Local elevation of the anti-inflammatory interleukin-10 in the pathogenesis of chronic subdural hematoma

Chronic subdural hematoma: What precisely are we treating?

Subdural hematoma (SDH) refers to the collection of blood between the dura matter and the arachnoid membrane. Advancements in imaging technology have enabled the categorization of SDH based on specific imaging characteristics, causative factors, and the onset of symptoms. Given that the prognosis of SDHs varies significantly and is contingent upon the size and chronicity of the hemorrhage, a comprehensive understanding of its subtypes may carry crucial treatment implications. For example, an acute SDH classically results from severe traumatic brain injury and appears as a homogenous, crescent-shaped hyperdense extra-axial collection. If not treated, over the course of 1-3 weeks, this hematoma will evolve into a sub-acute phenotype as a consequence of subdural effusion and demonstrate mixed-density hemorrhage on imaging. Chronic SDH (cSDH) becomes the end result of an untreated SDH, with neo-membranization and neo-angiogenesis from branches of the middle meningeal artery driving a mass-like growth pattern. This review article aims to elucidate the complex anatomical features of the end-stage cSDH, with a particular focus on reconceptualization of this entity based on its mass-like growth patterns, and how this is driving a shift towards endovascular treatment.

A randomised, double blind, placebo-controlled trial of a two-week course of dexamethasone for adult patients with a symptomatic Chronic Subdural Haematoma (Dex-CSDH trial)

Background

Chronic subdural haematoma is a collection of 'old blood' and its breakdown products in the subdural space and predominantly affects older people. Surgical evacuation remains the mainstay in the management of symptomatic cases.

Objective

The Dex-CSDH (DEXamethasone in Chronic SubDural Haematoma) randomised trial investigated the clinical effectiveness and cost-effectiveness of dexamethasone in patients with a symptomatic chronic subdural haematoma.

Design

This was a parallel, superiority, multicentre, pragmatic, randomised controlled trial. Assigned treatment was administered in a double-blind fashion. Outcome assessors were also blinded to treatment allocation.

Setting

Neurosurgical units in the UK.

Participants

Eligible participants included adults (aged ≥ 18 years) admitted to a neurosurgical unit with a symptomatic chronic subdural haematoma confirmed on cranial imaging.

Interventions

Participants were randomly assigned in a 1 : 1 allocation to a 2-week tapering course of dexamethasone or placebo alongside standard care.

Main outcome measures

The primary outcome was the Modified Rankin Scale score at 6 months dichotomised to a favourable (score of 0-3) or an unfavourable (score of 4-6) outcome. Secondary outcomes included the Modified Rankin Scale score at discharge and 3 months; number of chronic subdural haematoma-related surgical interventions undertaken during the index and subsequent admissions; Barthel Index and EuroQol 5-Dimension 5-Level utility index score reported at discharge, 3 months and 6 months; Glasgow Coma Scale score reported at discharge and 6 months; mortality at 30 days and 6 months; length of stay; discharge destination; and adverse events. An economic evaluation was also undertaken, during which the net monetary benefit was estimated at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year.

Results

A total of 748 patients were included after randomisation: 375 were assigned to dexamethasone and 373 were assigned to placebo. The mean age of the patients was 74 years and 94% underwent evacuation of their chronic subdural haematoma during the trial period. A total of 680 patients (91%) had 6-month primary outcome data available for analysis: 339 in the placebo arm and 341 in the dexamethasone arm. On a modified intention-to-treat analysis of the full study population, there was an absolute reduction in the proportion of favourable outcomes of 6.4% (95% confidence interval 11.4% to 1.4%; p = 0.01) in the dexamethasone arm compared with the control arm at 6 months. At 3 months, the between-group difference was also in favour of placebo (-8.2%, 95% confidence interval -13.3% to -3.1%). Serious adverse events occurred in 60 out of 375 (16.0%) in the dexamethasone arm and 24 out of 373 (6.4%) in the placebo arm. The net monetary benefit of dexamethasone compared with placebo was estimated to be -£97.19.

Conclusions

This trial reports a higher rate of unfavourable outcomes at 6 months, and a higher rate of serious adverse events, in the dexamethasone arm than in the placebo arm. Dexamethasone was also not estimated to be cost-effective. Therefore, dexamethasone cannot be recommended for the treatment of chronic subdural haematoma in this population group.

Future work and limitations

A total of 94% of individuals underwent surgery, meaning that this trial does not fully define the role of dexamethasone in conservatively managed haematomas, which is a potential area for future study.

Trial registration

This trial is registered as ISRCTN80782810.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 13/15/02) and is published in full in Health Technology Assessment; Vol. 28, No. 12. See the NIHR Funding and Awards website for further award information.

Inflammatory biomarkers differentiate the stage of maturation in chronic subdural hematomas

OBJECTIVE

Inflammation is a major pathophysiological driver of the development of chronic subdural hematomas (CSDH), but there is still limited knowledge on the key molecular processes and corresponding biomarkers involved in this disease. In this study, the aim was to study a subset of inflammatory biomarkers and their relation to the clinical status of the patient and the radiological characteristics of the CSDH.

