Development and internal validation of a clinical prediction model for serious complications after emergency laparotomy

PURPOSE

Emergency laparotomy (EL) is a common operation with high risk for postoperative complications, thereby requiring accurate risk stratification to manage vulnerable patients optimally. We developed and internally validated a predictive model of serious complications after EL.

METHODS

Data for eleven carefully selected candidate predictors of 30-day postoperative complications (Clavien-Dindo grade >  = 3) were extracted from the HELAS cohort of EL patients in 11 centres in Greece and Cyprus. Logistic regression with Least Absolute Shrinkage and Selection Operator (LASSO) was applied for model development. Discrimination and calibration measures were estimated and clinical utility was explored with decision curve analysis (DCA). Reproducibility and heterogeneity were examined with Bootstrap-based internal validation and Internal-External Cross-Validation. The American College of Surgeons National Surgical Quality Improvement Program's (ACS-NSQIP) model was applied to the same cohort to establish a benchmark for the new model.

RESULTS

From data on 633 eligible patients (175 complication events), the SErious complications After Laparotomy (SEAL) model was developed with 6 predictors (preoperative albumin, blood urea nitrogen, American Society of Anaesthesiology score, sepsis or septic shock, dependent functional status, and ascites). SEAL had good discriminative ability (optimism-corrected c-statistic: 0.80, 95% confidence interval [CI] 0.79-0.81), calibration (optimism-corrected calibration slope: 1.01, 95% CI 0.99-1.03) and overall fit (scaled Brier score: 25.1%, 95% CI 24.1-26.1%). SEAL compared favourably with ACS-NSQIP in all metrics, including DCA across multiple risk thresholds.

CONCLUSION

SEAL is a simple and promising model for individualized risk predictions of serious complications after EL. Future external validations should appraise SEAL's transportability across diverse settings.

Carotid artery stenting and endarterectomy surgery techniques: A 30‑year time‑lapse

Carotid endarterectomy or carotid artery stenting (CAS), are the most important axes in carotid artery interventional management. A bibliometric analysis permits an easier access to the current literature trends and information to design future studies. The aim of the present study was to identify the knowledge routes on CAS and examine the research front on the topic. The search was interpreted in Scopus, from 1994 to 2023, and included only original articles and reviews. The BibTex format was used to download all citation and bibliographic data. The present analysis was conducted in two parts, a descriptive one and a network extraction process. Between 1994 and 2023, 34,503 references and 7,758 authors were recorded. The annual growth rate was 21.64%. The CAVATAS trial was the most cited article. As regards word trends, since 2017, trans-carotid stenting, risk factors and plaque characteristics are highlighted. CAS remains an area of high interest with a publication growth rate of >20% per year. As numerous questions remain to be answered, the need to determine the role of CAS may drive further research.

Effect of circulating miR‑126 levels on intracranial aneurysms and their predictive value for the rupture of aneurysms: A systematic review and meta‑analysis

Intracranial aneurysm (IA) is a common cerebrovascular disease with a high risk of rupture. At present, the mechanisms underlying the formation and rupture of IAs is not clinically clear. MicroRNAs (miRNAs/miRs) are involved in the development of IAs. The present study aimed to determine the efficacy of circulating miRNA-126 (miR-126) levels as potential biomarkers for predicting aneurysmal ruptures. The present study searched comparative articles involving circulating miR-126 levels and intracranial aneurysms through electronic databases from 1980 to February, 2023. Collected variables included the first author's name, covered study period, publication year, total number of patients and age, and number of males. We collected information about the expression levels of circulating miR-126 in serum. Three articles met the eligibility criteria. The total number of patients was 379 [226 with IA rupture and 153 with non-rupture or/+ controls (healthy)]. The circulating miR-126 can be used as a biomarker for predicting aneurysmal rupture. Interestingly, an aneurysmal size >10 mm was associated with an IA rupture.

The nurse's role in managing gout in the modern era: A systematic review of the literature

The current treatment of gout is largely suboptimal, with up to 89% of hospitalizations being preventable due to inadequate care. The present study performed a systematic review in an aim to identify barriers to optimal gout treatment (Q1), understand how frequently nurses are involved in the management of gout (Q2), and examine the role of the nurse in the management of gout (Q3). A systematic review was performed, focusing on studies reporting on the nurse's role in the management of gout and the quality of the gathered items was appraised based on the risk of bias. In total, 15 records fulfilled the eligibility criteria and were used in the present systematic review. The main barriers were attributed to the patient's experiences with gout and lay beliefs, which affected seeking advice and adherence to treatment (Q1). Recently, however, several advances in patient care, including nurse-led clinics, have expanded the nurse's role, accounting for as much as 26% of the annual visits (Q2). Nurse-led interventions, such as education and lifestyle counseling, increased adherence to treatment (Q3). On the whole, nurses are key players in multidisciplinary teams and should be capable of engaging in shared decision-making processes, goal setting, providing patients with education and information, and making appropriate referrals.

Prospective multicenter external validation of postoperative mortality prediction tools in patients undergoing emergency laparotomy

BACKGROUND

Accurate preoperative risk assessment in emergency laparotomy (EL) is valuable for informed decision making and rational use of resources. Available risk prediction tools have not been validated adequately across diverse health care settings. Herein, we report a comparative external validation of four widely cited prognostic models.

