Origin of chronic subdural haematoma and relation to traumatic subdural lesions

The interdural hematoma: A subtype of convexity subdural/dural hematoma with specific radioanatomical characteristics

Background

Rare cases of biconvex hematomas splitting the convexity dura mater were reported and denominated interdural hematoma (IDH). Due to their rarity, little is known about their radiological characteristics, and in most cases, their invasive management with craniotomy and dural membrane excision is unnecessary.

Case Description

We report here a case of single burr-hole endoscopic evacuation of an IDH and its complete resolution after the 6-month follow-up imaging. The literature review reveals 11 reported cases of IDH. Most of them are male and the mean age is 65 years (range 51-90). Most of the reported IDHs were misdiagnosed as epidural hematoma or meningioma, and therefore, they have been managed invasively through craniotomy with dural excision. Diagnosis of the interdural nature was confirmed macroscopically during surgery in all cases and histology was reported for 6 cases. Image analysis found a double dural beak sign and biconvex shape on coronal planes, subarachnoid space enlargement at the collection extremities, and irregular thick inner wall as common radiological aspects of the IDH.

Conclusion

IDH is a rarely reported and often misdiagnosed dural hematoma subtype. Its invasive treatment through craniotomy is likely related to its unknown radiological characteristics. We review and raise awareness about potentially unique radiological anatomy that could avoid unnecessary invasive treatment. Moreover, we report the first case of endoscopically evacuated IDH with long-term follow-up imaging showing complete resolution.

Traumatic subdural hygroma and chronic subdural hematoma: A systematic review and meta-analysis

Recently, a relationship between traumatic subdural hygroma (SDG) and chronic subdural hematoma (CSDH) has been proposed. However, the role of traumatic SDG in development of CSDH has not been well characterized. This systematic review aimed to estimate the rate of evolution of traumatic SDG to CSDH, and to identify risk factors associated with traumatic SDG evolution to CSDH. We searched MEDLINE, EMBASE, and Cochrane Library databases from inception to May 26, 2021, using the combination of the terms "subdural hygroma" and "chronic subdural hematoma." Using a random-effects model, we calculated a pooled estimate of rate of evolution of traumatic SDG to CSDH. In addition, we conducted a systematic review of studies of risk factors for traumatic SDG evolution to CSDH. Nineteen studies with 1,335 patients met the inclusion criteria for meta-analysis. The pooled estimate of evolution rate was 25.0 % (95 % CI, 19.3 %-30.7 %; I² = 85.6 %), with significant heterogeneity among studies (P < 0.01). Age ≥ 60 years was associated independently with traumatic SDG evolution to CSDH, after adjustment for study design using multivariate meta-regression. Risk factors associated with evolution of traumatic SDG to CSDH were radiological characteristics such as thicker SDG and higher SDG CT value. The rate of traumatic SDGs evolution to CSDH is approximately 25 %. Patients aged 60 or older with traumatic SDGs are at increased risk of CSDH development. Thicker SDG and higher SDG CT value, are commonly reported risk factors for traumatic SDG evolution to CSDH. However, higher quality studies are needed.

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.

Hematoma subdural crónico: Una patología común de manejo complejo

Antecedentes:

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

Métodos:

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

Resultados:

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

Conclusiones:

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

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

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

Predictors of Brain Natriuretic Peptide Serum Level Elevation in Patients with Symptomatic Chronic Subdural Hematoma: A Prospective Study

Background: Brain natriuretic peptide serum levels (BNP) on admission are frequently elevated in patients with symptomatic chronic subdural hematoma (cSDH) and predict unfavorable long-term functional outcomes. However, the reasons for these elevated levels remain unclear. Therefore, we aimed to identify the predictors of BNP elevation. Methods: Patients with unilateral symptomatic cSDH who were surgically treated in our department between November 2016 and May 2020 were enrolled. Patients’ symptoms and neurological deficits were prospectively assessed using a study questionnaire. On initial computer tomography, hematoma volumes and midline shift (MLS) values were measured to analyze the degree of brain compression. Results: In total, 100 patients were analyzed. Linear regression analysis showed that higher BNP levels were significantly associated with smaller hematoma volumes (p = 0.003) and littler MLS values (p = 0.022). Multivariate analysis revealed that presence of a neurological deficit (p = 0.041), a hematoma volume < 140 mL (p = 0.047), advanced age (p = 0.023), and head trauma within 24 h of admission (p = 0.001) were independent predictors of BNP elevation. Conclusion: In symptomatic cSDH, BNP elevation is related, among others, to the presence of neurological deficits and smaller hematoma volumes. Whether BNP elevation may coincide with the early stage of hematoma growth, i.e., immaturity of cSDH neomembrane, requires further investigations.

Development of a delayed chronic subdural hematoma 2 months after mild traumatic brain injury with a normal initial brain computed tomography: A case report

This is a case involving the development of a delayed chronic subdural hematoma 2 months after a minor head injury with normal clinical neurological findings and brain computed tomography at initial presentation. An 84-year-old man visited the emergency department (ED) after a minor head trauma. The patient complained of dizziness and vomiting 8 hours after an injury. He was not on an antiplatelet or anticoagulant. He did not have any abnormal findings during neurological examination, and brain computed tomography did not show any intracranial pathology or skull fractures. He was admitted to the ED short-stay ward for observation and was discharged asymptomatic and stable 12 hours later. However, he presented 2 months later with dizziness and unsteady gait. He was asymptomatic within those 2 months. At the ED, his brain computed tomography showed a large right chronic subdural hematoma, compressing the right lateral and third ventricles, with a 1.2 cm midline shift, subfalcine and uncal herniations, and early hydrocephalus. An emergency burr-hole evacuation was performed. He was discharged without neurological deficit 3 days later. Emergency physicians attending to patients with normal neurologic examination and initial brain computed tomography after suffering a mild traumatic brain injury should be vigilant for a chronic subdural hematoma should the patient re-present for evaluation subsequently. The attending physician may be biased as patients could have symptoms attributed to postconcussion syndrome that may overlap with symptoms of chronic subdural hematoma. Unsteady gait and ataxia are uncommon clinical signs of postconcussion syndrome and should prompt the physician to consider a repeat brain computed tomography.

