Chronic Subdural Hematoma in the Aged, Trauma or Degeneration?

Advances in pathogenic mechanisms, diagnostic methods, surgical and non-surgical treatment, and potential recurrence factors of Chronic Subdural Hematoma: A review

Chronic Subdural Hematoma (CSDH) is a common hemorrhagic disease in neurosurgery, and with the intensification of global aging, its incidence is gradually increasing. With the advancement of scientific technology, the etiological concepts and surgical treatments for CSDH have continually evolved over time. Currently, neuroscientists' understanding of CSDH is no longer confined to bridging vein rupture; exploration of various mechanisms such as angiogenesis, maturation of blood vessels, and inflammation is also underway. In-depth exploration and discovery of pathogenic mechanisms guide the updating of clinical treatment strategies and methods. For different types of CSDH, there is now a clear guidance for the targeted selection of treatment methods. However, the current treatment of CSDH cannot completely solve all problems, and the updating of treatment methods as well as the development and validation of new effective drugs remain challenges for the future. In addition, the recurrence of CSDH is a significant issue that needs to be addressed. Although we have reviewed potential recurrent factors that may be associated, the strength of this evidence is insufficient. Future research should gradually focus on validating these recurrent factors and exploring new ones, in order to optimize the existing understanding and treatment of CSDH.

Incidence of surgically treated chronic subdural hematoma after head injury with normal initial computed tomography

PURPOSE

The objective was to determine the incidence of surgically treated chronic subdural hematoma (cSDH) within six months after head trauma in a consecutive series of head injury patients with a normal initial computed tomography (CT).

METHODS

A total of 1941 adult patients with head injuries who underwent head CT within 48 h after injury and were treated at the Tampere University Hospital's emergency department were retrospectively evaluated from medical records (median age = 59 years, IQR = 39-79 years, males = 58%, patients using antithrombotic medication = 26%). Patients with no signs of acute traumatic intracranial pathology or any type of subdural collection on initial head CT were regarded as CT negative (n = 1573, 81%).

RESULTS

Two (n = 2) of the 1573 CT negative patients received surgical treatment for cSDH. Consequently, the incidence of surgically treated cSDH after a normal initial head CT during a six-month follow-up was 0.13%. Both patients sustained mild traumatic brain injuries initially. One of the two patients was on antithrombotic medication (warfarin) at the time of trauma, hence incidence of surgically treated cSDH among patients with antithrombotic medication in CT negative patients (n = 376, 23.9%) was 0.27%. Additionally, within CT negative patients, one subdural hygroma was operated shortly after trauma.

CONCLUSION

The extremely low incidence of surgically treated cSDH after a normal initial head CT, even in patients on antithrombotic medication, supports the notion that routine follow-up imaging after an initial normal head CT is not indicated to exclude the development of cSDH. Additionally, our findings support the concept of cSDH not being a purely head trauma-related disease.

Clinical Characteristics and Prognoses of Chronic Subdural Hematoma Patients with and without Head Trauma: A Retrospective Comparative Study

OBJECTIVE

Head trauma is considered as the main cause of chronic subdural hematoma (CSDH). However, many patients develop CSDH with no identified cause. Herein, we conduct a comparative study to investigate the differences in clinical characteristics and surgical outcomes of CSDH patients with and without a history of head trauma.

METHODS

We retrospectively reviewed CSDH patients who underwent surgical treatment in our hospital between January 2013 and December 2021. Patients were categorized into a with head trauma (WHT) group and a without head trauma (WOHT) group for comparative analysis.

RESULTS

A total of 219 patients were included, 119 (54.3%) cases in the WHT group and 100 (45.7%) cases in the WOHT group. More cancer patients were found in the WOHT group than in the WHT group (P = 0.045). Both at discharge and 6-month follow-up, patients in the WOHT group achieved better clinical outcomes than the WHT group cases (P = 0.025 and 0.034, respectively). Furthermore, ordered multiclass logistic regression analyses indicated that a history of head trauma (odds ratio 2.151, 95% confidence interval 1.052-4.386; P = 0.036) was a risk factor significantly related to the unfavorable outcomes at 6-month follow-ups of CSDH. However, we did not find significant differences between the 2 groups in clinical manifestations, radiological characteristics, postoperative complications, mortality, and recurrence rates.

CONCLUSIONS

CSDH patients with a history of head trauma may be more susceptible to unfavorable outcomes; thus, they should be carefully evaluated and given more attention during hospitalization and after discharge.