METHODS

A multicenter cohort was prospectively composed of consecutive patients undergoing EL in 11 Greek hospitals from January 2020 to May 2021 using the National Emergency Laparotomy Audit (NELA) inclusion criteria. Thirty-day mortality risk predictions were calculated using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), NELA, Portsmouth Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (P-POSSUM), and Predictive Optimal Trees in Emergency Surgery Risk tools. Surgeons' assessment of postoperative mortality using predefined cutoffs was recorded, and a surgeon-adjusted ACS-NSQIP prediction was calculated when the original model's prediction was relatively low. Predictive performances were compared using scaled Brier scores, discrimination and calibration measures and plots, and decision curve analysis. Heterogeneity across hospitals was assessed by random-effects meta-analysis.

RESULTS

A total of 631 patients were included, and 30-day mortality was 16.3%. The ACS-NSQIP and its surgeon-adjusted version had the highest scaled Brier scores. All models presented high discriminative ability, with concordance statistics ranging from 0.79 for P-POSSUM to 0.85 for NELA. However, except the surgeon-adjusted ACS-NSQIP (Hosmer-Lemeshow test, p = 0.742), all other models were poorly calibrated ( p < 0.001). Decision curve analysis revealed superior clinical utility of the ACS-NSQIP. Following recalibrations, predictive accuracy improved for all models, but ACS-NSQIP retained the lead. Between-hospital heterogeneity was minimum for the ACS-NSQIP model and maximum for P-POSSUM.

CONCLUSION

The ACS-NSQIP tool was most accurate for mortality predictions after EL in a broad external validation cohort, demonstrating utility for facilitating preoperative risk management in the Greek health care system. Subjective surgeon assessments of patient prognosis may optimize ACS-NSQIP predictions.

LEVEL OF EVIDENCE

Diagnostic Test/Criteria; Level II.

Lower respiratory tract infections due to multi‑drug resistant pathogens in central nervous system injuries (Review)

Pneumonia is one of the most prevalent infections in the intensive care unit (ICU), where pneumonia may occur during hospitalization in the ICU as a complication. ICU patients with central nervous system (CNS) injuries are not an exception, and they may even be more susceptible to infections such as pneumonia due to issues such as swallowing difficulties, the requirement for mechanical ventilation, and extended hospital stay. Numerous common CNS injuries, such as ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage, can prolong hospital stay and increase the risk of pneumonia. Multidrug-resistant (MDR) microorganisms are a common and significant concern, with increased mortality in nosocomial pneumonia. However, research on pneumonia due to MDR pathogens in patients with CNS injuries is limited. The aim of the present review was to provide the current evidence regarding pneumonia due to MDR pathogens in patients with CNS injuries. The prevalence of pneumonia due to MDR pathogens in CNS injuries differs among different settings, types of CNS injuries, geographical areas, and time periods in which the studies were performed. Specific risk factors for the emergence of pneumonia due to MDR pathogens have been identified in ICUs and neurological rehabilitation units. Antimicrobial resistance is currently a global issue, although using preventive measures, early diagnosis, and close monitoring of MDR strains may lessen its impact. Since there is a lack of information on these topics, more multicenter prospective studies are required to offer insights into the clinical features and outcomes of these patients.

The Hellenic Emergency Laparotomy Study (HELAS): A Prospective Multicentre Study on the Outcomes of Emergency Laparotomy in Greece

BACKGROUND

Emergency laparotomy (EL) is accompanied by high post-operative morbidity and mortality which varies significantly between countries and populations. The aim of this study is to report outcomes of emergency laparotomy in Greece and to compare them with the results of the National Emergency Laparotomy Audit (NELA).

METHODS

This is a multicentre prospective cohort study undertaken between 01.2019 and 05.2020 including consecutive patients subjected to EL in 11 Greek hospitals. EL was defined according to NELA criteria. Demographics, clinical variables, and post-operative outcomes were prospectively registered in an online database. Multivariable logistic regression analysis was used to identify independent predictors of post-operative mortality.

RESULTS

There were 633 patients, 53.9% males, ASA class III/IV 43.6%, older than 65 years 58.6%. The most common operations were small bowel resection (20.5%), peptic ulcer repair (12.0%), adhesiolysis (11.8%) and Hartmann's procedure (11.5%). 30-day post-operative mortality reached 16.3% and serious complications occurred in 10.9%. Factors associated with post-operative mortality were increasing age and ASA class, dependent functional status, ascites, severe sepsis, septic shock, and diabetes. HELAS cohort showed similarities with NELA patients in terms of demographics and preoperative risk. Post-operative utilisation of ICU was significantly lower in the Greek cohort (25.8% vs 56.8%) whereas 30-day post-operative mortality was significantly higher (16.3% vs 8.7%).

CONCLUSION

In this study, Greek patients experienced markedly worse mortality after emergency laparotomy compared with their British counterparts. This can be at least partly explained by underutilisation of critical care by surgical patients who are at high risk for death.

Posterior Fossa Intra-Axial Lesion: There Are Pathologies Beyond Metastases

Cerebellar metastases represent the most common lesion requiring surgical treatment in the daily neurosurgical praxis. We report a rare case with Lhermitte-Duclos disease presenting to the neurosurgical outpatient department and describe our diagnostic and treatment challenges. A 57-year-old man presented with transient cerebellar manifestations, including walking difficulties, dizziness, and a persistent occipital headache. The magnetic resonance imaging demonstrated a high-intensity lesion in the right cerebellar hemisphere on T2-weighted images. We initially considered surgery to establish a histopathological diagnosis. However, the magnetic resonance spectroscopy was compatible with a dysplastic gangliocytoma of the cerebellum. Therefore, we preferred a more conservative approach. Posterior fossa contrast-enhancing lesions are much more than metastases. The role of advanced magnetic resonance in avoiding unnecessary surgical interventions is priceless.