METHODS

In this observational study, 58 patients who were operated on with CSDH evacuation, at the Department of Neurosurgery, Uppsala, Sweden, between 2019 and 2021, were prospectively included. The CSDH fluid was collected peri-operatively and was later analyzed with proximity extension assay (PEA) technique (Olink) for a panel of 92 inflammatory biomarkers. Demographic, neurological (Markwalder), radiological (general (Nakaguchi classification) and focal (septa below the burr holes)), and outcome variables were collected.

RESULTS

In 84 of the 92 inflammatory biomarkers, the concentration was above the detection limit in >50% of the patients. There was a significant difference in GDNF, NT-3, and IL-8 depending on the Nakaguchi class, with higher values in the trabeculated CSDH subtype. In addition, those with septa at the focal area of CSDH collection, had higher levels of GDNF, MCP-3, NT-3, CXCL1, CXCL5, IL8, and OSM. There was no association between Markwalder grade and the inflammatory biomarkers.

CONCLUSIONS

Our findings support the presence of local inflammation in the CSDH, a shift in biomarker pattern as the CSDH matures towards the trabeculated state, potentially differences in biomarker patterns within the CSDH depending on the focal environment with presence of septa, and that the brain might develop protective mechanisms (GDNF and NT-3) in case of mature and long-standing CSDHs.

A prospective randomized controlled trial of the effect of the number of burr hole on chronic subdural hematoma recurrence: An institutional experience

OBJECTIVE

The purpose of this study was to compare the effect of single burr hole (SBH) versus double burr hole (DBH) drainage on the recurrence rate of chronic subdural hematoma (CSDH).

METHOD

Forty-four patients undergoing burr hole craniostomy (BHC) between July 2022 and December 2022 were enrolled in a randomized clinical trial (RCT) comparing SBH to DBH surgeries. The primary endpoint of this study was the recurrence rate of CSDH. Radiological characteristics such as midline shift, thickness, volume, density, type of hematoma, brain atrophy and so on were secondary endpoints.

RESULTS

Forty-four patients participated in this study. Twenty-two hematomas underwent SBH craniostomy, and the other 22 had DBH craniostomy. The mean age in the SBH and DBH groups were 68.59 ± 7.94 and 69.54 ± 10.58, respectively. In each group, the proportion of males (SBH=16; DBH=15) was higher than that of females (SBH=6; DBH=7). The mean surgery time in the SBH group was significantly less than in the DBH group (p = 0.001). However, the two groups had no statistically significant difference in the CSDH recurrence rate (p = 0.312).

CONCLUSION

Our findings showed that SBH craniostomy is equally effective as DBH craniostomy at draining hematomas and does not increase the recurrence rate. Contrarily, the SBH craniostomy had a shorter surgical duration than the DBH craniostomy. As a result, we recommend SBH surgeries for all patients, with emphasis on the elderly and those with severe comorbidities, as well as in situations with few surgical facilities and a high patient admission rate.

The Effect of Statins on the Recurrence of Chronic Subdural Hematomas: A Systematic Review and Meta-Analysis

BACKGROUND

Statins have been proposed to improve the resolution of chronic subdural hematoma (cSDH), with conflicting results likely due to underpowered analysis or confounding factors, such as the use of antithrombotic medication. We performed a systematic literature review and meta-analysis to better elucidate the effect of statin therapy on cSDH recurrence.

METHODS

We performed a comprehensive search of PubMed, MEDLINE, and Embase databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles were included if the number of recurrences requiring surgical evacuation or leading to neurological deterioration was reported and could be extracted separately for patients who did or did not receive statin therapy.

RESULTS

Seven studies were included, comprising 1359 cSDH patients (statin therapy, 449 vs. non-statin therapy, 910). Age was not different between groups (P = 0.548). The proportion of men was significantly different (statin, 80.1% vs. non-statin, 74.7%; P = 0.02). Use of antithrombotic medication was significantly higher (P = 0.005) in the statin group (11.7%) than in the non-statin group (7.3%). The statin group had a non-significant lower odds of recurrence (odds ratio 0.80, 95% confidence interval 0.35-1.81). In an exploratory data analysis of 4 studies without a difference between groups in antithrombotic medication use, the statin group had significantly lower odds of recurrence (odds ratio 0.29, 95% confidence interval 0.17-0.50).

CONCLUSIONS

Overall, we found that statin use did not result in lower odds of cSDH recurrence, likely due to a dilution caused by the higher rate of patients on antithrombotic medications in the statin group.

Dexamethasone reduces vascular endothelial growth factor in comparison to placebo in post-operative chronic subdural hematoma samples: A target for future drug therapy?

Background

Chronic subdural hematoma (CSDH) is a collection of blood and fluid that arises on the brain surface due to a combination of trauma and/or inflammation. The mainstay of treatment is surgical drainage, but CSDH can recur. Dexamethasone has been shown to reduce CSDH recurrence, but its mechanism of action has not been fully elucidated. Understanding the inflammatory mediators driving CSDH formation and recurrence and how dexamethasone alters this can help develop new therapeutic strategies.

