Comparison of Clinical Characteristics of Traumatic Brain Injury Patients According to the Mechanism Before and After COVID-19.

Objective: This study investigated the change in the number of patients with head trauma according to the trauma mechanism among severely injured patients transferred to the emergency department of Wonju Severance Christian Hospital before and during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Medical records (sex, age, diagnosis, trauma mechanism, and injury severity score) of patients referred to the emergency room between January 2018 and December 2019 and January 2020 and December 2021 were retrospectively reviewed, verified, and compared. Results: Between 2020 and 2021, the number of patients with traumatic brain injury decreased by 251 (32%). No significant differences were observed in sex, age, or time of accident. From 2020 to 2021, among the trauma mechanisms, the number of cases involving rolling down slightly reduced compared with those involving other mechanisms. Furthermore, cerebral contusions among intracranial lesions significantly increased during the COVID-19 pandemic. Conclusion: Partial restrictions on social activities owing to COVID-19 are ongoing. Further investigation of the clinical characteristics of trauma patients over a longer period is required.

Case Report of a Post-Traumatic Hydrocephalus Patient: Ventriculo-Vesicle Shunt With a Review of the Literature.

Post-traumatic hydrocephalus (PTH) is treated through cerebrospinal fluid (CSF) diversion, typically through ventriculoperitoneal shunt (VPS) or other bypass techniques. As these shunts are associated with significant complications and high revision rates in certain populations, it is important to tailor a patient's shunt procedure according to their medical history and complications. Herein, we report the case of a 30-year-old man with PTH following a traffic accident on a motorcycle. VPS was chosen as the method of treatment but required multiple revisions and replacements due to persistent complications such as post-operative infection, shunt obstruction and abdominal problem. As the patient's heart failure and pleural effusion rendered both ventriculopleural and ventriculoatrial shunt not feasible, it was decided to move the shunt to the bladder (ventriculo-vesicle shunt [VVS]) in cooperation with a urologist. Follow-up examinations after about 3 months showed a decrease in ventricle size, improved hydrocephalus, and no complications such as urinary infection or bladder stone formation. In cases where the patient's underlying conditions, such as heart failure and pleural effusion, make it unsuitable to choose the pleural cavity or atrium as non-peritoneal spaces, VVS can be a suitable option for continuous CSF drainage when complications have occurred with the previous VPS.

Factors Associated With Short-Term Outcomes of Burr-Hole Craniostomy Associated With Brain Re-Expansion and Subdural Hematoma Shrinkage for Chronic Subdural Hematoma.

Objective: Chronic subdural hematoma (CSDH) is a commonly encountered neurosurgical pathology that frequently requires surgical intervention. With an increasingly aging demographic, more older people and patients with comorbidities will present with symptomatic CSDH. This study evaluated clinical and laboratory factors affecting the short-term outcomes of CSDH after surgical intervention. Methods: We retrospectively analyzed 170 patients who underwent burr-hole trephination for CSDH in a single institution from January 2019 to December 2021. All patients were examined for risk factors and evaluated for hematoma thickness change and midline shifting on brain computed tomography (CT) scans at 3 days after burr-hole trephination. Results: This consecutive series of patients included 114 males (67.1%) and 56 females (32.9%); mean age 72.4±12.5 years. Renal disease (p=0.044) and prior intracranial hemorrhage (p=0.004) were clinical factors associated with poorer prognosis. A statistically significant association was found between initial laboratory findings, including high creatine kinase (p=0.025) and low platelet (p=0.036) levels, and CT findings 3 days postoperatively. The 3-day mean arterial pressure and postoperative ambulation were not significantly associated with outcomes. Conclusion: Burr-hole craniostomy is an effective surgical procedure for initial CSDH. However, patients with a history intracranial hemorrhage and abnormal laboratory findings, such as low platelet levels, who underwent burr-hole trephination had poor short-term outcomes. Therefore, these patients should be carefully monitored.

A direct method to access various functional arylalkoxysilanes by Rh-catalysed intermolecular C-H silylation of alkoxysilanes.