Lack of an association between SCFD1 rs10139154 polymorphism and amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease. Through a genome‑wide association study (GWAS), the Sec1 family domain‑containing protein 1 (SCFD1) rs10139154 variant at 14q12 has emerged as a risk factor gene for ALS. Moreover, it has been reported to influence the age at onset (AAO) of patients with ALS. The aim of the present study was to assess the association of the SCFD1 rs10139154 polymorphism with the risk of developing ALS. For this purpose, 155 patients with sporadic ALS and 155 healthy controls were genotyped for the SCFD1 rs10139154. The effect of the SCFD1 rs10139154 polymorphism was then examined on the following parameters: i) The risk of developing ALS; ii) the AAO of ALS; iii) the site of ALS onset (patients with bulbar onset ALS vs. healthy controls; and patients with limb onset ALS vs. healthy controls); and iv) the AAO of ALS onset with subgroup analyses based on the site of onset (bulbar and limb, crude and adjusted for sex). The analysis of all the outcomes was performed assuming five genetic models. Crude and adjusted analyses were applied. The threshold for statistical significance was set at 0.05. The results revealed no association between SCFD1 rs10139154 and any of the examined phenotypes in any of the models examined. On the whole, based on the findings of the present study, SCFD1 rs10139154 does not appear to play a determining role in the risk of developing ALS.

The role of MiRNA-21 in gliomas: Hope for a novel therapeutic intervention?

Gliomas are the most common primary brain tumors in adults. They are generally very resistant to treatment and are therefore associated with negative outcomes. MicroRNAs (miRNAs) are small, non-coding RNA molecules that affect many cellular processes by regulating gene expression and, post-transcriptionally, the translation of mRNAs. MiRNA-21 has been consistently shown to be upregulated in glioma and research has shown that it is involved in a wide variety of biological pathways, promoting tumor cell survival and invasiveness. Furthermore, it has been implicated in resistance to treatment, both against chemotherapy and radiotherapy. In this review, we gathered the existent data on miRNA-21 and gliomas, in terms of its expression levels, association with grade and prognosis, the pathways it involves and its targets in glioma, and finally how it leads to treatment resistance. Furthermore, we discuss how this knowledge could be applied in clinical practice in the years to come. To our knowledge, this is the first review to assess in extent and depth the role of miRNA-21 in gliomas.

Effect of integrin AV and B8 gene polymorphisms in patients with traumatic brain injury

Background: Α few genetic variants are associated with the outcome after traumatic brain injury (TBI). Integrins are glycoprotein receptors that play an important role in the integrity of microvasculature of the brain. Objective: To examine the role of integrin-AV (ITGAV) and integrin-B8 (ITGB8) tag single nucleotide polymorphisms (SNPs) on the outcome of patients with TBI. Methods: 363 participants were included and genotyped for 11 SNPs for ITGAV and 11 for ITGB8 gene. SNPs were tested for associations with the 6-month outcome after TBI, the presence of a hemorrhagic event after TBI, and the initial TBI severity after adjustment for TBI's main predictors. Results: The ITGAV rs3911239 CC and rs7596996 GG genotypes were associated with an unfavorable outcome after TBI, compared to the TT and AA genotypes, respectively. The ITGB8 rs10239099 CC and rs3757727 CC genotypes were associated with increased risk of any cerebral hemorrhagic event after TBI compared to GG and TT respectively. The ITGAV rs7589470 and rs7565633 were associated with the TBI's initial severity. Conclusions: ITGAV gene SNPs may be implicated in the outcome after TBI, as well as in the initial TBI severity, and also of ITGB8 gene SNPs in the risk of hemorrhagic event after a TBI.

A Giant Tarlov Cyst Presenting with Hydronephrosis in a Patient with Marfan Syndrome: A Case Report and Review of the Literature

BACKGROUND

Giant Tarlov cysts are always symptomatic and mimic many serious pathologic entities. We present the largest, to our knowledge, reported Tarlov cyst.

CASE DESCRIPTION

A 33-year-old woman with Marfan syndrome suffered from right kidney hydronephrosis because of ureter obstruction, for which she was treated with nephrostomy. Her neurologic examination was unremarkable. The role of magnetic resonance imaging in the management of this case is described. Absence of intractranial hypotension symptoms after cerebrospinal fluid (CSF) overdrainage suggested the presence of a valve-like mechanism. The patient was planned for surgical cyst remodeling by the application of titanium clips. The cyst's neck was exposed through an L5-S2 laminectomy. L5 and S1 laminae were severely eroded. CSF leaked out of the underlying, bulging, and thinned dura at each attempt for clip application. Intraoperatively, multiple responses from the S1, S2, and S3 roots were simultaneously recorded at each stimulation. Therefore, we decided to abandon this technique and performed a nonwatertight duroplasty followed by a layered wound closure instead. A week later, the patient received a lumbar-peritoneal shunt. The patient remained neurologically intact, the cyst shrunk, and the nephrostomy was removed.

