Spinal cerebrospinal fluid leak as the cause of chronic subdural hematomas in nongeriatric patients

Chronic subdural hematoma: What precisely are we treating?

Subdural hematoma (SDH) refers to the collection of blood between the dura matter and the arachnoid membrane. Advancements in imaging technology have enabled the categorization of SDH based on specific imaging characteristics, causative factors, and the onset of symptoms. Given that the prognosis of SDHs varies significantly and is contingent upon the size and chronicity of the hemorrhage, a comprehensive understanding of its subtypes may carry crucial treatment implications. For example, an acute SDH classically results from severe traumatic brain injury and appears as a homogenous, crescent-shaped hyperdense extra-axial collection. If not treated, over the course of 1-3 weeks, this hematoma will evolve into a sub-acute phenotype as a consequence of subdural effusion and demonstrate mixed-density hemorrhage on imaging. Chronic SDH (cSDH) becomes the end result of an untreated SDH, with neo-membranization and neo-angiogenesis from branches of the middle meningeal artery driving a mass-like growth pattern. This review article aims to elucidate the complex anatomical features of the end-stage cSDH, with a particular focus on reconceptualization of this entity based on its mass-like growth patterns, and how this is driving a shift towards endovascular treatment.

Spontaneous intracranial hypotension - a spinal disease

Spontaneous intracranial hypotension (SIH) remains an underdiagnosed condition despite increasing awareness due to recent scientific advances. Diagnosis can be delayed by the broad clinical presentation and imaging pitfalls. This results in a high degree of physical impairment for patients, including social and psychological sequelae as well as long-term damage in the case of delayed diagnosis and treatment.The study is based on a selective literature search on PubMed including articles from 1990 to 2023 and the authors' clinical experience from working in a CSF center.SIH mostly affects middle-aged women, with the primary symptom being position-dependent orthostatic headache. In addition, there is a broad spectrum of possible symptoms that can overlap with other clinical conditions and therefore complicate the diagnosis. The causative spinal CSF loss can be divided into three main types: ventral (type 1) or lateral (type 2) dural leak and CSF-venous fistula (type 3). The diagnosis can be made using a two-stage workup. As a first step, noninvasive MRI of the head and spine provides indicators of the presence of SIH. The second step using focused myelography can identify the exact location of the cerebrospinal fluid leak and enable targeted therapy (surgical or interventional). Intrathecal pressure measurement or intrathecal injection of gadolinium is no longer necessary for primary diagnosis. Serious complications in the course of the disease can include space-occupying subdural hematomas, superficial siderosis, and symptoms of brain sagging, which can lead to misinterpretations. Treatment consists of closing the dural leak or the cerebrospinal fluid fistula. Despite successful treatment, a relapse can occur, which highlights the importance of follow-up MRI examinations and emphasizes the chronic nature of the disease. This paper provides an overview of the diagnostic workup of patients with suspected SIH and new developments in imaging and therapy. · SIH is an underdiagnosed condition with a wide range of possible symptoms.. · The first diagnostic step using MRI provides indications of the presence of SIH.. · The second diagnostic step using (dynamic) myelography can identify the CSF leak.. · Collaboration with a CSF center is advisable for further diagnosis and treatment.. · Prompt detection and treatment of SIH improves the outcome.. · Zander C, Wolf K, El Rahal A et al. Spontaneous intracranial hypotension - a spinal disease. Fortschr Röntgenstr 2024; DOI 10.1055/a-2318-8994.

Non-invasive biomarkers for spontaneous intracranial hypotension (SIH) through phase-contrast MRI

BACKGROUND AND OBJECTIVE

Spontaneous intracranial hypotension (SIH) is an underdiagnosed disease. To depict the accurate diagnosis can be demanding; especially the detection of CSF-venous fistulas poses many challenges. Potential dynamic biomarkers have been identified through non-invasive phase-contrast MRI in a limited subset of SIH patients with evidence of spinal longitudinal extradural collection. This study aimed to explore these biomarkers related to spinal cord motion and CSF velocities in a broader SIH cohort.