Role of brain natriuretic peptide in the prediction of long-term surgical outcome of chronic subdural hematoma

OBJECTIVE

To investigate the role of brain natriuretic peptide (BNP) in predicting long-term functional outcome and develop a new predictive score of poor functional outcome after surgery for chronic subdural hematoma (cSDH).

METHODS

Patients with cSDH that were surgically treated in our department between November 2016 and December 2019 were included in the study. Pre- and postoperative plasma BNP and clinical condition were prospectively recorded. At follow-up (5-6 months), a simplified modified Rankin Scale (mRS) questionnaire was conducted through a standardized telephone interview. A poor outcome was defined by a mRS > 3. Based on predictors of the long-term functional outcome, a score was calculated. Its accuracy was tested using the area under the curve (AUC) of the receiver operating characteristic analysis.

RESULTS

In total, 119 patients were analyzed (median age: 76 years, range: 44-94 years). Preoperative plasma BNP (BNP-1) was elevated in 77 patients (64.7%). For the follow-up phone interview, 101 patients (84.8%) were available. In the multivariate analysis, poor outcome at follow-up could be predicted using BNP-1 (p = 0.034), age (p = 0.036), motor deficit (p = 0.013) and Glasgow coma scale score on admission (p = 0.008). The "Functional Long-term Outcome Predictive score" (FLOP-score) was therefore computed, and revealed an excellent discriminative capacity compared to other scores, with an AUC of 0.86 (0.77-0.95).

CONCLUSIONS

Preoperative plasma BNP is an independent predictor of functional outcome at follow-up. Using the FLOP-score, the risk of experiencing a poor outcome could accurately be predicted.

Risk Factors for Progression of Conservatively Managed Acute Traumatic Subdural Hematoma: A Systematic Review and Meta-Analysis

BACKGROUND

Conservatively managed posttraumatic acute subdural hematoma (SDH) can present with progression of the size of the hematoma with increased mass effect, necessitating delayed surgery. The factors contributing to this progression remain largely unknown.

METHODS

A comprehensive search of the PubMed, Embase, and Scopus databases was performed to retrieve case control studies, retrospective cohort studies, and prospective studies with retrospective evaluation of risk factors until August 2, 2020. The different risk factors that were evaluated in the studies were compiled and the results were analyzed to arrive at a conclusion.

RESULTS

A total of 7 studies were included in the systematic review and 6 were included in the analysis, with an aggregate of 679 patients. The following factors were found to have a relation with progression of acute SDH: age (odds ratio, 7.12; 95% confidence interval [CI], 2.52-11.72), use of antiplatelet drugs (odds ratio, 1.89; 95% CI, 1.18-2.77), use of anticoagulants (odds ratio, 3.09; 95% CI, 1.21-7.88), thickness of SDH (odds ratio, 4.13; 95% CI, 3.29-4.97), midline shift (odds ratio, 1.86; 95% CI, 0.69-3.03), hypertension (odds ratio, 2.22; 95% CI, 1.25-3.96) and ischemic heart disease (odds ratio, 3.32; 95% CI, 1.63-6.76).

CONCLUSIONS

The results of this analysis showed that patients with the risk factors outlined are at higher risk of developing symptomatic chronic SDH after conservatively managed traumatic acute SDH compared with those without them. It is therefore necessary to provide more intensive follow-up for these patients to avoid an adverse outcome.

Computed tomography findings after head injury preceding chronic subdural hematoma

OBJECTIVE

Head CT is sometimes performed immediately after minor head injury; however, which cases develop into chronic subdural hematoma (CSDH) remains unclear. Here, the authors retrospectively reviewed the rare cases of CSDH treated surgically in which early head CT had been performed after the initial head trauma.

METHODS

A total of 172 patients (133 male and 39 female, median age 76 years) underwent surgery for CSDH at Gunma University Hospital between April 2010 and December 2017. Among these patients were 23 who had visited Gunma University Hospital or a nearby hospital and had undergone head CT within 7 days after the initial head trauma. Characteristics of the initial head CT were examined to identify indicators of subsequent CSDH.

RESULTS

Among the 23 CSDH cases (17 male and 6 female, median age 80 years), CT scans were obtained on the day of the initial injury (day 0) in 19 cases (25 sides) and 1-7 days after injury in 12 cases (19 sides); scans were obtained during both periods in 8 cases (12 sides), so that a total of 44 sides were examined. These CT scans were divided into two groups according to when they were obtained; cases in which scans were taken during both periods were included in both groups. Head CT performed on the day of injury showed normal findings in 5 (20%) of 25 sides, thin subdural effusion (SDE) ≤ 6 mm in 16 (64%) of 25 sides, thick SDE > 6 mm in 3 (12%) of 25 sides, and acute subdural hematoma (ASDH) in 1 (4%) of 25 sides. CT from 1-7 days after trauma showed thick SDE in 9 (47%) of 19 sides, thin SDE in 8 (42%) of 19 sides, and ASDH in 2 (11%) of 19 sides. A high-density line in the lateral direction (onion skin-like) was found between the skull and the brain in 9 (35%) of 26 sides with SDE on initial CT 0-7 days after the injury.

CONCLUSIONS

ASDH was not a common cause of CSDH. Head CT at the time of trauma that precedes CSDH often showed SDE. Such SDE that precedes CSDH was often close to the detection limit of CT immediately after the injury but became more apparent from the day after the injury.