CONCLUSIONS

Indirect evidence was helpful to assess for the presence of a valve-like mechanism. Intraoperatively, the surgeon must keep on high alert for sacral erosion to avoid inadvertent dural tear and rootlet injury. Finally, lumboperitoneal diversion remains a valid alternative in the management of our giant Tarlov cyst because it reduced the intracystic pressure that resulted in cyst regression.

AQP4 tag SNPs in patients with intracerebral hemorrhage in Greek and Polish population

BACKROUND

A relatively small number of genetic variants are implicated to pathophysiology of intracerebral hemorrhage (ICH). Aquaporin-4 (AQP4) has been reported to be implicated in the pathophysiological processes of ICH development.

OBJECTIVE

To examine the role of AQP4 gene region polymorphisms on the ICH risk.

METHODS

A total of 250 Greek and 193 Polish patients with primary ICH and 250 and 322 respective controls were enrolled, forming two independent cohorts in order to validate any significant effect. With logistic regression analyses, 7 AQP4 tag single nucleotide polymorphisms (SNPs) were examined for association with ICH risk, lobar/non-lobar ICH risk, and 6-month disability after ICH. Cox regression analysis was applied in order to the effect of AQP4 SNPs on ICH age of onset be tested. Correction for multiple comparisons was applied.

RESULTS

Multivariate logistic regression analysis showed that rs3875089 in the Greek cohort and rs3763043, rs335931 in the Polish cohort had a significant influence on the risk of ICH, lobar and non-lobar ICH. Regarding the age of onset, rs3875089 in the Greek cohort and rs3763043, rs11661256 in the Polish cohort were found to significantly alter the age of onset of ICH and its subtypes. However, all of the above associations did not survive the Bonferroni correction (p-value >0.007). Finally, AQP4 tag SNPs were not found to have any significant effect on long-term disability after ICH.

CONCLUSIONS

In conclusion, the present study provides an indication that AQP4 gene variants may affect susceptibility to primary ICH and may influence the ICH age of onset.

Anterior cervical spine surgery-associated complications in a retrospective case-control study

Anterior cervical spine procedures have been associated with satisfactory outcomes. However, the occurrence of troublesome complications, although uncommon, needs to be taken into consideration. The purpose of our study was to assess the actual incidence of anterior cervical spine procedure-associated complications and identify any predisposing factors. A total of 114 patients undergoing anterior cervical procedures over a 6-year period were included in our retrospective, case-control study. The diagnosis was cervical radiculopathy, and/or myelopathy due to degenerative disc disease, cervical spondylosis, or traumatic cervical spine injury. All our participants underwent surgical treatment, and complications were recorded. The most commonly performed procedure (79%) was anterior cervical discectomy and fusion (ACDF). Fourteen patients (12.3%) underwent anterior cervical corpectomy and interbody fusion, seven (6.1%) ACDF with plating, two (1.7%) odontoid screw fixation, and one anterior removal of osteophytes for severe Forestier's disease. Mean follow-up time was 42.5 months (range, 6-78 months). The overall complication rate was 13.2%. Specifically, we encountered adjacent intervertebral disc degeneration in 2.7% of our cases, dysphagia in 1.7%, postoperative soft tissue swelling and hematoma in 1.7%, and dural penetration in 1.7%. Additionally, esophageal perforation was observed in 0.9%, aggravation of preexisting myelopathy in 0.9%, symptomatic recurrent laryngeal nerve palsy in 0.9%, mechanical failure in 0.9%, and superficial wound infection in 0.9%. In the vast majority anterior cervical spine surgery-associated complications are minor, requiring no further intervention. Awareness, early recognition, and appropriate management, are of paramount importance for improving the patients' overall functional outcome.

The Role of TOR1A Polymorphisms in Dystonia: A Systematic Review and Meta-Analysis

Importance

A number of genetic loci were found to be associated with dystonia. Quite a few studies have been contacted to examine possible contribution of TOR1A variants to the risk of dystonia, but their results remain conflicting. The aim of the present study was to systematically evaluate the effect of TOR1A gene SNPs on dystonia and its phenotypic subtypes regarding the body distribution.

Methods

We performed a systematic review of Pubmed database to identify all available studies that reported genotype frequencies of TOR1A SNPs in dystonia. In total 16 studies were included in the quantitative analysis. Odds ratios (ORs) were calculated in each study to estimate the influence of TOR1A SNPs genotypes on the risk of dystonia. The fixed-effects model and the random effects model, in case of high heterogeneity, for recessive and dominant mode of inheritance as well as the free generalized odds ratio (OR_G) model were used to calculate both the pooled point estimate in each study and the overall estimates.

Results

Rs1182 was found to be associated with focal dystonia in recessive mode of inheritance [Odds Ratio, OR (95% confidence interval, C.I.): 1.83 (1.14–2.93), Pz = 0.01]. In addition, rs1801968 was associated with writer’s cramp in both recessive and dominant modes [OR (95%C.I.): 5.99 (2.08–17.21), Pz = 0.00009] and [2.48 (1.36–4.51), Pz = 0.003) respectively and in model free-approach [OR_G (95%C.I.): 2.58 (1.45–4.58)].

Conclusions

Our meta-analysis revealed a significant implication of rs1182 and rs1801968 TOR1A variants in the development of focal dystonia and writer’s cramp respectively. TOR1A gene variants seem to be implicated in dystonia phenotype.

