Magnetic resonance images of chronic subdural hematomas

Advances in chronic subdural hematoma and membrane imaging

Chronic subdural hematoma (cSDH) is projected to become the most common cranial neurosurgical disease by 2030. Despite medical and surgical management, recurrence rates remain high. Recently, middle meningeal artery embolization (MMAE) has emerged as a promising treatment; however, determinants of disease recurrence are not well understood, and developing novel radiographic biomarkers to assess hematomas and cSDH membranes remains an active area of research. In this narrative review, we summarize the current state-of-the-art for subdural hematoma and membrane imaging and discuss the potential role of MR and dual-energy CT imaging in predicting cSDH recurrence, surgical planning, and selecting patients for embolization treatment.

Efficacy and safety of bedside percutaneous three-millimeter twist-drill trephination under local anesthesia-a retrospective study of 1000 patients

PURPOSE

Percutaneous 3-mm twist-drill trephination (TDT) under local anesthesia as a bedside operative technique is an alternative to the conventional open surgical trephination in the operating theatre. The aim of this study was to verify the efficacy and safety of this minimal invasive procedure.

METHODS

This retrospective study comprises 1000 patients who were treated with TDT under local anesthesia at bedside due to chronic subdural hematoma (cSDH), intracerebral hemorrhage (ICH), and hydrocephalus (HYD) as a result of subarachnoid hemorrhage or non-hemorrhagic causes, increased intracranial pressure (IIP) in traumatic brain injury or non-traumatic brain edema, and other pathologies (OP) requiring drainage. Medical records, clinical outcome, and results of pre- and postoperative computed tomography (CT) and/or magnetic resonance tomography (MRT) were analyzed.

RESULTS

Indications for TDT were cSDH (n = 275; 27.5%), ICH (n = 291; 29.1%), HYD (n = 316; 31.6%), IIP (n = 112; 11.2%), and OP (n = 6; 0.6%). Overall, primary catheter placement was sufficient in 93.8% of trephinations. Complication rate was 14.1% and mainly related to primary catheter malposition (6.2%), infections (5.2%), and secondary hemorrhage (2.7%); the majority of which were clinically inapparent puncture channel bleedings not requiring surgical intervention. The revision rate was 13%.

CONCLUSIONS

Bedside TDT under local anesthesia has proven to be an effective and safe alternative to the conventional burr-hole operative technique as usually performed under general anesthesia in the operation theatre, and may be particularly useful in emergency cases as well as in elderly and multimorbid patients.

Comparison of craniotomy and limited membranectomy with conventional techniques in the treatment of chronic subdural hematoma

Background/aim

Chronic subdural hematoma is the most frequently operated on intracranial hemorrhage worldwide. Although surgical results are satisfactory, recurrence remains an important problem. In this study, it was aimed to evaluate patients who underwent craniotomy with limited membranectomy (CwLM) in terms of recurrence rate and other complications.

Materials and methods

Electronic records of 291 consecutive patients who were operated on at our clinic (Atatürk University Yakutiye Research Hospital) between 2015 and 2020 were retrospectively reviewed. Their radiological images at the time of admission, clinical status, any early postoperative complications, and clinical status at the 6-month follow-up were all evaluated.

Results

According to the results of the study, postoperative mortality and morbidity of patients who underwent CwLM were similar to those with minimally invasive methods, and it reduced recurrence, especially in laminar and separated subtypes.

Conclusion

It is our belief that CwLM will be an appropriate treatment approach in suitable patients (radiologically detected) in chronic subdural hematoma, where recurrence is an important problem.

MRI appearance of chronic subdural hematoma

Objective

We aimed to describe the magnetic resonance imaging (MRI) characteristics of chronic subdural hematoma (cSDH) and to ascribe MRI patterns.

Methods

A total of 20 patients having 27 subdural hematomas underwent contrast-enhanced (CE) MRI of the brain at our institution between April 2019 and May 2021. The images were independently evaluated by two experienced neuroradiologists with regard to imaging characteristics on T1w, T2w, T2*-GRE, FLAIR, diffusion-weighted magnetic resonance imaging (DWI), and CE images.

Results

The signal characteristics of cSDH on T1- and T2-weighted images were rather heterogeneous. The majority of hematomas (74%) had internal septations. Surprisingly, contrast enhancement along the outer membrane adjacent to the cranium was noticed in all hematomas. There was also contrast enhancement along the inner membrane adjacent to the brain in more than one-third of the hematomas (37%). In approximately two-thirds of the cSDH (62%), there was a mass-like enhancement of the hematoma. Most hematomas (89%) were partially hypointense on T2*-GRE and/or susceptibility-weighted imaging (SWI). Restricted diffusion was detected in approximately one-third of the hematomas (33%).

Conclusion

Consistent contrast enhancement along the outer membrane, triangular-shaped contrast enhancement at the borders of the cSDH, and infrequent enhancement of the inner membrane may help to distinguish cSDH from other entities such as empyema and tumors. Mass-like enhancement may refer to non-solid hematomas and could be an indicator for hematoma growth and a possible surrogate for successful endovascular embolization. Restricted diffusion in a subdural mass is not specific for empyema but may also be found in cSDH.