Methods

A subgroup of adult patients recruited to the Dex-CSDH trial, randomized to dexamethasone or placebo, who had surgery for their CSDH, were included. CSDH fluid and peripheral blood were collected intraoperatively, from post-operative drains and operated recurrences. Samples were analyzed using a 12-plex panel of inflammatory mediators. Clinical patient data were also reviewed.

Results

A total of 52 patients, with a mean age of 76 years, were included. Five recurrent CSDHs occurred. Vascular endothelial growth factor (VEGF) had the highest concentration across all CSDHs, and only matrix metalloproteinase (MMP)-9 had lower concentrations in CSDH compared to plasma but was increased in recurrent CSDHs. The interleukin (IL)-10 concentration was significantly lower in primary CSDHs that recurred. Most inflammatory mediators increased post-operatively, and dexamethasone significantly reduced the post-operative peak in VEGF on day 2, compared to placebo.

Conclusion

It is evident that VEGF plays a critical role in the inflammatory response in CSDH. The post-operative reduction with dexamethasone could signal the mechanism by which it reduces recurrence. Novel therapies with a better side-effect profile than dexamethasone should be targeted at VEGF or potential alternatives such as IL-10 supplementation.

Immunoexpression of MMP-8 and MMP-9 in chronic subdural hematoma

To determine the possible role of matrix metallopeptidase (MMP)-8 and MMP-9 in the development of chronic subdural hematoma (CSDH), we investigated their expression in CSDH. In our previous study, we analyzed hematoma fluid and peripheral blood of 83 patients with CSDH, including 17 postoperative patients. Based on these results, we included 50 people in the normal group and analyzed 20 markers in the peripheral blood of each person. In order to identify representative markers, it was assessed by using overall differential gene expression. The concentration of MMP-8 was significantly higher in the normal group than that in the preoperative and postoperative groups. The concentration of MMP-9 was significantly lower in the normal group than in both preoperative and postoperative groups. Immunohistochemistry confirmed the expression of MMP-8 and MMP-9 in CSDH membranes. In conclusion, our results provide evidence of the expression of MMP-8 and MMP-9 in CSDH. In addition, the expression of MMP-8 and MMP-9 suggests angiogenesis in CSDH formation.

Serum Levels of MMP-8 and MMP-9 as Markers in Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is a common neurological disease that involves the collection of blood products in the subdural space. The progression of CSDH is an angiogenic and inflammatory process, but the multifactorial mechanisms underlying CSDH are still not fully understood. We aimed to identify one or more factors that may play an important role in the development of CSDH. We enrolled 83 patients with CSDH, including 17 postoperative patients, and analyzed 20 markers in the hematoma fluid and peripheral blood of each patient. Overall differential gene expression was examined to identify the representative markers. The concentration of MMP-8 was significantly lower in the postoperative group than in the preoperative group. The concentration of MMP-9 was significantly higher in the postoperative group than in the preoperative group. These findings indicate that MMP-8 and MMP-9 may play important roles in the pathophysiology of CSDH. Understanding the pathways associated with CSDH may provide insights for improving disease outcomes.

Hematoma subdural crónico: Una patología común de manejo complejo

Antecedentes:

El hematoma subdural crónico (HSDC) es una patología ampliamente estudiada, muy frecuente, sobre todo en adultos mayores; su cuadro clínico tiene una apariencia benigna y suele ir acompañado de múltiples comorbilidades asociadas a la edad, lo que resulta en un aumento de las complicaciones e incluso la muerte. Con el incremento de la expectativa de vida a nivel mundial, el uso de medicamentos antitrombóticos es cada vez más frecuente. El papel de estos fármacos en la evolución de la enfermedad como en la recurrencia, sigue siendo motivo de discusión.

Métodos:

Los autores revisaron la fisiopatología y características clínicas del HSDC. El presente artículo discute acerca de las terapéuticas actuales y las nuevas opciones de tratamiento que podrían mejorar los resultados. Este manuscrito es susceptible de cambios en el tiempo, con el desarrollo científico y tecnológico.

Resultados:

El HSDC puede ser abordado por vía quirúrgica y farmacológica; no obstante, un manejo individualizado requiere la consideracion cuidadosa de diversos factores. A pesar de los avances en el campo de la neurocirugía, la clásica trepanación craneal sigue siendo el Gold estándar en el HSDC y sobre todo en pacientes con síntomas graves. Se debe resaltar que aún hay aspectos de este procedimiento (como la localización del dren, número de drenajes, el efecto de la irrigación, la temperatura de la solución con que se irriga, etc.) que siguen siendo materia de estudio.

Conclusiones:

Entender el mecanismo de la enfermedad ha permitido explicar su historia natural y a su vez proponer nuevas alternativas de tratamiento. El manejo médico (atorvastatina, corticoides) ha generado gran interés por sus alentadores resultados preliminares. Recientemente, se ha reportado la terapia endovascular como una alternativa segura y existe gran expectativa por confirmar su efecto en estudios más grandes.