METHODS

A retrospective, monocentric pooled-data analysis was conducted of patients suspected to suffer from SIH who underwent phase-contrast MRI for spinal cord and CSF velocity measurements at segment C2/C3 referred to a tertiary center between February 2022 and June 2023. Velocity ranges (mm/s), total displacement (mm), and further derivatives were assessed and compared to data from the database of 70 healthy controls.

RESULTS

In 117 patients, a leak was located (54% ventral leak, 20% lateral leak, 20% CSF-venous fistulas, 6% sacral leaks). SIH patients showed larger spinal cord and CSF velocities than healthy controls: e.g., velocity range 7.6 ± 3 mm/s vs. 5.6 ± 1.4 mm/s, 56 ± 21 mm/s vs. 42 ± 10 mm/s, p < 0.001, respectively. Patients with lateral leaks and CSF-venous fistulas exhibited an exceptionally heightened level of spinal cord motion (e.g., velocity range 8.4 ± 3.3 mm/s; 8.2 ± 3.1 mm/s vs. 5.6 ± 1.4 mm/s, p < 0.001, respectively).

CONCLUSION

Phase-contrast MRI might become a valuable tool for SIH diagnosis, especially in patients with CSF-venous fistulas without evidence of spinal extradural fluid collection.

Distinct Pattern of Membrane Formation With Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension

BACKGROUND AND OBJECTIVES

To systematically describe pertinent, intraoperative anatomic findings encountered when approaching spinal cerebrospinal fluid (CSF) leaks and CSF-venous fistulas in spontaneous intracranial hypotension (SIH).

METHODS

In a retrospective study, we included surgically treated patients suffering from SIH at our institution from April 2018 to March 2022. Anatomic, intraoperative data were extracted from operative notes and supplemented with data from surgical videos and images. Prominent anatomic features were compared among different types of CSF leaks.

RESULTS

The study cohort consists of 120 patients with a mean age of 45.2 years. We found four distinct patterns of spinal membranes specifically associated with different types of CSF leaks: (i) thick, dorsal membranes, which were hypervascular and may mimic the dura (pseudodura); (ii) thin, lateral membranes encapsulating a ventral epidural CSF compartment (confining the spinal longitudinal extradural CSF collection); (iii) ventral membranes constituting a transdural funnel-like CSF channel; and (iv) lateral membranes forming spinal cysts/meningeal diverticulae associated with lateral CSF leaks. The latter three types resemble a layer of arachnoid herniated through the dural defect.

CONCLUSION

We describe four distinct spinal (neo-)membranes in association with spinal CSF leaks. Formation of these membranes, or emergence by herniation of arachnoid through a dural defect, constitutes a specific pathoanatomic feature of patients with SIH and CSF leaks. Recognition of these membranes is of paramount importance for diagnosis and treatment of patients with spinal CSF leaks.

Patient-reported symptomatology and its course in spontaneous intracranial hypotension - Beware of a chameleon

OBJECTIVE

Although orthostatic headache is the hallmark symptom of spontaneous intracranial hypotension (SIH), patients can present with a wide range of different complaints and thereby pose a diagnostic challenge for clinicians. Our aim was to describe and group the different symptoms associated with SIH and their course over time.

METHODS

We retrospectively surveyed consecutive patients diagnosed and treated for SIH at our institution from January 2013 to May 2020 with a specifically designed questionnaire to find out about their symptomatology and its course.

RESULTS

Of 112 eligible patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 67 (84.8%) reported initial orthostatic headaches, whereas 12 (15.2%) denied having this initial symptom. All except one (98.7%) patients reported additional symptoms: most frequently cephalic pressure (69.6%), neck pain (68.4%), auditory disturbances (59.5%), nausea (57%), visual disturbances (40.5%), gait disturbance (20.3%), confusion (10.1%) or sensorimotor deficits (21.5%). Fifty-seven (72.2%) patients reported a development of the initial symptoms predominantly in the first three months after symptom onset. Age and sex were not associated with the symptomatology or its course (p > 0.1).

CONCLUSION

Although characteristic of SIH, a relevant amount of patients present without orthostatic headaches. In addition, SIH can manifest with non-orthostatic headaches at disease onset or during the course of the disease. Most patients report a wide range of associated complaints. A high degree of suspicion is crucial for an early diagnosis and targeted treatment.