A Radiological Assessment of Chronic Subdural Hematomas

Chronic subdural hematoma (CSDH), which generally occurs in elderly patients, is a frequently diagnosed condition in neurosurgical departments. Computed tomography (CT) and magnetic resonance imaging (MRI) are the most preferred diagnostic modalities for CSDH assessment. With early diagnosis and adequate management, CSDH may show favorable prognosis in majority of the patients; however, recurrence after surgery can occur in a significant number of patients. The recently increasing number of CSDH studies could reveal the prognostic factors affecting CSDH recurrence. Particularly, radiological characteristics regarding the internal architecture of CSDH are considered closely associated with recurrence in surgically treated CSDH patients. In this literature review, we evaluated the various diagnostic modalities of CSDH and its radiological characteristics on CT and MRI. Furthermore, we summarized the prognostic factors of recurrence for the hematoma type based on the radiological findings.

The Potential of Diffusion-Weighted Magnetic Resonance Imaging for Predicting the Outcomes of Chronic Subdural Hematomas

Objective

Diffusion-weighted magnetic resonance imaging (DW-MRI) has proven useful in the study of the natural history of ischemic stroke. However, the potential of DW-MRI for the evaluation of chronic subdural hematoma (CSDH) has not been established. In this study, we investigated DW-MRI findings of CSDH and evaluated the impact of the image findings on postoperative outcomes of CSDH.

Methods

We studied 131 CSDH patients who had undergone single burr hole drainage surgery. The images of the subdural hematomas on preoperative DW-MRI and computed tomography (CT) were divided into three groups based on their signal intensity and density: 1) homogeneous (iso or low) density on CT and homogeneous low signal intensity on DW-MRI; 2) homogeneous (iso or low) density on CT and mixed signal intensity on DW-MRI; and 3) heterogeneous density on CT and mixed signal intensity on DW-MRI. On the basis of postoperative CT, we also divided the patients into 3 groups of surgical outcomes according to residual hematoma and mass effect.

Results

Analysis showed statistically significant differences in surgical (A to B: p<0.001, A to C: p<0.001, B to C: p=0.129) and functional (A to B: p=0.039, A to C: p<0.001, B to C: p=0.108) outcomes and treatment failure rates (A to B: p=0.037, A to C: p=0.03, B to C: p=1) between the study groups. In particular, group B and group C showed worse outcomes and higher treatment failure rates than group A.

Conclusion

CSDH with homogeneous density on CT was characterized by signal intensity on DW-MRI. In CSDH patients, performing DW-MRI as well as CT helps to predict postoperative treatment failure or complications.

Cortical membranectomy in chronic subdural hematoma: Report of two cases

Different surgical procedures have been used in the management of chronic subdural hematoma (CSDH). Nowadays treatment with burr hole is more preferable than craniotomy in most clinics. We present two cases of CSDH, which caused neurological deficits. In both cases cortical membranectomy was performed following craniotomy. After this procedure, significant improvement was observed in patients neurological deficits. We recommend that craniotomy and subtotal membranectomy may be a more adequate choice in such cases. This report underlined that craniotomy is still an acceptable, safe, efficient and even a better procedure in selected patients with CSDH.

Role of Matrix Metalloproteinase-2, Matrix Metalloproteinase-9, and Vascular Endothelial Growth Factor in the Development of Chronic Subdural Hematoma

Chronic subdural hematoma (CSDH) is an inflammatory and angiogenic disease. Vascular endothelial growth factor (VEGF) has an important effect on the pathological progression of CSDH. The matrix metalloproteinases (MMPs) and VEGF also play a significant role in pathological angiogenesis. Our research was to investigate the level of MMPs and VEGF in serum and hematoma fluid. Magnetic Resonance Imaging (MRI) shows the characteristics of different stages of CSDH. We also analyzed the relationship between the level of VEGF in subdural hematoma fluid and the appearances of the patients' MRI. We performed a study comparing serum and hematoma fluid in 37 consecutive patients with primary CSDHs using enzyme-linked immunosorbent assay (ELISA). MMP-2 and MMP-9 activity was assayed by the gelatin zymography method. The patients were divided into five groups according to the appearance of the hematomas on MRI: group 1 (T1-weighted low, T2-weighted low, n=4), group 2 (T1-weighted high, T2-weighted low, n=11), group 3 (T1-weighted mixed, T2-weighted mixed, n=9), group 4 (T1-weighted high, T2-weighted high, n=5), and group 5 (T1-weighted low, T2-weighted high, n=8). Neurological status was assessed by Markwalder score on admission and at follow-up. The mean age, sex, and Markwalder score were not significantly different among groups. The mean concentration of VEGF, MMP-2, and MMP-9 were significantly higher in hematoma fluid than in serum (p<0.01). The level of pro-MMP-2 was higher in hematoma fluid (p<0.01). Measurement of MMP-9 showed both pro and active forms in both groups, but levels were higher in hematoma fluid (p<0.01 and p<0.01, respectively). Mean VEGF concentration was highest in group 1 (21,979.3±1387.3 pg/mL), followed by group 2 (20,060.1±1677.2 pg/mL), group 3 (13,746.5±3529.7 pg/mL), group 4 (7523.2±764.9 pg/mL), and lowest in group 5 (6801.9±618.7 pg/mL). There was a significant correlation between VEGF concentrations and MRI type (r=0.854). The present investigation is the first report showing that the concentrations of MMP-2 and MMP-9 are significantly elevated in hematoma fluid, suggesting that the MMPs/VEGF system may be involved in the angiogenesis of CSDH. We also demonstrate a significant correlation between the concentrations of VEGF and MRI appearance. This finding supports the hypothesis that high VEGF concentration in the hematoma fluid is of major pathophysiological importance in the generation and steady increase of the hematoma volume, as well as the determination of MRI appearance.