A novel rat model of chronic subdural hematoma: Induction of inflammation and angiogenesis in the subdural space mimicking human-like features of progressively expanding hematoma

Pathophysiological mechanisms of chronic subdural hematoma (CSDH) involve localized inflammation, angiogenesis, and dysregulated coagulation and fibrinolysis. The scarcity of reproducible and clinically relevant animal models of CSDH hinders further understanding the underlying pathophysiology and improving new treatment strategies. Here, we developed a novel rat model of CSDH using extracellular matrices (Matrigel) and brain microvascular endothelial cell line (bEnd.3 cells). One hundred-microliter of Matrigel-bEnd.3 cell (10⁶ cells per milliliter) mixtures were injected into the virtual subdural space of elderly male Sprague-Dawley rats. This approach for the first time led to a spontaneous and expanding subdural hematoma, encapsulated by internal and external neomembranes, formed as early as 3 d, reached its peak at 7 d, and lasted for more than 14 d, mimicking the progressive hemorrhage observed in patients with CSDH. The external neomembrane and hematoma fluid involved numerous inflammatory cells, fibroblasts, and highly fragile neovessels. Furthermore, a localized pathophysiological process was validated as evidenced by the increased expressions of inflammatory and angiogenic mediators in external neomembrane and hematoma fluid rather than in peripheral blood. Notably, the specific expression profiles of these mediators were closely associated with the dynamic changes in hematoma volume and neurological outcome. In summary, the CSDH model described here replicated the characteristics of human CSDH, and might serve as an ideal translational platform for preclinical studies. Meanwhile, the crucial roles of angiogenesis and inflammation in CSDH formation were reaffirmed.

Impact of inflammatory cell ratio, biomarkers, activated partial thromboplastin time and prothrombin time on chronic subdural haematoma severity and outcome

INTRODUCTION

Chronic subdural haematoma (CSH) has multifactorial mechanisms involved in its development and progression. Identifying readily available inflammatory and coagulation indices that can predict the prognosis of CSH will help in clinical care, prognosis, generating objective criteria for assessing efficacy of treatment strategies and comparisons of treatment efficacy between clinical studies. We conducted a study in which we evaluated the impact value of neutrophil to lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), inflammatory biomarkers (erythrocyte sedimentation rate and C-reactive protein), activated partial thromboplastin time (APTT), prothrombin time (PT) and international normalized ratio (INR) at presentation on CSH severity and outcome using Glasgow outcome scale (GOS), Markwalder grading scale (MGS) and Lagos brain disability examination scale (LABDES).

METHODS

We prospectively studied patients in a single healthcare system with clinical and radiological features of chronic subdural haematoma. Only patients who were managed surgically were recruited. The primary outcome was predictors of severe form CSH (using admission Glasgow coma scale score, MGS grade, inflammatory cells and biomarkers, APTT, PT, and INR) and outcome (using GOS, MGS and LABDES grades 3 months) with secondary outcome being mortality rate, 3 months following surgery. Good outcome was defined as GOS score > 3, LABDES score ≥ 40 at three months and MGS score < 2. Differences in categorical and continuous variables between groups were compared using Fisher's exact test or Chi-square test (χ2) analysis, one-way ANOVA or Kruskal-Wallis test (in case of non-normal distribution).

RESULTS

We included 61 patients with a male-to-female ratio of 2.6:1 and mean age of 57.5 ± 13.3 years (median 58 years; 27-83 years). The pre-op MGS grade was significantly associated with the LABDES (p = 0.034), GOS (p = 0.011) and post-op MGS (p = 0.007) grade. All the patients that died had elevated APTT and PT with low PLR. A low admission PLR was significantly associated with a poor outcome using the GOS (p = 0.001), MGS (p = 0.011) and LABDES grade (p = 0.006) (Table 3). A high APTT was also significantly associated with a worse outcome using GOS (p = 0.007), MGS (p = 0.007) and LABDES grade (p = 0.003). There were three (4.9%) deaths with post-mortem diagnosis of pulmonary embolism, chronic renal failure and irreversible craniocaudal herniation syndrome. All the patients that died had elevated APTT and PT with low PLR.

CONCLUSION

Patients' admission APTT, PT, INR and PLR are good predictors of outcome using the GOS. A high admission INR is also associated with a worse outcome using MGS and LABDES grade.

Statistical analysis plan for the Dex-CSDH trial: a randomised, double-blind, placebo-controlled trial of a 2-week course of dexamethasone for adult patients with a symptomatic chronic subdural haematoma

BACKGROUND

The incidence of chronic subdural haematoma (CSDH) is increasing. Although surgery remains the mainstay of management for symptomatic patients, uncertainty remains regarding the role of steroids. Hence, the Dex-CSDH trial was launched in the UK in 2015 aiming to determine whether, compared to placebo, dexamethasone can improve the 6-month functional outcome of patients with symptomatic CSDH by reducing the rate of surgical intervention and recurrence rate.

METHODS AND DESIGN

Dex-CSDH is a multi-centre, pragmatic, parallel group, double-blind, randomised trial assessing the clinical utility of a 2-week course of dexamethasone following a CSDH. Seven hundred fifty patients were randomised to either dexamethasone or placebo. The primary outcome is the modified Rankin Scale at 6 months which is dichotomised to favourable (a score of 0-3) versus unfavourable (a score of 4-6).

