The "subdural" space: a new look at an outdated concept

Endovascular embolisation of the middle meningeal artery to treat chronic subdural haematomas: Effectiveness, safety, and the current controversy. A systematic review

INTRODUCTION

Chronic subdural haematoma (CSDH) represents a clinical challenge due to its high recurrence rate. Endovascular middle meningeal artery embolisation (eMMAE) has emerged as an alternative for those patients presenting health problems or multiple recurrences of CSDH. Despite several encouraging reports, the safety profile, indications, and limitations of the technique are not clearly established.

DEVELOPMENT

This study aimed to evaluate the current evidence on eMMAE in patients with CSDH. We performed a systematic review of the literature, following the PRISMA guidelines. Our search yielded a total of 6 studies, in which a total of 164 patients with CSDH underwent eMMAE. The recurrence rate across all studies was 6.7%, and complications occurred in up to 6% of patients.

CONCLUSIONS

eMMAE is a feasible technique for treating CSDH, with a relatively low recurrence rate and an acceptable rate of complications. Further prospective and randomised studies are needed to formally establish a clear profile of the safety and effectiveness of the technique.

Factors involved in the development of subdural hygroma after decompressive craniectomy for traumatic brain injury. A systematic review and meta-analysis

Subdural hygroma (SDG) represents a common complication following decompressive craniectomy (DC). To our knowledge we present the first meta-analysis investigating the role of clinical and technical factors in the development of SDG after DC for traumatic brain injury. We further investigated the impact of SDG on the final prognosis of patients. The systematic review of the literature was done according to the PRISMA guidelines. Two different online medical databases (PubMed/Medline and Scopus) were screened. Four articles were included in this meta-analysis. Data regarding age, sex, trauma dynamic, Glasgow Coma Scale (GCS), pupil reactivity and CT scan findings on admission were collected for meta-analysis in order to evaluate the possible role in the SDG formation. Moreover we studied the possible impact of SDG on the outcome by evaluating the rate of patients dead at final follow-up and the Glasgow Outcome Scale (GOS) at final follow-up. Among the factors available for meta-analysis only the basal cistern involvement on CT scan was associated with the development of a SDG after DC (p < 0.001). Moreover, patients without SDG had a statistically significant better outcome compared with patients who developed SDG after DC in terms of GOS (p < 0.001). The rate of patients dead at follow-up was lower in the group of patients without SDH (8.25%) compared with patients who developed SDG (11.51%). SDG after DC is a serious complication affecting the prognosis of patients. Further studies are needed to define the role of some adjustable technical aspect of DC in preventing such a complication.

Embolization of the middle meningeal artery in patients with chronic subdural hematoma-a systematic review and meta-analysis

BACKGROUND

Chronic subdural hematoma (CSDH) remains a neurosurgical condition with high recurrence rate after surgical treatment. The primary pathological mechanism is considered to be repeated microbleedings from fragile neo-vessels within the outer hematoma membrane. The neo-vessels are supplied from peripheral branches of the middle meningeal artery, and embolization of MMA (eMMA) has been performed to prevent re-bleeding episodes and thereby CSDH recurrence.

OBJECTIVE

To evaluate the published evidence for the effect of eMMA in patients with recurrent CSDH. Secondarily, to investigate the effect of eMMA as an alternative to surgery for primary treatment of CSDH.

METHOD

A systematic review of the literature on eMMA in patients with recurrent CSDH was conducted. PubMed, Embase, and Cochrane databases were reviewed using the search terms: Embolization, Medial Meningeal Artery, Chronic Subdural Haematoma, and Recurrence. Furthermore, the following mesh terms were used: Chronic Subdural Haematoma AND embolization AND medial meningeal artery AND recurrence. Eighteen papers were found and included. No papers were excluded. The number of patients with primary CSDH and the number of patients with recurrent CSDH treated with eMMA were listed. Furthermore, the number of recurrences in both categories was registered.

RESULTS

Eighteen papers with a total of 191 included patients diagnosed with CSDH treated with eMMA for primary and recurrent CSDH were identified. Recurrence rate for patients treated with eMMA for recurrent CSDH was found to be 2.4%, 95% CI (0.5%; 11.0%), whereas the recurrence rate for patients treated with eMMA for primary CSDH was 4.1%, 95% CI (1.4%; 11.4%).

CONCLUSION

eMMA is a minimally invasive procedure for treatment of CSDH. Although this study is limited by publication bias, it seems that this procedure may reduce recurrence rates compared with burr hole craniostomy for both primary and recurrent hematomas. A controlled study is warranted.

Arachnoid cyst in young soccer players complicated by chronic subdural hematoma: personal experience and review of the literature

Arachnoid cysts (ACs) are congenital intracranial benign cavities originating from the meninges during embryological development. Several studies have shown the existence of a relationship between AC and a higher risk to develop ipsilateral chronic subdural hematoma (CSH) especially in a young population. In the presence of an AC, the practice of sport activities may expose young patients to minor head trauma and to an increased risk of developing CSH. We describe three cases of young soccer players with AC associated with CSH. Then, we performed a literature review of all the reported cases in the literature of patients younger than 18 years with AC-associated CSH related to sport practice. A total of 33 cases, including the three cases reported by us, are analyzed. Soccer is the most represented sport activity in this association (39% of cases). The treatment of choice is surgical in all patients, with burr hole or craniotomy in similar proportions. In one-third of patients, the AC has been fenestrated. Outcome is good in all the reported cases. We reviewed the main pathogenic theories, the main surgical strategies described in literature, as well as recurrence rate of CSH, the association of AC and cranial deformities, and the clinical outcome. AC might be associated with skull deformities, but their real incidence remains unclear. The clinical detection of such anomalies should suggest performing further radiological investigations. If the presence of AC is confirmed, the practice of sport activities should not be avoided, as the real incidence of AC-associated CSH is not clear yet and the reported outcomes in literature are good. Surgical treatment of AC-associated CSH should be hematoma removal through burr hole, reserving AC fenestration only for cases with intracystic bleeding or recurrences. The surgeon should adequately advise and inform the young patients and their families that they could have an increased risk of developing CSH given by the presence of the AC, and that they should be referred to a neurosurgical center if they become symptomatic.

Efficacy and safety of middle meningeal artery embolization in the management of refractory or chronic subdural hematomas: a systematic review and meta-analysis

INTRODUCTION

Refractory or chronic subdural hematomas (cSDH) constitute a challenging entity that neurosurgeons face frequently nowadays. Middle meningeal artery embolization (MMAE) has emerged in the recent years as a promising treatment option. However, solid evidence that can dictate management guidelines is still lacking.