Efficient protocols for intermolecular C-H silylations of unactivated arenes and heteroarenes with HMe2SiOEt are disclosed. The silylations are catalysed by a Rh-complex (0.5 mol%) derived from commercially available [Rh(coe)2Cl]2 and (S,S)-Ph-BPE in the presence of cyclohexene at 100 °C, furnishing desired arylethoxydimethylsilanes up to 99% yield. The regioselectivity is mainly affected by the steric bulk of the substituents in arenes and by electronic effects as an ancillary factor. Mechanistic study revealed that the mono-hydrido dimeric Rh-complex, [Rh2(Ph-BPE)2(µ-H)(µ-Cl)], is an active catalytic intermediate, which further suppresses the formation of redistribution byproducts in the silylation. Preliminary results show that the current protocol can be extended to double C-H silylations affording bis-silylated arenes and is applicable to the silylation of HMeSi(OEt)2 to deliver the corresponding (aryl)SiMe(OEt)2.

Spinal Cord Infarction After Transarterial Chemoembolization for Hepatocellular Carcinoma.

Transarterial chemoembolization (TACE) is an effective treatment for unresectable hepatocellular carcinoma (HCC). It is considered relatively safe. However, fatal complications such as pulmonary edema and liver abscesses can occur. Spinal infarction due to local embolism of the central nervous system after TACE is a very rare, but fatal complication. Here, we report a case of spinal cord infarction after TACE for ruptured HCC. Paraplegia occurred at the T10 sensory level 6 hours after the procedure. The patient received steroid megadose therapy but died 5 days later due to exacerbation of metabolic acidosis and blood loss. This case demonstrates the need for a comprehensive and extensive study of arterial blood flow prior to angiography.

Factors Associated With Subdural Hygroma Following Mild Traumatic Brain Injury.

Objective: Subdural hygroma (SDG) is a complication of traumatic brain injury (TBI). In particular, the outcome and outpatient treatment period may vary depending on the occurrence of SDG. However, the pathogenesis of SDG has not been fully elucidated. Therefore, this study aimed to identify the risk factors associated with the occurrence of SDG after mild TBI. Methods: We retrospectively analyzed 250 patients with mild TBI admitted to a single institution between January 2021 and December 2021. The SDG occurrence and control groups were analyzed according to the risk factors of SDG, such as age, history, initial computed tomography (CT) findings, and initial laboratory findings. Results: The overall occurrence rate of SDG was 31.6% (n=79). A statistically significant association was found between preoperative diagnoses and the occurrence of SDG, such as subarachnoid hemorrhage (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.26-4.39) and basal skull fracture (OR, 0.32; 95% CI, 0.12-0.83). Additionally, age ≥70 years (OR, 3.20; 95% CI, 1.74-5.87) and the use of tranexamic acid (OR, 2.12; 95% CI, 1.05-4.54) were statistically significant factors. The prognostic evaluation of patients using the Glasgow Outcome Scale (GOS) did not show any statistical differences between patients with and without SDG. Conclusion: SDG was not associated with the prognosis of patients assessed using the GOS. However, depending on the occurrence of SDG, differences in patient symptoms may occur after mild TBI. Therefore, the early evaluation of patients with mild TBI and determination of the probability of developing SDG are important.

Factors associated with rebleeding after coil embolization in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Aneurysmal subarachnoid hemorrhage (aSAH) has a high mortality rate, and hemorrhage amounts and perioperative rebleeding importantly determines prognosis. However, despite adequate treatment, prognosis is poor in many ruptured aneurysm cases. In this study, we identified and evaluated factors related to perioperative rebleeding in patients with aSAH. METHODS: The medical and surgical records of 166 patients that underwent endovascular embolization for a ruptured cerebral aneurysm at a single institution from 2014 to 2016 were retrospectively analyzed to identify risk factors of rebleeding. All patients were examined for risk factors and evaluated for increased hemorrhage by brain computed tomography at 3 days after surgery. RESULTS: This series included 54 men (32.5%) and 112 women (67.5%) of mean age 58.3±14.3 years. After procedures, 26 patients (15.7%) experienced rebleeding, and 1 of these (0.6%) experienced an intraoperative aneurysmal rupture. External ventricular drainage (EVD) (odds ratio [OR] 5.389, [95% confidence interval (CI) 1.171- 24.801]) and modified Fisher grade (OR 2.037, [95% CI 1.077-3.853]) were found to be independent risk factors of rebleeding, and perioperative rebleeding was strongly associated with patient outcomes (p＜0.001). Conclusions: We concluded the rebleeding risk after aSAH is greater in patients with large hemorrhage amounts and a high pre-operative modified Fisher grade, and thus, we caution neurosurgeons should take care in such cases.