CONCLUSIONS

This paper and the accompanying additional material describe the statistical analysis plan for the trial.

TRIAL REGISTRATION

ISRCTN, ISRCTN80782810. Registered on 7 November 2014. http://www.isrctn.com/ISRCTN80782810. EudraCT, 2014-004948-35. Registered on 20 March 2015.

Dex-CSDH randomised, placebo-controlled trial of dexamethasone for chronic subdural haematoma: report of the internal pilot phase

The Dex-CSDH trial is a randomised, double-blind, placebo-controlled trial of dexamethasone for patients with a symptomatic chronic subdural haematoma. The trial commenced with an internal pilot, whose primary objective was to assess the feasibility of multi-centre recruitment. Primary outcome data collection and safety were also assessed, whilst maintaining blinding. We aimed to recruit 100 patients from United Kingdom Neurosurgical Units within 12 months. Trial participants were randomised to a 2-week course of dexamethasone or placebo in addition to receiving standard care (which could include surgery). The primary outcome measure of the trial is the modified Rankin Scale at 6 months. This pilot recruited ahead of target; 100 patients were recruited within nine months of commencement. 47% of screened patients consented to recruitment. The primary outcome measure was collected in 98% of patients. No safety concerns were raised by the independent data monitoring and ethics committee and only five patients were withdrawn from drug treatment. Pilot trial data can inform on the design and resource provision for substantive trials. This internal pilot was successful in determining recruitment feasibility. Excellent follow-up rates were achieved and exploratory outcome measures were added to increase the scientific value of the trial.

Dexamethasone for adult patients with a symptomatic chronic subdural haematoma (Dex-CSDH) trial: study protocol for a randomised controlled trial

Background

Chronic subdural haematoma (CSDH) is a common neurosurgical condition, typically treated with surgical drainage of the haematoma. However, surgery is associated with mortality and morbidity, including up to 20% recurrence of the CSDH. Steroids, such as dexamethasone, have been identified as a potential therapy for reducing recurrence risk in surgically treated CSDHs. They have also been used as a conservative treatment option, thereby avoiding surgery altogether. The hypothesis of the Dex-CSDH trial is that a two-week course of dexamethasone in symptomatic patients with CSDH will lead to better functional outcome at six months. This is anticipated to occur through reduced number of hospital admissions and surgical interventions.

Methods

Dex-CSDH is a UK multi-centre, double-blind randomised controlled trial of dexamethasone versus placebo for symptomatic adult patients diagnosed with CSDH. A sample size of 750 patients has been determined, including an initial internal pilot phase of 100 patients to confirm recruitment feasibility. Patients must be recruited within 72 h of admission to a neurosurgical unit and exclusions include patients already on steroids or with steroid contraindications, patients who have a cerebrospinal fluid shunt and those with a history of psychosis. The decision regarding surgical intervention will be made by the clinical team and patients can be included in the trial regardless of whether operative treatment is planned or has been performed. The primary outcome measure is the modified Rankin Scale (mRS) at six months. Secondary outcomes include the number of CSDH-related surgical interventions during follow-up, length of hospital stay, mRS at three months, EQ-5D at three and six months, adverse events, mortality and a health-economic analysis.

Discussion

This multi-centre trial will provide high-quality evidence as to the effectiveness of dexamethasone in the treatment of CSDH. This has implications for patient morbidity and mortality as well as a potential economic impact on the overall health service burden from this condition.

Trial registration

ISRCTN, ISRCTN80782810. Registered on 7 November 2014. EudraCT, 2014-004948-35. Registered on 20 March 2015.

Dex-CSDH trial protocol version 3, 27 Apr 2017.

This protocol was developed in accordance with the SPIRIT checklist. Available as a separate document on request.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3050-4) contains supplementary material, which is available to authorized users.

Pathophysiology and Nonsurgical Treatment of Chronic Subdural Hematoma: From Past to Present to Future

BACKGROUND

Chronic subdural hematoma (CSDH) is one of the more frequent pathologic entities in daily neurosurgical practice. Historically, CSDH was considered progressive recurrent bleeding with a traumatic cause. However, recent evidence has suggested a complex intertwined pathway of inflammation, angiogenesis, local coagulopathy, recurrent microbleeds, and exudates. The aim of the present review is to collect existing data on pathophysiology of CSDH to direct further research questions aiming to optimize treatment for the individual patient.

METHODS

We performed a thorough literature search in PubMed, Ovid, EMBASE, CINAHL, and Google scholar, focusing on any aspect of the pathophysiology and nonsurgical treatment of CSDH.

RESULTS

After a (minor) traumatic event, the dural border cell layer tears, which leads to the extravasation of cerebrospinal fluid and blood in the subdural space. A cascade of inflammation, impaired coagulation, fibrinolysis, and angiogenesis is set in motion. The most commonly used treatment is surgical drainage. However, because of the pathophysiologic mechanisms, the mortality and high morbidity associated with surgical drainage, drug therapy (dexamethasone, atorvastatin, tranexamic acid, or angiotensin-converting enzyme inhibitors) might be a beneficial alternative in many patients with CSDH.

