Chronic subdural haematoma and the enigmatic eosinophil

Peripheral blood eosinophil and classification of residual hematoma help predict the recurrence of chronic subdural hematoma after initial surgery

Chronic subdural hematoma (CSDH) is a common type of intracranial hemorrhage in neurosurgical practice, whose incidence has increased markedly in recent years. However, CSDH still troubles clinicians with a high postoperative recurrence rate. The presence of eosinophils has been confirmed in some CSDH surgical specimens. Furthermore, postoperative residual hematoma has not been classified, and its association with the recurrence of CSDH remains unknown. The present study aimed to test the hypothesis that the peripheral blood eosinophils and the classification of postoperative residual hematoma are significant for the prediction of CSDH recurrence after burr-hole surgery. A retrospective review of 258 CSDH patients who received burr-hole surgery was performed. A complete blood picture with differential count was taken before surgery. Clinical, laboratory, and radiographic factors predicting CSDH recurrence were identified in univariable and multivariable analyses. Univariable analysis showed that the percentage of eosinophils, peripheral blood eosinophil count <0.15 × 10⁹/L, gradation and separated types, postoperative volume of the residual cavity ≥70 ml, residual air volume ≥28 ml, residual hematoma volume ≥55 ml, residual hematoma width ≥1.4 cm, postoperative midline shift ≥5.6 mm, postoperative brain re-expansion rate <41%, postoperative low-density type, and postoperative high-density type correlated with the recurrence of CSDH. Multivariable analysis, however, showed that peripheral blood eosinophil count <0.15 × 10⁹/L, gradation and separated types, preoperative midline shift ≥9.5 mm, postoperative brain re-expansion rate <41%, postoperative low-density type, and postoperative high-density type are independent predictors for the recurrence of CSDH. We expect that peripheral blood eosinophils and the classification of postoperative residual hematoma may facilitate our understanding of the recurrence of CSDH after initial surgery.

Amyloid-β related angiitis presenting as eosinophilic meningitis: a case report

BACKGROUND

Eosinophilic meningitis is uncommon and often attributed to infectious causes.

CASE PRESENTATION

We describe a case of a 72-year-old man who presented with subacute onset eosinophilic meningitis, vasculitis, and intracranial hypertension with progressive and severe neurologic symptoms. Brain MRI demonstrated multifocal strokes and co-localized right temporo-parieto-occipital vasogenic edema, cortical superficial siderosis, and diffuse leptomeningeal enhancement. He ultimately underwent brain biopsy with immunohistochemical stains for amyloid-β and Congo red that were extensively positive in the blood vessel walls and in numerous diffuse and neuritic parenchymal confirming a diagnosis of amyloid-β related angiitis. He was treated with immunosuppression with clinical stabilization.

CONCLUSIONS

Amyloid-β related angiitis is an underrecognized cause of eosinophilic meningitis that can present fulminantly and is typically responsive to immunosuppression. The presence of eosinophils may provide additional clues to the underlying pathophysiology of amyloid-β related angiitis.

The Crucial Role of Eosinophils in the Life Cycle, Radiographical Architecture, and Risk of Recurrence of Chronic Subdural Hematomas

Chronic subdural hematomas (CSDHs) are a common neurological condition, whose incidence is expected to increase with an aging population. Although surgical evacuation is the mainstay of treatment, it results in a recurrence requiring reoperation (RrR) in 3-30% of cases. Recurrence is thought to be driven by a combination of inflammatory and angiogenic processes occurring within the CSDH outer membrane. Pathological specimens of 72 primary CSDHs were examined for eosinophilic infiltrate. For each case, the pre-operative computed tomography (CT) scan was graded according to the Nakaguchi grading scheme as homogeneous, laminar, separated, or trabecular. Rate of RrR was compared based on eosinophilic infiltrate and CT grade. A dense eosinophilic infiltrate was observed in 22% of specimens. The rate of RrR among specimens with a dense eosinophilic infiltrate was 0%, whereas it was 14.3% among specimens without a dense eosinophilic infiltrate. Incidence among homogeneous, laminar, separated, and trabecular CT subtypes was 4%, 27%, 58%, and 24%, respectively. A dense eosinophilic infiltrate found within the outer membrane of a CSDH may be a marker of hematoma maturation, signaling a transition toward healing and fibrosis, and a lower risk of RrR.

