (NN-Au)2 -1 o and the other complexes are due to intramolecular aurophilic interactions.

[Two Cases of Synchronous Double Primary Prostate Cancer Accompanying Bone Metastasis and Colon Cancer].

We report two cases of synchronous double primary cancers, which were composed of prostate cancer accompanied by bone metastasis and colon cancer, within only five months of each other. The first was a 77-year-old man whose ECOG PS was 0. He was referred to our hospital in March 2020 because abdominal CT scan, which was performed at a clinic for the purpose of close examination of poor control of diabetes, showed wall thickening of the sigmoid colon. A further examination revealed prostate cancer accompanied by metastatic bone cancer and sigmoid colon cancer. Laparoscopic sigmoid colectomy was performed in April. Currently, six months after the surgery, both the prostate cancer and its accompanying metastatic bone cancer are well controlled by hormonal therapy. The second case was an 86-year-old man with an ECOG PS of 3 who was brought to our hospital by ambulance in August, 2020 because of fever and abdominal pain. A close examination revealed cecal cancer accompanying acute appendicitis. Prostate cancer accompanied by metastatic bone cancer was also diagnosed. Laparoscopic ileocecal resection was performed in the same month, but, unfortunately, the patient had repeated aspiration pneumonia and he finally passed away 43 days after surgery. We discuss the treatment strategy for colorectal cancer with synchronous or metachronous prostate cancer, which has been increasing in recent years, and include epidemiological considerations.

Tropical cyclone motion in a changing climate.

The locally accumulated damage by tropical cyclones (TCs) can intensify substantially when these cyclones move more slowly. While some observational evidence suggests that TC motion might have slowed significantly since the mid-20th century (1), the robustness of the observed trend and its relation to anthropogenic warming have not been firmly established (2-4). Using large-ensemble simulations that directly simulate TC activity, we show that future anthropogenic warming can lead to a robust slowing of TC motion, particularly in the midlatitudes. The slowdown there is related to a poleward shift of the midlatitude westerlies, which has been projected by various climate models. Although the model's simulation of historical TC motion trends suggests that the attribution of the observed trends of TC motion to anthropogenic forcings remains uncertain, our findings suggest that 21st-century anthropogenic warming could decelerate TC motion near populated midlatitude regions in Asia and North America, potentially compounding future TC-related damages.

Global warming changes tropical cyclone translation speed.

Slow-moving tropical cyclones (TCs) can cause heavy rain because of their duration of influence. Combined with expected increase in rain rates associated with TCs in a warmer climate, there is growing interest in TC translation speed in the past and future. Here we present that a slowdown trend of the translation speed is not simulated for the period 1951-2011 based on historical model simulations. We also find that the annual-mean translation speed could increase under global warming. Although previous studies show large uncertainties in the future projections of TC characteristics, our model simulations show that the average TC translation speed at higher latitudes becomes smaller in a warmer climate, but the relative frequency of TCs at higher latitudes increases. Since the translation speed is much larger in the extratropics, the increase in the relative frequency of TCs at higher latitudes compensates the reduction of the translation speed there, leading to a global mean increase in TC translation speed.