Factors for predicting recurrence after burr hole drainage for chronic subdural hematoma: a retrospective study

Chronic subdural hematoma (SDH) is a common disease in the neurosurgical field, and hematoma drainage through burr hole trephination has been widely considered the optimal treatment for SDH. Despite numerous investigations aimed at predicting recurrence rates and associated factors, studies have demonstrated inconsistent results. In this study, we aimed to comprehensively determine the predictive factors of chronic SDH recurrence in surgically treated patients. We retrospectively evaluated 578 consecutive patients who underwent single burr hole surgery for chronic SDH at our institute between January 2008 and December 2021. Various clinical and radiological factors in patients with and without recurrence were compared using univariate and multivariate logistic regression analyses. A total of 438 patients (531 hemispheres) were analyzed. Fifty-four (10.17%) of the 531 hemispheres had recurrence of chronic SDH within 6 months. Male sex (adjusted odds ratio (aOR) = 3.48; 95% confidence interval (CI), 1.42-8.49), bilateral hematomas (aOR = 2.14; 95% CI, 1.05-4.35), laminar hematoma type (aOR = 2.87; 95% CI, 1.23-6.71), > 30-cm3 volume of postoperative residual hematoma (aOR = 2.99; 95% CI, 1.01-8.83), and preoperative blood glucose level of ≥ 150 mg/dL (aOR = 2.11; 95% CI, 1.10-4.05) were identified as independent factors associated with recurrence in multivariate logistic regression analysis. The present study revealed that male patients and those who had bilateral hematomas, laminar hematoma type, a large volume of hematoma after surgery, and a high preoperative blood glucose level had a higher probability of experiencing recurrent chronic SDH. We recommend close monitoring of patients 6 months postoperatively to detect subsequent chronic SDH recurrence.

Cortical atrophy in chronic subdural hematoma from ultra-structures to physical properties

Several theories have tried to elucidate the mechanisms behind the pathophysiology of chronic subdural hematoma (CSDH). However, this process is complex and remains mostly unknown. In this study we performed a retrospective randomised analysis comparing the cortical atrophy of 190 patients with unilateral CSDH, with 190 healthy controls. To evaluate the extent of cortical atrophy, CT scan images were utilised to develop an index that is the ratio of the maximum diameter sum of 3 cisterns divided by the maximum diameter of the skull at the temporal lobe level. Also, we reported, for the first time, the ultrastructural analyses of the CSDH using a combination of immunohistochemistry methods and transmission electron microscopy techniques. Internal validation was performed to confirm the assessment of the different degrees of cortical atrophy. Relative Cortical Atrophy Index (RCA index) refers to the sum of the maximum diameter of three cisterns (insular cistern, longitudinal cerebral fissure and cerebral sulci greatest) with the temporal bones' greatest internal distance. This index, strongly related to age in healthy controls, is positively correlated to the preoperative and post-operative maximum diameter of hematoma and the midline shift in CSDH patients. On the contrary, it negatively correlates to the Karnofsky Performance Status (KPS). The Area Under the Receiver Operating Characteristics (AUROC) showed that RCA index effectively differentiated cases from controls. Immunohistochemistry analysis showed that the newly formed CD-31 positive microvessels are higher in number than the CD34-positive microvessels in the CSDH inner membrane than in the outer membrane. Ultrastructural observations highlight the presence of a chronic inflammatory state mainly in the CSDH inner membrane. Integrating these results, we have obtained an etiopathogenetic model of CSDH. Cortical atrophy appears to be the triggering factor activating the cascade of transendothelial cellular filtration, inflammation, membrane formation and neovascularisation leading to the CSDH formation.

Subdural Lesions Linking Additional Intracranial Spaces and Chronic Subdural Hematomas: A Narrative Review with Mutual Correlation and Possible Mechanisms behind High Recurrence

The purpose of this study was two-fold. The first was to investigate the pathologic mechanisms underlying the formation of subdural fluid collection, an umbrella term referring to a condition commonly seen in the clinical setting. Accumulation of the cerebrospinal fluid (CSF) in the subdural space can be referred to in this disease category, disregarding the underlying source of the subdural fluid. However, in these two clinical situations, especially after trauma or brain surgery, fluid collection from the subarachnoid space (subdural hygroma) or from the ventricle to the subarachnoid space and infusion into the subdural space (external hydrocephalus), surgical management of critical patients may adopt the strategies of burr-hole, subduroperitoneal shunt, or ventriculoperitoneal shunt, which present distinctly different thoughts. Crucially, the former can be further transformed into chronic subdural hematoma (CSDH). The second significant theme was the pathogenesis of CSDH. Once the potential dural border cell (DBC) layer is separated such as if a wound is formed, the physiological mechanisms that seem to promote wound healing will resume in the subdural space as follows: coagulation, inflammation, fibroblast proliferation, neovascularization, and fibrinolysis. These aptly correspond to several key characteristics of CSDH formation such as the presence of both coagulation and fibrinolysis signals within the clot, neomembrane formation, angiogenesis, and recurrent bleeding, which contribute to CSDH failing to coagulate and absorb easily. Such a complexity of genesis and the possibility of arising from multiple pathological patterns provide a reasonable explanation for the high recurrence rate, even after surgery. Among the various complex and clinically challenging subdural lesions, namely, CSDH (confined to the subdural space alone), subdural hygroma (linked in two spaces), and external hydrocephalus (linked in three spaces), the ability to fully understand the different pathological mechanisms of each, differentiate them clinically, and devote more interventional strategies (including anti-inflammatory, anti-angiogenic, and anti-fibrinolysis) will be important themes in the future.