Sequential Expression of Chemokines in Chronic Subdural Hematoma Fluids after Trepanation Surgery

Chronic subdural hematoma (CSDH) is considered an angiogenic and inflammatory disease. Chemokines attract leukocytes, and invading neutrophils and monocytes/macrophages play important roles in wound healing. However, no studies have been reported regarding changes in expression of chemokines in CSDH fluid after trepanation surgery. We randomly divided patients who underwent trepanation surgery into two groups. One was the irrigation group, in which irrigation of CSDH fluids was performed and a drainage tube was placed (n = 10). The other was the non-irrigation group, in which a drainage tube was inserted without irrigation (n = 10). CSDH fluids were collected during the trepanation surgery, immediately after surgery and on day 1 through the drainage tube. The concentrations of interleukin-8 (IL-8), growth-regulated oncogene-α (GRO-α), epithelial neutrophil-activating peptide 78 (ENA-78), monocyte chemoattractant protein-1 (MCP-1), interferon-γ-induced protein-10 (IP-10), tissue plasminogen activator (tPA), von Willebrand factor (vWF), eotaxin-3, and myeloperoxidase (MPO) in each CSDH fluid sample were measured using enzyme-linked immunosorbent assay kits. After irrigation, concentrations of all chemokines decreased. However, concentrations of IL-8, GRO-α, ENA-78, MCP-1, and MPO were significantly increased on day 1 compared with concentrations during surgery with or without irrigation. In contrast, there were no changes in concentrations of IP-10, eotaxin-3, tPA, or vWF after trepanation surgery. Moreover, there were significant relationships among concentrations of IL-8, GRO-α, ENA-78, and MCP-1 during the surgery and on day 1. In CSDH fluids, chemokines that attract neutrophils, such as IL-8, GRO-α, ENA-78, and macrophage-attracting MCP-1, appear first after trepanation surgery, whereas lymphocyte-attracting IP-10 and eosinophil-attracting eotaxin-3 levels do not change within 1 day of surgery. These findings suggest that neutrophils and macrophages may play important roles in the healing process of CSDH at an early stage.

Gradation density hematoma is a predictor of chronic subdural hematoma recurrence associated with inflammation of the outer membrane

OBJECTIVES

Chronic subdural hematoma (CSDH) is a common form of intracranial hemorrhage with a high recurrence rate. This study aimed to determine the CSDH recurrence rate associated with preoperative computed tomography (CT) findings and the pathological examination of the dura and the outer membrane.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of patients with CSDH who underwent surgery in our hospital between May 2010 and November 2019. CSDHs were classified into four groups according to the hematoma density on CT: low-density hematoma (LDH), gradation-density hematoma (GDH), iso-density-hematoma (IDH), and mixed-density hematoma (MDH). The postoperative recurrence rate was calculated for each group, and we examined whether the recurrence rate correlated with the CT findings. We also took samples of the dura to analyze inflammatory cell infiltration and the blood vessels.

RESULTS

A total of 388 patients were analyzed. The total recurrence rate was 13.7%. CT findings at admission showed LDH in 50, GDH in 136, IDH in 110, and MDH in 92 patients. The recurrence rate of GDH (23.5%, 32/136) was comparable to the rate of the other CSDH types (11.5%, 61/388). Univariate and multivariate analyses found GDH to be an independent risk factor for the recurrence of CSDH. GDH patients displayed much more angiogenesis and inflammatory cell infiltration in the outer membrane and the dura.

CONCLUSION

GDH is an independent predictor for CSDH recurrence. The presence of inflammation in GDH might be the primary cause of CSDH recurrence.