CONCLUSIONS

Based on pathophysiologic mechanisms, animal experiments, and small patient studies, medical treatment may play a role in the treatment of CSDH. There is a lack of level I evidence in the nonsurgical treatment of CSDH. Therefore, randomized controlled trials, currently lacking, are needed to assess which treatment is most effective in each individual patient.

Statins in conditions other than hypocholesterolemic effects for chronic subdural hematoma therapy, old drug, new tricks?

Chronic subdural hematoma (CSDH) is one of the most common intracranial hematomas worldwide with a high incidence in the general population. However, the optimum treatment for CSDH is Burr-hole drainage with or without rinse Considering the poor outcomes of CSDH in aged patients, and ambiguous prediction of recurrence in many sides of recurrent CSDHs who have been analyzed, new effective therapies are needed for those CSDHs who are predicated to have poor prognosis for surgery and/or have a higher risk of recurrence. Statins, which is the first-line treatment for patients with high cholesterol and coronary heart disease. However, statins are still not solely limited in the treatment of these diseases. It has been demonstrated that statins could improve CSDH due to its effect of regulation of angiogenesis and inflammation. In this review, in order to provide potential new treatment for CSDH we summarize the recent findings of statins in CSDH in order to try to clarify the mechanisms of this effect.

Association between biomarkers and clinical characteristics in chronic subdural hematoma patients assessed with lasso regression

Chronic subdural hematoma (CSDH) is characterized by an “old” encapsulated collection of blood and blood breakdown products between the brain and its outermost covering (the dura). Recognized risk factors for development of CSDH are head injury, old age and using anticoagulation medication, but its underlying pathophysiological processes are still unclear. It is assumed that a complex local process of interrelated mechanisms including inflammation, neomembrane formation, angiogenesis and fibrinolysis could be related to its development and propagation. However, the association between the biomarkers of inflammation and angiogenesis, and the clinical and radiological characteristics of CSDH patients, need further investigation. The high number of biomarkers compared to the number of observations, the correlation between biomarkers, missing data and skewed distributions may limit the usefulness of classical statistical methods. We therefore explored lasso regression to assess the association between 30 biomarkers of inflammation and angiogenesis at the site of lesions, and selected clinical and radiological characteristics in a cohort of 93 patients. Lasso regression performs both variable selection and regularization to improve the predictive accuracy and interpretability of the statistical model. The results from the lasso regression showed analysis exhibited lack of robust statistical association between the biomarkers in hematoma fluid with age, gender, brain infarct, neurological deficiencies and volume of hematoma. However, there were associations between several of the biomarkers with postoperative recurrence requiring reoperation. The statistical analysis with lasso regression supported previous findings that the immunological characteristics of CSDH are local. The relationship between biomarkers, the radiological appearance of lesions and recurrence requiring reoperation have been inclusive using classical statistical methods on these data, but lasso regression revealed an association with inflammatory and angiogenic biomarkers in hematoma fluid. We thus suggest that lasso regression should be a recommended statistical method in research on biological processes in CSDH patients.

Clinical Investigation of Refractory Chronic Subdural Hematoma: A Comparison of Clinical Factors Between Single and Repeated Recurrences

BACKGROUND

Chronic subdural hematoma (CSDH) is sometimes refractory, and this is troublesome for neurosurgeons. Although many studies have reported risk factors or treatments in efforts to prevent recurrence, those have focused on single recurrence, and few cumulative data are available to analyze refractory CSDH.

METHODS

We defined refractory CSDH as ≥2 recurrences, then analyzed and compared clinical factors between patients with single recurrence and those with refractory CSDH in a cohort study, to clarify whether patients with refractory CSDH experience different or more risk factors than patients with single recurrence, and whether burr-hole irrigation with closed-system drainage reduces refractory CSDH.

RESULTS

Seventy-five patients had at least 1 recurrence, with single recurrence in 62 patients and ≥2 recurrences in 13 patients. In comparing clinical characteristics, patients with refractory CSDH were significantly younger (P = 0.04) and showed shorter interval to first recurrence (P < 0.001). Organized CSDH was also significantly associated with refractory CSDH (P = 0.02). Multivariate logistic regression analysis identified first recurrence interval <1 month (odds ratio, 6.66, P < 0.001) and age <71 years (odds ratio, 4.16, P < 0.001) as independent risk factors for refractory CSDH. On the other hand, burr-hole irrigation with closed-system drainage did not reduce refractory CSDH.

CONCLUSIONS

When patients with risk factors for refractory CSDH experience recurrence, alternative surgical procedures may be considered as the second surgery, because burr-hole irrigation with closed-system drainage did not reduce refractory CSDH in our study.