Factors associated with hemodynamic instability following carotid artery stenting.

OBJECTIVE: Carotid artery stenting (CAS) is a major treatment option for carotid artery stenosis, and a recognized alternative to carotid endarterectomy (CEA). However, CAS-related hemodynamic instability occurs frequently and is a known major risk factor of associated complications. This study was undertaken to identify the risk factors of hemodynamic instability associated with CAS. METHODS: We analyzed the medical records of 128 patients with carotid artery stenosis treated by CAS at our institution from 2014 to 2019 to identify the risk factors of hemodynamic instability after CAS. In addition, the incidences of hemodynamic instability, including bradycardia and hypotension, during and after the procedure were investigated. RESULTS: Overall, periprocedural bradycardia requiring atropine occurred in 18 (14.1 %) of the 128 study subjects, and postprocedural persistent hypotension requiring vasopressors occurred in 15 (11.7 %). Risk-adjusted analysis showed carotid bulb involvement of a stenotic lesion was an independent risk factor of periprocedural bradycardia (OR 4.25, 95 % CI 1.34-13.40) and postprocedural persistent hypotension (OR 7.36, 95 % CI 1.86-29.12). However, though a preoperative regimen of ≥ 2 antihypertensives was found to be an independent protective factor against postprocedural persistent hypotension (OR 0.17, 95 % CI 0.04-0.81), it was not associated with periprocedural bradycardia (OR 0.37 95 % CI 0.08-1.60). CONCLUSIONS: The risk of hemodynamic instability development is greater when a carotid stenotic lesion involves the carotid bulb, which cautions that careful evaluation is necessary. In addition, the receipt of antihypertensive regimens before CAS had a protective effect on persistent hypotension after CAS, but did not affect bradycardia.

Safety of heparin loading during endovascular embolization in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Of the complications that can occur during endovascular surgery in aneurysmal subarachnoid hemorrhage (aSAH) patients, thromboembolism remains a particular challenge for many surgeons. Heparin has been widely used for its prevention, but it has not been able to eliminate concerns about bleeding. Therefore, in this study, we tried to determine the risk of rebleeding associated with heparin use. METHODS: We retrospectively analyzed the medical and surgical records of 109 patients that underwent endovascular embolization for a ruptured cerebral aneurysm at a single institution from 2010 to 2014. These patients were divided into two groups according to whether heparin was loaded or not, to determine the effect of heparin on rebleeding and to identify other risk factors of rebleeding. RESULTS: This series included 40 men (36.7 %) and 69 women (63.3 %) of mean age 57.9 ± 14.8 years. In 80 patients (73.4 %), endovascular embolization was conducted using an intraoperative bolus of 5000 units of heparin, whereas in the other 29 (26.6 %) endovascular embolization was performed without an intraoperative heparin bolus. After procedures, 16 patients (14.7 %) experienced rebleeding and 2 (1.8 %) a thromboembolic event. Intraoperative heparin loading (OR 0.683 [95 % CI 0.199-2.338]) was not found to be related to postoperative rebleeding. Rather, logistic regression analysis showed preoperative modified Fisher grade (OR 2.037 [95 % CI 1.077-3.853]) and external ventricular drainage (OR 5.389 [95 % CI 1.171-24.801]) independently predicted rebleeding. CONCLUSIONS: Heparin loading during endovascular treatment of ruptured cerebral aneurysms did not affect rebleeding. We conclude heparin loading to prevent thromboembolism during endovascular treatment may be considered a good option in aSAH patients.

Missed Skeletal Trauma Detected by Whole Body Bone Scan in Patients with Traumatic Brain Injury.