Expressions of Eotaxin-3, Interleukin-5, and Eosinophil-Derived Neurotoxin in Chronic Subdural Hematoma Fluids

Eosinophils induce inflammation by releasing cytokines and cytotoxic granule proteins. Infiltration of eosinophilic granulocytes occurs in the outer membrane of chronic subdural hematomas (CSDHs). Eosinophils play an important role in the growth of CSDHs. However, the manner in which eosinophils accumulate within CSDH fluid remains undetermined. In the current study, we assessed the expression of eosinophil chemoattractants in CSDH fluids according to growth stage of CSDHs and examined the correlation between the two. CSDH fluids were obtained from 38 patients during trepanation surgery. Ecalectin, eotaxin-3, interleukin-5 (IL-5), and eosinophil-derived neurotoxin (EDN) concentrations were measured using enzyme-linked immunosorbent assay kits. For use as controls, serum samples were collected from 5 healthy adults, and cerebrospinal fluid (CSF) samples were collected from 5 adults with unruptured aneurysms. The percentage of eosinophils (%eosinophil) in CSDH fluids was calculated using Giemsa staining. Concentrations of ecalectin, eotaxin-3, IL-5, and EDN were nearly equivalent in serum and CSF samples; however, their concentrations were high in CSDH fluids. In particular, ecalectin and EDN levels in CSDH fluids were significantly higher than those in serum and CSF. Levels of eotaxin-3, IL-5, EDN, and %eosinophil were significantly higher in laminar type of CSDH, whereas that of ecalectin was not. The correlations between eotaxin-3 and IL-5, IL-5 and EDN, and EDN and %eosinophil were statistically significant (p < 0.01). Our data suggest that eotaxin-3 is a chemoattractant of eosinophils. IL-5 induces the activation of eosinophils subsequent to degranulation of EDN into CSDH fluids. These factors may serve as novel therapeutic targets for managing CSDH.

Armored Brain Associated with Secondary Craniostenosis Development at 7-year following Ventriculoperitoneal Shunt Surgery during Infancy: Extremely Unusual Association and Review

Calcification is uncommon in chronic subdural hematoma and popularly known as calcified chronic subdural hematoma (CSSDH), and about hundred cases are reported in the form of isolated cases report. The calcified inner membrane of chronic subdural hematoma gets adherent to underlying cerebral cortex preventing re-expansion of the brain and producing mass effect. Calcification can develop in chronic subdural hematoma of traumatic origin or postmeningitic effusion or extremely rarely after shunt surgery. CCSDH is also known as armored brain or Matrioska head and those related to cerebrospinal fluid diversion ventriculoperitoneal (VP) shunt surgery, constitute one of the rare complications of shunt, and development is attributed to overdrainage of shunt. Authors report a unique case with bilateral calcified chronic subdural hematoma in an 8-year-old boy, who had VP shunt surgery for obstructive hydrocephalus at the age of 1 year of life, presented with feature of nonlocalized raised intracranial pressure; a diagnosis of suspected VP shunt malfunction was also considered; however, cranial computed tomography scan on current admission revealed the presence of bilateral calcified chronic subdural hematoma with secondary craniostenosis and managed successfully with burr-hole craniostomy and drainage of CCSDH. In a detailed PubMed and Medline search, authors could not get any publication regarding CSSDH associated with secondary craniostenosis developing following VP shunt surgery in infancy. The current case represents the first case in the Western literature developing secondary craniostenosis-associated CCSDH following shunt surgery in infancy, requiring surgical management. The clinical features, neuroimaging, and management of such rare case along with pertinent literature are reviewed briefly.

Risk Factors of Delayed Surgical Intervention after Conservatively Treated Acute Traumatic Subdural Hematoma

Objective

Acute subdural hematoma (ASDH) is generally considered a condition that should be managed surgically. However, some patients initially receive conservative treatment, a subset of whom require surgical intervention later. This study aimed to evaluate the predictors of delayed surgical intervention in ASDH patients who are initially managed conservatively.