Correlation of the Beta-trace protein and inflammatory cytokines with magnetic resonance imaging in chronic subdural hematomas : a prospective study

Objective

Magnetic resonance imaging (MRI) of chronic subdural hematoma (CSDH) detects various patterns, which can be attributed to many factors. The purpose of this study was to measure the level of interleukin-6 (IL-6), interleukin-8 (IL-8), and highly specific protein [beta-trace protein (βTP)] for cerebrospinal fluid (CSF) in CSDHs, and correlate the levels of these markers with the MRI findings.

Methods

Thirty one patients, treated surgically for CSDH, were divided on the basis of MRI findings into hyperintense and non-hyperintense groups. The concentrations of IL-6, IL-8, and βTP in the subdural fluid and serum were measured. The βTP was considered to indicate an admixture of CSF to the subdural fluid if βTP in the subdural fluid (βTP_SF)/βTP in the serum (βTP_SER)>2.

Results

The mean concentrations of IL-6 and IL-8 of the hyperintense group (n=17) of T1-WI MRI were 3975.1±1040.8 pg/mL and 6873.2±6365.4 pg/mL, whereas them of the non-hyperintense group (n=14) were 2173.5±1042.1 pg/mL and 2851.2±6267.5 pg/mL (p<0.001 and p=0.004). The mean concentrations of βTP_SF and the ratio of βTP_SF/βTP_SER of the hyperintense group (n=13) of T2-WI MRI were 7.3±2.9 mg/L and 12.6±5.4, whereas them of the non-hyperintense group (n=18) were 4.3±2.3 mg/L and 7.5±3.9 (p=0.011 and p=0.011).

Conclusion

The hyperintense group on T1-WI MRI of CSDHs exhibited higher concentrations of IL-6 and IL-8 than non-hyperintense group. And, the hyperintese group on T2-WI MRI exhibited higher concentrations of βTP_SF and the ratio of βTP_SF/βTP_SER than non-hyperintense group. These findings appear to be associated with rebleeding and CSF admixture in the CSDHs.

Magnetic resonance imaging findings predict the recurrence of chronic subdural hematoma

The exact predictive factors for postoperative recurrence of chronic subdural hematoma (CSDH) are still unknown. Based on the preoperative magnetic resonance imaging (MRI), low recurrence rate of T1-hyperintensity hematoma was previously reported. We investigated the other types of radiological findings which are related to the recurrence rate of CSDH in large number of patients analyzed by multivariate logistic regression model. Preoperative MRI and postoperative computed tomography (CT) were performed and the influence of the preoperative use of antiplatelet or anticoagulant drugs was also studied. The overall recurrence rate was 9.3% (47 of 505 hematomas). The MRI T1-iso/hypointensity group showed a significantly higher recurrence rate (18.2%, 29 of 159) compared to the other groups (5.2%, 18 of 346; p < 0.001). Multivariate logistic regression analysis showed T1 classification was the solo significant prognostic predictor among various factors such as bilateral hematoma, antiplatelet or anticoagulant drug usage, residual hematoma on postoperative CT, and MRI classification (p < 0.001): adjusted odds ratio for the recurrence in T1-iso/hypointensity group relative to the T1-hyperintensity group was 5.58 [95% confidence interval (CI), 2.09-14.86] (p = 0.001). Postoperative residual hematoma and antiplatelet or anticoagulant drug usage did not increase the recurrence risk. The preoperative MRI findings, especially T1WI findings, have predictive value for postoperative recurrence of CSDH and the T1-iso/hypointensity group can be assumed to be a high recurrence risk group.

Multiple Episodes of Hemorrhage Identified in MRI of Chronic Subdural Hematomas

Objective

Septa within the hematoma cavity are common, especially in the mixed density chronic subdural hematomas (CSHs). Although CT remains the diagnosis of choice, MRI is superior to detect the membranes in CSHs. We could obtain MRIs in 64 patients with CSH. We examined the value of MRI to understand the history of CSH.

Methods

We retrospectively examined the medical records and MRIs of 64 consecutive patients. MRI was selected to find any organic causes of neurologic symptoms. We classified the CSHs into septated or non-septated group, since classification of the septa was frequently obscure.