Larger Middle Meningeal Arteries on Computed Tomography Angiography in Patients with Chronic Subdural Hematomas as Compared with Matched Controls

Chronic subdural hematomas (CSDHs) are one of the most prevalent head-trauma-related conditions. The middle meningeal artery (MMA) may participate in the pathophysiology of CSDHs. The aim of this study was to determine whether CSDHs are associated with large MMAs. Patients referred for CSDH embolization and having undergone a computed tomography angiography (CTA) before embolization were retrospectively included. For each CSDH patient, two age- and sex-matched controls with a CTA performed during the study period were selected. Size comparisons of the MMA were performed between MMAs ipsilateral to CSDHs, on the contralateral side, and in controls. Comparison was also made with angiographic measurements from CSDH embolization procedures. Seventy-five patients with CSDH with available CTAs prior to embolization were enrolled and 146 MMAs were measured. One hundred fifty controls were included and 288 MMAs were measured. The median diameter of the 94 MMAs ipsilateral to a CSDH (1.5 mm; interquartile range [IQR] 1.3-1.7) was significantly larger than that of control MMAs (1.28 mm; IQR 1.15-1.4) (p < 0.001). The median diameter of 52 MMAs on the side of a unilateral CSDH (1.6 mm; IQR 1.4-1.8) was larger than that of the 52 contralateral MMAs (1.4 mm; IQR 1.25-1.6) (p < 0.001). Among the characteristics of patients with CSDH, multiple surgeries were associated with significantly larger MMAs (>1.7 mm; p = 0.01). MMAs ipsilateral to CSDHs appear to be significantly larger as compared with contralateral MMAs and MMAs in a control population, suggesting the involvement of the MMA in the pathophysiology of CSDH.

Analysis of Brain Natriuretic Peptide Serum Levels in Patients with Symptomatic Chronic Subdural Hematoma: A Potential Reliable Biomarker

The purpose of this study was to analyze brain natriuretic peptide (BNP) serum levels of patients with chronic subdural hematoma (cSDH) and their clinical implication. Patients with cSDH who underwent surgery in our department between November 2016 and October 2019 were eligible for enrollment in the study. Patients with recurrent bleedings, traumatic brain injury, cSDH associated with other intracranial pathologies, and those with a history of congestive heart failure, renal or endocrine disease were excluded. We measured BNP serum levels pre- and post-operatively and at discharge. The BNP values were analyzed with respect to patient medical history and neurological condition. The Glasgow Coma Scale score and the modified Rankin Scale score classified the clinical and neurological condition at the time of admission and discharge, respectively. The data of 100 surgically treated patients with cSDH (mean age 73.2, range 42 − 94 years, male/female 3.5:1) were analyzed. Pre-operative BNP serum levels (BNP-1) were elevated in 67% of the patients (n = 67; median = 101.6 pg/mL; p < 0.001). These serum levels increased after surgery (p < 0.001) and decreased thereafter (p < 0.001), reaching a level at discharge (day 7) that was not statistically different from BNP-1 (p > 0.05). In addition, elevated BNP-1 showed a significant statistical association with the presence of atrial fibrillation (p < 0.01) and antiplatelet and/or anticoagulant therapy (p < 0.01). This study provides new evidence regarding BNP serum levels and their secretion pattern in patients with cSDH. Whether BNP-1 can predict the long-term functional outcome of patients with cSDH is being investigated in this ongoing prospective study.

Risk factors for the development of chronic subdural hematoma in patients with subdural hygroma

OBJECTIVE

Patients with subdural hygroma (SDG) are at increased risk of developing chronic subdural hematoma (CSDH). However, the factors that increase the risk of conversion are not fully understood. This study was to assess the risk factors of SDG conversion to CSDH.

METHODS

We reviewed the literature and retrospectively studied a series of cases in which CSDH was preceded by SDG to understand the natural history. We reviewed 45 cases of SDG from our hospital between 2015 and 2018. The cases were divided into two groups according to whether SDG converted into CSDH. Data were collected clinical presentation, imaging findings et al. Univariate and multivariate logistic regression analyses were performed to identify factors associated with SDG conversion.

RESULTS

Univariate analysis showed that the SDG thickness (p = .009), SDG location (p = .026), and bilateral SDG (p = .042) were significantly associated with CSDH development. Multivariate analysis revealed that SDG thickness (odds ratio, 1.6; 95% confidence interval, 1.111-2.324; p = .012) and bilateral SDG (odds ratio, 27.6; 95% confidence interval 2.889-263.548; p = .004) were independent risk factors for SDG development. Receiver operating characteristic curve analysis revealed that SDG thickness was a significant variable for predicting SDG development. A thickness >11.37 mm was an appropriate cutoff value, and the possibility of SDG conversion had a sensitivity 50.0% and specificity of 87.0%.

CONCLUSIONS

Bilateral SDG and SDG thickness were independent risk factors for SDG progression into CSDH. An SDG thickness >11.37 mm had a high risk of SDG conversion.

Causes and Trauma Apportionment Score of Chronic Subdural Hematoma

Objective

The pathophysiology of chronic subdural hematoma (CSH) is not yet clear. Trauma alone is not sufficient to result in CSH in young individuals, while a trivial injury can result in CSH in older adults. Although the causality and apportionment of trauma are important issues in CSH, especially in terms of insurance, it is too obscure to solve all struggles.

Methods

There are three key factors for producing CSH. First, CSH necessitates a potential subdural reservoir. Other important precipitating factors are trauma and coagulopathy. However, these factors are not sufficient to cause CSH development. The trauma apportionment score (TAS) can be used to compare the relative importance of these three factors. Here, we applied the TAS to 239 consecutive cases of CSH. We retrospectively obtained the patients' history and laboratory results from their medical records.

Results

The TAS ranged from −5 to 5. The most common score was 0. If we defined the cause of CSH as being combined when the TAS was 0, then the cause was combined in 30 cases (12.6%). If we extended the criteria for a combined cause from 0 to −1 to 1, the cause was combined in 107 cases (44.8%). Regardless of the criteria used, traumatic CSHs were more common than were spontaneous CSHs. Spontaneous CSHs were more common in older than in younger patients (p<0.01, Fisher's exact test).

Conclusion

The TAS is a useful tool for differentiating the causality of CSH.

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.

Do Age and Anticoagulants Affect the Natural History of Acute Subdural Hematomas?