Intradural extramedullary Ewing's sarcoma: A case report and review of the literature

INTRODUCTION

Extra-skeletal Ewing's sarcomas are very rare lesions to the spine surgeon, with the intradural, extramedullary lesions being even rarer. Herein we present a patient with an intradural, extramedullary form of Ewing's sarcoma and review the relevant literature. The medical records, operative reports, radiographical studies and histological examinations of a single patient are retrospectively reviewed.

CASE REPORT

A 31-year old male presented with back-pain, right-leg progressive paraparesis, and inability to walk. Both motor and sensory disturbances were revealed on the right leg at the clinical examination. Lumbar MRI showed two lesions. The first one was an intradural, extramedullary lesion at the L2-L3 level, while the second was smaller, located at the bottom of the dural sac. The patient underwent gross total resection of the L2-L3 lesion after a bilateral laminectomy. Histological examination was compatible with Ewing's sarcoma, and was verified by molecular analysis. No other extra-skeletal or skeletal lesion was found. A chemotherapy scheme was tailored to the patients' histological diagnosis. The patient presented with local recurrence and bone metastasis 2 years after his initial diagnosis. A second operation was performed and the follow up of the patient showed no disease progression 18 months after revision surgery.

CONCLUSION

The spine surgeon should be aware of the existence of such rare entities, in order to timely fulfill the staging process and institute the proper therapy. The management of patients with extra-skeletal Ewing's sarcomas involves professionals as members of a multidisciplinary team, all of which should co-operate for the patient's optimal outcome.

Integrins AV and B8 Gene Polymorphisms and Risk for Intracerebral Hemorrhage in Greek and Polish Populations

Α limited number of genetic variants have been linked to the development of intracerebral hemorrhage (ICH). Ιntegrin AV and/or B8-deficient mice were found to develop ICH. The present candidate gene association study was designed to investigate possible influence of integrin AV (ITGAV) and integrin B8 (ITGB8) gene region polymorphisms on the risk of ICH. 1015 participants (250 Greek and 193 Polish patients with primary ICH and 250 Greek and 322 Polish controls) were included in the study. Using logistic regression analyses, 11 tag single nucleotide polymorphisms (SNPs) for ITGAV and 11 for ITGB8 gene were tested for associations with ICH risk, lobar ICH risk and non-lobar ICH after adjustment for age, gender, history of hypertension and country of origin. Linear regression models were used to test the effect of tag SNPs on the ICH age of onset. Correction for multiple comparisons was carried out. The rs7565633 tag SNP of the ITGAV gene was independently associated with the risk of lobar ICH in the codominant model of inheritance [odds ratio (95 % confidence interval (CI)) 0.56 (0.36-0.86), p = 0.0013]. Furthermore, heterozygous individuals of the rs10251386 and the rs10239099 of the ITGB8 gene had significantly lower age of ICH onset compared to the wild-type genotypes [regression coefficient (b) -3.884 (95 % CI -6.519, -1.249), p = 0.0039 and b = -4.502 (95 % CI -7.159, -1.845), p = 0.0009, respectively]. The present study provides preliminary indication for an influence of ITGAV gene tag SNP in the development of lobar ICH and of ITGB8 gene variants in the age of ICH onset.

Traumatic brain injury and gene knockout animal models: an up-to-date review

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Identification of endogenous neuroprotective mechanisms after TBI and the development of therapeutic targets to improve TBI outcomes are areas of intense scientific research. In this review, we summarize genetically modified TBI mouse models and highlight the recent scientific findings from using such models, including mediators of inflammation, programmed cell death and metabolism, modulators of vascular tone and membrane channel proteins. A deeper understanding of the complex biochemical processes and genetic pathways in TBI could offer personalized genomic-based therapies for and improve clinical outcomes in TBI patients.

AQP4 tag single nucleotide polymorphisms in patients with traumatic brain injury

Accumulating evidence suggests that the extent of brain injury and the clinical outcome after traumatic brain injury (TBI) are modulated, to some degree, by genetic variants. Aquaporin-4 (AQP4) is the predominant water channel in the central nervous system and plays a critical role in controlling the water content of brain cells and the development of brain edema after TBI. We sought to investigate the influence of the AQP4 gene region on patient outcome after TBI by genotyping tag single nucleotide polymorphisms (SNPs) along AQP4 gene. A total of 363 patients with TBI (19.6% female) were prospectively evaluated. Data including the Glasgow Coma Scale (GCS) scores at admission, the presence of intracranial hemorrhage, and the 6-month Glasgow Outcome Scale (GOS) scores were collected. Seven tag SNPs across the AQP4 gene were identified based on the HapMap data. Using logistic regression analyses, SNPs and haplotypes were tested for associations with 6-month GOS after adjusting for age, GCS score, and sex. Significant associations with TBI outcome were detected for rs3763043 (OR [95% confidence interval (CI)]: 5.15 [1.60-16.5], p=0.006, for recessive model), rs3875089 (OR [95% CI]: 0.18 [0.07-0.50] p=0.0009, for allele difference model), and a common haplotype of AQP4 tag SNPs (OR [95% CI]: 2.94, [1.34-6.36], p=0.0065). AQP4 tag SNPs were not found to influence the initial severity of TBI or the presence of intracranial hemorrhages. In conclusion, the present study provides evidence for possible involvement of genetic variations in AQP4 gene in the functional outcome of patients with TBI.