Methods

From January 2007 to December 2015, 842 patients diagnosed with ASDH were treated at our institution. Among them, 158 patients with convexity ASDH were initially treated conservatively. Patients were divided into a delayed surgery group and a conservative group. Demographic characteristics, past medication and medical histories, and radiological and laboratory data were collected by retrospective chart review. Independent risk factors were identified with univariate and multivariate analyses.

Results

Twenty-eight patients (17.7%) underwent delayed surgical intervention. Their mean age was 69.0 years, and 82.1% were male. Hypertension, diabetes mellitus, and heart disease prevalence and use of anti-platelet agents did not significantly differ from the conservative group. However, age (p=0.024), previous cerebral infarction history (p=0.026), increased maximal hematoma thickness (p<0.001), midline shifting (p=0.001) and accompanying subarachnoid hemorrhage (p=0.022) on initial brain computed tomography (CT) scan, low hemoglobin level (p<0.001), high leukocyte count (p=0.004), and low glucose level (p=0.002) were significantly associated with delayed surgical intervention. In multivariate analysis, increased maximal hematoma thickness (odds ratio [OR]=1.279, 95% confidence interval [CI] 1.075–1.521; p=0.006), low hemoglobin level (OR=0.673, 95% CI 0.467–0.970; p=0.034), and high leukocyte count (OR=1.142, 95% CI 1.024–1.272; p=0.017) were independent risk factors for delayed surgical intervention.

Conclusion

Due to the high likelihood of delayed surgical intervention among minimal ASDH patients with a thicker hematoma on initial brain CT, lower hemoglobin level, and higher leukocyte count, these patients should receive more careful observation.

Chronic Subdural Hematoma: A Perspective on Subdural Membranes and Dementia

OBJECTIVE

To review the complex pathogenesis of the subdural membrane and the link between head trauma, dementia, and dural lymphatics.

METHODS

A thorough literature search of published English-language articles was performed using PubMed, Ovid, and Cochrane databases.

RESULTS

Chronic subdural hematoma (cSDH) is a common intracranial pathology and a leading cause of reversible dementia. cSDH is projected to affect at least 60,000 new individuals in the United States annually by 2030. This condition can result from mild to moderate head trauma that leads to hemorrhaging in the dura-arachnoid interface. The short-term and long-term effects of cSDH and the subdural membrane on the pathogenesis of dementia and the newly discovered dural lymphatics is a topic of increasing importance.

CONCLUSIONS

Further research into the possible link between traumatic brain injury and cSDH in particular and dural lymphatics and intracranial fluid dynamics is warranted.

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.

Infants dying suddenly and unexpectedly share demographic features with infants who die with retinal and dural bleeding: a review of neural mechanisms

The cause of death in infants who die suddenly and unexpectedly (sudden unexpected death in infancy [SUDI]) remains a diagnostic challenge. Some infants have identified diseases (explained SUDI); those without explanation are called sudden infant death syndrome (SIDS). Demographic data indicate subgroups among SUDI and SIDS cases, such as unsafe sleeping and apparent life-threatening events. Infants dying suddenly with retinal and dural bleeding are often classified as abused, but in many there is no evidence of trauma. Demographic features suggest that they may represent a further subgroup of SUDI. This review examines the neuropathological hypotheses to explain SIDS and highlights the interaction of infant oxygen-conserving reflexes with the brainstem networks considered responsible for SIDS. We consider sex- and age-specific vulnerabilities related to dural bleeding and how sensitization of the dural innervation by bleeding may influence these reflexes, potentially leading to collapse or even death after otherwise trivial insults.