Bilateral post-traumatic hygromas in patient with frontotemporal dementia

Background

Frontotemporal dementia (FTD) is a highly disabling neurologic disorder characterized by behavioral alterations and movement disorders, involving patients with a mean age of 58 years. We present a unique case of a patient suffering from FTD who developed post traumatic bilateral hygromas.

Case Description

A 52-year-old male patient, with an history of head trauma 3 months before, was admitted to our department for recurrent motor seizures. Anamnesis was positive for FTD with severe frontal syndrome. Brain computed tomography and magnetic resonance imaging (MRI) showed the typical "knife-blade" appearance of the cortical atrophy associated to bilateral hemispheric hygromas exerting mild mass effect. Brain MRI showed the signs of the cortical and "anti-cortical" vein. The two subdural collections were evacuated through two bilateral burr holes and controlled drainage. Despite anti-epileptic drugs therapy, in the early postoperative period, the patient presented further tonic-clonic seizures. The patient showed progressive recovery and was transferred to the neurorehabilitation center. After 6-month follow-up, he completely recovered.

Conclusion

In FTD, severe cortical atrophy leads to space increase between arachnoid and pia mater that could affect the anatomical integrity especially after trauma, with possible development of hygromas. The coexistence of radiological findings of the cortical vein and sign of the "anti-cortical" vein can make difficult an exact differential diagnosis between a primitive hygroma and a Virchow hygroma from resorption of previous blood collection. Surgical treatment may be indicated in selected patients, but it is burdened by higher postoperative risks compared to the general population.

Age effects on the mechanical behavior of human cerebral bridging veins

BACKGROUND

It is well established that the probability of occurrence of acute subdural hematomas in traumatic situations increases with age, since the main cause of such hematomas is the mechanical failure of cerebral blood vessels known as bridging veins. This research aims to determine whether there is an effect of age on the mechanical properties of these cerebral vessels, because previous reported studies were conflicting.

METHODS

This study used mechanical tests blue of cerebral bridging veins from post-mortem human subjects. In particular, a series of in vitro tensile tests were performed on a balanced sample of bridging veins from different human subjects.

FINDINGS

The mechanical parameters measured from the tests were analyzed by means of regression analysis looking for age related effects. The results show that there is a significant effect on both the ultimate strength, maximum stress and strain that the specimens can withstand. The quantitative analysis shows reductions of nearly 50% in ultimate stress, and almost 35% in ultimate strain.

INTERPRETATION

Mechanical deterioration of the mechanical strength of cerebral blood vessels seems to be a major factor involved in the increase of frequency of acute subdural hematoma in elderly people in a wide range of life-threatening traumatic situations.

A Validation Study of Kwon's Prognostic Scoring System for Chronic Subdural Hematoma

OBJECTIVE

Surgery for chronic subdural hematoma is one of the most frequent operations in neurosurgical practice. Chronic subdural hematoma mostly afflicts the elderly population. In 2018, Kwon and co-workers, published the Kwon scoring system (KSS), whereby 6 clinical and radiological factors are used to facilitate, and promote quality in, surgical decision-making and counseling of relatives. The aim of this study is to validate the KSS.

METHODS

Patients operated on for unilateral chronic subdural hematoma at Örebro University Hospital, Sweden, between 2013 and 2019 constituted the study population. General data and the 6 outcome predictors according to the KSS were extracted from the electronic patient records. The preoperative modified Rankin Scale score and the postoperative 6-month modified Rankin Scale score were assessed.

RESULTS

We identified 133 patients (69.2% male) with a median age of 80.2 years (interquartile range 72.6-85.9). The median Glasgow Coma Scale score at admission was 15; 57.1% had motor deficits and 36.81% were disoriented. For 39.1% of the patients, the prognosis was a favorable outcome (modified Rankin Scale 0-1) at 6 months. The median KSS score was 9; 63.9% of the patients scored ≥9, and 36 (42.4%) of these patients actually achieved a favorable outcome. This corresponds to a prediction model sensitivity of 0.667 and specificity of 0.424. A receiver operator characteristic curve analysis of the model yielded an area under the receiver operator characteristic curve of 0.62441.

CONCLUSIONS

In our material, the KSS did not predict outcome precisely enough to base treatment decisions or counseling of relatives on the scores obtained.

Microvascular proliferation in the clots: The key finding of acute subdural hematoma transforming into chronic subdural hematoma?

Background:

Despite extensive investigations, the exact etiology of chronic subdural hematoma (CSDH) remains elusive. Organized CSDHs are a distinct but less-understood type of CSDH.