The FGA Thr312Ala polymorphism and risk of intracerebral haemorrhage in Polish and Greek populations

BACKGROUND AND PURPOSE

Spontaneous intracerebral haemorrhage (ICH) is the most fatal form of stroke with the highest morbidity and disability rate of all stroke types. Recent data suggest that the genetic background has a sizeable and mostly undiscovered effect on the brain haemorrhage risk. Since the coagulation system is crucial to ICH pathology, we studied the significance of the FGA Thr312Ala polymorphism in two European populations.

MATERIALS AND METHODS

We genotyped 550 and 224 controls as well as 261 and 242 stroke patients in Polish and Greek populations, respectively. The ICH diagnosis was confirmed by computed tomography. The FGA Thr312Ala polymorphism was analysed using real-time polymorphism chain reaction.

RESULTS

Both crude and multivariable regression analyses showed that the studied polymorphism is a protective factor in the Polish population under the dominant and additive models of inheritance. Those results did not replicate in the Greek population. The meta-analysis of results from the Polish and the Greek populations proved that FGA Thr312Ala polymorphism affects the risk of ICH in the dominant model of inheritance.

CONCLUSIONS

The FGA Thr312Ala polymorphism affects a risk for ICH in the Polish but not in the Greek population. An advanced meta-analysis of well-designed studies with a significant number of cases might provide useful information of novel polymorphisms, including the FGA Thr312Ala polymorphism, and their role in ICH pathology.

Ten years of clinical experience in the use of fixed-pressure versus programmable valves: a retrospective study of 159 patients

AIM

The aim of this study was to present our 10-year experience with the use of fixed-pressure and programmable valves in the treatment of adult patients requiring cerebrospinal fluid (CSF) diversion.

MATERIAL AND METHODS

Patients (n = 159; 89 male and 70 female) suffering from hydrocephalus of various causes underwent CSF shunt implantation. Forty fixed-pressure and 119 programmable valves were initially implanted.

RESULTS

The observed revision rate was 40% in patients with fixed-pressure valves. In 20% of these patients, a revision due to valve mechanism malfunction was undertaken, and the initial valve was replaced with a programmable one. The revision rate in the adjustable-pressure valve subgroup was 20%. The infection rate for the fixed-pressure and programmable valve subgroups were 3%, and 1.7%, respectively. Similarly, subdural fluid collections were noticed in 17% and 4% of patients with fixed-pressure valves and programmable valves, respectively.

CONCLUSIONS

The revision and over-drainage rates were significantly lower when using programmable valves, and thus, this type of valve is preferred whenever CSF has to be diverted.

Cerebral perfusion pressure, microdialysis biochemistry and clinical outcome in patients with traumatic brain injury

BACKGROUND

Traumatic Brain Injury (TBI) is a major cause of death and disability. It has been postulated that brain metabolic status, intracranial pressure (ICP) and cerebral perfusion pressure (CPP) are related to patients' outcome. The aim of this study was to investigate the relationship between CPP, ICP and microdialysis parameters and clinical outcome in TBIs.

RESULTS

Thirty four individuals with severe brain injury hospitalized in an intensive care unit participated in this study. Microdialysis data were collected, along with ICP and CPP values. Glasgow Outcome Scale (GOS) was used to evaluate patient outcome at 6 months after injury. Fifteen patients with a CPP greater than 75 mmHg, L/P ratio lower than 37 and Glycerol concentration lower than 72 mmol/l had an excellent outcome (GOS 4 or 5), as opposed to the remaining 19 patients. No patient with a favorable outcome had a CPP lower than 75 mmHg or Glycerol concentration and L/P ratio greater than 72 mmol/l and 37 respectively. Data regarding L/P ratio and Glycerol concentration were statistically significant at p = 0.05 when patients with favorable and unfavorable outcome were compared. In a logistic regression model adjusted for age, sex and Glasgow Coma Scale on admission, a CPP greater than 75 mmHg was marginally statistically significantly related to outcome at 6 months after injury.

CONCLUSIONS

Patients with favorable outcome had certain common features in terms of microdialysis parameters and CPP values. An individualized approach regarding CPP levels and cut -off points for Glycerol concentration and L/P ratio are proposed.

Biochemical markers analyzed using microdialysis and traumatic brain injury outcomes

AIM

Traumatic brain injury is a leading cause of disability and mortality among young people. Multiparametric cerebral bedside monitoring is a safe and promising technique for preventing secondary brain damage. The objective of this study was to investigate the usefulness of cerebral microdialysis in predicting the outcomes of patients with traumatic brain injury.

METHODS

Thirty-eight patients (33 males) were included in the study. The GCS on admission was ≤8. The outcome was assessed using the GOS over six months of follow-up.

RESULTS

Among the patients included, 18 had a favorable outcome (GOS=4.5) and the remaining 20 had an unfavorable outcome. L/P ratio and glycerol concentration were statistically significantly higher in the patients with unfavorable prognosis.

CONCLUSION

Biochemical parameters analysed using microdialysis could serve as predictor indexes of clinical outcome several months after the injury.

Cerebral perfusion pressure, microdialysis biochemistry, and clinical outcome in patients with spontaneous intracerebral hematomas

PURPOSE

The aim of our study was to investigate the roles of cerebral perfusion pressure (CPP) and microdialysis marker values on the clinical outcome of patients with spontaneous intracerebral hematoma.

MATERIALS AND METHODS

Twenty-seven patients (18 men; mean ± SD age, 54.17 ± 10.05 years; 9 women, mean ± SD age, 65.00 ± 4.24 years) with a GCS of 8 or less upon admission were included in this study. After a 6-month follow-up period, a linear regression model was applied to evaluate the outcomes using the Glasgow Outcome Scale (GOS).