METHODS

We conducted a systematic review and meta-analysis (MA) in compliance with the PRISMA guidelines to evaluate the efficacy and safety of MMAE compared with conventional treatments for refractory or cSDH. Databases were searched up to March 2019. Using a random-effects model, meta-analyses of proportions and risk difference were conducted recurrence, need for surgical rescue, and complications.

RESULTS

Eleven studies (177 patients) were included. Majority (116, 69%) were males with a weighted mean age of 71 + -19.5 years. Meta-analysis of proportions showed treatment failure to be 2.8%, need for surgical rescue 2.7%, and embolization-related complications 1.2%. Meta-analysis of risk-difference between embolized and non-embolized patients showed a 26% (p < 0.001, 95% CI 21%-31%, I² = 0) lower risk of hematoma recurrence in MMAE. Similarly, in the embolized group, the need for surgical rescue was 20% less (p < 0.001, 95% CI = 12%-27%, I² = 12.4), and complications were 3.6% less (p = 0.008, 95% CI 1%-6%, I² = 0) compared to conventional groups.

CONCLUSIONS

Although MMAE appears to be a promising treatment for refractory or cSDH, drawing definitive conclusions remains limited by paucity of data and small sample sizes. Multicenter, randomized, prospective trials are needed to compare embolization to conventional treatments like watchful waiting, medical management, or surgical evacuation. More extensive research on MMAE could begin a new era in the minimally invasive management of cSDH.

Histologic Comparison of the Dura Mater among Species

The biocompatibility, biodegradation, feasibility, and efficacy of medical devices like dural sealants and substitutes are often evaluated in various animal models. However, none of these studies explain the rationale for choosing a particular species, and a systematic interspecies comparison of the dura is not available. We hypothesized that histologic characteristics of the dura would differ among species. We systematically investigated basic characteristics of the dura, including thickness, composition, and fibroblast orientation of the dura mater, in 34 samples representing 10 animal species and compared these features with human dura by using hematoxylin and eosin staining and light microscopy. Dura showed many similarities between species in terms of composition. In all species, dura consisted of at least one fibrovascular layer, which contained collagen, fibroblasts, and blood vessels, and a dural border cell layer beneath the fibrovascular layer. Differences between species included the number of fibrovascular layers, fibroblast orientation, and dural thickness. Human dura was the thickest (564 μm) followed by equine (313 μm), bovine (311 μm), and porcine (304 μm) dura. Given the results of this study and factors such as gross anatomy, feasibility, housing, and ethical considerations, we recommend the use of a porcine model for dural research, especially for in vivo studies.

Post-traumatic hydrocephalus following decompressive hemicraniectomy: Incidence and risk factors in a prospective cohort of severe TBI patients

BACKGROUND

In severe traumatic brain injury (TBI) patients undergoing decompressive hemicraniectomy (DHC), the rate of post-traumatic hydrocephalus (PTH) is high at 12-36%. Early diagnosis and shunt placement can improve outcomes. Herein, we examined the incidence of and predictors of PTH after craniectomy.

METHODS

A retrospective analysis of prospectively collected database of severe TBI patients at a single U.S. Level 1 trauma center from May 2000 to July 2014 was performed. Demographics, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), bleeding pattern and time-to-cranioplasty were analyzed. Glasgow Outcome Scale (GOS) scores at 6 and 12-months were studied. Statistical significance was assessed at p < 0.05.

RESULTS

A total of 402 patients were enrolled and 105 patients had DHC. Twenty-two (21.0%) of 105 required ventriculoperitoneal shunt (VPS), compared to 18 (6%) of 297 patients without DHC. There was increased odds ratio for shunting after DHC at 3.62 (95%CI:1.62-8.07; p < 0.01). Mean age at time of DHC was 43.8 ± 17.7 years old, and 81.9% were male. Subdural hematoma (SDH) was most common at 57.1%. Median time from admission to cranioplasty was 63 days. Patients who experienced PTH after DHC were younger (35.5 ± 17.7 versus 46.0 ± 17.7 years, p < 0.01) and had higher ISS scores (35 versus 26, p = 0.04) compared to patients without shunt after DHC.

CONCLUSIONS

After severe TBI requiring hemicraniectomy, shunt-dependent hydrocephalus was 21%. Younger patients and higher ISS score were associated with PTH. Shunt-dependent patients achieved similar 6- and 12-month outcomes as those without PTH. Early diagnosis and shunt placement can enhance long-term neurological recovery.

Middle meningeal artery embolization as an adjuvant treatment to surgery for symptomatic chronic subdural hematoma: a pilot study assessing hematoma volume resorption

Background

Chronic subdural hematoma (CSDH) is a common condition requiring surgical treatment; however, recurrence occurs in 15% of cases at 1 year. Middle meningeal artery (MMA) embolization has recently emerged as a promising treatment to prevent CSDH recurrence.

Objective

To investigate the effect of MMA embolization on hematoma volume resorption (HVR) after surgery in symptomatic patients.

Methods

From April 2018 to October 2018, participants with CSDH requiring surgery were prospectively randomized in a pilot study, and received either surgical treatment alone (ST group) or surgery and adjuvant MMA embolization (ST+MMAE group). The primary outcome was HVR measured on the 3 month CT scan compared with the immediate pre-embolization CT scan. Secondary outcomes were clinical recurrence of CSDH and safety measures.

Results

46 patients were randomized and 41 of these achieved a 3 month follow-up . Twenty-one patients received MMA embolization. At 3 months, the HVR from postsurgical level was higher in the ST+MMAE group (mean difference 17.5 mL, 95% CI 3.87 to 31.16 mL; p=0.015). Two participants presented a CSDH recurrence (one in each group). One patient died (ST group). No MMA embolization-related adverse events were reported.

Conclusion

The addition of MMA embolization to surgery led to an increase in CSDH resorption at 3 months. One recurrence of CSDH was reported in each group, and there were no treatment-related complications.

The extradural minipterional pretemporal approach for the treatment of spheno-petro-clival meningiomas

BACKGROUND

Cavernous sinus and petroclival region is an anatomically complex region in close relationship with important neurovascular structures. As such, the surgical treatment of spheno-petro-clival (SPC) meningiomas represents an operative challenge, in which several routes and its combinations might be used.

METHODS

We describe in detail the surgical technique of the extradural minipterional pretemporal approach (eMPT-P) to the SPC region and highlight the main anatomical key elements involved in this approach as well as the technical aspects for avoiding surgical complications.