Intraoperative Visualization of Flow in Direct Cerebrospinal Fluid-Venous Fistulas Using Intrathecal Fluorescein

BACKGROUND

Cerebrospinal fluid-venous fistulas (CVFs) are a rare cause of spontaneous intracranial hypotension. Intraoperatively, CVFs are not readily identifiable and difficult to differentiate from normal veins.

OBJECTIVE

To assess the utility of intrathecal fluorescein injection intraoperatively to visualize and identify the CVF.

METHODS

We report a case series of patients treated surgically for a CVF. After surgical exposure, we injected intrathecal fluorescein (5-10 mg) through a lumbar catheter, which we placed immediately before surgery.

RESULTS

Four patients with spontaneous intracranial hypotension with a suspected CVF underwent surgical ligation with adjunctive intrathecal fluorescein application. Intraoperative fluorescein injection confirmed the presence of a CVF in 3 cases. In 2 cases, we observed rapid fluorescein filling of a single epidural vein constituting the CVF. Other epidural vessels did not fill with fluorescein. In 1 case, fluorescein helped to identify a residual CVF after previous incomplete embolization. In the fourth case, no CVF was found intraoperatively. By contrast, a meningeal nerve root diverticulum was visualized, wrapped, and clipped.

CONCLUSION

We demonstrate for the first time the direct intraoperative visualization of CVF using intrathecal fluorescein. CVF can be identified intraoperatively using fluorescein dye, which can be a valuable adjunct for the surgeon confronted with this disease.

Postoperative hemorrhage after biomedical glue sling technique in microvascular decompression for vertebrobasilar artery-associated cranial nerve diseases: A retrospective study of 14 cases

Background

The biomedical glue sling technique is a convenient and effective method for vertebrobasilar artery-associated cranial nerve diseases but postoperative hemorrhage is poorly understood.

Methods

We retrospectively reviewed 14 of 1157 patients associated with cranial nerve diseases who were subjected to the biomedical glue sling technique in microvascular decompression at our hospital from January 2015 to January 2020.

Results

There were 14 patients with cranial nerve diseases included in this study. A clinical diagnosis of postoperative hemorrhage was made after an average of 41.75 h (ranging between 0.5 and 95 h). A cerebellopontine angle hemorrhage was presented in 5 patients, while basal ganglia hemorrhage was observed in 2 patients. Both a cerebellopontine angle and brainstem hemorrhage was seen in 1 patient. Distal supratentorial subdural hemorrhage was recorded in 6 patients. The correlation coefficient was -0.1601 (p = 0.7094) between the standard deviation of systolic blood pressure and the Hemphill Score, -0.2422 (p = 0.5633) between the coefficient of variation of systolic blood pressure and the Hemphill Score, and -0.0272 (p = 0.9489) between the range of systolic blood pressure and the Hemphill Score.

Conclusions

The incidence of postoperative hemorrhage after MVD with the biomedical glue sling technique is higher than with traditional MVD and most cases have a favorable prognosis. Postoperative symptoms are the main area of concern and changes in symptoms usually suggest the occurrence of hemorrhage. Several factors, including surgical procedures, the release of CSF, and blood pressure might be associated with hemorrhaging. We still believe such a technique is an efficient approach to treating complicated cranial nerve diseases.

The impact of spontaneous intracranial hypotension on social life and health-related quality of life

Objective

Spontaneous intracranial hypotension (SIH), which is often caused by a spinal cerebrospinal fluid leak, is an important cause of disabling headaches. Many patients report devastating changes in their quality of life because of their symptoms. This study aimed to evaluate the impact of SIH on patients’ social/ working life and health-related quality of life (HRQoL).

Methods

We included consecutive patients with proven SIH treated at our institution from January 2013 to May 2020. Patients were contacted and asked to complete the 15D questionnaire for the collection of HRQoL data and to provide additional information on their social life status.

Results

Of 112 patients, 79 (70.5%) returned the questionnaire and were included in the analysis. Of those, 69 were treated surgically (87.3%), and 10 were managed non-operatively (12.7%). Twenty-five (31.6%) patients reported a severe impact on their partnership, 32 (41.5%) reported a moderate or severe impact on their social life. Forty (54.8%) patients reported sick leave for more than 3 months. The mean 15D score was 0.890 (± 0.114) and significantly impaired compared to an age- and sex-matched general population (p = 0.001), despite treatment. Patients with residual SIH-symptoms (36, 45.6%) had significantly impaired HRQoL compared to those without any residual symptoms (41, 51.9%) (p < 0.001).