OBJECTIVE: Unclear mental state is one of the major factors contributing to diagnostic failure of occult skeletal trauma in patients with traumatic brain injury (TBI). The aim of this study was to evaluate the overlooked co-occurring skeletal trauma through whole body bone scan (WBBS) in TBI. METHODS: A retrospective study of 547 TBI patients admitted between 2015 and 2017 was performed to investigate their cooccurring skeletal injuries detected by WBBS. The patients were divided into three groups based on the timing of suspecting skeletal trauma confirmed : 1) before WBBS (pre-WBBS); 2) after the routine WBBS (post-WBBS) with good mental state and no initial musculoskeletal complaints; and 3) after the routine WBBS with poor mental state (poor MS). The skeletal trauma detected by WBBS was classified into six skeletal categories : spine, upper and lower extremities, pelvis, chest wall, and clavicles. The skeletal injuries identified by WBBS were confirmed to be simple contusion or fractures by other imaging modalities such as X-ray or computed tomography (CT) scans. Of the six categorizations of skeletal trauma detected as hot uptake lesions in WBBS, the lesions of spine, upper and lower extremities were further statistically analyzed to calculate the incidence rates of actual fractures (AF) and actual surgery (AS) cases over the total number of hot uptake lesions in WBBS. RESULTS: Of 547 patients with TBI, 112 patients (20.4 %) were presented with TBI alone. Four hundred and thirty-five patients with TBI had co-occurring skeletal injuries confirmed by WBBS. The incidences were as follows : chest wall (27.4%), spine (22.9%), lower extremities (20.2%), upper extremities (13.5%), pelvis (9.4%), and clavicles (6.3%). It is notable that relatively larger number of positive hot uptakes were observed in the groups of post-WBBS and poor MS. The percentage of post-WBBS group over the total hot uptake lesions in upper and lower extremities, and spines were 51.0%, 43.8%, and 41.7%, respectively, while their percentages of AS were 2.73%, 1.1%, and 0%, respectively. The percentages of poor MS group in the upper and lower extremities, and spines were 10.4%, 17.4%, and 7.8%, respectively, while their percentages of AS were 26.7%, 14.2%, and 11.1%, respectively. There was a statistical difference in the percentage of AS between the groups of post-WBBS and poor MS (p=0.000). CONCLUSION: WBBS is a potential diagnostic tool in understanding the skeletal conditions of patients with head injuries which may be undetected during the initial assessment.

Influence of Antithrombotic Medication on the Risk of Chronic Subdural Hematoma Recurrence after Burr-Hole Surgery.

OBJECTIVE: Chronic subdural hematoma (CSDH) is one of the most common intracranial hemorrhages. It can be managed with a simple surgical treatment such as burr-hole trephination and drainage. However, it has a relatively high recurrence rate. The mechanisms and risk factors for the recurrence have not yet been clearly identified and studies have reported varying results. METHODS: We analyzed 230 patients with CSDH who were treated with burr-hole trephination and drainage at our institution from March 2011 to March 2016. The patients were divided into recurrence and non-recurrence groups and the medical records of each group were used to analyze the risk factors associated with CSDH recurrence. RESULTS: After burr-hole trephination and drainage, CSDH recurrence was observed in 49 (21.3%) of the 230 patients. In univariate analysis, none of the factors showed statistical significance with respect to CSDH recurrence. In multivariate analysis, preoperative antithrombotic medication was the only independent risk factor for CSDH recurrence (odds ratio, 2.407; 95% confidence interval, 1.047-5.531). CONCLUSION: The present study found that preoperative antithrombotic medication was independently associated with CSDH recurrence.

Cicletanine-induced hyponatremia and hypokalemia in kidney transplant patients.