Acute subdural hematoma is a serious complication following traumatic brain injury. Large volume hematomas or those with underlying brain injury can cause mass effect, midline shift, and eventually herniation of the brain. Acute subdural hematomas in the young are associated with high-energy trauma and often have underlying contusions, while acute subdural hematomas in the elderly are associated with minor trauma and an absence of underlying contusions, even though the elderly are more likely to be on anticoagulants or anti-platelet therapy. In the young patients with high impact injuries the hematomas tend to be small and the underlying brain injury and swelling is responsible for the increased intracranial pressure and midline shift. In the elderly, the injuries are low impact (e.g fall from standing), the underlying brain is intact, and the volume of the hematoma itself produces symptoms. In addition the use of anticoagulants and antiplatelet agents in the elderly population has been thought to be a poor prognostic indicator and is considered to be responsible for larger hematomas and poor outcome. When managed conservatively, acute subdural hematomas can sometimes progress to chronic subdural hematoma formation, further enlargement, seizures, and progressive midline shift. Another potential difference in the young and the elderly is brain atrophy, which increases the potential space to accommodate a larger hematoma. It is not known if these two groups differ in other ways that might have implications for treatment or prognosis. In this paper, we investigate the clinical course of 80 patients admitted to our institution with acute subdural hematomas, to identify differences in patients above or below the age of 65 years. The natural progression/resolution of acute subdural hematomas was mapped by measuring volume expansion/regression over time. In this retrospective chart review, we investigated clinical baseline metrics and subsequent volumetric expansion outcomes between patients < 65 years old (N=44) and those > 65 years old (N=36). Volume was estimated by the ABC/2 method. We observed a statistically significant difference between groups in use of anticoagulants χ² =40.305 with p < 0.001, corrective platelet administration χ² =19.380 with p < 0.001, gender χ² =14.573 with p < 0.001, and Glasgow Coma Scale with χ² =23.125 (p=0.026). Overall outcomes were similar in the two groups. Younger patients on average had worse presenting GCS scores, but recovered comparable to older patients. No significant difference in rate of volume expansion, resolution time, or need for surgical treatment was seen between these two groups. We conclude that the initial volume, size, and severity of subdural hematoma determined by the Glasgow Coma Scale score is more likely to predict surgery or future expansion than age of the patient. Patients on oral anti-coagulants that are given appropriate medical reversal agents early do quite well and no impact on the eventual outcome could be demonstrated. Further work is needed to establish better predictors of future volume expansion, and progression to chronic subdural hematoma based on improved severity scales.

Histopathological study of the outer membrane of the dura mater in chronic sub dural hematoma: Its clinical and radiological correlation

Background:

A chronic subdural hematoma is an old clot of blood on the surface of the brain between dura and arachnoid membranes. These liquefied clots most often occur in patients aged 60 and older with brain atrophy. When the brain shrinks inside the skull over time, minor head trauma can cause tearing of blood vessels over the brain surface, resulting in a slow accumulation of blood over several days to weeks.

Aim of the Study:

To evaluate the role of membrane in hematoma evaluation and to correlate its histopathology with clinic-radiological aspects of the condition and overall prognosis of patients.

Material and Methods:

The study incorporated all cases of chronic SDH admitted to the Neurosurgery department of JLN Hospital and Research Centre, Bhilai, between November 2011 and November 2013. All such cases were analyzed clinically, radiologically like site, size, thickness in computed tomography, the attenuation value, midline shift and histopathological features were recorded.

Criteria for Inclusion:

All cases of chronic subdural haematoma irrespective of age and sex were incorporated into the study.

Criteria for Exclusion:

All cases of acute subdural haematoma and cases of chronic sub dural hematoma which were managed conservatively irrespective of age and sex were excluded from the study

Results:

In our series of cases, the most common histopathological type of membrane was the inflammatory membrane (Type II) seen in 42.30% of cases followed by hemorrhagic inflammatory membrane (Type III) seen in 34.62% of cases while scar inflammatory type of membrane (Type IV) was seen in 23.08% of cases. No case with noninflammatory type (Type I) was encountered.

Extended Pneumocephalus after Drainage of Chronic Subdural Hematoma Associated with Intracranial Hypotension : Case Report with Pathophysiologic Consideration

Chronic subdural hematoma (SDH) is a well-known disease entity and is traditionally managed with surgery. However, when associated with spontaneous intracranial hypotension (SIH), the treatment strategy ought to be modified, as classical treatment could lead to unwanted consequences. A 59-year-old man presented with a case of SIH that manifested as a bilateral chronic SDH. He developed fatal extensive pneumocephalus and SDH re-accumulation as a complication of burr-hole drainage. Despite application of an epidural blood patch, the spinal cerebrospinal fluid leak continued, which required open spinal surgery. Chronic SDH management should not be overlooked, especially if the exact cause has not been determined. When chronic SDH assumed to be associated with SIH, the neurosurgeon should determine the exact cause of SIH in order to effectively correct the cause.

Chronic Subdural Hematoma in the Aged, Trauma or Degeneration?

Chronic subdural hematomas (CSHs) are generally regarded to be a traumatic lesion. It was regarded as a stroke in 17th century, an inflammatory disease in 19th century. From 20th century, it became a traumatic lesion. CSH frequently occur after a trauma, however, it cannot occur when there is no enough subdural space even after a severe head injury. CSH may occur without trauma, when there is sufficient subdural space. The author tried to investigate trends in the causation of CSH. By a review of literature, the author suggested a different view on the causation of CSH. CSH usually originated from either a subdural hygroma or an acute subdural hematoma. Development of CSH starts from the separation of the dural border cell (DBC) layer, which induces proliferation of DBCs with production of neomembrane. Capillaries will follow along the neomembrane. Hemorrhage would occur into the subdural fluid either by tearing of bridge veins or repeated microhemorrhage from the neomembrane. That is the mechanism of hematoma enlargement. Trauma or bleeding tendency may precipitate development of CSH, however, it cannot lead CSH, if there is no sufficient subdural space. The key determinant for development of CSH is a sufficient subdural space, in other words, brain atrophy. The most common and universal cause of brain atrophy is the aging. Modifying Virchow's description, CSH is sometimes traumatic, but most often caused by degeneration of the brain. Now, it is reasonable that degeneration of brain might play pivotal role in development of CSH in the aged persons.