CONCLUSION

The eMPT-P is a versatile approach that uses the extradural route, and thereby reduces brain retraction, while provides a good angle of exposure of the SPC region.

Double-crescent sign as a predictor of chronic subdural hematoma recurrence following burr-hole surgery

OBJECTIVE

Subdural hygroma has been reported as a causative factor in the development of a chronic subdural hematoma (CSDH) following a head trauma and/or neurosurgical procedure. In some CSDH cases, the presence of a 2-layered space delineated by the same or similar density of CSF surrounded by a superficial, residual hematoma is seen on CT imaging after evacuation of the hematoma. The aims of the present study were to test the hypothesis that the double-crescent sign (DCS), a unique imaging finding described here, is associated with the postoperative recurrence of CSDH, and to investigate other factors that are related to CSDH recurrence.

METHODS

The authors retrospectively analyzed data from 278 consecutive patients who underwent single burr-hole surgery for CSDH between April 2012 and March 2017. The DCS was defined as a postoperative CT finding, characterized by the following 2 layers: a superficial layer demonstrating residual hematoma after evacuation of the CSDH, and a deep layer between the brain's surface and the residual hematoma, depicted as a low-density space. Correlation of the recurrence of CSDH with the DCS was evaluated by multivariate logistic regression modeling. The authors also investigated other classic predictive factors including age, sex, past history of head injury, hematoma laterality, anticoagulant and antiplatelet therapy administration, preoperative hematoma volume, postoperative residual hematoma volume, and postoperative brain reexpansion rate.

RESULTS

A total of 277 patients (320 hemispheres) were reviewed. Fifty (18.1%) of the 277 patients experienced recurrence of CSDH within 3 months of surgery. CSDH recurred within 3 months of surgery in 32 of the 104 hemispheres with a positive DCS. Multivariate logistic analyses revealed that the presence of the DCS (OR 3.36, 95% CI 1.72-6.57, p < 0.001), large postoperative residual hematoma volume (OR 2.88, 95% CI 1.24-6.71, p = 0.014), anticoagulant therapy (OR 3.03, 95% CI 1.02-9.01, p = 0.046), and bilateral hematoma (OR 3.57, 95% CI 1.79-7.13, p < 0.001) were significant, independent predictors of CSDH recurrence.

CONCLUSIONS

In this study, the authors report that detection of the DCS within 7 days of surgery is an independent predictive factor for CSDH recurrence. They therefore advocate that clinicians should carefully monitor patients for postoperative DCS and subsequent CSDH recurrence.

Disappearance of Arachnoid Cyst after Burrhole Trephination: Case Series

We report 3 cases of arachnoid cysts (ACs) that completely disappeared after burr hole drainage, without cyst fenestration into the subarachnoid space or cystoperitoneal shunt. The first patient was a 21-year-old female with an AC of the right cerebral convexity, found incidentally. After endoscopic AC fenestration was performed, the patient complained of persistent headache. Two-month postoperative brain imaging revealed reaccumulated AC and associated multi-stage subdural hematoma. Burr hole drainage was performed to resolve the chronic subdural hematoma (CSDH). Three months later, brain computed tomography showed that the CSDH and the AC had disappeared. The second patient was an 11-year-old male who had a history of trauma 1 month prior to presentation at the clinic. Brain magnetic resonance imaging revealed an AC in the left sylvian fissure with CSDH. We performed burr hole drainage to treat the CSDH first. Subsequently, the AC as well as the CSDH disappeared. The third case was an AC of the right parietal convexity, found incidentally. Only burr hole drainage was performed, following which, the AC disappeared. This case series shows that an AC can disappear naturally after rupture into the subdural space by trauma or the burr hole procedure.

The Basal Subarachnoid Cisterns: Surgical and Anatomical Considerations

The basal subarachnoid cisterns are expansions of the subarachnoid space and transmit cranial nerves and intracranial vessels. Providing neurosurgeons with key concepts, anatomical landmarks, and techniques can result in safer procedures and better patient outcomes. In this review, we discuss the major basal subarachnoid cisterns including their embryology, history, anatomical descriptions, and use during surgical approaches.

Cerebral blood vessel damage in traumatic brain injury

Traumatic brain injury is a devastating cause of death and disability. Although injury of brain tissue is of primary interest in head trauma, nearly all significant cases include damage of the cerebral blood vessels. Because vessels are critical to the maintenance of the healthy brain, any injury or dysfunction of the vasculature puts neural tissue at risk. It is well known that these vessels commonly tear and bleed as an immediate consequence of traumatic brain injury. It follows that other vessels experience deformations that are significant though not severe enough to produce bleeding. Recent data show that such subfailure deformations damage the microstructure of the cerebral vessels, altering both their structure and function. Little is known about the prognosis of these injured vessels and their potential contribution to disease development. The objective of this review is to describe the current state of knowledge on the mechanics of cerebral vessels during head trauma and how they respond to the applied loads. Further research on these topics will clarify the role of blood vessels in the progression of traumatic brain injury and is expected to provide insight into improved strategies for treatment of the disease.

Non-Traumatic Acute Subdural Hemorrhage Due To Cranial Venous Hypertension

Acute subdural hemorrhage is typically associated with a history of head trauma, and as such it is a finding with significant potential medicolegal consequences. In this article, 37 adult and post-infantile pediatric sudden death autopsy cases with small volume ("thin film" or "smear") acute subdural hemorrhage are presented-in which there is either no further evidence of head trauma or only features of minor head injury. The possible underlying pathophysiological mechanisms are explored, and it is concluded that a common thread in many of these cases is likely to have been cranial venous hypertension at around the time of death. These findings may have implications in instances where small volume subdural hemorrhage is identified in the absence of other evidence of significant head injury.

Surgical treatment of progressive cauda equina compression caused by spontaneous spinal subdural hematoma: A case report

RATIONALE

Spontaneous spinal subdural hematoma (SSDH) without an underlying pathology is a very rare condition. The treatment protocol for SSDH is early diagnosis and treatment before irreversible damage to neural tissue. However, there is no agreement on the etiopathogenesis, as well as the need for surgery to treat spontaneous SSDH. Here, we report a rare case of spontaneous SSDH with progressive deterioration and symptoms of cauda equina syndrome after ineffective conservative treatment.

PATIENT'S CONCERN

A 38-year-old male patient presented with sudden lower back and bilateral leg pain.