Case Description:

A 50-year-old hypertensive woman experienced headache without any previous head injury. At presentation, the patient showed no focal neurological deficits. Cranial computed tomography (CT) revealed a slightly compressive subdural hematoma that spontaneously regressed and no intracranial vascular lesions. Cerebral magnetic resonance imaging identified a non-enhancing nodular lesion in the subdural hematoma. After the patient presented disorientation and aphasia on post hospitalization day 14, CT showed a considerable enlargement of the subdural hematoma. Partial removal of the bi-layered hematoma was performed through a parietal craniotomy. Histological examination revealed microvascular proliferation in both the outer membrane and the nodular lesion. On postoperative day 35, CT demonstrated a remarkable resolution of the residual hematoma.

Conclusion:

Development of microvascular proliferation in the clots of an acute subdural hematoma may lead to its rapid enlargement as an organized CSDH. Organized CSDH can be managed by partial removal of the outer membrane and hematoma through a craniotomy.

Clinical Characteristics and Current Managements for Patients with Chronic Subdural Hematoma : A Retrospective Multicenter Pilot Study in the Republic of Korea

Objective

Chronic subdural hematoma (CSDH) is a common disease in neurosurgical departments, but optimal perioperative management guidelines have not yet been established. We aimed to assess the current clinical management and outcomes for CSDH patients and identify prognostic factors for CSDH recurrence.

Methods

We enrolled a total of 293 consecutive patients with CSDH who underwent burr hole craniostomy at seven institutions in 2018. Clinical and surgery-related characteristics and surgical outcomes were analyzed. The cohort included 208 men and 85 women.

Results

The median patient age was 75 years. Antithrombotic agents were prescribed to 105 patients. History of head trauma was identified in 59% of patients. Two hundred twenty-seven of 293 patients (77.5%) had unilateral hematoma and 46.1% had a homogenous hematoma type. About 70% of patients underwent surgery under general anesthesia, and 74.7% underwent a single burr hole craniostomy surgery. Recurrence requiring surgery was observed in 17 of 293 patients (5.8%), with a median of 32 days to recurrence. The postoperative complication rate was 4.1%. In multivariate analysis, factors associated with CSDH recurrence were separated hematoma type (odds ratio, 3.906; p=0.017) and patient who underwent surgery under general anesthesia had less recurrence (odds ratio, 0.277; p=0.017).

Conclusion

This is the first retrospective multicenter generalized cohort pilot study in the Republic of Korea as a first step towards the development of Korean clinical practice guidelines for CSDH. The type of hematoma and anesthesia was associated with CSDH recurrence. Although the detailed surgical method differs depending on the institution, the surgical treatment of CSDH was effective. Further studies may establish appropriate management guidelines to minimize CSDH recurrence.

Mechanical Behavior of Blood Vessels: Elastic and Viscoelastic Contributions

The mechanical properties of the cerebral bridging veins (CBVs) were studied using advanced microtensile equipment. Detailed high-quality curves were obtained at different strain rates, showing a clearly nonlinear stress-strain response. In addition, the tissue of the CBVs exhibits stress relaxation and a preconditioning effect under cyclic loading, unequivocal indications of viscoelastic behavior. Interestingly, most previous literature that conducts uniaxial tensile tests had not found significant viscoelastic effects in CBVs, but the use of more sensitive tests allowed to observe the viscoelastic effects. For that reason, a careful mathematical analysis is presented, clarifying why in uniaxial tests with moderate strain rates, it is difficult to observe any viscoelastic effect. The analysis provides a theoretical explanation as to why many recent studies that investigated mechanical properties did not find a significant viscoelastic effect, even though in other circumstances, the CBV tissue would clearly exhibit viscoelastic behavior. Finally, this study provides reference values for the usual mechanical properties, as well as calculations of constitutive parameters for nonlinear elastic and viscoelastic models that would allow more accurate numerical simulation of CBVs in Finite Element-based computational models in future works.

Comparisons of Radiological and Clinical Characteristics between Traumatic and Non-traumatic Subdural Hematoma Patients

Objective

Subdural hematoma (SDH) primarily occurs in elderly patients. While most patients have good prognosis, some do not. Hematoma recurrence is one of the factors influencing prognosis. Moreover, some characteristic radiological factors may increase the recurrence rate. The aim of this study was to investigate whether the presence of trauma influenced radiological characteristics and hematoma recurrence in SDH patients treated with burr hole trephination.

Methods

From January 2012 to December 2014, we selected 83 patients diagnosed with unilateral SDH using computed tomography and/or magnetic resonance imaging. We divided the patients into 2 groups based on the presence of trauma. We compared the 2 groups with multiple parameters, such as patient factors, radiological characteristics, and recurrence rate.

Results

Patients who had a prolonged international normalized ratio (INR) were significantly more common in the non-traumatic SDH group (22.2%:55.2%, p=0.002). There was no statistical difference in radiological parameters between the 2 groups. The recurrence rate was marginally higher in the non-traumatic SDH group (14.8%:17.2%, p=0.502), but this difference was not statistically significant.

Conclusion

There were no statistically significant differences in the radiological findings, including brain atrophy, hematoma density, thickness of hematoma, and degree of midline shifting between the 2 groups. The associated trauma history may not influence recurrence. Anticoagulants medication influence INR prolongation, and commonly shown in non-traumatic group, but not statistically. INR prolongation was statistically more common in non-traumatic SDH patients than in traumatic SDH patients. INR prolongation is only a different characteristic between 2 groups.