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

Background

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

Methods/Design

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

Discussion

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

Trial registration

ClinicalTrials.gov Identifier – NCT02024373

The date of trial registration: 7 August 2013

Electronic supplementary material

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

Nonsurgical acute traumatic subdural hematoma: what is the risk?

OBJECT

The Brain Trauma Foundation has published guidelines on the surgical management of traumatic subdural hematoma (SDH). However, no data exist on the proportion of patients with SDH that can be selected for conservative management and what is the outcome of these patients. The goals of this study were as follows: 1) to establish what proportion of patients are initially treated conservatively; 2) to determine what proportion of patients will deteriorate and require surgical evacuation; and 3) to identify risk factors associated with deterioration and delayed surgery.

METHODS

All cases of acute traumatic SDH (869 when inclusion criteria were met) presenting over a 4-year period were reviewed. For all conservatively treated SDH, the proportion of delayed surgical intervention and the Glasgow Outcome Scale score were taken as outcome measures. Multiple factors were compared between patients who required delayed surgery and patients without surgery.

RESULTS

Of the 869 patients with acute traumatic SDH, 646 (74.3%) were initially treated conservatively. A good outcome was achieved in 76.7% of the patients. Only 6.5% eventually required delayed surgery, and the median delay for surgery was 9.5 days. Factors associated with deterioration were as follows: 1) thicker SDH (p < 0.001); 2) greater midline shift (p < 0.001); 3) location at the convexity (p = 0.001); 4) alcohol abuse (p = 0.0260); and 5) history of falls (p = 0.018). There was no significant difference in regard to age, sex, Glasgow Coma Scale score, Injury Severity Score, abnormal coagulation, use of blood thinners, and presence of cerebral atrophy or white matter disease.

CONCLUSIONS

The majority of patients with SDH are treated conservatively. Of those, only 6.5% later required surgery, for raised intracranial pressure or SDH progression. Patients at risk can be identified and followed more carefully.

Chronic subdural hematoma: Surgical management and outcome in 986 cases: A classification and regression tree approach

BACKGROUND

Chronic subdural hematoma (CSDH) is one of the most common clinical entities in daily neurosurgical practice which carries a most favorable prognosis. However, because of the advanced age and medical problems of patients, surgical therapy is frequently associated with various complications. This study evaluated the clinical features, radiological findings, and neurological outcome in a large series of patients with CSDH.

METHODS

A classification and regression tree (CART) technique was employed in the analysis of data from 986 patients who were operated at Asclepeion General Hospital of Athens from January 1986 to December 2011. Burr holes evacuation with closed system drainage has been the operative technique of first choice at our institution for 29 consecutive years. A total of 27 prognostic factors were examined to predict the outcome at 3-month postoperatively.

RESULTS

Our results indicated that neurological status on admission was the best predictor of outcome. With regard to the other data, age, brain atrophy, thickness and density of hematoma, subdural accumulation of air, and antiplatelet and anticoagulant therapy were found to correlate significantly with prognosis. The overall cross-validated predictive accuracy of CART model was 85.34%, with a cross-validated relative error of 0.326.

CONCLUSIONS

Methodologically, CART technique is quite different from the more commonly used methods, with the primary benefit of illustrating the important prognostic variables as related to outcome. Since, the ideal therapy for the treatment of CSDH is still under debate, this technique may prove useful in developing new therapeutic strategies and approaches for patients with CSDH.

Subdural hygromas in abusive head trauma: pathogenesis, diagnosis, and forensic implications

Are subdural hygromas the result of abusive head trauma? CT and MR imaging represent important tools for the diagnosis of abusive head trauma in living infants. In addition, in-depth understanding of the pathogenesis of subdural hygromas is increasingly required by neuroradiologists, pediatricians, and forensic physicians. Therefore, the current knowledge on subdural hygromas is summarized and forensic conclusions are drawn. The most important diagnostic pitfalls, benign enlargement of the subarachnoid space, and chronic subdural hematoma, are discussed in detail. Illustrative cases from forensic practice are presented. Literature analysis indicates that subdural hygromas can occur immediately or be delayed. If other infrequent reasons can be excluded, the presence of subdural hygromas strongly suggests a posttraumatic state and should prompt the physician to search for other signs of abuse. To differentiate subdural hygromas from other pathologies, additional MR imaging of the infant's head is indispensable after initial CT scan.

Prediction of Chronic Subdural Hematoma in Minor Head Trauma Patients

OBJECTIVE

Chronic subdural hematoma (CSDH) is relatively common in neurosurgical field. However not all patients develop CSDH after minor head trauma. In this study, we evaluate the risk factors of post-traumatic CSDH.

METHODS

Two-hundred and seventy-seven patients were enrolled and analyzed in this study from January 2012 to December 2013. Of those, 20 participants had minor head trauma developed CSDH afterward. We also included 257 patients with minor head trauma who did not develop CSDH during the same follow-up period as the control group. We investigated the risk factors related to the development of CSDH after minor head trauma.

RESULTS

Old age (p=0.014), preexisting diabetes mellitus (p=0.010), hypertension (p=0.026), history of cerebral infarction (p=0.035), antiplatelet agents (p=0.000), acute subdural hematoma in the convexity (p=0.000), encephalomalacia (p=0.029), and long distance between skull and brain parenchyma (p=0.000) were significantly correlated with the development of CSDH after trauma. Multivariate analysis revealed that only the maximum distance between the skull and the cerebral parenchyma was the independent risk factor for the occurrence of CSDH (hazard ratio 2.55, p=0.000).

CONCLUSION

We should consider the possibility of developing CSDH in the post-traumatic patients with the identified risk factors.