DIAGNOSIS

A magnetic resonance imaging (MRI) scan on the third day after the onset of symptoms revealed a subdural hematoma from L1 to S1, presenting as hyperintensities on T1 weighted sequences and hypointensities to isointensities on T2 weighted sequences.

INTERVENTION

Laminectomy and subdural evacuation were performed immediately.

OUTCOMES

An abnormal ligamentum flavum was observed intraoperatively. A histological examination revealed extravasation of blood in the degenerated ligamentum flavum. Postoperatively, the lower limb pain improved immediately. At the 6-month follow-up, the pain and numbness of the lower limb disappeared, and the muscle strength of both legs recovered completely with normal gait.

LESSONS

Spontaneous SSDH with ligamentum flavum hematoma was caused by a sudden increase of intravenous pressure, resulting from a marked surge in the intra-abdominal or intrathoracic pressure. Consecutive MRI scans provided valuable information, leading to a diagnosis of spontaneous SSDH. The treatment protocol for spontaneous SSDH should be determined based on the location and stage of the hematoma, as well as the subject's neurological status.

Subdural Spinal Haematoma after Epidural Anaesthesia in a Patient with Spinal Canal Stenosis

A 60-year-old male with a past history of T12 fracture had epidural analgesia for a radical prostatectomy. It was unknown prior to epidural insertion that the patient had a canal stenosis at T12 from the previous injury. The patient developed severe bilateral buttock pain after epidural catheter removal. Magnetic resonance imaging demonstrated a spinal subdural haematoma from T10 to L2 with mild cord compression. The patient made a successful recovery with conservative management. Neuraxial blockade should be approached with caution in patients with previous back injury, and only after a thorough assessment has been obtained to exclude spinal canal stenosis.

Histological investigations on the dura mater vascular system of mice

The human dura mater encephali is a well innervated and vascularized membrane. Its vascular system plays a crucial role in disorders and pathological cases like dural hematoma, meningitis, and different headache types. To investigate these diseases mouse models are increasingly being used. However, the literature on the vascular system of the mouse dura mater is sparse and explicit studies concerned exclusively with its vasculature are lacking. Here we present a detailed light and scanning electron microscopic investigation of the supratentorial dura mater of the mouse species, with a focus on the largest part of it, the parietal dura mater. By utilizing different immunohistochemical and classical staining methods, a "cartography" of the vascular system was achieved. Additionally, the different blood vessel types with their mural cells were characterized. In contrast to humans, no arteries were found in the mouse parietal dura mater. Its supply is assured through frontolateral and occipital localized arteriolar branches. These arteriolar vessels exhibit in some specimens arteriolar anastomoses with one another. The venous blood is drained to the superior sagittal and transverse sinus through satellite venules accompanying the arterioles or through solitary venules. In all samples, large ruptured venules were identified in the frontolateral dural area. Scanning electron microscopy revealed that these vessels were ruptured on the dorsal side (skull bones-oriented side) of the dura. Our results contribute to the anatomical data on the mouse species and may set up a basis for fundamental investigation of disorders, for which the role of dural blood vessels is not yet clarified.

Analysis of detailed clinical characteristics of spinal subdural hematoma following lumbar decompression surgery

BACKGROUND

Only a few reports have described symptomatic patients with postoperative spinal subdural hematoma (SSH) for which further surgery may have been required. No report has focused on the detailed clinical characteristics of postoperative SSH, including asymptomatic cases, in a case series. The reasons for this may be that SSH is an implicitly recognized rare entity, and there is no established consensus regarding the significance of performing postoperative magnetic resonance imaging (MRI) for all cases and the time at which to perform it. In this case-controlled retrospective analysis, we attempted to identify a detailed clinical presentation of SSH after open lumbar decompression surgery using MRI taken uniformly at 14 days before hospital discharge.

METHODS

We retrospectively studied 196 patients who underwent routine MRI following open lumbar spinous process-splitting decompression surgery between 2012 and 2016. We assessed the frequency, clinical presentation, and radiological findings of SSH that developed postoperatively. Furthermore, we used a multivariate analysis to identify factors that were postulated to increase the risk of SSH postoperatively.

RESULTS

None of the patients developed serious neurologic deficits, such as paresis or bladder and bowel dysfunction that required emergency evacuation. However, our results showed that postoperative SSHs, including asymptomatic SSHs, developed considerably frequently (43/182 patients, 23.6%). Furthermore, of the 43 patients with SSH, three presented with new postoperative neurologic findings that were strongly suspected to be associated with SSH. Multivariate analysis identified that preoperative hypertension (adjusted odds ratio [aOR]: 2.501, P = 0.018), anticoagulant therapy (aOR: 2.716, P = 0.021), and multilevel procedures (aOR: 2.327, P = 0.034) were significant risk factors of postoperative SSH.

CONCLUSIONS

Spine surgeons should be aware that postoperative SSH is not rare and is a potential cause of recurrent pain or neurologic deterioration perioperatively.

The Risk Factors of Subdural Hygroma after Decompressive Craniectomy

Objective

Subdural effusion, also known as subdural hygroma (SDG), is a secondary complication that can occur after decompressive craniectomy (DC). However, the pathogenesis of SDG is not fully understood. It is unclear whether SDG occurrence is related to preoperative patient status or surgical technique. The purpose of this study is to identify risk factors for SDG after DC.

Methods

Fifty-nine patients who underwent DC from January 2016 to December 2016 at the same institution were analyzed. We retrospectively reviewed the clinical and radiological features of the patients. We divided the patients into two groups based on the occurrence of SDG after DC. The risk factors for SDG were analyzed.

Results

The overall SDG rate after DC was 39% (23 patients). A statistically significant association was observed between preoperative diagnosis, e.g., subdural hemorrhage (SDH; odds ratio [OR], 4.99; 95% confidence interval [CI], 1.36–18.34) or subarachnoid hemorrhage (SAH; OR, 4.18; 95% CI, 1.07–16.32), and the occurrence of SDG after DC. Traumatic brain injury (OR, 4.91; 95% CI, 1.35–17.91) and preoperative cortical opening (OR, 4.77; 95% CI, 1.39–16.32) were important risk factors for SDG. Several surgical techniques did not show a statistically significant association with SDG. The occurrence of SDG after DC was related to the length of hospital stay (p=0.012), but not to prognosis.

Conclusion

After DC, SDG is not related to patients' prognosis but to the length of hospital stay. Therefore, it is necessary to study the occurrence of postoperative SDG by confirming the presence of preoperative SDH, SAH, and cortical opening.