Conclusion

SIH had a notable impact on the patients’ social life and HRQoL. It caused long periods of incapacity for work, and is therefore, associated with high economic costs. Although all patients were appropriately treated, reduced HRQoL persisted after treatment, underlining the chronic character of this disease.

Case of extensive cerebrospinal fluid leak postlumbar puncture in a paediatric patient with idiopathic intracranial hypertension

Lumbar punctures are frequently used in the diagnostic evaluation of central nervous system diseases such as infections, administration of medications such as chemotherapy and for reduction in intracranial pressure in cases of idiopathic intracranial hypertension. Cerebrospinal fluid (CSF) leak through a dural tear can result in temporary side effects such as headache (postlumbar puncture headache) and backache. Rarely, more severe side effects may occur with neurological deficits if there is an extensive CSF collection or epidural haematoma. However, the majority of these lesions can be managed conservatively.

Spontaneous intracranial hypotension: the role of radiology in diagnosis and management

Spontaneous intracranial hypotension (SIH) is a condition that results from leakage of cerebrospinal fluid (CSF) from the spine, and which typically presents with debilitating orthostatic headache, but can be associated with a wide range of other symptoms. The causes of spontaneous CSF leaks that lead to SIH include dural tears, leaking meningeal diverticula, and CSF-venous fistulas. Imaging plays a central role in the initial diagnosis of SIH and in its subsequent investigation and management. This article reviews the typical neuroimaging manifestations of SIH and discusses the utility of different myelographic techniques for localising spinal CSF leaks as well as the role of image-guided treatment.

Incidence of Spinal CSF Leakage on CT Myelography in Patients with Nontraumatic Intracranial Subdural Hematoma

The aim of the present study was to demonstrate the incidence of spinal cerebrospinal fluid (CSF) leaks in patients with nontraumatic intracranial subdural hematoma (SDH) and determine clinical parameters favoring such leaks. This retrospective study was approved by the institutional review board. Patients diagnosed with nontraumatic intracranial SDH who underwent computed tomography (CT) myelography between January 2012 and March 2018 were selected. 60 patients (male: female, 39:21; age range, 20–82 years) were enrolled and divided into CSF leak-positive and CSF leak-negative groups according to CT myelography data. Clinical findings were statistically compared between the two groups. Spinal CSF leak was observed in 80% (48/60) of patients, and it was significantly associated with an age of <69 years (p = 0.006). However, patients aged ≥69 years also had a tendency to exhibit spontaneous intracranial hypotension (SIH)-induced nontraumatic intracranial SDH (60.87%; 14/23). Therefore, CT myelography is recommended to be performed for the evaluation of possible SIH in patients with nontraumatic intracranial SDH, particularly those aged <69 years. Patients aged ≥69 years are also good candidates for CT myelography because SIH tends to occur even in this age group.

Heavily T2-Weighted Magnetic Resonance Myelography as a Safe Cerebrospinal Fluid Leakage Detection Modality for Nontraumatic Subdural Hematoma

Objective

Nontraumatic subdural hematoma (SDH) is a common disease, and spinal cerebrospinal fluid (CSF) leakage is a possible etiology of unknown significance, which is commonly investigated by several invasive studies. This study demonstrates that heavily T2-weighted magnetic resonance myelography (HT2W-MRM) is a safe and clinically effective imaging modality for detecting CSF leakage in patients with nontraumatic SDH.

Methods

All patients who underwent HT2W-MRM for nontraumatic SDH workup at our institution were searched and enrolled in this study. Several parameters were measured and analyzed, including patient demographic data, initial modified Rankin Scale (mRS) score upon presentation, SDH bilaterality, hematoma thickness upon presentation, CSF leakage sites, treatment modalities, followup hematoma thickness, and follow-up mRS score.

Results

Forty patients were identified, of which 22 (55.0%) had CSF leakage at various spinal locations. Five patients (12.5%) showed no change in mRS score, whereas the remaining (87.5%) showed decreases in follow-up mRS scores. In terms of the overall hematoma thickness, four patients (10.0%) showed increased thickness, two (5.0%) showed no change, 32 (80.0%) showed decreased thickness, and two (5.0%) did not undergo follow-up imaging for hematoma thickness measurement.