Results

Septa were identified by MRI in 43 patients (67%). They were more common in the over 70-years-old group. Unknown causes were more common in the septated group, which implies they might suffer from multiple traumas. The signal intensity of the CSH was variable. The methods of treatment were different between two groups. Surgery was more common in the septated group (p=0.021). Surgery was performed in 57 patients (89%). Burr-hole drainage was successful in 55 patients, even in the septated group.

Conclusion

Septa within the hematoma cavity may be related to the multiple episodes of head trauma. Repeated trauma may cause acute bleedings over the CSHs, which is one of the pathogenic mechanisms of hematoma enlargement. MRI could show the history of CSH.

Age determination of subdural hematomas with CT and MRI: a systematic review

OBJECTIVES

To systematically review the literature on dating subdural hematomas (SDHs) on CT and MRI scans.

METHODS

We performed a systematic review in MEDLINE, EMBASE and Cochrane to search for articles that described the appearance of SDHs on CT or MRI in relation to time between trauma and scanning. Two researchers independently screened the articles, assessed methodological quality and performed data extraction. Medians with interquartile ranges were calculated. Differences were tested with a Mann-Whitney U or Kruskal-Wallis H test.

RESULTS

We included 22 studies describing 973 SDHs on CT and 4 studies describing 83 SDHs on MRI. Data from 17 studies (413 SDHs) could be pooled. There were significant differences between time intervals for the different densities on CT (p<0.001). Time interval differed significantly between children and adults for iso- and hypodensity (p=0.000) and hyperdensity (p=0.046). Time interval did not differ significantly between abused and non-abused children. On MRI, time intervals for different signal intensities on T1 and T2 did not differ significantly (p=0.108 and p=0.194, respectively).

CONCLUSIONS

Most time intervals of the different appearances of SDHs on CT and MRI are broad and overlapping. Therefore CT or MRI findings cannot be used to accurately date SDHs.

Primary enlarged craniotomy in organized chronic subdural hematomas

The aim of the study is to evaluate the efficacy of craniotomy and membranectomy as initial treatment of organized chronic subdural hematoma (OCSH). We retrospectively reviewed a series of 34 consecutive patients suffering from OCSH, diagnosed by magnetic resonance imaging (MRI) or contrast computer tomography (CCT) in order to establish the degree of organization and determine the intrahematomal architecture. The indication to perform a primary enlarged craniotomy as initial treatment for non-liquefied chronic subdural hematoma (CSDH) with multilayer loculations was based on the hematoma MRI appearance—mostly hyperintense in both T₁- and T₂-weighted images with a hypointense web- or net-like structure within the hematoma cavity. The reason why some hematomas evolve towards a complex and organized architecture remains unclear; the most common aspect to come to light was the “long standing” of the CSDHs which, in our series, had an average interval of 10 weeks between head injury and initial scan. Recurrence was found to have occurred in 2 patients (6% of cases) in the form of acute subdural hematoma. One patient died as the result of an intraventricular and subarachnoid haemorrhage, while 2 patients (6%) suffered an haemorrhagic stroke ipsilateral to the OCSH. Eighty-nine percent of cases had a good recovery, while 11% remained unchanged or worsened. In select cases, based on the MRI appearance, primary enlarged craniotomy seems to be the treatment of choice for achieving a complete recovery and a reduced recurrence rate in OCSH.

Chronic subdural hematoma after eccentric exercise using a vibrating belt machine

We report a case of bilateral chronic subdural hematoma (CSDH) in a 75-year-old man after exercise using a vibrating belt machine on the head. He suffered from headache and intermittent left side numbness for ten days. He denied any head injuries except eccentric exercise using a vibrating belt on his own head for 20 days. An MRI revealed bilateral CSDH. The hematoma was isodense on the CT scan. We made burr-holes on the both sides under local anesthesia. We identified the neomembrane and dark red subdural fluid on both sides. In the postoperative CT scan, we found an arachnoid cyst on the left temporal pole. Although the arachnoid cyst itself is asymptomatic, trivial injury such as vibrating the head may cause a CSDH.

Bilateral retrocerebellar arachnoid cysts exerting mass effect and associated with cerebellar tonsillar ectopia in an otherwise healthy adult

Rarely, midline or unilateral posterior fossa arachnoid cysts (ACs) exert local mass effect resulting in the symptoms and signs of cerebellar and brainstem dysfunction. These cysts are sometimes seen in conjunction with cerebellar tonsillar ectopia (TE), although the relationship between these two entities is unclear. Bilateral ACs in the posterior fossa are virtually unprecedented. We describe the case of a 33-year-old man with a history of multiple minor head injuries observed to harbour asymptomatic, bilateral cerebrospinal fluid-density collections over the cerebellar hemispheres. Six years later, he presented with headaches, limb paraesthesias, and drop attacks. Computed tomography, magnetic resonance imaging, and operative findings during burrhole drainage of the lesions showed bilateral posterior fossa ACs, with associated cerebellar TE of 11 mm. The cysts partially recurred, necessitating reopening of the burrholes, after which the patient's symptoms resolved entirely. We then discuss the challenges in diagnosing this unusual case, the relationship between AC and TE, and the role of minor head injury in the symptomatic progression of AC.