Eosinophil Infiltrates in Pilocytic Astrocytomas of Children and Young Adults

Objective

Eosinophils may affect each stage of tumour development. Many studies have suggested that tumour-associated tissue eosinophilia (TATE) is associated with favourable prognosis in some malignant tumours. However, only a few studies exist on TATE in central nervous system (CNS) tumours. Our recent study exhibited eosinophils in atypical teratoid/rhabdoid tumours (AT/RTs), pediatric malignant CNS tumours with divergent differentiation. This study examines eosinophils in pilocytic astrocytomas (PAs).

Methods

The study included 44 consecutive cases of patients with PAs and no concurrent CNS inflammatory disease.

Results

We found eosinophils in 19 (43%) of 44 PAs (patient age range, 0.5-72 years). Eosinophils were intratumoural and clearly distinguishable. The density of eosinophils was rare to focally scattered. PAs containing eosinophils were located throughout the CNS. Furthermore, eosinophilic infiltration was identified in 18 (62%) of 29 pediatric (age range, 0.5-18 years) PAs but only 1 (7%) of 15 (p<0.001, significantly less) adult (age range, 20-72 years) PAs. Eosinophilic infiltration showed no significant differences between PAs with and without MRI cystic formation, surgical procedures, or PAs with and without leptomeningeal infiltration. In comparison, eosinophils were absent in 10 pediatric (age range, 0.5-15 years) ependymomas (or anaplastic ependymomas).

Conclusions

These results suggest that eosinophils are common in pediatric PAs but rare in adult PAs. This difference is probably related to the developing immune system and different tumour-specific antigens in children. TATE may play a functional role in the development of pediatric PAs, as well as some other pediatric CNS tumours such as AT/RTs.

Diffuse Presence of Myeloblasts in Chronic Subdural Hematoma of a Young Adult Patient without Systemic Hematologic Disorder

Objective Myeloblasts are rarely found in the composition of a chronic subdural hematoma (CSH), and reported cases with myeloblasts in CSH have all been associated with systemic hematologic disorders. We present a young man with CSH manifesting the diffuse presence of myeloblasts, although no systemic hematologic disorders were identified.

Participant A 27-year-old man, complaining of a headache lasting for a few months, was diagnosed with right CSH, and the aspirated hematoma was sent for cytological evaluation because no apparent etiologic episode was found. The diffuse presence of precursor cells, such as myeloblasts and erythroblasts, mimicking the aspirated bone marrow, was confirmed. This finding was suggestive of a systemic hematologic disorder, although the systemic evaluations were negative.

Results The patient's hematoma reaccumulated twice, and finally hematoma and enhanced dura were removed by craniotomy under general anesthesia. Further histologic evaluation did not show any precursor cells, and he has remained asymptomatic for > 2 years without any evidence of the hematologic disorder.

Conclusion We believe this is the first case with CSH that contained myeloblasts as well as erythroblasts in an otherwise healthy patient. A possible etiology was considered for the origin of precursor cells in his CSH.

Acute epidural-like appearance of an encapsulated solid non-organized chronic subdural hematoma

We report the exceptional case of an encapsulated solid non-organized chronic subdural hematoma (SDH) in a 67-year-old woman that was admitted with acute hemiplegia followed by rapid deterioration in consciousness 5 months after a minor head trauma. Computed tomography (CT) showed an extracerebral biconvex shaped hyperdense mass that led to the misdiagnosis of an acute epidural hematoma. Urgent craniotomy revealed an encapsulated mass filled with solid fresh clot in the subdural space. Complete evacuation of this SDH, including both its inner and outer membranes, was achieved, and the patient recovered successfully. Histological analysis confirmed that the content of the hematoma corresponded to a newly formed clot that was enclosed between an inner membrane, composed of two collagen layers, and an outer membrane with a three layered structure. Chronic SDH may seldom present as an encapsulated solid non-organized lesion that consists of a fibrous capsule enclosing a fresh clot and lacking the thick fibrous septations that typically connect the inner and outer membranes of organized chronic SDH. This entity mimics the clinical course and radiological appearance of acute epidural hematomas and should be considered in the differential diagnosis of extracerebral hyperdense biconvex shaped lesions.