Conclusion

HT2W-MRM is not only safe but also clinically effective as a primary diagnostic imaging modality to investigate CSF leakage in patients with nontraumatic SDH. Moreover, this study suggests that CSF leakage is a common etiology for nontraumatic SDH, which warrants changes in the diagnosis and treatment strategies.

Spontaneous intracranial hypotension secondary to congenital spinal dural ectasia and genetic mosaicism for tetrasomy 10p: illustrative case

BACKGROUND

Spontaneous intracranial hypotension has historically been a poorly understood pathology that is often unrecognized and undertreated. Even more rarely has it been described in pediatric patients with an otherwise benign past medical history.

OBSERVATIONS

Herein the authors describe one of the youngest patients ever reported, a 2-year-old girl who developed severe headaches, nausea, and vomiting and experienced headache relief after lying down. Imaging revealed tonsillar herniation 14 mm below the foramen magnum, presumed to be a Chiari malformation, along with extensive dural cysts starting from thoracic level T2 down to the sacrum. She was found to have streaky skin pigmentary variation starting from the trunk down to her feet. Genetic analysis of skin biopsies revealed mosaicism for an isodicentric marker chromosome (10p15.3–10q11.2 tetrasomy) in 27%–50% of cells. After undergoing a suboccipital and cervical decompression at an outside institution, she continued to be symptomatic. She was referred to the authors’ hospital, where she was diagnosed with spontaneous intracranial hypotension.

LESSONS

After receiving a series of epidural blood patches, the patient experienced almost complete relief of her symptoms. To the authors’ knowledge, this is the first time this chromosomal anomaly has ever been reported in a living child, and this may represent a new genetic association with dural ectasia.

Hydrocephalus Revisited: New Insights into Dynamics of Neurofluids on Macro- and Microscales

New experimental and clinical findings question the historic view of hydrocephalus and its 100-year-old classification. In particular, real-time magnetic resonance imaging (MRI) evaluation of cerebrospinal fluid (CSF) flow and detailed insights into brain water regulation on the molecular scale indicate the existence of at least three main mechanisms that determine the dynamics of neurofluids: (1) inspiration is a major driving force; (2) adequate filling of brain ventricles by balanced CSF upsurge is sensed by cilia; and (3) the perivascular glial network connects the ependymal surface to the pericapillary Virchow-Robin spaces. Hitherto, these aspects have not been considered a common physiologic framework, improving knowledge and therapy for severe disorders of normal-pressure and posthemorrhagic hydrocephalus, spontaneous intracranial hypotension, and spaceflight disease.

Spontaneous intracranial hypotension presenting with progressive cognitive decline

A 63-year-old woman presented with headache, progressive somnolence, neurocognitive decline and urinary incontinence through a year. Medical history was unremarkable except for hypertension and hypercholesterolaemia. Neurological examination was normal. Brain MRI showed findings typical for spontaneous intracranial hypotension (subdural fluid collection, pachymeningeal enhancement, brain sagging) and pituitary tumour. The patient's complaints improved dramatically but temporarily after treatment with each of repeated targeted as well as non-targeted blood patches and a trial with continuous intrathecal saline infusion. Extensive work up including repeated MRI-scans, radioisotope cisternographies, CT and T2-weighted MR myelography could not localise the leakage, but showed minor root-cysts at three levels. Finally, lateral decubitus digital subtraction dynamic myelography with subsequent CT myelography identified a tiny dural venous fistula at the fourth thoracic level. After surgical venous ligation, the patient fully recovered. Awareness of spontaneous dural leaks and their heterogeneous clinical picture are important and demands an extensive workup.

Outcome after surgical treatment of cerebrospinal fluid leaks in spontaneous intracranial hypotension-a matter of time

Objective

Spinal cerebrospinal fluid (CSF) leaks cause spontaneous intracranial hypotension (SIH). Microsurgery can sufficiently seal spinal CSF leaks. Yet, some patients suffer from residual symptoms. Aim of the study was to assess predictors for favorable outcome after surgical treatment of SIH.