Spinal subdural hygroma

A spinal subdural hygroma is a rare entity. In this review, we try to contribute to the pooling of current knowledge about spinal subdural hygroma, from embryology and physiology until radiological detection and treatment. The relevant articles in the literature regarding spinal subdural hygroma were reviewed, using a sensitive search strategy on Internet databases. A spinal subdural hygroma is associated with trauma, iatrogenic causes, spontaneous intracranial hypotension headache, and probably meningitis. MR imaging is the golden standard for diagnosis. Treatment of the hygroma is almost always conservative and surgery is seldom necessary, however treating the underlying cause is important. The physiology, in spite of numerous suggestions and hypotheses in literature, remains unclear. The prevalence of spinal subdural hygroma is also still unknown. Only a few articles deal with spinal subdural hygroma, because it is an uncommon entity, without specific symptoms. Probably it is often not diagnosed because of the frequent association with other cranial or spinal pathologies and the need for high-resolution imaging. More research is required to examine the prevalence, importance, and pathophysiology of spinal subdural hygroma.

A Comparative Study of Chronic Subdural Hematoma in Patients With and Without Head Trauma: A Retrospective Cross Sectional Study

Background: The clinical features of chronic subdural hematomas (CSDHs) in patients with and without a history of head trauma have remained unclear. Here, we investigated differences in clinical characteristics in CSDH patients with and without head trauma. Methods: We retrospectively collected clinical characteristics of CSDH patients who had undergone exhaustive drainage strategies via burr-hole craniostomies from August 2011 to May 2019. We divided patients into a trauma group (i.e., head trauma) and a no-trauma group. Chi-square tests or t-tests were used to analyze differences in clinical characteristics between the two groups. Multiple linear regression analysis was performed to analyze the relationships between the clinical characteristics and either reduction of the hematoma cavity or length of the hospital stay in CSDH patients with trauma. Results: We collected data from 1,307 CSDH patients, among whom 805 patients had a history of head trauma whereas 502 patients did not. The mean age of patients with head trauma was 64.0 ± 16.1 years, while that of patients without head trauma was significantly younger at 61.5 ± 17.9 years (p = 0.010). Furthermore, more patients in the no-trauma group had a history of hypertension compared to those in the trauma group (40.2 vs. 32.9%, p = 0.007). Dizziness occurred in 29.2% of patients with trauma and in 23.1% of patients without trauma (p = 0.016). A greater number of patients with trauma showed a reduction of hematoma cavity after surgery compared to that of patients without trauma (p = 0.002). The length of hospital stay in patients with trauma was 7.9 ± 4.5 days, which was longer than that of patients without trauma (7.3 ± 3.7 days, p = 0.016). In contrast, there were no significant different differences between the two groups in terms of the densities of hematomas on computed-tomography scans, complications, mortality rates, recurrence rates, or outcomes. Conclusion: Our findings indicate that there were some noteworthy differences in the clinical and pathogenic characteristics of CSDH patients with and without head trauma. However, our findings also indicate that if an optimal treatment method is employed, such as our exhaustive drainage strategy, similar treatment outcomes can be achieved between these groups.

Effects of Possible Osteoporotic Conditions on the Recurrence of Chronic Subdural Hematoma

The recurrence rate of chronic subdural hematoma (CSDH) has been reported to range from 2.3 to 33%. As bridging veins are composed of abundant collagen bundles and bone matrix, we aimed to investigate the possible associations between skull Hounsfield unit (HU) values and the recurrence of CSDH. We retrospectively enrolled patients with CSDH who underwent burr hole surgery. The HU values of the frontal skull were measured on brain CT scans. The cumulative hazard for recurrence was estimated according to predictive factors. To identify the independent predictors associated with the recurrence of CSDH, hazard ratios (HRs) were estimated using multivariate Cox regression analysis. A total of 208 consecutive patients who underwent burr hole trephination for CSDH over a 7-years period at a single institution were enrolled in this study. We found that age, greater midline shift (≥10.5 mm), lower skull HU (<769.5), and diabetes were independent predictors for the recurrence of CSDH (HR 1.06, 95% confidence interval [CI] 1.00–1.12, p = 0.042; HR 5.37, 95% CI 1.48–19.46, p = 0.010; HR 6.71, 95% CI 1.84–24.45, p = 0.004; and HR 3.30, 95% CI 1.05–10.43, p = 0.042, respectively). A relationship between possible low bone mineral density (BMD) and CSDH recurrence was observed. In addition, age, greater preoperative midline shift, and diabetes were also identified as predictive factors for recurrence. We expect that our findings may facilitate our understanding of the possible association between CSDH and BMD.

Long-term excess mortality after chronic subdural hematoma

OBJECTIVE

To assess possible long-term excess mortality and causes of death of patients with chronic subdural hematoma (CSDH).