Mast cells in the human dura: effects of age and dural bleeding

BACKGROUND

Animal studies have shown that the dura mater contains mast cells. We investigated the density of mast cells in the human dura mater, and the changes associated with subdural haemorrhage (SDH).

METHODS

Samples of the human dura were stained with tryptase antibody and were examined for mast cells. We used control cases with no dural bleeding (n = 9) and cases of fresh (n = 24) and old (n = 18) dural haemorrhage.

RESULTS

Mast cells were easily found in dural samples. The mean density in controls (11.05 cells per mm(2)) was less than that in fresh SDH (15.69), which was less than that in old SDH (23.09).

CONCLUSIONS

Subdural haemorrhage is associated with an increase in dural mast cell density, and the density increases as the haematoma ages. We hypothesise that dural mast cells may contribute to neurogenic inflammation and the clinical features of subdural haemorrhage.

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.

Morphometric study of eosinophils, mast cells, macrophages and fibrosis in the colon of chronic chagasic patients with and without megacolon

The mechanisms involved in the pathogenesis of chagasic megacolon are not completely characterized. Although autoimmunity may play a role in the pathogenesis of Chagas' disease, recent studies suggest a positive association of tissue parasitism, inflammation, and severity of lesions. The aim of this study was to evaluate the role of inflammatory cells and the occurrence of fibrosis in the colon of chagasic patients with and without megacolon. Samples from 26 patients were randomly selected and paraffin-embedded tissue blocks were sectioned and evaluated by histology and immunohistochemistry to analyse the occurrence and relation among eosinophils, mast cells, macrophages and fibrosis. Section analyses showed that the presence of eosinophils and mast cells in the analysed inflammatory cells has a direct correlation with fibrosis density in the chagasic megacolon. These data suggest that the megacolon's pathogenesis is based on a continuous process of cell damage. Our data propose that eosinophils, mast cells and macrophages may have a direct connection with the occurrence of fibrosis in the colon of chagasic patients. We believe that potential therapeutic agents against these cells could avoid the fibrosis process and contribute to prevent the development of chagasic megacolon.

Treatment of chronic subdural hematoma by burr-hole craniostomy in adults: influence of some factors on postoperative recurrence

BACKGROUND

The study was conducted to determine the causative factors in the postoperative recurrence (PR) of chronic subdural haematomas (CSDHs) and to evaluate the efficacy of surgery in adults enrolled in this trial.

METHODS

99 patients with 121 CSDHs, who were operated on between January 1999 and December 2001, were studied. We evaluated the PR rate related to anamnestic, clinical, surgical and neuroradiological imaging variables. In addition, we reviewed the number and the type of repeated operations, complications of surgery and the outcomes at one, three and 12 months.

FINDINGS

82.6% of lesions were successfully treated following the initial evacuation, and 95.9% of lesions following a second procedure. The PR rate was 14.9%. A significantly high PR rate was found to be associated with separated type, frontal base type, a midline displacement >5 mm and the presence of acute subdural clots in cranial base type on CT scans obtained within four days postsurgery. The interval from head trauma to initial surgery <60 days, the maximum width of subdural space >10 mm and massive collection of air in the subdural space tended to give a high PR rate. The PR rate associated with the homogeneous type of CSDHs was significantly low.Age, sex, cause of CSDH, anticoagulant therapy, preoperative neurological presentation, concomitant disease, variables on preoperative CT scans, and surgical factors such as the extent of the surgical procedure, use of drainage, duration and volume of drainage were not significantly associated with PR rate.

CONCLUSIONS

It is important to identify factors leading to a high or a low PR rate in the treatment of CSDHs because this may help to select appropriate surgical procedures and postoperative management to treat this condition efficiently.