Management of Subdural Hematomas: Part I. Medical Management of Subdural Hematomas

PURPOSE OF REVIEW

Subdural hematomas (SDH) represent common neurosurgical problem associated with significant morbidity, mortality, and high recurrence rates. SDH incidence increases with age; numbers of patients affected by SDH continue to rise with our aging population and increasing number of people taking antiplatelet agents or anticoagulation. Medical and surgical SDH management remains a subject of investigation.

RECENT FINDINGS

Initial management of patients with concern for altered mental status with or without trauma starts with Emergency Neurological Life Support (ENLS) guidelines, with a focus on maintaining ICP < 22 mmHg, CPP > 60 mmHg, MAP 80-110 mmHg, and PaO₂ > 60 mmHg, followed by rapid sequence intubation if necessary, and expedited acquisition of imaging to identify a space-occupying lesion. Patients are administered anti-seizure medications, and their antiplatelet medications or anticoagulation may be reversed if neurosurgical interventions are anticipated, or until hemorrhage is stabilized on imaging. Medical SDH care focuses on (a) management of intracranial hypertension; (b) maintenance of adequate cerebral perfusion; (c) seizure prevention and treatment; (d) maintenance of normothermia, eucarbia, euglycemia, and euvolemia; and (e) early initiation of enteral feeding, mobilization, and physical therapy. Post-operatively, SDH patients require ICU level care and are co-managed by neurointensivists with expertise in treating increased intracranial pressure, seizures, and status epilepticus, as well as medical complications of critical illness. Here, we review various aspects of medical management with a brief overview of pertinent literature and clinical trials for patients diagnosed with SDH.

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.

Prediction of brain deformations and risk of traumatic brain injury due to closed-head impact: quantitative analysis of the effects of boundary conditions and brain tissue constitutive model

In this study, we investigate the effects of modelling choices for the brain-skull interface (layers of tissues between the brain and skull that determine boundary conditions for the brain) and the constitutive model of brain parenchyma on the brain responses under violent impact as predicted using computational biomechanics model. We used the head/brain model from Total HUman Model for Safety (THUMS)-extensively validated finite element model of the human body that has been applied in numerous injury biomechanics studies. The computations were conducted using a well-established nonlinear explicit dynamics finite element code LS-DYNA. We employed four approaches for modelling the brain-skull interface and four constitutive models for the brain tissue in the numerical simulations of the experiments on post-mortem human subjects exposed to violent impacts reported in the literature. The brain-skull interface models included direct representation of the brain meninges and cerebrospinal fluid, outer brain surface rigidly attached to the skull, frictionless sliding contact between the brain and skull, and a layer of spring-type cohesive elements between the brain and skull. We considered Ogden hyperviscoelastic, Mooney-Rivlin hyperviscoelastic, neo-Hookean hyperviscoelastic and linear viscoelastic constitutive models of the brain tissue. Our study indicates that the predicted deformations within the brain and related brain injury criteria are strongly affected by both the approach of modelling the brain-skull interface and the constitutive model of the brain parenchyma tissues. The results suggest that accurate prediction of deformations within the brain and risk of brain injury due to violent impact using computational biomechanics models may require representation of the meninges and subarachnoidal space with cerebrospinal fluid in the model and application of hyperviscoelastic (preferably Ogden-type) constitutive model for the brain tissue.

Iatrogenic Spinal Subdural Hematoma due to Apixaban: A Case Report and Review of the Literature

In the last decade, the clinical relevance for developing safer oral anticoagulants prompted the development of new classes of drugs that have shown a lower risk of life-threatening bleeding events as compared to standard warfarin. Nontraumatic spinal subdural hematoma is an uncommon urgent complication that can be associated with the use of these agents. An unusual case of spinal subdural hematoma related to apixaban treatment for nonrheumatic atrial fibrillation is reported here.

Evidence based diagnosis and management of chronic subdural hematoma: A review of the literature

Chronic subdural hematomas are encapsulated blood collections within the dural border cells with characteristic outer "neomembranes". Affected patients are more often male and typically above the age of 70. Imaging shows crescentic layering of fluid in the subdural space on a non-contrast computed tomography (CT) scan, best appreciated on sagittal or coronal reformats. Initial medical management involves reversing anticoagulant/antiplatelet therapies, and often initiation of anti-epileptic drugs (AEDs). Operative interventions, such as twist-drill craniostomy (TDC), burr-hole craniostomy (BHC), and craniotomy are indicated if imaging implies compression (maximum fluid collection thickness >1 cm) or the patient is symptomatic. The effectiveness of various surgical techniques remains poorly characterized, with sparse level 1 evidence, variable outcome measures, and various surgical techniques. Postoperatively, subdural drains can decrease recurrence and sequential compression devices can decrease embolic complications, while measures such as early mobilization and re-initiation of anticoagulation need further study. Non-operative management, including steroid therapy, etizolam, tranexamic acid, and angiotensin converting enzyme inhibitors (ACEI) also remain poorly studied. Recurrent hemorrhages are a major complication affecting around 10-20% of patients, and therefore close follow-up is essential.

Neurotrauma

Traumatic brain injury remains a major cause of morbidity and mortality throughout the world, affecting young and old alike. Pathologic data have been developed through observations of human autopsies and developing animal models to investigate mechanisms, although animal models do not represent the polypathology of human brain injury and there are likely to be significant differences in the anatomic basis of injury and cellular responses between species. Traumatic brain injury can be defined pathologically as either focal or diffuse, and can be considered to be either primary, directly related to the force associated with the neurotrauma, or secondary, developing as a downstream consequence of the neurotrauma. While neuropathology has traditionally focused on severe head injury, there is increasing recognition of the long-term consequences of traumatic brain injury, particularly repetitive mild traumatic brain injury, and a possible long-term association with chronic traumatic encephalopathy.

Spinal Meninges and Their Role in Spinal Cord Injury: A Neuroanatomical Review

Current recommendations support early surgical decompression and blood pressure augmentation after traumatic spinal cord injury (SCI). Elevated intraspinal pressure (ISP), however, has probably been underestimated in the pathophysiology of SCI. Recent studies provide some evidence that ISP measurements and durotomy may be beneficial for individuals suffering from SCI. Compression of the spinal cord against the meninges in SCI patients causes a "compartment-like" syndrome. In such cases, intentional durotomy with augmentative duroplasty to reduce ISP and improve spinal cord perfusion pressure (SCPP) may be indicated. Prior to performing these procedures routinely, profound knowledge of the spinal meninges is essential. Here, we provide an in-depth review of relevant literature along with neuroanatomical illustrations and imaging correlates.

Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

Purpose To evaluate the effect of middle meningeal artery (MMA) embolization on chronic subdural hematoma (CSDH) and compare the treatment outcomes of MMA embolization and conventional treatment. Materials and Methods All consecutive patients 20 years or older with CSDH were assessed for eligibility. CSDHs with a focal location, a thickness of 10 mm or less, no mass effect, or underlying conditions were excluded. Seventy-two prospectively enrolled patients with CSDH underwent MMA embolization (embolization group; as the sole treatment in 27 [37.5%] asymptomatic patients and with additional hematoma removal for symptom relief in 45 [62.5%] symptomatic patients). For comparison, 469 patients who underwent conventional treatment were included as a historical control group (conventional treatment group; close, nonsurgical follow-up in 67 [14.3%] and hematoma removal in 402 [85.7%] patients). Primary outcome was treatment failure defined as a composite of incomplete hematoma resolution (remaining or reaccumulated hematoma with thickness > 10 mm) or surgical rescue (hematoma removal for relief of symptoms that developed with continuous growth of initial or reaccumulated hematoma). Secondary outcomes included surgical rescue as a component of the primary outcome and treatment-related complication for safety measure. Six-month outcomes were compared between the study groups with logistic regression analysis. Results Spontaneous hematoma resolution was achieved in all of 27 asymptomatic patients undergoing embolization without direct hematoma removal. Hematoma reaccumulation occurred in one (2.2%) of 45 symptomatic patients receiving embolization with additional hematoma removal. Treatment failure rate in the embolization group was lower than in the conventional treatment group (one of 72 patients [1.4%] vs 129 of 469 patients [27.5%], respectively; adjusted odds ratio [OR], 0.056; 95% confidence interval [CI]: 0.011, 0.286; P = .001). Surgical rescue was less frequent in the embolization group (one of 72 patients [1.4%] vs 88 of 469 patients [18.8%]; adjusted OR, 0.094; 95% CI: 0.018, 0.488; P = .005). Treatment-related complication rate was not different between the two groups (0 of 72 patients vs 20 of 469 patients [4.3%]; adjusted OR, 0.145; 95% CI: 0.009, 2.469; P = .182). Conclusion MMA embolization has a positive therapeutic effect on CSDH and is more effective than conventional treatment. ^© RSNA, 2017.

Problems of reconstructive cranioplasty after traumatic brain injury in children

Cranial repair after traumatic brain injury in children is still burdened by unsolved problems and controversial issues, mainly due to the high rate of resorption of autologous bone as well as the absence of valid alternative material to replace the autologous bone. Indeed, inert biomaterials are associated to satisfactory results in the short period but bear the continuous risk of complications related to the lack of osteointegration capacity. Biomimetic materials claiming osteoconductive properties that could balance their mechanical limits seem to allow good cranial bone reconstruction. However, these results should be confirmed in the long term and in larger series. Further complicating factors that may affect cranial reconstruction after head injury should be identified in the possible associated alterations of CSF dynamics and in difficulties to manage the traumatic skin lesion and the surgical wound, which also might impact on the cranioplasty outcome. All the abovementioned considerations should be taken into account when dealing with the cranial reconstruction after decompressive craniectomy in children.

Where are we? The anatomy of the murine cortical meninges revisited for intravital imaging, immunology, and clearance of waste from the brain

Rapid progress is being made in understanding the roles of the cerebral meninges in the maintenance of normal brain function, in immune surveillance, and as a site of disease. Most basic research on the meninges and the neural brain is now done on mice, major attractions being the availability of reporter mice with fluorescent cells, and of a huge range of antibodies useful for immunocytochemistry and the characterization of isolated cells. In addition, two-photon microscopy through the unperforated calvaria allows intravital imaging of the undisturbed meninges with sub-micron resolution. The anatomy of the dorsal meninges of the mouse (and, indeed, of all mammals) differs considerably from that shown in many published diagrams: over cortical convexities, the outer layer, the dura, is usually thicker than the inner layer, the leptomeninx, and both layers are richly vascularized and innervated, and communicate with the lymphatic system. A membrane barrier separates them and, in disease, inflammation can be localized to one layer or the other, so experimentalists must be able to identify the compartment they are studying. Here, we present current knowledge of the functional anatomy of the meninges, particularly as it appears in intravital imaging, and review their role as a gateway between the brain, blood, and lymphatics, drawing on information that is scattered among works on different pathologies.

Spinal subdural hematoma: a rare case of spinal subdural hematoma complicating routine, minimally invasive lumbar discectomy and decompression and relevant literature review

We present a case of apparently uncomplicated lumbar decompression and discectomy with delayed postoperative neurological deterioration secondary to subdural hematoma at the thoracolumbar level of the spinal cord. Previously described subdural hematomas have occurred spontaneously or related to iatrogenic injury. Hitherto, no case of acute postoperative subdural hematoma has been reported in the postoperative setting in the absence of known iatrogenic dural injury. A 76-year-old male with central and lateral recess spinal stenosis underwent apparently uncomplicated bilateral L3-4 and left sided L4-5 decompressive partial laminectomies and discectomy. No incidental dural injury or cerebrospinal fluid leak was detected. On postoperative day two, he developed progressive, profound weakness, sensory changes and urinary retention. Magnetic resonance imaging (MRI) demonstrated a compressive subdural fluid collection extending between T11-L2, which was confirmed to be xanthochromic and under pressure superficial to an undisturbed arachnoid at emergent surgical exploration and evacuation. The mechanism of this complication is unknown. The patient went on to a complete recovery following surgical evacuation of the fluid via durotomy. While this is a very rare event, it reminds that a high index of suspicion is required with a low threshold for urgent imaging and intervention in the postoperative period upon development of unexpected, progressive and/or profound neurological findings regardless of intraoperative course.