Methods

We included consecutive patients with SIH treated surgically from January 2013 to May 2020. Subjects were surveyed by a questionnaire. Primary outcome was resolution of symptoms as rated by the patient. Secondary outcome was postoperative headache intensity on the numeric rating scale (NRS). Association between variables and outcome was assessed using univariate and multivariate regression. A cut-off value for continuous variables was calculated by a ROC analysis.

Results

Sixty-nine out of 86 patients (80.2%) returned the questionnaire and were analyzed. Mean age was 46.7 years and 68.1% were female. A significant association with the primary and secondary outcome was found only for preoperative symptom duration (p = 0.001 and p < 0.001), whereby a shorter symptom duration was associated with a better outcome. Symptom duration remained a significant predictor in a multivariate model (p = 0.013). Neither sex, age, type of pathology, lumbar opening pressure, nor initial presentation were associated with the primary outcome. ROC analysis yielded treatment within 12 weeks as a cut-off for better outcome.

Conclusion

Shorter duration of preoperative symptoms is the most powerful predictor of favorable outcome after surgical treatment of SIH. While an initial attempt of conservative treatment is justified, we advocate early definitive treatment within 12 weeks in case of persisting symptoms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10710-7.

Iatrogenic Intracranial Hypotension after Surgery of Adolescent Idiopathic Scoliosis due to a Misplaced Screw within the Thoracic Thecal Sac

We present the case of a postoperative intracranial hypotension due to a misplaced intrathecal screw. Although typical symptoms such as orthostatic headache were present immediately after surgery, diagnosis was hidden until 20 years later, resulting in a disastrous clinical course.

Renal Pelvis Opacification on Postmyelography Computed Tomography as an Indicator for Cerebrospinal Fluid Loss in Spontaneous Intracranial Hypotension

Purpose

To assess early renal pelvis opacification on postmyelography computed tomography (CT) as a marker for cerebrospinal fluid (CSF) loss in patients with spontaneous intracranial hypotension (SIH).

Methods

The SIH patients referred to our hospital between January 2012 and May 2018 were retrospectively reviewed and divided into 2 groups based on the presence of spinal longitudinal extrathecal CSF collection (SLEC): (1) SLEC(+) with, and (2) SLEC(−) without proof of SLEC on multimodal imaging. Non-SIH patients (n = 20) undergoing CT myelography served as controls. The renal pelvis density on postmyelography CT was measured in all patients. Mean difference in renal pelvis density between the groups was calculated.

Results

In total, 111 SIH patients (mean age 48 ± 13 years; 60% female) were included, 71 (64%) SLEC(+) and 40 (36%) SLEC(−). The adjusted renal pelvis density in the SLEC(+), SLEC(−), and the non-SIH group was 108 Hounsfield unit (HU), 83 HU, and 32 HU, respectively, resulting in a significant difference between SLEC(+) vs. control group 1 (75 HU, p < 0.001), SLEC(−) vs. control group 1 (50 HU, p < 0.001), and a tendency for higher density in SLEC(+) than SLEC(−) (25 HU, p = 0.16).

Conclusion

Increased renal pelvis opacification on postmyelography CT was observed in SIH patients, even in the absence of a CSF leak or a CSF venous fistula, when compared to non-SIH patients. Although the provenance of early renal opacification in SLEC (−) SIH patients remains unclear, our results suggest that it may be a surrogate for increased spinal CSF resorption via spinal arachnoid granulations and along spinal nerve sheaths occult to direct imaging.

Dural leakage due to ipsilateral needle placement for spinal level localization in unilateral decompression surgery: A case report

Background:

A spinal dural defect caused by needle placement for spinal level localization is an uncommon complication of cerebrospinal fluid leak with the potential for the development of intracranial hypertension.

Case Description:

Our 48-year-old patient underwent unilateral fenestration and sequestrectomy for intractable L5 radiculopathy due to disc herniation at the level L4–5 on the right side. The spinal level was identified with fluoroscopy after placement of a 24-gauge Sprotte spinal needle on the right side. Intraoperatively, a sub-millimeter spinal dural defect was visualized on the ipsilateral side.

Conclusion:

Caution is needed when needle placement is used to localize the spinal level for unilateral surgery.