BACKGROUND: Cicletanine is an antihypertensive agent with vasorelaxant and diuretic properties. It has been widely used in European countries; however, cicletanine-associated electrolyte disturbances have yet to be defined. We investigated cicletanine-induced hyponatremia and hypokalemia in kidney transplant patients. METHODS: Data from a total of 68 kidney transplant recipients who were treated for hypertension with cicletanine were retrospectively analyzed. Cicletanine-induced hyponatremia and hypokalemia were defined as serum sodium < 135 mmol/L and potassium < 3.5 mmol/L, respectively, after the use of cicletanine. RESULTS: The average patient age was 50 (±11) years, and 44 (65%) were male. The daily dose of cicletanine was 171 ± 46 mg, and the duration of drug use was 215 ± 514 days. Hyponatremia occurred in 11 patients (16.2%), and hypokalemia occurred in 8 patients (11.8%). Three patients (4.4%) had hyponatremia and hypokalemia simultaneously. The duration of cicletanine administration was significantly longer in patients with hyponatremia than in those without hyponatremia (943 ± 958 vs. 74 ± 166 days, P < 0.05). The occurrence of hypokalemia was not affected by either daily dose or duration of drug use. Among 11 patients with hyponatremia, 10 were corrected within 2 weeks after withdrawal of the drug and 1 was spontaneously corrected. Among 8 cases of hypokalemia, 7 were corrected after withdrawal of the drug and 1 was spontaneously corrected. CONCLUSION: We demonstrate that cicletanine may induce hyponatremia or hypokalemia in kidney transplant patients. Hyponatremia is more frequently associated with cicletanine than hypokalemia, and extended use of cicletanine may increase the risk of hyponatremia.

Cleavage of ether, ester, and tosylate C(sp3)-O bonds by an iridium complex, initiated by oxidative addition of C-H bonds. Experimental and computational studies.

A pincer-ligated iridium complex, (PCP)Ir (PCP = κ(3)-C6H3-2,6-[CH2P(t-Bu)2]2), is found to undergo oxidative addition of C(sp(3))-O bonds of methyl esters (CH3-O2CR'), methyl tosylate (CH3-OTs), and certain electron-poor methyl aryl ethers (CH3-OAr). DFT calculations and mechanistic studies indicate that the reactions proceed via oxidative addition of C-H bonds followed by oxygenate migration, rather than by direct C-O addition. Thus, methyl aryl ethers react via addition of the methoxy C-H bond, followed by α-aryloxide migration to give cis-(PCP)Ir(H)(CH2)(OAr), followed by iridium-to-methylidene hydride migration to give (PCP)Ir(CH3)(OAr). Methyl acetate undergoes C-H bond addition at the carbomethoxy group to give (PCP)Ir(H)[κ(2)-CH2OC(O)Me] which then affords (PCP-CH2)Ir(H)(κ(2)-O2CMe) (6-Me) in which the methoxy C-O bond has been cleaved, and the methylene derived from the methoxy group has migrated into the PCP Cipso-Ir bond. Thermolysis of 6-Me ultimately gives (PCP)Ir(CH3)(κ(2)-O2CR), the net product of methoxy group C-O oxidative addition. Reaction of (PCP)Ir with species of the type ROAr, RO2CMe or ROTs, where R possesses ß-C-H bonds (e.g., R = ethyl or isopropyl), results in formation of (PCP)Ir(H)(OAr), (PCP)Ir(H)(O2CMe), or (PCP)Ir(H)(OTs), respectively, along with the corresponding olefin or (PCP)Ir(olefin) complex. Like the C-O bond oxidative additions, these reactions also proceed via initial activation of a C-H bond; in this case, C-H addition at the ß-position is followed by ß-migration of the aryloxide, carboxylate, or tosylate group. Calculations indicate that the ß-migration of the carboxylate group proceeds via an unusual six-membered cyclic transition state in which the alkoxy C-O bond is cleaved with no direct participation by the iridium center.

Fractional excretion of uric acid as a predictor for saline responsiveness in long-term kidney transplant patients.

BACKGROUND/AIMS: Subclinical hypovolemia may contribute to allograft dysfunction in long-term kidney transplant (KT) patients. In order to predict responsiveness to saline hydration, indices for tubular transport were investigated. METHODS: Fifty-four clinically euvolemic long-term KT patients with recently aggravated azotemia were given intravenous hydration as follows: 0.9% saline 5 ml/kg over 1 h, followed by 0.9% saline 1 ml/kg/h over 12 h and 1 liter of 0.45% saline over the next 24 h. Serum and urine data were collected and analyzed to assess responses. RESULTS: In all patients, saline hydration relieved azotemia, as shown by blood urea nitrogen (46.9 ± 17.2 vs. 39.3 ± 15.4 mg/dl; p < 0.01) and serum creatinine levels (2.9 ± 1.1 vs. 2.5 ± 1.1 mg/dl; p < 0.01) on day 0 versus day 2. In 38 patients, serum creatinine did not increase in the following month (70% responders). Compared with the nonresponders, the responders had a higher urine-to-plasma creatinine ratio and lower fractional excretion of sodium, uric acid and urea at admission. Multivariate logistic regression analysis revealed that responsiveness to saline hydration was independently associated with lower fractional excretion of uric acid. CONCLUSION: Subclinical hypovolemia should be considered in long-term KT patients with azotemia of unexplainable causes. Fractional excretion of uric acid may predict responsiveness to saline hydration.