A single center's experience with the bedside subdural evacuating port system: a useful alternative to traditional methods for chronic subdural hematoma evacuation

Object

The traditional methods for managing symptomatic chronic subdural hematoma (SDH) include evacuation via a bur hole or craniotomy, both with or without drain placement. Because chronic SDH frequently occurs in elderly patients with multiple comorbidities, the bedside approach afforded by the subdural evacuating port system (SEPS) is an attractive alternative method that is performed under local anesthesia and conscious sedation. The goal of this study was to evaluate the radiographic and clinical outcomes of SEPS as compared with traditional methods.

Methods

A prospectively maintained database of 23 chronic SDHs treated by bur hole or craniotomy and of 23 chronic SDHs treated by SEPS drainage at Tufts Medical Center was compiled, and a retrospective chart review was performed. Information regarding demographics, comorbidities, presenting symptoms, and outcome was collected. The volume of SDH before and after treatment was semiautomatically measured using imaging software.

Results

There was no significant difference in initial SDH volume (94.5 cm3 vs 112.6 cm3, respectively; p = 0.25) or final SDH volume (31.9 cm3 vs 28.2 cm3, respectively; p = 0.65) between SEPS drainage and traditional methods. In addition, there was no difference in mortality (4.3% vs 9.1%, respectively; p = 0.61), length of stay (11 days vs 9.1 days, respectively; p = 0.48), or stability of subdural evacuation (94.1% vs 83.3%, respectively; p = 0.60) for the SEPS and traditional groups at an average follow-up of 12 and 15 weeks, respectively. Only 2 of 23 SDHs treated by SEPS required further treatment by bur hole or craniotomy due to inadequate evacuation of subdural blood.

Conclusions

The SEPS is a safe and effective alternative to traditional methods of evacuation of chronic SDHs and should be considered in patients presenting with a symptomatic chronic SDH.

Volume and densities of chronic subdural haematoma obtained from CT imaging as predictors of postoperative recurrence: a prospective study of 107 operated patients

Background

Chronic subdural haematoma (CSDH) is a common entity in neurosurgery with a considerable postoperative recurrence rate. Computerised tomography (CT) scanning remains the most important diagnostic test for this disorder. The aim of this study was to characterise the relationship between the recurrence of CSDH after treatment with burr-hole irrigation and closed-system drainage technique and CT scan features of these lesions to assess whether CT findings can be used to predict recurrence.

Methods

We investigated preoperative and postoperative CT scan features and recurrence rate of 107 consecutive adult surgical cases of CSDH and assessed any relationship with univariate and multivariate regression analyses.

Results

Seventeen patients (15.9 %) experienced recurrence of CSDH. The preoperative haematoma volume, the isodense, hyperdense, laminar and separated CT densities and the residual total haematoma cavity volume on the 1st postoperative day after removal of the drainage were identified as radiological predictors of recurrence. If the preoperative haematoma volume was under 115 ml and the residual total haematoma cavity volume postoperatively was under 80 ml, the probability of no recurrence was very high (94.4 % and 97.4 % respectively).

Conclusions

These findings from CT imaging may help to identify patients at risk for postoperative recurrence.

Spontaneous chronic subdural hematoma in a 22-year-old healthy woman

BACKGROUND

Chronic subdural hematoma is a common presentation to the neurosurgical practice that tends to occur among the elderly.

METHODS

We identify a rare occurrence of a chronic subdural hematoma in a young and otherwise healthy female patient who denied a traumatic brain injury.

RESULTS

Upon reviewing the literature, we found only one reported case of a spontaneous nature in a young patient. The subtle presentation of headaches and absence of neurological deficit could be mistaken as migraine and result in a delay in obtaining imaging and necessary treatment. In this report, we present a 22-year-old patient who complained of persistent headaches and was neurologically intact on examination. Cranial computed tomography revealed the presence of a right-sided chronic subdural hematoma; this was followed by magnetic resonance imaging plus angiogram, which ruled out the presence of a vascular abnormality. A burr-hole craniostomy procedure was used that resulted in resolution of symptoms.

CONCLUSION

Without a heightened clinical suspicion, a similar presentation could be missed, resulting in delayed management.

Diplopia from subacute bilateral subdural hematoma after spinal anesthesia

Subdural hematoma (SDH) is a rare, but life-threatening complication of spinal anesthesia. Subdural hematoma resulting from this procedure could present with vague symptoms such as chronic headache and could easily be missed. Chronic headache is one of the symptoms of chronic SDH in postpartum women. Diplopia as the presenting complaint in SDH secondary to peripartum spinal anesthesia has not, to our knowledge, been previously reported. Here, we report a case of diplopia secondary to postpartum subacute bilateral SDHs with transtentorial herniation after spinal anesthesia in a healthy primagravid 25-year-old woman. SDH can expand gradually and the initial symptoms might be subtle as in our case, despite critically high intracranial pressure.

Quantitative assessment of impaired postevacuation brain re-expansion in bilateral chronic subdural haematoma: possible mechanism of the higher recurrence rate

INTRODUCTION

Recurrence of chronic subdural haematoma (CSDH) occurs in up to 30% of patients. The rate of recurrence is higher in bilateral versus unilateral CSDH and the reason for this has not been fully elucidated. There are few quantitative studies of temporal changes in brain re-expansion after haematoma evacuation. The aim of this study is to use a simple volumetric image analysis method to quantify temporal changes of postoperative brain re-expansion in unilateral and bilateral CSDH.

METHODS

We reviewed computed tomography (CT) scans of 20 consecutive patients (16 men, 4 women; median age, 73.5 years) with CSDH (unilateral, n=10; bilateral, n=10) who underwent surgery (burr hole drainage on one or both sides) at our institutions during the period from June 2006 to August 2008. Haematoma volume was quantified preoperatively and on postoperative days 14 and 30 by computer-based image analysis (PACS Web 1000 System) of CT scans. We then calculated the brain re-expansion rate (BRR) for postoperative days 14 and 30.