Subdural Thoracolumbar Spine Hematoma after Spinal Anesthesia: A Rare Occurrence and Literature Review of Spinal Hematomas after Spinal Anesthesia

Spinal hematomas are a rare but serious complication of spinal epidural anesthesia and are typically seen in the epidural space; however, they have been documented in the subdural space. Spinal subdural hematomas likely exist within a traumatically induced space within the dural border cell layer, rather than an anatomical subdural space. Spinal subdural hematomas present a dangerous clinical situation as they have the potential to cause significant compression of neural elements and can be easily mistaken for spinal epidural hematomas. Ultrasound can be an effective modality to diagnose subdural hematoma when no epidural blood is visualized. We have reviewed the literature and present a full literature review and a case presentation of an 82-year-old male who developed a thoracolumbar spinal subdural hematoma after spinal epidural anesthesia. Anticoagulant therapy is an important predisposing risk factor for spinal epidural hematomas and likely also predispose to spinal subdural hematomas. It is important to consider spinal subdural hematomas in addition to spinal epidural hematomas in patients who develop weakness after spinal epidural anesthesia, especially in patients who have received anticoagulation.

Membrane Surface Area to Volume Ratio in Chronic Subdural Hematomas: Critical Size and Potential Postoperative Target

BACKGROUND

It is unknown why some chronic subdural hematomas (CSDHs) grow and require surgery, whereas others spontaneously resolve. Although a relatively small CSDH volume (V) reduction may induce resolution, V percent reduction is often unreliable in predicting resolution. Although CSDHs evolve distinctive inner neomembranes and outer neomembranes (OMs), the OM likely dominates the dynamic growth-resorption equilibrium. If other factors remain constant, one previous hypothesis is that resorption could fail as the surface area (SA) to V ratio decreases when CSDHs exceed a critical size. We aimed to identify a critical size and an ideal target, which implies resolution without recurrence.

METHODS

Three-dimensional computed tomography CSDH SA to V ratios were obtained using computer software to compare CSDH SA to V between cases requiring surgery (surgical) and cases managed conservatively with spontaneous resolution (nonsurgical).

RESULTS

Data were obtained in 45 patients (surgical: n = 28; nonsurgical: n = 17). CSDH risk factors did not significantly differ between surgical and nonsurgical cases. Surgical V was 2.5× the nonsurgical V (119.9 ± 33.1 mL vs. 48.4 ± 27.4 mL, respectively; P < 0.0001). Surgical total SA was 1.4× nonsurgical SA (256.63 ± 70.65 cm² vs. 187.67 ± 77.72 cm², respectively; P = 0.004). Surgical total SA to V ratio was approximately one half that of nonsurgical SA to V ratio (2.14 ± 0.90 mL^-1 vs. 3.88±1.22 mL^-1, respectively; P < 0.0001). Surgical OM SA (SA_OM) was 120.63 ± 52 cm², and nonsurgical SA_OM was 94.10 ± 41 cm² (P < 0.0001). Nonsurgical SA_OM to V ratio was 1.94 mL^-1, whereas surgical SA_OM to V ratio was 1.005 mL^-1 (i.e., surgical SA_OM ≈ V).

CONCLUSIONS

Because surgical total SA to V ratio was ≈2:1, one neomembrane may indeed dominate the dynamic growth-resorption equilibrium. CSDH critical size therefore appears to be when SA_OM ≈ V, which is intuitive. Practically, subtotal CSDH evacuation which approximately doubles total SA to V ratio or SA_OM to V ratio implies CSDH resolution without recurrence. This could guide subdural drain removal timing, discharge, or transfer. Prospective validation studies are required.

Imaging characteristics of cervical spine extra-arachnoid fluid collections managed conservatively

OBJECTIVE

Determine the MRI characteristics of large post-traumatic cervical spine extra-arachnoid collections managed conservatively in clinically stable patients and whether evidence of clinical or imaging deterioration materialized.

MATERIALS AND METHODS

Following IRB approval, we conducted a retrospective search for all patients (>16 years old) over a 17-months period who had an extra-arachnoid fluid collection reported on a post-traumatic cervical spine MRI. Patients were excluded if they had surgery for an unstable fracture (n = 21), emergent decompression (n = 1) or lacked a follow-up MRI within 15 days (n = 1). Two MSK radiologists recorded the size, morphology and MRI signal characteristics of the collections.

RESULTS

Eight patients (5 male, 3 female) met the inclusion criteria (mean age 40 years; range 19-78 years). Seven of the eight patients had fluid collections that demonstrated thin, tapered margins, extended >7 vertebral bodies and involved >180 degrees of the spinal canal. The signal characteristics of these collections varied: hyper-T1/iso-T2 (n = 1), iso-T1/T2 (n = 3), hyper-T1/hypo-T2 (n = 3) and mixed-T1/T2 (n = 1). Six of seven collections were ventral. Follow-up MRI demonstrated resolution/significant decrease in size (n = 4 between 1 and 12 days) or no change/slight decrease in size (n = 3; between 2 and 11 days). None of the seven fluid collections enlarged, no patient had abnormal cord signal, and no patient's neurologic symptoms worsened. One of eight patients had a dorsal "mass-like" collection that was slightly smaller 9 days later.

CONCLUSION

In stable patients with large, tapered post-traumatic cervical spine extra-arachnoid collections managed non-surgically, none developed (1) clinical worsening, (2) abnormal cord signal or (3) collection enlargement, regardless of the collection's signal characteristics.

External drains versus no drains after burr-hole evacuation for the treatment of chronic subdural haematoma in adults

BACKGROUND

Chronic subdural haematoma (CSDH) is one of the most common types of intracranial haematoma, and often occurs in older people. Burr-hole craniostomy, which is an evacuation through one or two burr holes drilled over the site of the haematoma, has been widely accepted as the most effective way to manage CSDH. Recurrences are a major problem and need reoperation, sometimes repeatedly.

OBJECTIVES

To assess the effects and safety of the use of external drains versus no drains after burr-hole evacuation for the treatment of CSDH in adults.

SEARCH METHODS

We ran our first search on 27 November 2014. We searched the Cochrane Injuries Group's Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Library), MEDLINE (OvidSP), Embase Classic+Embase (OvidSP), PubMed, ISI WOS (SCI-EXPANDED, SSCI, CPCI-S and CPSI-SSH), Chinese databases, and clinical trials registers, and screened reference lists. In compliance with the MECIR conduct standard 37, the Cochrane Injuries Group Information Specialist ran an update search within 12 months of publication (25 April 2016). We have screened these results but not incorporated the findings into the current review; as a result of the update search, one trial is awaiting classification.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared external subdural drains with no drains after burr-hole evacuation for the treatment of CSDH in adults.

DATA COLLECTION AND ANALYSIS

Two review authors identified potential articles from the literature search, extracted data independently using a data extraction form and assessed risk of bias using the Cochrane 'Risk of bias' tool. For dichotomous data, where statistical heterogeneity was low, we calculated summary risk ratios with 95% confidence intervals using a fixed-effect model.