Net oxidative addition of C(sp3)-F bonds to iridium via initial C-H bond activation.

Carbon-fluorine bonds are the strongest known single bonds to carbon and as a consequence can prove very hard to cleave. Alhough vinyl and aryl C-F bonds can undergo oxidative addition to transition metal complexes, this reaction has appeared inoperable with aliphatic substrates. We report the addition of C(sp(3))-F bonds (including alkyl-F) to an iridium center via the initial, reversible cleavage of a C-H bond. These results suggest a distinct strategy for the development of catalysts and promoters to make and break C-F bonds, which are of strong interest in the context of both pharmaceutical and environmental chemistry.

Cleavage of sp3 C-O bonds via oxidative addition of C-H bonds.

(PCP)Ir (PCP = kappa(3)-C(6)H(3)-2,6-[CH(2)P(t-Bu)(2)](2)) is found to undergo oxidative addition of the methyl-oxygen bond of electron-poor methyl aryl ethers, including methoxy-3,5-bis(trifluoromethyl)benzene and methoxypentafluorobenzene, to give the corresponding aryloxide complexes (PCP)Ir(CH(3))(OAr). Although the net reaction is insertion of the Ir center into the C-O bond, density functional theory (DFT) calculations and a significant kinetic isotope effect [k(CH(3))(OAr)/k(CD(3))(OAr) = 4.3(3)] strongly argue against a simple insertion mechanism and in favor of a pathway involving C-H addition and alpha-migration of the OAr group to give a methylene complex followed by hydride-to-methylene migration to give the observed product. Ethoxy aryl ethers, including ethoxybenzene, also undergo C-O bond cleavage by (PCP)Ir, but the net reaction in this case is 1,2-elimination of ArO-H to give (PCP)Ir(H)(OAr) and ethylene. DFT calculations point to a low-barrier pathway for this reaction that proceeds through C-H addition of the ethoxy methyl group followed by beta-aryl oxide elimination and loss of ethylene. Thus, both of these distinct C-O cleavage reactions proceed via initial addition of a C(sp(3))-H bond, despite the fact that such bonds are typically considered inert and are much stronger than C-O bonds.

Unusually weak metal-hydrogen bonds in HV(CO)4(P-P) and their effectiveness as H(*) donors.

The V-H bonds in HV(CO)4(P-P) are unusually weak (55 to 58 kcal/mol). They transfer H* to styrene more rapidly than CpCr(CO)3H does and are effective stoichiometric reagents for the cyclization of appropriate 1,6-dienes.

Kinetics of hydrogen atom transfer from (eta(5)-C(5)H(5))Cr(CO)(3)H to various olefins: influence of olefin structure.

Treating (etha(5)-C(5)H(5))Cr(CO)3H (1) or (etha(5)-C(5)H(5))Cr(CO)3D (1-d(1)) with an excess of olefin containing the opposite isotope generally leads to H/D exchange, although hydrogenation is also observed in some cases. Application of an appropriate statistical correction to the observed exchange rate gives kH and kD, the rate constants for H* (D*) transfer from (etha(5)-C(5)H(5))Cr(CO)(3)H (D) to various olefins. The values of kH and kD vary appreciably with the substituents on the double bond. Phenyl-substituted olefins accept H* more readily than do carbomethoxy-substituted olefins, although the latter accept H* more readily than do alkyl-substituted olefins. A methyl substituent on the incipient radical site increases k(H) at 323 K by a factor between 5 and 50. A methyl substituent on the carbon to which the H* is being transferred decreases kH substantially. On the whole, the rate constants for H* transfer reflect steric effects as well as the stability of the resulting carbon-centered radicals.