RESULTS

Of the 27 patients, 16 died within the first 6 months after discharge from the hospital. Six patients had a favorable prognosis after 6 months. In the patients who had a favorable outcome (GOS = 4 or GOS = 5), the CPP was above 75.46 mm Hg, and intracranial pressure was below 14.21 mm Hg. No patient with a favorable prognosis had a lactate-pyruvate (L/P) ratio greater than 37.40. An inverse linear relationship was found among the L/P ratio, the CPP, and patient outcome.

CONCLUSION

The L/P ratio and CPP were found to be related to patient outcome. In addition, a CPP greater than 75.46 mm Hg and an L/P ratio lower than 37.40 mm Hg were related to a favorable outcome.

Genetic Susceptibility to Primary Intracerebral Haemorrhage

Primary intracerebral haemorrhage (PICH) originates from the spontaneous rupture of cerebral arteries as a result of chronic degenerative alterations. Although the aetiology of PICH has not been fully elucidated, it may be the result of an interaction between genetic and environmental risk factors. Several genetic association studies have been conducted in patients with PICH with both positive and negative results. Most of them investigated the role of mutations in genes affecting the lipid metabolism, the coagulation processes, the inflammation and the regulation of blood pressure. In this article we briefly discuss the majority of these studies reporting the susceptibility genes that have been implicated in PICH.

Low RLS prevalence and awareness in central Greece: an epidemiological survey

Restless legs syndrome (RLS) is a sensorimotor disorder with a general population prevalence of 3-10%. A single, previous epidemiological study performed in south-east Europe reported the lowest prevalence rate amongst European countries. We conducted a population-based survey of RLS in central Greece. A total of 4200 subjects were randomly recruited. We used the international RLS study group criteria for diagnosis and the severity scale for severity assessment in subjects with RLS. We also included questions to assess the level of awareness of RLS in our region. A total of 3033 subjects were screened. The overall lifetime prevalence was 3.9% with a female-to-male ratio of 2.6:1. Nearly half of RLS patients reported moderate to severe intensity of symptoms. After adjustment for multiple comparisons we found no association of RLS with education level, smoking, alcohol intake, caffeine consumption, shift work, professional pesticide use or comorbid illness. Our study revealed a low level of awareness amongst the population and physicians in our region and sub-optimal management. We provide further evidence for low prevalence of RLS in south-east Europe and a low level of awareness of RLS in our region.

IL-1RN and IL-1B gene polymorphisms and cerebral hemorrhagic events after traumatic brain injury

OBJECTIVE

To investigate the association of (variable number tandem repeat) interleukin (IL) 1RN and (-511) IL-1B gene polymorphisms with brain hemorrhagic events after traumatic brain injury (TBI).

METHODS

Data from brain CT, Glasgow Coma Scale (GCS) at admission, and 6-month Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) were collected for 151 prospectively recruited patients with TBI. IL-1RN and IL-1B genotypes were determined using standard methods. Presence vs absence of any type of brain hemorrhage was the main outcome. Type of brain hemorrhage, GCS at admission, and 6-month GOS and mRS were secondary outcomes. Odd ratios (ORs) and corresponding 95% CI were calculated using logistic regression analyses. In adjusted models, the associations were controlled for age, gender, diffuse brain edema, volume of intracranial hematoma, neurosurgical intervention, and GCS at admission. p values less than 0.01 were considered significant.

RESULTS

Compared with noncarriers, IL-1RN allele 2 carriers had higher odds of having cerebral hemorrhages after TBI (adjusted OR = 4.57; 95% CI = 1.67 to 12.96; p = 0.004). The associations for (-511) IL-1B polymorphism were not significant.

CONCLUSION

There is an association between the presence of interleukin-1RN allele 2 and posttraumatic brain hemorrhage.

One trocar laparoscopic placement of peritoneal shunt for hydrocephalus: A simplified technique

Peritoneal catheter placement for the treatment of hydrocephalus can nowadays be performed laparoscopically. We report our experience using a single trocar technique, with emphasis to a modification applied especially for the obese patients.

Contribution of MRI and MR angiography in early diagnosis of brain death

The objective of this study was to investigate whether the findings of MR imaging and MR angiography could accurately and early diagnose brain death in comatose patients. Thirty comatose patients were studied with MRI and MR arteriography. In 20 patients (group A) presenting with a Glasgow coma scale (GCS) 3-6, the final clinical diagnosis was brain death. In ten comatose patients with a GCS 4-6 and no clinical signs of brain death (group B), the clinical follow-up did not reveal brain death in a period of 12 months. The MRI examination consisted of turbo fluid-attenuated inversion recovery and T2 turbo spin-echo pulse sequences. The MR arteriography was performed with a 3D inflow pulse sequence. In 12 patients with brain death and 5 patients with no signs of brain death, a 3D phase contrast MR venography was also applied. Magnetic resonance imaging in all patients showed variable edema with swelling of the cerebral gyri, small ventricular system, and basilar subarachnoid spaces. In group A, MRI in addition showed tonsillar herniation. In group A, MR arteriography revealed no arterial flow in the intracranial circulation, whereas MR venography showed in 9 patients no opacification of the sagittal and straight sinuses or visualization of intracranial veins. In contrast, MR angiography showed intact intracranial vessels in patients of group B. In conclusion, MR imaging and MR angiography may be reliable ancillary tests for use in early diagnosis of brain death and further work is required to validate its utility.