Pathophysiology of chronic subdural haematoma: inflammation, angiogenesis and implications for pharmacotherapy

Chronic subdural haematoma (CSDH) is an encapsulated collection of blood and fluid on the surface of the brain. Historically considered a result of head trauma, recent evidence suggests there are more complex processes involved. Trauma may be absent or very minor and does not explain the progressive, chronic course of the condition. This review focuses on several key processes involved in CSDH development: angiogenesis, fibrinolysis and inflammation. The characteristic membrane surrounding the CSDH has been identified as a source of fluid exudation and haemorrhage. Angiogenic stimuli lead to the creation of fragile blood vessels within membrane walls, whilst fibrinolytic processes prevent clot formation resulting in continued haemorrhage. An abundance of inflammatory cells and markers have been identified within the membranes and subdural fluid and are likely to contribute to propagating an inflammatory response which stimulates ongoing membrane growth and fluid accumulation. Currently, the mainstay of treatment for CSDH is surgical drainage, which has associated risks of recurrence requiring repeat surgery. Understanding of the underlying pathophysiological processes has been applied to developing potential drug treatments. Ongoing research is needed to identify if these therapies are successful in controlling the inflammatory and angiogenic disease processes leading to control and resolution of CSDH.

Chronic subdural hematoma

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. There is lack of uniformity in the treatment of CSDH amongst surgeons in terms of various treatment strategies. Clinical presentation may vary from no symptoms to unconsciousness. CSDH is usually diagnosed by contrast-enhanced computed tomography scan. Magnetic resonance imaging (MRI) scan is more sensitive in the diagnosis of bilateral isodense CSDH, multiple loculations, intrahematoma membranes, fresh bleeding, hemolysis, and the size of capsule. Contrast-enhanced CT or MRI could detect associated primary or metastatic dural diseases. Although definite history of trauma could be obtained in a majority of cases, some cases may be secondary to coagulation defect, intracranial hypotension, use of anticoagulants and antiplatelet drugs, etc., Recurrent bleeding, increased exudates from outer membrane, and cerebrospinal fluid entrapment have been implicated in the enlargement of CSDH. Burr-hole evacuation is the treatment of choice for an uncomplicated CSDH. Most of the recent trials favor the use of drain to reduce recurrence rate. Craniotomy and twist drill craniostomy also play a role in the management. Dural biopsy should be taken, especially in recurrence and thick outer membrane. Nonsurgical management is reserved for asymptomatic or high operative risk patients. The steroids and angiotensin converting enzyme inhibitors may also play a role in the management. Single management strategy is not appropriate for all the cases of CSDH. Better understanding of the nature of the pathology, rational selection of an ideal treatment strategy for an individual patient, and identification of the merits and limitations of different surgical techniques could help in improving the prognosis.

Effect of ATorvastatin On Chronic subdural Hematoma (ATOCH): a study protocol for a randomized controlled trial

Background

Chronic subdural hematoma (CSDH) is a common disease that is more prevalent in older people. Surgical intervention is a safe treatment of choice. However, the recurrence rate is relatively high and the outcome is not always satisfactory among surgically treated patients. It is believed that aberrant angiogenesis and intracapsular inflammation contribute to the development of CSDH. Atorvastatin is reported to promote angiogenesis and suppress inflammation. We have recently shown that atorvastatin is effective to non-surgically reduce and eliminate CSDH with minimal side effects. Here, we report a clinical research trial protocol that is designed to evaluate the therapeutic effects of atorvastatin on CSDH.

Methods/Design

We have designed a multi-center, randomized, placebo-controlled, double blind clinical trial for evaluating the efficacy of oral atorvastatin in reducing CSDH. We have so far recruited 96 patients with CT-confirmed or MRI-confirmed CSDHs from 16 medical centers in China. These patients were originally recruited for the Oriental Neurosurgical Evidence-based Study Team (ONET) study. After informed consent is provided, patients are randomized to receive either atorvastatin (oral 20 mg/night for 8 weeks) or placebo (dextrin for 8 weeks); and followed for 16 weeks after the treatment. The primary outcome is the change in hematoma volume at the end of 8-week treatment. Secondary outcomes include: changes in 1) the hematoma volume at the 4^th, 12^th, and 24^th weeks; 2) Markwalder’s Grading Scale and Glasgow Coma Scale (MGS-GCS); 3) Glasgow Outcome Score (GOS) and 4) Activities of Daily Life – the Barthel Index scale (ADL-BI). Safety will be assessed during the study by monitoring adverse events, laboratory tests, electrocardiography (ECG), measurements of vital signs (temperature, pulse, and blood pressure) and body weight.

Discussion

Results of this trial will provide critical information regarding whether atorvastatin is an effective and safe alternative to surgical treatment of CSDH.

Trial registration

ClinicalTrials.gov Identifier – NCT02024373

The date of trial registration: 7 August 2013

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-015-1045-y) contains supplementary material, which is available to authorized users.

Surgical management of the patients with chronic subdural haematoma and contralateral subdural effusion: Operation or no-operation?

OBJECTIVE

Patients with chronic subdural haematoma and contralateral subdural effusion are rare after head injury. Surgery might reduce clinical progression of subdural effusion, but is not used routinely. This study aimed to investigate the effect of surgery on subdural effusion and clinical outcome.