Unilateral chronic subdural hematoma due to spontaneous intracranial hypotension: a report of four cases

Background: Chronic subdural hematoma (CSDH) is a common neurosurgical disease. A subset of patients with CSDH may exhibit underlying spontaneous intracranial hypotension (SIH). Bilateral CSDH has a causal relationship with SIH, but there is no known causal relationship between unilateral CSDH and SIH.Case description: We encountered four cases of unilateral CSDH due to SIH. The patients' age ranged between 44 and 64 years; there were three males and one female. All patients presented with headache as their initial symptom, and then became comatose. Computed tomography demonstrated unilateral CSDH and transtentorial herniation in all patients. Treatments were emergency epidural blood patch (EBP) and evacuation of CSDH. The site of cerebrospinal fluid leak could not be identified in three patients; therefore, EBP was performed at upper and lower spine. All patients recovered from SIH; however, one patient experienced poor outcome due to Duret hemorrhage and ischemic complications of transtentorial herniation. Cranial asymmetry was present in all four patients, and unilateral CSDH was located on the side of the most curved cranial convexity.Conclusions: Unilateral CSDH, asymmetric cranial morphology, and transtentorial herniation in relatively young patients may indicate underlying SIH.

Monro-Kellie Hypothesis: Increase of Ventricular CSF Volume after Surgical Closure of a Spinal Dural Leak in Patients with Spontaneous Intracranial Hypotension

BACKGROUND AND PURPOSE

CSF loss in spontaneous intracranial hypotension disrupts a well-regulated equilibrium. We aimed to evaluate the volume shift between intracranial compartments in patients with spontaneous intracranial hypotension before and after surgical closure of the underlying spinal dural breach.

MATERIALS AND METHODS

In total, 19 patients with spontaneous intracranial hypotension with a proved spinal CSF leak investigated at our institution between July 2014 and March 2017 (mean age, 41.8 years; 13 women) were included. Brain MR imaging-based volumetry at baseline and after surgery was performed with FreeSurfer. In addition, the spontaneous intracranial hypotension score, ranging from 0 to 9, with 0 indicating very low and 9 very high probability of spinal CSF loss, was calculated.

RESULTS

Total mean ventricular CSF volume significantly increased from baseline (15.3 mL) to posttreatment MR imaging (18.0 mL), resulting in a mean absolute and relative difference, +2.7 mL and +18.8% (95% CI, +1.2 to +3.9 mL; P < .001). The change was apparent in the early follow-up (mean, 4 days). No significant change in mean total brain volume was observed (1136.9 versus 1133.1 mL, P = .58). The mean spontaneous intracranial hypotension score decreased from 6.9  ± 1.5 at baseline to 2.9 ± 1.5 postoperatively.

CONCLUSIONS

Our study demonstrated a substantial increase in ventricular CSF volume in the early follow-up after surgical closure of the underlying spinal dural breach and may provide a causal link between spinal CSF loss and spontaneous intracranial hypotension. The concomitant decrease in the spontaneous intracranial hypotension score postoperatively implies the restoration of an equilibrium within the CSF compartment.

Role of Conventional Dynamic Myelography for Detection of High-Flow Cerebrospinal Fluid Leaks

Background

Spinal imaging is essential to identify and localize cerebrospinal fluid (CSF) leaks in spontaneous intracranial hypotension (SIH) patients when targeted treatment is necessary.

Purpose

Provide an in-depth presentation of the conventional dynamic myelography (CDM) technique for localizing spinal CSF leaks in SIH patients.

Material and Methods

Consecutive SIH patients with a CSF leak confirmed on CDM and postmyelography computed tomography (CT) investigated at our institution between 2013 and 2019 were retrospectively analyzed. Intraoperative reports were reviewed to confirm the accuracy of CDM.

Results

In total, 62 patients (mean age 45 years) were included; 48 with a ventral dural tear, 12 with a meningeal diverticulum, and in 2 patients positive for spinal longitudinal extradural CSF collection the site remained unclear. The leak was identified during the first and the second CDM in 43 and 17 patients, respectively. The use of CDM correctly identified the site of the CSF leak in all but one patient undergoing surgical closure (45/46, 98%). The mean fluoroscopy time was 7.8 min (range 1.8–14.4 min) with a radiation dose for a single examination of 310 mGy (range 28–1237 mGy).