Increased mRNA Expression of VEGF within the Hematoma and Imbalance of Angiopoietin-1 and -2 mRNA within the Neomembranes of Chronic Subdural Hematoma

The aim of the study was to determine the source of vascular endothelial growth factor (VEGF) in hematoma fluid of patients suffering from chronic subdural hematoma (CSH) and to identify the level of gene expression of the pro-angiogenic factors angiopoietin 1 (ANG-1) and ANG-2 in hematoma membranes. Samples of venous blood, hematoma fluid, and outer membrane were obtained during surgery for CSH. The numbers of mononuclear cells were determined in hematoma fluid and in venous blood samples taken from 11 patients. The concentration of VEGF was measured by ELISA technique in hematoma fluid and in plasma. RT-PCR methodology was used to study the expression of different mRNA species in 11 patients. The mRNA species analyzed include VEGF and its receptors, VEGFR-1 and VEGFR-2, and ANG-1, ANG-2 and their receptor, Tie-2. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) served as housekeeping gene and was used for semiquantitative analysis. The VEGF concentration was several hundred fold higher in the hematoma fluid than in corresponding plasma samples. A significant correlation was found between the number of neutrophils and the VEGF content in the hematoma fluid. The expression levels of VEGF, mainly VEGF165 and VEGF121 mRNA were highest in cells obtained from the hematoma fluid. In membrane samples, mRNA encoding for VEGF and its receptors was only inconsistently detected while the mRNA species encoding for ANG-1, ANG-2, and Tie-2 were found throughout all samples. The mean ratio of ANG-1/ANG-2 mRNA expression was 0.48 as opposed to 1.9 in a normal human brain tissue sample. The results suggest that the hematoma cells are the primary source of VEGF. A marked increase in the expression of ANG-2 mRNA over ANG-1 mRNA demonstrates a pro-angiogenic pattern in the hematoma membranes. Persistent activation of the ANG/Tie-2 system in addition to high levels of VEGF may keep the vasculature in a destabilized condition and may account for the continuous formation of new and immature blood vessels resulting in massive plasma extravasation and repeated bleeding episodes. Thus, the present study provides new evidence in favor of pro-angiogenic mechanisms playing an important role in the pathophysiology of CSH.

Inflammation markers and risk factors for recurrence in 35 patients with a posttraumatic chronic subdural hematoma: a prospective study

Object. To evaluate the role of local inflammation in the pathogenesis and postoperative recurrence of chronic subdural hematoma (CSDH), the authors conducted an investigation in a selected group of patients who could clearly recall a traumatic event and who did not have other risk factors for CSDH. Inflammation was analyzed by measuring the concentration of the proinflammatory and inflammatory cytokines interleukin (IL)-6 and IL-8. The authors also investigated the possible relationship between high levels of local inflammation that were measured and recurrence of the CSDH.

Methods. A prospective study was performed between 1999 and 2001. Thirty-five patients who could clearly recall a traumatic event that had occurred at least 3 weeks previously and who did not have risk factors for CSDH were enrolled. All patients were surgically treated by burr hole irrigation plus external drainage.

The concentration of inflammatory cytokines was very high in the lesion, whereas it was normal in serum. In five cases in which recurrence occurred, concentrations of both IL-6 and IL-8 were significantly increased (p < 0.01) in comparison with cases without a recurrence. In a layering hematoma, the IL-6 and IL-8 concentrations were significantly higher (p < 0.05). Layering CSDHs were also significantly correlated with recurrence. Trabecular hematoma had the lowest cytokine levels and the longest median interval between trauma and clinical onset. The interval from trauma did not significantly influence recurrence, although it did differ significantly between the trabecular and layering CSDH groups. Concentrations of IL-6 and IL-8 in the CSDHs did not differ significantly in relation to either the age of the hematoma (measured as the interval from trauma) or the age of the patient.

Conclusions. Brain trauma causes the onset of an inflammatory process within the dural border cell layer; high levels of inflammatory cytokines were significantly correlated with recurrence and layering CSDH. A prolonged postoperative antiinflammatory medicine given as prophylaxis may help prevent the recurrence of a CSDH.