METHODS

A retrospective study was performed, comparing operation and non-operation in the patients with chronic subdural haematoma and contralateral subdural effusion, in a series of 47 patients divided into two groups. The operation group of 21 patients underwent bilateral surgery. The non-operation group of 26 patients underwent surgery on the side with chronic subdural haematoma. Neurological status was assessed by the Glasgow Coma score and Modified Rankin Scale score on admission and at follow-up. All cases underwent pre- and post-operative computed tomography scans.

RESULTS

Pre-operative clinical and radiological data were similar in the two groups. The rate of subdural effusion progression was significantly lower in the operation group than in the non-operation group (p < 0.05). Thirteen cases (50%) in the non-operation group and three cases (14.3%) in the operation group had progression of subdural effusion to chronic subdural haematoma (p < 0.05). Chronic subdural haematoma recurrence rate, mortality and neurological recovery were similar, with no significant difference between groups.

CONCLUSIONS

The patients benefitted from surgery for subdural effusion when they had chronic subdural haematoma and contralateral subdural effusion.

Measurement of inflammatory cytokines and thrombomodulin in chronic subdural hematoma

Inflammation and the coagulation system may influence the genesis of chronic subdural hematoma (CSDH). The appearance of CSDH on computed tomography (CT) varies with the stage of the hematoma. This study investigated the pathogenesis and the recurrence of CSDH by comparing cytokine levels with the CT features of CSDH in 26 patients with 34 CSDHs who underwent single burr-hole surgery at our hospital between October 2004 and November 2006. The hematoma components removed during the procedure were examined, and the hematoma serum levels of cytokines measured such as thrombomodulin (TM), interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), and interleukin-10 (IL-10). Using CT, mixed density hematomas were distinguished from other homogeneous hematomas, and found that the TM level was significantly higher in mixed density hematomas than in homogeneous hematomas (p = 0.043). Mixed density hematomas were classified into three subtypes (laminar, separated, and trabecular hematomas). The TM level was significantly higher in laminar and separated hematomas than in other hematomas (p = 0.01). The levels of IL-6, TNFα, and IL-10 were extremely high, but showed no significant differences in relation to the CT features. Mixed density hematomas had high recurrence rate, as reported previously, and TM level was high in mixed density hematomas such as laminar and separated mixed density hematomas. The present findings suggest that the types of CSDH associated with high TM levels tend to have higher recurrence rate.

Ambivalence among neurologists and neurosurgeons on the treatment of chronic subdural hematoma: a national survey

No class I evidence exists about the optimal treatment of chronic subdural hematoma (CSDH). The aim of this study was to evaluate current practice of CSDH patients with different neurological grades, and probable ambivalence towards various treatment paradigms, especially primary treatment with high-dose corticosteroids, among vascular neurologists and neurosurgeons. A questionnaire survey containing 4 questions, 1 consisting of cases, was sent to every vascular neurologist (n = 83) and neurosurgical centre (n = 15) in the Netherlands. The various treatment options were related to the treating physician, geographical distribution, both in general and for individual case. Sixty-two percent of surveys were returned. The proportion of patients primarily treated with corticosteroids was 17.5 % in 2009 and 20.5 % in 2010. Surgery by either burr holes or craniotomy was favoured by 61.1 % as primary treatment, and conservative treatment with corticosteroids by 22.4 %. Case studies revealed that surgery was preferred in case of severe neurological symptoms, whereas wait-and-see policy was preferred in case of mild symptoms without midline shift, of which 28 % would administer corticosteroids. Variety in answers was obtained in less pronounced cases. In the Netherlands, neurologists and neurosurgeons appear to favour surgery in CSDH patients as primary treatment, especially in severe cases. An ambivalent approach towards treatment protocols was shown, especially in patients with mild symptoms, regardless of hematoma size. A regimen of high-dose corticosteroids only, is preferred by about a quarter and predominantly in milder cases, and might depend on geographical distribution. These results suggest the need for a well-designed randomized trial.

Chemokines as markers of local inflammation and angiogenesis in patients with chronic subdural hematoma: a prospective study

OBJECTIVE

The goal of this study was to investigate the chemokines CCL2, CXCL8, CXCL9 and CXCL10 as markers of the inflammatory responses in chronic subdural hematoma (CSDH).

METHODS

Samples of peripheral venous blood and CSDH fluid (obtained during surgery) in 76 adult patients were prospectively analyzed. Chemokine values were assessed by a Multiplex antibody bead kit.

RESULTS

We found significantly higher levels of chemokines CCL2, CXCL8, CXCL9 and CXCL10 in hematoma fluid compared with serum.

CONCLUSIONS

Chemokines are elevated in the hematoma cavity of patients with CSDH. It is likely that these signaling modulators play an important role in promoting local inflammation. Furthermore, biological activity of CCL2 and CXCL8 may promote neovascularization within the outer CSDH membrane, and a compensatory angiostatic activity of CXCL9 and CXCL10 may contribute to repairing this disorder. This phenomenon was restricted to the hematoma site, and the systemic chemokine levels might not reflect local immune responses.