METHODS

A retrospective study (1990-2015) of adult patients (n = 1133, median age = 76 years old, men = 65%) with CSDH identified by ICD-codes and verified by medical records. All patients were followed until death or the end of 2017. Cumulative relative survival ratios and relative excess risks of death (RER) were estimated by comparing patients' mortality with that in the entire regional matched population. The causes of death were compared with a separate reference group formed by randomly choosing sex, age, and calendar time matched controls (4 controls per each CSDH patient).

RESULTS

The median follow-up time was 4.8 years (range = 0-27 years), and 710 (63%) of the patients died (median age at death = 84 years old). The cumulative excess mortality was 1 year = 9%, 5 years = 18%, 10 years = 27%, 15 years = 37%, and 20 years = 48%. A subgroup of CSDH patients (n = 206) with no comorbidity had no excess mortality. Excess mortality was related to poor modified Rankin score at admission (RER = 4.93) and at discharge (RER = 8.31), alcohol abuse (RER = 4.47), warfarin (RER = 2.94), age ≥ 80 years old (RER = 1.83), non-operative treatment (RER = 1.56), and non-traumatic etiology (RER = 1.69). Hematoma characteristics or recurrence were unrelated to excess mortality. Dementia was the most common cause of death among the CSDH patients (21%) and the third most common cause in the reference group (15%, p < 0.001).

CONCLUSIONS

Patients with CSDH have continuous excess mortality up to 20 years after diagnosis. Patient-related characteristics have a strong association with excess mortality, whereas specific CSDH-related findings do not. CSDH patients have an increased risk for dementia-related mortality.

The incidence of chronic subdural hematomas from 1990 to 2015 in a defined Finnish population

OBJECTIVE

The aim of this study was to determine the population-based epidemiology of chronic subdural hematoma (CSDH) over a 26-year period.

METHODS

A retrospective study was conducted of all adult patients (≥ 18 years and residents of Pirkanmaa [Finland]) with a diagnosis of CSDH between 1990 and 2015. The cases were identified using ICD codes. Detailed data collection was performed using medical records and death certificates. All patients were monitored until death or the end of year 2017. The annual number of inhabitants in the Pirkanmaa region was obtained from Statistics Finland (Helsinki, Finland).

RESULTS

A total of 1168 patients with CSDH were identified from hospital records and death certificates; patients were considered as new-incidence cases if 2 years had elapsed following primary treatment and in cases involving a new contralateral CSDH. From 1990 to 2015, the overall incidence of CSDH doubled from 8.2 to 17.6/100,000/year. Among adults younger than 70 years, the incidence remained quite stable, whereas the incidence clearly increased among the ≥ 80-year-old population, from 46.9 to 129.5/100,000/year. The median age for a CSDH diagnosis increased from 73 to 79 years during the 26-year period. Head trauma was documented in 59% of cases. A ground-level fall was related to the CSDH in 31% of patients younger than 60 years and in 54% of those 80 years or older. The proportion of alcohol-related cases decreased toward the end of the study period (1990–1995: 16% and 2011–2015: 7%), because alcohol abuse was less frequent among the growing group of elderly patients. In contrast, the percentage of patients receiving anticoagulant or antiplatelet medication almost doubled toward 2015 (1990–1995, 27%; and 2011–2015, 49%). The patients’ neurological condition on admission, based on both Glasgow Coma Scale score (score < 13: 1990–1995, 18%; and 2011–2015, 7%; p < 0.001) and the modified Rankin Scale score (score 0–2: 1990–1995, 8%; and 2011–2015, 19%; p < 0.001), was better in recent years than in the early 1990s.

CONCLUSIONS

From 1990 to 2015, the incidence of CSDH has increased markedly. The incidence of CSDH among the population 80 years or older has nearly tripled since 1990. The use of anticoagulants has increased, but there has been no change regarding the ratio between a traumatic and a spontaneous CSDH etiology. As the world population becomes progressively older, the increasing incidence of CSDH will be a burden to patients and a future challenge for neurosurgical clinics.

Causes, clinical presentation, management, and outcomes of chronic subdural hematoma at Mbarara Regional Referral Hospital

OBJECTIVE

Causes, clinical presentation, management, and outcomes of chronic subdural hematoma (CSDH) in low- and middle-income countries are not well characterized in the literature. Knowledge regarding these factors would be beneficial in the development and implementation of effective preventive and management measures for affected patients. The authors conducted a study to gain a better understanding of these factors in a low-income setting.

METHODS

This prospective study was performed at Mbarara Regional Referral Hospital (MRRH) in Uganda between January 2014 and June 2017. Patients of any age who presented and were diagnosed with CSDH during the aforementioned time period were included in the study. Variables were collected from patients' files at discharge and follow-up clinic visits. The primary outcome of interest was death. Secondary outcomes of interest included discharge Glasgow Coma Scale (GCS) score, ICU admission, wound infection, and CSDH recurrence.