RESULTS

Haematoma volume remained significantly higher (p<0.001) in bilateral versus unilateral CSDHs at both postoperative time points, and the BRR was significantly greater (p<0.001) in unilateral versus bilateral CSDH at both time points.

CONCLUSION

Results of this quantitative analysis provide definitive evidence for a poor BRR in bilateral compared to unilateral CSDH. This impairment may result in shifting of the brain and shearing of blood vessels, resulting in a higher recurrence rate.

A preliminary study of aquaporin 1 immunolocalization in chronic subdural hematoma membranes

Aquaporin 1 (AQP1) is a molecular water channel expressed in many anatomical locations, particularly in epithelial barriers specialized in water transport. The aim of this study was to investigate AQP1 expression in chronic subdural hematoma (CSDH) membranes. In this preliminary study, 11 patients with CSDH underwent burr hole craniectomy and drainage. Membrane specimens were stained with a monoclonal antibody targeting AQP1 for immunohistochemical analysis. The endothelial cells of the sinusoid capillaries of the outer membranes exhibited an elevated immunoreactivity to AQP1 antibody compared to the staining intensity of specimens from the inner membrane and normal dura. These findings suggest that the outer membrane might be the source of the increased fluid accumulation responsible for chronic hematoma enlargement.

Traumatic subdural hydroma: clinical characteristics and classification

BACKGROUND

Traumatic subdural hydroma (TSH) is a common complication of head injuries. The aim of this study was to examine the clinical characteristics and classification of TSH.

METHODS

One hundred and ninety-two patients with TSH were treated in Qilu hospital during a 13-year period (1989-2001). We reviewed each patient's clinical records and radiological findings.

RESULTS

Based on clinical features and dynamic observation of CT scanning, TSHs were classified into four types: resolution, steadiness, development and evolution. The resolution type often occurred in the prime of life, and the patients had normal intracranial pressure and good prognoses after conservative treatment. The elderly made up the majority of the steadiness type. Their main clinical manifestations included headaches, dizziness, nausea, vomiting, abnormal mentality, etc. Generally, no positive nervous systemic sign related to TSH was observed. The prognoses of the steadiness type treated by conservative therapy were also satisfactory. The development type was common in babies and children and mainly manifested as progressively increasing intracranial pressure, mild hemiplegia, aphasia and abnormal mentality. The patients with development type often needed surgical treatment where there was an associated risk of dying from accompanying cerebral parenchymal damage or postoperative complications once in a while. The evolution type with chronic subdural haematoma occurred between 22 and 100 days after TSH and in the cases of small hydromas treated conservatively, with mild accompanying cerebral damage, characterised by the polarised age, and chronic increased intracranial pressure, there was always a good prognosis after surgery.

CONCLUSIONS

The mechanism, clinical characteristics, treatment methods and prognoses varied with the different types of TSH.

ReviewNatural history of chronic subdural haematoma

This review will clarify the natural history of chronic subdural haematoma (SDH). Chronic SDH has dual origins, one from subdural hygromas (SDG) and the other from acute SDHs. It occurs only in patients with a suitable pre-morbid condition, i.e. sufficient potential subdural space (PSS). In unresolved SDGs, proliferation of dural border cells produces the neomembrane. Unresolved SDGs become chronic SDHs by repeated micro-haemorrhages from fragile new vessels, which were grown into the neomembrane. When PSS is sufficient, acute SDHs may become chronic SDHs. Chronic SDHs enlarge when rebleeding exceeds absorption and they become symptomatic. When the neomembrane is matured, the neocapillary is no longer fragile. If absorption exceeds rebleeding, the haematoma will disappear. Maturation of the neomembrane and stabilization of the neovasculature eventually result in spontaneous resolution. The fate of chronic SDH depends on the pre-morbid status, the dynamics of absorption-expansion and maturation of the neomembrane.

Inflicted traumatic brain injury in infants and young children

This article will discuss the subject of inflicted or abusive head injury in infants and young children. Inflicted neurotrauma is a very common injury and a frequent problem in attempting to distinguish between inflicted and accidental injury. Inflicted head injury occurs usually in the home in the presence of the individual who has inflicted the injury outside the view of unbiased witnesses. Distinguishing between inflicted and accidental injury may be dependent upon the pathological findings and consideration of the circumstances surrounding the injury. The most common finding in an inflicted head injury is the presence of subdural hemorrhage. Subdural hemorrhage may occur in a variety of distributions and appearances. The natural history of subdural bleeding and the anatomy of the "subdural" will be considered. The anatomy of the dura and its attachment to the skull and to the arachnoid determines how subdural bleeding evolves into the cleaved dural border cell layer and as well as how bridging veins are torn and anatomically where bleeding will occur. Different biomechanical mechanisms result in different distributions of subdural blood and these differences will be discussed.

Traumatic subdural hygroma: five cases with changed density and spontaneous resolution

Thirty-four consecutive adult patients with subdural traumatic hygroma were analysed for clinical evolution, serial computed tomography scan (CT), and magnetic resonance imaging (MRI) over a period of several months. Five of the patients presented CT scan and MRI evolution data showing increasing density over a period of 11 days to 6 months post trauma. In these five patients, final clinical and CT scan data were benign, with complete spontaneous resolution. Descriptions in literature of evolving traumatic subdural hygroma have presented CT scan density modifications changing into chronic subdural hematoma. Our patients show another possibility, density transformation, which sometimes show as subdural hematoma in CT scan and MRI, but with final evolution where clinical condition and CT scan return to normal.

Persistent postpartum headache from a chronic subdural hematoma after peridural anesthesia

BACKGROUND

Postpartum headache after peridural anesthesia is usually attributed to accidental perforation of the dura causing postlumbar puncture headache.

CASE

In a patient with persistent headache after peridural anesthesia for labor, a chronic subdural hematoma was diagnosed 5 weeks postpartum.

CONCLUSION

Caution is warranted in patients with peridural anesthesia for labor who present with unusually persistent headache.