A new stop codon mutation (Y52X) in the myophosphorylase gene in a Greek patient with McArdle's disease

We identified a novel stop codon mutation in the myophosphorylase gene in a Greek patient with typical symptoms of McArdle's disease. This is the first genetic study of myophosphorylase deficiency in a Greek family, showing that the proband was a compound heterozygous for the common "caucasian" mutation (R49X) and a new nonsense mutation (Y52X), both within exon 1. The new point mutation, a C-to-G transversion at codon 52, converts an encoded tyrosine to a stop codon. Our study confirms that the R49X is also present in the Greek population. The Y52X may represent a private mutation or a common mutation among Greeks. Our data further expand the already remarkable genetic heterogeneity of McArdle's disease. The prevalence of the Y52X mutation in Greek patients with McArdle's disease remains to be determined.

Outcome of patients with diffuse axonal injury: the significance and prognostic value of MRI in the acute phase

BACKGROUND

To compare the magnetic resonance imaging (MRI) findings in the acute phase with outcome in patients with diffuse axonal injury (DAI).

METHODS

A group of 33 patients with closed head injury and discrepancy between the apparently normal computed tomographic scan findings and their neurologic statuses were studied with MRI during the first 48 hours. Among them, 24 were found to suffer from DAI-type lesions. According to the Glasgow Coma Scale (GCS), 19 patients suffered from severe head injury (GCS score <8) and 5 patients had moderate head injury (GCS score of 9-12). Four MRI sequences in various planes were applied. Patients were divided into three groups, according to staging described in the literature.

RESULTS

In five patients, MRI demonstrated nonhemorrhagic DAI lesions stage 1. In 11 patients, findings were consistent with DAI lesions stage 2, eight nonhemorrhagic and three hemorrhagic. Eight patients showed DAI lesions stage 3, six of which were nonhemorrhagic.

CONCLUSIONS

MRI is more sensitive compared with computed tomography in the detection of traumatic brain lesions, especially the nonhemorrhagic DAI. The presence of hemorrhage in DAI-type lesions and the association with traumatic space-occupying lesions is a poor prognostic sign. Isolated nonhemorrhagic DAI-type lesions are not associated with poor clinical outcome.

Brainstem abscess: preoperative MRI appearance and survival following stereotactic aspiration

Brainstem abscesses are rare and until recently were uniformly fatal. The case of a 49 year old lady with an abscess extending through the midbrain, pons and cerebellar peduncle is presented. She survived following stereotactic aspilation; only the seventh such case. The report is illustrated with very rare preoperative MRI scans.

The tertiary structure of salt-extracted ribosomal proteins from Escherichia coli as studied by proton magnetic resonance spectroscopy and limited proteolysis experiments

Ribosomal proteins from Escherichia coli have been isolated by a mild purification procedure. Their tertiary structure has been explored by two techniques, proton magnetic resonance and limited proteolysis. A number of proteins when subjected to limited proteolysis produce resistant fragments in good yields. In most cases this does not depend on the specificity of the enzyme used. The proteins S15, S16, S17 and L30 are not degraded at all, whereas a few proteins are very susceptible to proteolysis. 1H-NMR experiments show that the majority of the ribosomal proteins have a uniquely folded tertiary structure. This is particularly pronounced in the four proteins mentioned above which resist proteolysis. In general, a good agreement is observed between the degree of proteolytic resistance and the amount of folding indicated by NMR spectroscopy. Similar studies on a few ribosomal proteins purified under denaturing conditions show that, in contrast, these protein preparations are not structurally homogeneous and that they contain a mixture of denatured and renatured molecules. The results are interpreted in terms of a compactly folded tertiary structure for the four proteinase-resistant proteins while the majority of the other proteins appear to have two domains, one compactly folded and resistant to proteinase and the other flexible and susceptible to proteolysis. A few proteins seem to have a completely flexible structure and can therefore be easily degraded.

Structural and functional studies on protein S20 from the 30-S subunit of the Escherichia coli ribosome

Fragments resistant to proteolysis have been obtained from the ribosomal protein S20. They provide evidence for a structural domain stretching from the middle of the protein to its C terminus. With the exception of a large fragment of this protein lacking only 14 residues at the N terminus, all fragments had lost their ability to bind to 16-S rRNA. The protein in the S20 . 16-S-RNA complex was highly protected against enzymic digestion, indicating that the entire protein is involved in interaction with the nucleic acid. Circular dichroism showed a high alpha helix content (36%) for the intact protein and a low alpha helix content (2%) for the large fragment. Intrinsic fluorescence studies demonstrated that the single tyrosine residue in protein S20 is exposed to the solvent in the intact protein and is not exposed in the S20 . 16-S-RNA complex. Irreversible thermal denaturation of the protein was followed by fluorescence of the tyrosine and was found between 50 degrees C and 70 degrees C.

Structural domains of ribosomal protein S8 and their relationship to ribosomal RNA binding

Escherichia coli ribosomal protein S8 has been subjected to mild proteolytic digestion in order to search for structural domains within the protein [1]. A characteristic fragment produced in high yield after chymotrypsin treatment has been located with the protein sequence. Circular dichroism has shown this domain to be rich in alpha helix. However, the fragment loses its ability to bind to 16S rRNA as does a similar fragment produced by trypsin cleavage. The intact protein is required for rRNA binding and is highly protected against proteolytic digestion when bound to the RNA.