Chronic subdural hematoma treated by small or large craniotomy with membranectomy as the initial treatment

OBJECTIVE

There are few studies comparing small and large craniotomies for the initial treatment of chronic subdural hematoma (CSDH) which had non-liquefied hematoma, multilayer intrahematomal loculations, or organization/calcification on computed tomography and magnetic resonance imaging. These procedures were compared to determine which would produce superior postoperative results.

METHODS

Between 2001 and 2009, 317 consecutive patients were surgically treated for CSDH at our institution. Of these, 16 patients underwent a small craniotomy with partial membranectomy and 42 patients underwent a large craniotomy with extended membranectomy as the initial treatment. A retrospective review was performed to compare the postoperative outcomes of these two techniques, focusing on improvement of neurological status, complications, reoperation rate, and days of post-operative hospitalization.

RESULTS

The mean ages were 69.4±12.1 and 55.6±9.3 years in the small and large craniotomy groups, respectively. The recurrence of hematomas requiring reoperation occurred in 50% and 10% of the small and large craniotomy patients, respectively (p<0.001). There were no significant differences in postoperative neurological status, complications, or days of hospital stay between these two groups.

CONCLUSION

Among the cases of CSDH initially requiring craniotomy, the large craniotomy with extended membranectomy technique reduced the reoperation rate, compared to that of the small craniotomy with partial membranectomy technique.

Bilateral biconvex frontal chronic subdural hematoma mimicking extradural hematoma

Chronic subdural hematoma (CSDH) is one of the most common clinical entities encountered in daily neurosurgical practice. The advent of computed tomography (CT) has made a major impact on the radiological diagnosis of CSDH. Although unilateral chronic isodense subdural hematomas as a result of indirect signs of a space-occupying lesion are easily recognizable on CT, bilateral CSDH may cause considerable difficulty, particularly when it is biconvex in shape as discussed in the present case. A judicious use of magnetic resonance imaging will help in making the diagnosis and for the management of such lesions.

Hemin-induced necroptosis involves glutathione depletion in mouse astrocytes

Intracerebral hemorrhage (ICH) is a devastating neurological injury associated with significant mortality. Astrocytic inflammation may contribute to the pathogenesis of ICH, although the underlying cellular mechanisms remain unclear. In this study, the hemoglobin oxidation by-product, hemin, concentration dependently induced necroptotic cell death in cortical astrocytes within 5 h of treatment. Hemin-induced cell death was preceded by increased inflammatory gene expression (COX-2, IL-1beta, TNF-alpha, iNOS). Inhibition of the NF-kappaB transcription factor reversed inflammatory gene expression and attenuated cell death after hemin treatment, suggesting a possible role for inflammatory mediators in astrocytic injury. Superoxide production paralleled the increase in iNOS expression, and inhibition of either iNOS (aminoguanidine or iminopiperdine) or superoxide (apocynin) significantly reduced cell death. Similarly, reduced formation of peroxynitrite, the damaging product of nitric oxide and superoxide, significantly reduced hemin injury. Hemin-induced peroxidative injury was associated with a rapid depletion of intracellular glutathione (GSH), culminating in lipid peroxidation and cell death, effects that were reduced by cotreatment with exogenous GSH, N-acetyl-L-cysteine, or the glutathione peroxidase mimetic ebselen. Together, these studies suggest a novel role for GSH depletion in necroptotic astrocyte injury after a hemorrhagic injury and indicate that therapeutic targeting of GSH may exert a beneficial effect after ICH.

Membranectomy in organized chronic subdural hematomas: indications and technical notes

BACKGROUND

The aim of the present study is to present our operative method of removing organized CSDHs and to structure the criteria for choosing this approach as first treatment.

METHODS

Between 1991 and 1999 at our Institution, 14 consecutive patients with organized CSDHs required 16 craniotomies with membranectomy. They represent 5.8% of all patients (243) treated for CSDHs in the same period. All the patients had preoperative contrast-enhanced CT, and 9 patients also had contrast MRI.

RESULTS

Initially, 9 patients underwent one burr hole or twist-drill hole. Of these 9 patients, 3 were treated at the same surgery with craniotomy and membranectomy as second treatment, 3 underwent a second burr hole and then membranectomy at the same surgery, and 3 patients underwent a second burr hole 3, 4, and 21 days after the first one and then membranectomy. Five patients underwent immediate craniotomy and membranectomy. There were no morbidity or mortality associated with this procedure. All patients had a full recovery without recurrence.

CONCLUSIONS

Contrast-enhanced MRI has greatly improved opportunities for discovering neomembrane before surgical intervention. We believe that MRI detection of thick and extensive membranes or solid clot with mass effect makes an immediate craniotomy to remove CSDH necessary.