MAIN RESULTS

Nine RCTs, including a total of 968 participants, reported outcomes specified by this review. Only one RCT reported the use of an adequate method of allocation concealment; this trial was a large, single-centre, high quality study and was adequately reported. All included trials reported a reduced recurrence of CSDH with external subdural drains. We found a significant reduction in the risk of recurrence with subdural drains (RR 0.45, 95% CI 0.32 to 0.61, I(2) = 38%; 9 studies, 968 participants; moderate-quality evidence). There was no strong evidence of any increase in complications (RR 1.15; 95% CI 0.77 to 1.72, I(2) = 0%; 7 studies, 710 participants; low-quality evidence), mortality (RR 0.78, 95% CI 0.45 to 1.33, I(2) = 22%; 5 studies, 539 participants; low-quality evidence), or poor functional outcome (which included deaths) (RR 0.68, 95% CI 0.44 to 1.05, I(2) = 31%; 5 studies, 490 participants; low-quality evidence).

AUTHORS' CONCLUSIONS

There is some evidence that postoperative drainage is effective in reducing the symptomatic recurrence of CSDH. Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Due to the low quality of the evidence for the secondary outcomes, the effect of drainage on the occurrence of surgical complications, mortality and poor functional outcome is uncertain. This uncertainty can be clarified with data from high-quality studies which may be conducted in the future. There is no strong evidence of any increase in complications when drains are used.

Alterazioni meningee da ipotensione liquorale essenziale

Gli autori descrivono un caso di ipotensione liquorale essenziale con sindrome clinica ad esordio acuto, costituita da cefalea gravativa che si riduceva parzialmente in decubito orizzontale, regredita in cinque mesi. Vari esami RM dimostrarono la presenza di un ispessimento durale con accentuazione dopo contrasto, sia in sede endocranica che a livello cervicale, ed anche un sottile e circoscritto scollamento durale con lievi fenomeni emorragici; alla remissione clinica si accompagnò la normalizzazione del quadro neuroradiologico. Vengono discussi i possibili meccanismi patogenetici delle alterazioni durali alla luce dell'anatomia degli strati profondi della dura e ne vengono sottolineati gli aspetti radiologici.

'Subarachnoid cyst' after evacuation of chronic subdural hematoma: Case report of an unusual postoperative morbidity

Burr-hole drainage of chronic subdural hematomas are routine operative procedures done by neurosurgical residents. Common postoperative complications include acute epidural and/or subdural bleeding, tension pneumocephalus, intracranial hematomas and ischemic cerebral infarction. We report an interesting post-operative complication of a 'subarachnoid cyst' after burr-hole evacuation of a chronic subdural hematoma. The authors hypothesize that the 'cyst' is likely secondary to the splitting of the adjacent neomembrane within its arachnoid-brain interface by iatrogenic irrigation of the subdural space. Over time, this 'cyst' develops into an area of gliosis which eventually causes long-term scar epilepsy in the patient. As far as we are aware, this is the first complication of such a 'subarachnoid cyst' post burr-hole drainage reported in the literature.

Simultaneous Spinal and Intracranial Chronic Subdural Hematoma Cured by Craniotomy and Laminectomy: A Video Case Report

Simultaneous spinal and intracranial chronic subdural hematoma (CSDH) is a rare entity. A 67-year-old man visited our hospital due to headache after diving into a river 2 weeks before. Non-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) revealed bilateral intracranial CSDH. The bilateral CSDH was evacuated and his symptoms improved. Three days after craniotomy, he complained of sensory disturbance on his buttocks. Lumbar MRI showed a space-occupying lesion behind the thecal sac at L5. CT with myelography showed a subdural mass lesion; there was no communication with the subarachnoid space. Fourteen days after craniotomy, L5 laminectomy was performed and the dura mater was incised carefully. The video shows that a liquid hematoma similar to the intracranial CSDH flowed out, followed by cerebrospinal fluid. His symptoms improved after the operation and the hematoma did not recur. This is a rare condition of spinal CSDH demonstrated by neuroimaging and intraoperative video.

Characterization and morphological comparison of human dura mater, temporalis fascia, and pericranium for the correct selection of an autograft in duraplasty procedures

PURPOSE

The objective of this study was to characterize and compare the morphological characteristics of the dura mater, the pericranium, and the temporal fascia to ascertain the most adequate tissue to use as a dura graft.

METHODS

20 dura mater, 20 pericranium and 20 temporalis fascia samples were analyzed. Each of the samples was stained with hematoxylin and eosin, orcein, Van Gieson, Masson's trichrome and Verhoeff-Van Gieson (600 slides in total) for a general morphological evaluation, as well as a quantitative, morphometric and densitometric analysis of elastic fibers present in each of the tissues.

RESULTS

The micro-densitometric analysis of the tissues indicated that the area occupied by the elastic fibers showed values of 1.766 ± 1.376, 4.580 ± 3.041, and 8.253 ± 4.467 % for the dura mater, the temporalis fascia and the pericranium, respectively (p < 0.05, all pairs). The values observed in the analysis of the density intensity were 3.42E+06 ± 2.57E+06, 1.41E+07 ± 1.28E+07, and 1.63E+07 ± 9.19E+06 for the dura mater, the temporalis fascia and the pericranium, respectively (p < 0.05), dura mater vs. temporalis fascia and dura mater vs. pericranium).

CONCLUSIONS

This is the first study to compare the dura mater with tissues for dural autograft and to quantify the elastic component present in these tissues. The results indicate that the temporalis fascia is a better dural graft because of its intrinsic tissue properties.

A role for PDGF-C/PDGFRα signaling in the formation of the meningeal basement membranes surrounding the cerebral cortex

Platelet-derived growth factor-C (PDGF-C) is one of three known ligands for the tyrosine kinase receptor PDGFRα. Analysis ofPdgfcnull mice has demonstrated roles for PDGF-C in palate closure and the formation of cerebral ventricles, but redundancy with other PDGFRα ligands might obscure additional functions. In search of further developmental roles for PDGF-C, we generated mice that were double mutants forPdgfc(-/-)andPdgfra(GFP/+) These mice display a range of severe phenotypes including spina bifida, lung emphysema, abnormal meninges and neuronal over-migration in the cerebral cortex. We focused our analysis on the central nervous system (CNS), where PDGF-C was identified as a critical factor for the formation of meninges and assembly of the glia limitans basement membrane. We also present expression data onPdgfa,PdgfcandPdgfrain the cerebral cortex and microarray data on cerebral meninges.