Diagnostic method for differentiating external hydrocephalus from simple subdural hygroma

Object

The various terms used to describe subdural fluid collection—“external hydrocephalus,” “subdural hygroma,” “subdural effusion,” “benign subdural collection,” and “extraventricular obstructive hydrocephalus”—reflect the confusion surrounding the diagnoses of these diseases. Differentiating external hydrocephalus from simple subdural hygroma may be difficult, but the former appears to be a distinct clinical entity separate from the latter. In this report, the authors present a diagnostic method for differentiating external hydrocephalus from simple subdural hygroma, based on their clinical experience in treating subdural fluid collection after mild head trauma.

Methods

Twenty patients with subdural fluid collection after mild head trauma were included in this study. Ventricle size was measured using a modified frontal horn index (mFHI); that is, the largest width of the frontal horns divided by the bicortical distance in the same plane, instead of the inner table distance. Bur hole trephination was performed on the appearance of a subdural fluid collection thicker than 15 mm on computed tomography (CT), persistent (longer than 4 weeks) or increasing in size, and accompanied by neurological symptoms (confusion or memory impairment). During the procedure, subdural pressure was measured using a manometer before opening the dura mater. Subdural pressure varied among the patients, ranging from 3 to 27.5 cm H2O. Four patients with a subdural pressure greater than 15 cm H2O had hydrocephalus after surgery (p < 0.05). Hydrocephalus developed in a pediatric patient (2 years old) with a subdural pressure of 12 cm H2O. All of the patients in whom hydrocephalus developed after bur hole trephination had had enlarged ventricles (mFHI > 33%) on preoperative CT scans.

Conclusions

Monitoring subdural pressure may be a valuable tool for differentiating subdural hygroma from external hydrocephalus in patients with mild head trauma. Additionally, the mFHI reflects the nature of the subdural collection more accurately than the standard frontal horn index.

Progressive spontaneous unilateral enlargement of the breast twenty-two years after prosthetic breast augmentation

Late spontaneous enlargement of the breast is a rare complication after prosthetic breast augmentation. It has been intermittently described in the literature over the last 24 years but its exact aetiology remains unknown. Several possible aetiologies have been proposed. We present a case of a 46-year-old female who developed spontaneous asymmetrical breast enlargement 22 years post-bilateral breast augmentation without any known precipitating factors. Radiographic imaging revealed a periprosthetic collection occupying 70% of the volume inside the capsule. Initial recommendations for capsulectomy and removal of the breast implant were delayed for a year by the patient who subsequently represented with ongoing enlargement of the affected breast. Pathological findings revealed an intact silicone implant surrounded by laminated blood clot, similar in appearance to a chronic subdural haematoma. The literature is reviewed and the possible pathophysiological mechanisms of this unusual condition discussed.

Shaken baby syndrome

Shaken baby syndrome is the most common cause of death or serious neurological injury resulting from child abuse. It is specific to infancy, when children have unique anatomic features. Subdural and retinal haemorrhages are markers of shaking injury. An American radiologist, John Caffey, coined the name whiplash shaken infant syndrome in 1974. It was, however, a British neurosurgeon, Guthkelch who first described shaking as the cause of subdural haemorrhage in infants. Impact was later thought to play a major part in the causation of brain damage. Recently improved neuropathology and imaging techniques have established the cause of brain injury as hypoxic ischaemic encephalopathy. Diffusion weighted magnetic resonance imaging is the most sensitive and specific method of confirming a shaking injury. Families of children with subdural haemorrhages should be thoroughly investigated by social welfare agencies.

Intracranial hemorrhage and rebleeding in suspected victims of abusive head trauma: addressing the forensic controversies

Does an expanded subarachnoid space predispose to subdural bleeding? What does heterogeneity in the appearance of a subdural collection on CT or MRI imaging indicate? Spontaneous rebleeding? Minor re-injury? Major re-injury? In some specific cases, answers to these questions have important forensic implications. To conclude objectively that an infant's intracranial hemorrhage or rebleeding resulted from inflicted injury or re-injury requires an in-depth understanding of the pathogenesis of posttraumatic subdural and subarachnoid collections. The authors present two cases of indoor, accidental, pediatric, closed-head trauma that resulted in intracranial rebleeding. Both accidental cranial impacts occurred in medical settings and were independently witnessed by medical personnel. In addition, the authors summarize the relevant medical literature regarding pediatric intracranial bleeding and rebleeding.

Surgical treatment of chronic subdural hematoma in 500 consecutive cases: clinical characteristics, surgical outcome, complications, and recurrence rate

Chronic subdural hematoma (CSDH) is one of the most common clinical entities in daily neurosurgical practice. The diagnosis and treatment are well established, but recurrence, complications, and factors related to these problems, especially in the elderly, are not completely understood. This study evaluated the clinical features, radiological findings, and surgical results in a large series of the patients treated at the same institution. 500 consecutive patients (359 men and 141 women) with CSDH were treated by burr hole craniostomy with closed system drainage from January 1987 through February 1999. Causes, clinical and computed tomographic findings, surgical results, re-expansion of brain after surgery, and hematoma recurrence were statistically analyzed to elucidate the potential risks of CSDH. Most patients (89.4%) had good recovery, 8.4% showed no change, and 2.2% worsened. Six patients (1.2%) died, three due to disseminated intravascular coagulation. Recurrence of hematoma was recognized in 49 patients (9.8%), at 1 to 8 weeks (3.5 +/- 1.9 weeks) after the first operation. The brain re-expansion rate at one week after operation was 45.0 +/- 21.4% in patients with hematoma recurrence and significantly lower than 55.3 +/- 19.1% in patients without recurrence (p < 0.001). Old age, pre-existing cerebral infarction, and persistence of subdural air after surgery were significantly correlated with poor brain re-expansion (p < 0.001). Twenty-seven patients (5.4%) suffered postoperative complications, of which 13 cases were acute subdural hematoma caused by incomplete hemostasis of the scalp wound and four cases were tension pneumocephalus. Careful hemostasis and complete replacement of subdural hematoma by normal saline to prevent influx of air into the subdural space will further improve the surgical outcome for patients with CSDH.