Subdural hyperintense band on diffusion-weighted imaging of chronic subdural hematoma indicates bleeding from the outer membrane

The diffusion-weighted magnetic resonance (MR) imaging characteristics of chronic subdural hematoma and the correlation between hematoma liquidity and apparent diffusion coefficient (ADC) were investigated in 26 consecutive patients, 16 males and 10 females aged 42 to 92 years (mean +/- SD 73.3 +/- 13.1 years), with 31 chronic subdural hematomas. The chronic subdural hematomas were divided into homogeneous, separate, and trabecular types based on diffusion-weighted MR imaging findings. Almost all hematomas were low intensity on diffusion-weighted imaging, and the mean ADC value was 1.81 +/- 0.79 x 10(-3) mm2/sec. The high intensity areas in the subdural hematomas consisted of several types: high intensity line along the dura mater (subdural hyperintense band), high intensity along the intrahematoma septum, and laminar shape along the inner membrane. The subdural hyperintense bands accounted for almost all high intensity areas in the subdural hematomas. The mean ADC value of the high intensity areas was 0.76 +/- 0.24 x 10(-3) mm2/sec, close to that of the normal brain. The subdural hyperintense bands were considered to be intracellular and/or extracellular methemoglobin based on the T1- and T2-weighted imaging and intraoperative findings. The subdural hyperintense band is an important finding indicating relatively fresh bleeding from the outer membrane. Diffusion-weighted imaging shows liquid subdural hematoma as low intensity, and measurement of the ADC values can differentiate between liquid and solid components of the chronic subdural hematoma.

Diffusion-Weighted Magnetic Resonance Imaging of Organized Subdural Hematoma-Case Report-

A 59-year-old male presented with a left organized subdural hematoma. The hematoma appeared as a homogeneous low density area on brain computed tomography and as hyperintense and isointense area on both fluid-attenuated inversion recovery and T2-weighted magnetic resonance (MR) imaging. Echo-planar diffusion-weighted MR imaging showed a crescent hyperintense area under the dura mater and an irregular hypointense area over the brain surface in the left subdural space. The apparent diffusion coefficient (ADC) values of the solid and liquid hematoma were 0.86 +/- 0.32 x 10(-3) and 2.56 +/- 0.39 x 10(-3) mm2/sec, respectively. The ADC value of the solid hematoma was similar to acute subdural or intraparenchymal hematoma, and that of the liquid was similar to cerebrospinal fluid. Burr-hole surgery failed to remove all the hematoma, and he complained of persistent headache. The hematoma was removed through a craniotomy without further neurological deficits. Organized subdural hematoma often requires craniotomy for evacuation because of its solid content. Diffusion-weighted MR imaging and measurement of ADC values can differentiate solid from liquid hematoma, so are useful for selection of the surgical procedure.

Huge chronic subdural hematoma mimicking cerebral infarction on computed tomography--case report

A 70-year-old male presented with progressive consciousness disturbance. He had a history of cerebrovascular accident in the left cerebral hemisphere. The initial diagnosis was newly developed extensive left cerebral hemispheric infarction based on computed tomography. However, magnetic resonance imaging and surgical findings were consistent with chronic subdural hematoma (CSDH). The preexisting neurological disease may have allowed such unexpected CSDH expansion.

Chronic subdural haematoma in the elderly

Chronic subdural haematoma is predominantly a disease of the elderly. It usually follows a minor trauma. A history of direct trauma to the head is absent in up to half the cases. The common manifestations are altered mental state and focal neurological deficit. Neurological state at the time of diagnosis is the most important prognostic factor. Morbidity and mortality is higher in the elderly but outcome is good in patients who undergo neurosurgical intervention.

Activation of extracellular signal-regulated kinases potentiates hemin toxicity in astrocyte cultures

Hemin is present in intracranial hematomas in high micromolar concentrations and is a potent, lipophilic oxidant. Growing evidence suggests that heme-mediated injury may contribute to the pathogenesis of CNS hemorrhage. Extracellular signal-regulated kinases (ERKs) are activated by oxidants in some cell types, and may alter cellular vulnerability to oxidative stress. In this study, the effect of hemin on ERK activation was investigated in cultured murine cortical astrocytes, and the consequence of this activation on cell viability was quantified. Hemin was rapidly taken up by astrocytes, and generated reactive oxygen species (ROS) within 30 min. Increased immunoreactivity of dually phosphorylated ERK1/2 was observed in hemin-treated cultures at 30-120 min, without change in total ERK. Surprisingly, ERK activation was not attenuated by concomitant treatment with antioxidants (U74500A or 1,10-phenanthroline) at concentrations that blocked ROS generation. Cell death commenced after 2 h of hemin exposure and was reduced by antioxidants and by the caspase inhibitor Z-VAD-FMK. Cytotoxicity was also attenuated by MEK inhibition with PD98059 or U0126 at concentrations that were sufficient to prevent ERK activation. Whereas the effect of Z-VAD-FMK on cell survival was transient, the effect of MEK inhibitors was long-lasting. MEK inhibitors had no effect on cellular hemin uptake or subsequent ROS generation. The present results suggest that hemin activates ERK in astrocytes via a mechanism that is independent of ROS generation. This activation sensitizes astrocytes to hemin-mediated oxidative injury.