RESULTS

Two hundred five patients, the majority of whom were male (147 [72.8%]), were enrolled in the study. The mean patient age was 60.2 years (SD 17.7). Most CSDHs occurred as a result of motor vehicle collisions (MVCs) and falls, 35.6% (73/205) and 24.9% (51/205), respectively. The sex ratio and mean age varied depending on the mechanism of injury. Headache was the most common presenting symptom (89.6%, 173/193), whereas seizures were uncommon (11.5%, 23/200). Presenting symptoms differed by age. A total of 202 patients underwent surgical intervention with burr holes and drainage, and 22.8% (46) were admitted to the ICU. Two patients suffered a recurrence, 5 developed a postoperative wound infection, and 18 died. Admission GCS score was a significant predictor of the discharge GCS score (p = 0.004), ICU admission (p < 0.001), and death (p < 0.001).

CONCLUSIONS

Trauma from an MVC is the commonest cause of CSDH among the young. For the elderly, falling is common, but the majority have CSDH with no known cause. Although the clinical presentation is broad, there are several pronounced differences based on age. Burr hole surgery plus drainage is a safe and reliable intervention. A low preoperative GCS score is a risk factor for ICU admission and death.

Contrast enhancement of chronic subdural hematomas after embolization of the middle meningeal artery

Chronic subdural hematomas are a common neurosurgical presentation. They are difficult to treat, and current interventions - namely surgical evacuation - are not without complications or recurrences. Embolization of the middle meningeal artery is a promising new treatment option for this pathology. We have noted an interesting phenomenon in our patients following endovascular embolization, which is that the subdural hematoma is stained with contrast following the procedure. This ties into the basic physiology of chronic subdurals, which parasitize the middle meningeal artery during the process of membrane formation and neovascularization, which has previously been reported.

Does time from diagnostic CT until surgical evacuation affect outcome in patients with chronic subdural hematoma?

Background

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. Patients diagnosed with CSDH’s are often planned for subacute surgery. This means that time from diagnostic CT scan until actual surgery might often be prolonged. There are no previous studies that highlight the effect of delayed intervention in this population.

Method

Patients that underwent surgical evacuation for a CSDH at Skåne University Hospital between 1 January 2015 and 31 December 2016 were included in this retrospective cohort study (n = 179). The primary aim was to determine if time from initial diagnosis by head-CT until surgical evacuation had a significant effect on outcome. The following was assessed by mortality, re-operation, number of days spent in hospital, discharge to home/institution, and functional outcome assessed by GOS. Secondary aims were to evaluate the effect of NOAC, vitamin K antagonists, and antiplatelet drugs on time from CT to surgery and re-operation frequency.

Results

Mean time from diagnostic CT scan until surgery was 76 h. No significant relationship was found between time from CT to surgical evacuation and number of days spent in hospital, discharge to own home/institution, 1-year mortality, or outcome assessed by GOS at discharge from hospital. The clear majority (95.5%) of the patients were GCS ≥ 13 pre-operatively. No correlation could be seen between use of NOAC, vitamin K antagonists, or antiplatelet drugs regarding the risk for reoperation within 6 months, and no correlation between the use of these agents and time from CT to surgery. The 30-day mortality was too low to draw any statistically significant conclusions (n = 4).

Conclusion

In this retrospective cohort study, we could conclude that a delay from initial diagnosis confirming a CSDH to surgical evacuation had no negative effect on outcome when surgery was performed within the time frames and on patients with pre-operatively favorable GCS scores (≥ 13) outlined in our study.

Subarachnoid Trabeculae: A Comprehensive Review of Their Embryology, Histology, Morphology, and Surgical Significance

INTRODUCTION

Brain is suspended in cerebrospinal fluid (CSF)-filled subarachnoid space by subarachnoid trabeculae (SAT), which are collagen-reinforced columns stretching between the arachnoid and pia maters. Much neuroanatomic research has been focused on the subarachnoid cisterns and arachnoid matter but reported data on the SAT are limited. This study provides a comprehensive review of subarachnoid trabeculae, including their embryology, histology, morphologic variations, and surgical significance.

METHODS

A literature search was conducted with no date restrictions in PubMed, Medline, EMBASE, Wiley Online Library, Cochrane, and Research Gate. Terms for the search included but were not limited to subarachnoid trabeculae, subarachnoid trabecular membrane, arachnoid mater, subarachnoid trabeculae embryology, subarachnoid trabeculae histology, and morphology. Articles with a high likelihood of bias, any study published in nonpopular journals (not indexed in PubMed or MEDLINE), and studies with conflicting data were excluded.

RESULTS

A total of 1113 articles were retrieved. Of these, 110 articles including 19 book chapters, 58 original articles, 31 review articles, and 2 case reports met our inclusion criteria.

CONCLUSIONS

SAT provide mechanical support to neurovascular structures through cell-to-cell interconnections and specific junctions between the pia and arachnoid maters. They vary widely in appearance and configuration among different parts of the brain. The complex network of SAT is inhomogeneous and mainly located in the vicinity of blood vessels. Microsurgical procedures should be performed with great care, and sharp rather than blunt trabecular dissection is recommended because of the close relationship to neurovascular structures. The significance of SAT for cerebrospinal fluid flow and hydrocephalus is to be determined.