Chronic subdural haematomas in patients aged under 50

The clinical findings in 31 patients with chronic subdural haematoma (CSH), aged between 20 and 50, are described. Aetiopathogenetic factors responsible for the formation of CSH match those of patients aged over 50 with CSH. A history of cranial trauma was present in 77% of the cases. In the remaining patients, a defect of haemostatic mechanisms was responsible for the subdural blood collection. On the computed tomography (CT) the haematoma generally appears as a thin subdural layer. The reliability of magnetic resonance imaging for detection of CSH makes it the most desirable investigation in such patients. Prognosis is influenced by preoperative clinical status and by the disease responsible for the formation of CSH.

The relationship of preoperative magnetic resonance imaging findings and closed system drainage in the recurrence of chronic subdural hematoma

Although chronic subdural hematoma (CSDH) is a well-known entity, its recurrence rate has remained uncertain. There is little knowledge concerning whether the results of radiological imaging can be used to predict CSDH recurrence or whether surgical methods can influence this rate. The first aim of this study is to evaluate the relationship between the recurrence rate of CSDHs and their appearance on preoperative magnetic resonance (MR) or computerized tomography images. The second aim is to evaluate by means of a prospective randomized method the usefulness of closed-system drainage. From January 1988 through June 1996, the authors surgically treated 257 consecutive adult patients with CSDHs. Data obtained in 199 patients who were evaluated preoperatively by MR imaging were analyzed. Thirty-one of these patients underwent bilateral operations and thus 230 operative sites of CSDH were included in the analyses. The cases of CSDH were separated into high- and nonhigh-intensity groups on the basis of the appearance on T1-weighted MR images. From July 1992 to June 1996, the authors conducted a prospective randomized study on the recurrence rate of CSDH in patients undergoing burr-hole irrigation with or without closed system drainage. The recurrence rate of 3.4% in the high-intensity group was significantly lower than the 11.6% rate found in the nonhigh-intensity group (p < 0.05). The recurrence rates following irrigation with and without closed system drainage were significantly different (p < 0.025): 3.1% with closed system drainage and 17% following burr-hole irrigation alone. The surgical procedures were correlated with the MR findings. In the high-intensity group, 1.1% of CSDHs recurred in patients in whom closed system drainage was used and 11.1% in patients without closed system drainage. In the nonhigh-intensity group, 8.1% of CSDHs recurred in patients in whom drainage was used and 23.1% in patients without closed system drainage. Magnetic resonance T1-weighted imaging was useful in predicting the propensity of CSDHs to recur. Closed system drainage significantly reduced the recurrence rate of CSDHs regardless of MR findings.

Chronic subdural hematoma: surgical treatment and outcome in 104 patients

BACKGROUND

The common occurrence of chronic subdural hematoma (CSDH) in older patients raises some diagnostic and therapeutic difficulties. Despite general agreement about the indication of operation, the extent of surgery is still discussed controversially. We have, therefore, reviewed operative findings and outcome in 104 patients with CSDH.

METHODS

Retrospective analysis was performed by differentiating age < or = 60 years (n = 28) versus age > 60 years (n = 76) and burr hole craniostomy with a size range from 12-30 mm (n = 94) versus larger craniotomy (n = 10). All patients received closed-system drainage of the subdural space for 2-4 days.

RESULTS

Four patients older than 60 years died within 30 days after surgery, two in each operative group. Excluding these postoperative deaths, 17 out of 92 patients (18.5%) after burr hole trepanation and one out of eight patients (12.5%) after craniotomy required reoperation due to rebleeding (n = 6), residual subdural fluid (n = 4), and residual thick hematoma membranes (n = 8). Eight patients, who had been initially treated by burr hole craniostomy despite preoperative detection of neomembranes by contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), recovered without further intervention. Clinical outcome was good in both operative groups. The percentage of patients without or with only mild neurologic deficits at the time of discharge from the hospital was 72.3% in the burr hole and 70.0% in the craniotomy group, respectively.

CONCLUSIONS

The clinical data of the present study suggest that burr hole craniostomy with closed-system drainage should be the method of choice for the initial treatment of CSDH, even in cases with preoperative detection of neomembranes. Craniotomy should be carried out only in patients with reaccumulating hematoma or residual hematoma membranes, which prevent reexpansion of the brain.

Connective tissue reactions in subdural haematomas: imaging with contrast-enhancement MRI

The sensitivity of contrast enhanced magnetic resonance imaging (MRI) in the detection of connective tissue reactions accompanying the maturation of subdural haematomas (SDH) was studied. An outer enhancing layer between the SDH and the tabula interna of the vault was shown in 16 out of 17 cases. In early SDH this outer enhancing layer presumably is due to vascular congestion and/or increased vascular permeability. A thickening of the outer enhancing layer and/or an inner enhancing layer between the haematoma and the subarachnoid space was visible in 9 patients and represented a haematoma capsule formed by proliferating granulation tissue. In 5 SDH septations were found, 3 SDH consisted almost completely of enhancing granulation tissue. Thus, contrast enhanced MRI delivers additional information about the structure of SDH, which are useful for determining the extent of surgical treatment especially in chronic SDH.

[Chronic subdural hematoma: analysis of 35 cases]

Thirty five patients with chronic subdural hematoma were treated surgically between 1988 and 1995. The patients, aged 19 to 80 years, were graded retrospectively according to the Bender scale. The clots were removed via burr-holes with irrigation of the subdural space to ensure as complete an evacuation of subdural collection, and craniotomy with membranectomy. The mortality rate was 16.6% with craniotomy and 0% with burr-hole. The patients who died, 80% were in grade III or IV. The pathogenesis and surgical treatment of chronic subdural hematoma has been controversial, and still remains obscure.

Kallikrein-kinin system in chronic subdural haematomas: its roles in vascular permeability and regulation of fibrinolysis and coagulation

The kallikrein-kinin system is closely related to both fibrinolysis and coagulation, and bradykinin--the end product of this system--is a powerful mediator which increases vascular permeability. In the present study, to test the hypothesis that the kallikrein-kinin system plays a part in the aetiology of chronic subdural haematomas, components of this system (prekallikrein, high molecular weight kininogen (HMW-kininogen), and bradykinin), and those of the fibrinolytic and coagulation systems were measured at 134 haematoma sites in 119 patients. The activities of prekallikrein and HMW-kininogen in the haematomas were significantly lower than those in the plasma of the patients, and showed a parallel decrease. The bradykinin concentration in the haematomas was significantly higher than that in the plasma. These results indicate activation of the kallikrein-kinin system in chronic subdural haematomas. The activation of both fibrinolysis and coagulation was also shown, and there was a significant correlation between HMW-kininogen and plasminogen, fibrin/fibrinogen degradation products, or platelets in the haematomas. This suggests regulation of fibrinolysis and coagulation by the kallikrein-kinin system or mutual stimulation of these systems. In the outer membrane, perivascular haemorrhage, interstitial oedema, and leucocyte migration were evident microscopically, indicating an increase in vascular permeability. The protein concentration in the haematomas was significantly higher than that in the peripheral blood, indicating plasma exudation from the capillaries in the outer membrane. The activation of the kallikrein-kinin system, by increasing vascular permeability, may cause blood extravasation and plasma exudation from the capillaries into both the outer membrane and the haematoma cavity, resulting in enlargement of the haematoma.

Pathogenetic factors in chronic subdural haematoma and causes of recurrence after drainage

The radiological aspect, pathology, treatment and results of 132 subdural haematomas observed in 100 patients, are discussed. The majority of these cases were characterized by a nonhomogenous CT scan picture, resulting from repeated bleeding in a previous subdural haematoma evolving to chronicity, or in a pre-existent subdural hygroma. Taking aspirin may have constituted a predisposing factor in 16% of our patients, whilst coagulation disturbances, including anticoagulant treatment, were observed in another 6%; ethylism was present in 11%. A traumatic origin was ascertained in 80% of the patients. The treatment consisted of burr hole evacuation and drainage in 91.5% of the haematomas, corresponding to 92% of the patients; it was eventually repeated once or twice in some cases. In 6% of the patients, a subduro-peritoneal drainage had to be placed ultimately and in 2%, a membranectomy had to be performed because the haematoma had become nearly completely fibrous. The necessity for repeated evacuation and eventual subduro-peritoneal drainage seems to depend mainly on a slow brain re-expansion in some elderly people, who are actually more frequently referred. Two patients died; one was deeply comatose and another in poor general condition. Morbidity in the 96 remaining patients, 2 being lost to follow-up, was 11%: 5% related to the haematoma or to the causal trauma, and 6% from other concomitant neurological disease. The functional result was satisfactory in 85%.

Bilateral organized chronic subdural haematomas: high field magnetic resonance images and histological considerations

The authors describe a 66-year-old man with progressive gait disturbance caused by bilateral organized chronic subdural haematomas. The characteristics of these lesions on magnetic resonance (MR) images have not yet been clarified. The organized haematoma in our patient exhibited slight hypo-intensity on T 1-weighted MR images and marked hypo-intensity on T 2-weighted MR images obtained at 1.5T. Preoperative MR imaging may give us useful information about surgical strategy in the case of chronic subdural haematoma with an unusual appearance on computed tomographic (CT) scans.

Spontaneous dissecting aneurysms of the basilar artery presenting with a subarachnoid hemorrhage. Report of two cases

A spontaneous dissecting aneurysm of the basilar artery is a rare disorder, usually presenting with ischemia rather than a subarachnoid hemorrhage (SAH). Two cases are described of a dissecting aneurysm of the basilar artery presenting with an SAH. Vertebral angiography revealed a double lumen to the basilar artery. Magnetic resonance (MR) imaging detected the intramural hematoma. One patient was treated conservatively, and the other underwent operative intervention with wrapping of the aneurysm. The usefulness of MR imaging in the diagnosis and the treatment options are discussed.