Predictive factors for recurrence and clinical outcomes in patients with chronic subdural hematoma

OBJECTIVE Chronic subdural hematoma (CSDH) is a common type of intracranial hemorrhage in elderly patients. Many studies have suggested various factors that may be associated with the recurrence of CSDH. However, the results are inconsistent. The purpose of this study was to determine the associations among patient factors, recurrence, and clinical outcomes of CSDH after bur hole surgery performed during an 11-year period at twin hospitals. METHODS Kaplan-Meier analysis was performed to evaluate the risk factors for CSDH recurrence. Univariate and multivariate Cox proportional hazards regression analyses were used to calculate hazard ratios with 95% CIs for CSDH recurrence based on many variables. One-way repeated-measures ANOVA was used to assess the differences in the mean modified Rankin Scale score between categories for each risk factor during each admission and at the last follow-up. RESULTS This study was a retrospective analysis of 756 consecutive patients with CSDH who underwent bur hole surgery at the Hanyang University Medical Center (Seoul and Guri) between January 1, 2004, and December 31, 2014. During the 6-month follow-up, 104 patients (13.8%) with recurrence after surgery for CSDH were identified. Independent risk factors for recurrence were as follows: age > 75 years (HR 1.72, 95% CI 1.03-2.88; p = 0.039), obesity (body mass index ≥ 25.0 kg/m²), and a bilateral operation. CONCLUSIONS This study determined the risk factors for recurrence of CSDH and their effects on outcomes. Further studies are needed to account for these observations and to determine their underlying mechanisms.

[Chronic subdural haematomas in very elderly patients]

INTRODUCTION

Chronic subdural haematoma (CSDH) is one of the most common neurosurgical conditions and is especially prevalent among elderly individuals. The objective of this study was to analyse the demographic, clinical and radiological findings, and surgical outcomes in a series of chronic subdural haematoma in patients older than 85 years.

PATIENTS AND METHODS

A review was carried out on all patients over 85 years with CSDH treated in our neurosurgical service from April 1986 to November 2015. A record was made of the baseline patient characteristics (age, sex, comorbidities, known risk factors, imaging characteristics, and number of burr-holes) and surgical outcomes (complications, especially recurrences and mortality). An analysis was carried out on the special characteristics of these patients, as well as the relationships between gender, clinical grade, anti-platelet or anticoagulant therapy, internal architecture of the haematoma, and midline shift, with mortality and recurrence of the haematoma.

RESULTS

A total of 200 patients were included, with a mean age of 88.5 (range 85-104) years, and the male: female sex ratio was 1:1.1. History of injury was reported in 114 (57%) cases. Anti-platelet or anticoagulant therapy was being used by 71 (35.5%) patients. On admission, 114 patients (57%) were in satisfactory condition (Markwalder grades 0-2). The main symptom was behavioural disturbance in 82 (41%) cases. CSDH was left-sided in 89 (44.5%) patients, right-sided in 78 (39%) cases (39%), and bilateral in the remaining 33 (16.5%) cases). Postoperative complications were observed in 59 cases (29 recurrences). Preoperative Markwalder grade correlated significantly with recurrence rate and mortality (P<.0001).

CONCLUSIONS

CSDH was a very common disease in very elderly patients. Behavioural disturbance and neurological deficits are the most common first symptom. Preoperative neurological status at admission is the most important factor in recurrences and mortality.

Correlation between Head Trauma and Outcome of Chronic Subdural Hematoma

Objective

Our study examined the prognostic factors involved in the outcome of patients with chronic subdural hematoma (CSDH) who had undergone burr hole drainage procedures, and investigated the association between outcome and traumatic head injury. In addition, we explored factors related to recurrence.

Methods

This study enrolled 238 patients with CSDH who had undergone burr hole drainage. Patients with history of head injury were categorized into the head trauma group and were compared with the no head trauma group. Outcome was considered good when modified Rankin Scale scores improved from admission to discharge and the final follow-up.

Results

Among 238 patients, 127 (53.4%) were included in the head trauma group. One hundred thirty-three (55.9%) patients demonstrated good outcome at discharge, and 171 (71.8%) patients demonstrated good outcome at the final follow-up. None of the factors examined was significantly correlated with good outcome at discharge. However, only history of head injury (p=0.033, odds ratio 0.511, 95% confidence interval 0.277-0.946) was significantly correlated with poor outcome at long-term follow-up. Recurrence occurred in 20 (8.4%) cases in the total cohort and 11 (55%) patients in the head trauma group.

Conclusion

History of head trauma is correlated with poor outcome at long-term follow-up in CSDH patients having undergone burr hole drainage. Therefore, CSDH patients with history of head injury are susceptible to poor outcome, warranting more careful evaluation and treatment after burr hole drainage.