Conclusion

The CDM procedure has a high accuracy for spinal CSF leak localization including dural tears and spinal nerve diverticula. It is the technique with the highest temporal resolution, is robust to breathing artifacts, allows great flexibility regarding patient positioning, compares favorably to other dynamic examinations with respect to the radiation dose and does not require general anesthesia. For CSF venous fistulas, however, other dynamic examinations, such as digital subtraction myelography, seem more appropriate.

Video online

The online version of this article contains 4 videos. The article and the videos are online available (10.1007/s00062-020-00943-w). The videos can be found in the article back matter as “Electronic Supplementary Material”.

Spontaneous Intracranial Hypotension

BACKGROUND

Spontaneous intracranial hypotension (SIH) is an underdiagnosed disease. Its incidence is estimated at 5 per 100 000 persons per year.

METHODS

This review is based on a selective literature search in PubMed covering the years 2000-2019, as well as on the authors' personal experience.

RESULTS

The diagnostic and therapeutic methods discussed here are supported by level 4 evidence. SIH is caused by spinal leakage of cerebrospinal fluid (CSF) out of ventral dural tears or nerve root diverticula, or, in 2-5% of cases, through a fistula leading directly into the periradicular veins (CSF-venous fistula). In half of all patients, no CSF leak is demonstrable. A low CSF opening pressure on lumbar puncture is present in only one-third of patients; imaging studies are thus needed to confirm and localize a spinal CSF leak. Half of all patients in whom myelographic computed tomography (CT) reveals contrast medium reaching the epidural space have ventral dural tears, which tend to be located at upper thoracic spinal levels. Epidural blood patches applied under fluoroscopic or CT guidance can seal the CSF leak in 30-70% of patients, but 90% of patients with ventral dural tears will need operative closure. Some patients who have no visible epidural contrast medium on CT presumably do not have SIH, while others do, in fact, have a CSF leak from a diverticulum or a CSF-venous fistula and will need to have the site of the leak demonstrated with the aid of further studies, such as dynamic (subtraction) myelography in the lateral decubitus position.

CONCLUSION

The management of patients with SIH calls for complementary imaging studies to demonstrate the causative spinal CSF leak. Often, successful treatment requires surgical closure of the leak. In view of the sparse evidence available to date, controlled studies should be performed.

Management of spontaneous intracranial hypotension: a series of 31 cases over 15-years with a challenging outlier

Spontaneous intracranial hypotension (SIH) has been classified as a triad of postural headache, low CSF opening pressure (below 60mmH₂0) and diffuse pachymeningeal gadolinium enhancement on MRI. SIH is due to a non-iatrogenic defect in the dura somewhere along the neuraxis (usually in the spine). The resultant leak depressurizes the system and undermines the buoyancy-providing quality of CSF. In many cases the site of leak is not identified. Epidural blood patch (EBP) is a well-established treatment of SIH but is not always effective. We retrospectively analysed thirty-one cases of SIH who required at least one EBP. They were managed over a fifteen-year period at a single institution. EBP resulted in a significant improvement in headache for 77% of patients. We report in more detail on a particularly challenging outlier where severe SIH resulted in coma. Serial epidural blood patches, burr hole evacuation of chronic subdural haematomata, and infusion of 0.9% NaCl via an intradural spinal catheter were all required to enable long-term recovery.

Assessing Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension With a Scoring System Based on Brain Magnetic Resonance Imaging Findings

Importance

Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice.

Objective

To develop a probability score based on the most relevant brain MRI findings to assess the likelihood of an underlying spinal cerebrospinal fluid (CSF) leak in patients with SIH.

Design, Setting, and Participants

This case-control study in consecutive patients investigated for SIH was conducted at a single hospital department from February 2013 to October 2017. Patients with missing brain MRI data were excluded. Three blinded readers retrospectively reviewed the brain MRI scans of patients with SIH and a spinal CSF leak, patients with orthostatic headache without a CSF leak, and healthy control participants, evaluating 9 quantitative and 7 qualitative signs. A predictive diagnostic score based on multivariable backward logistic regression analysis was then derived. Its performance was validated internally in a prospective cohort of patients who had clinical suspicion for SIH.

Main Outcomes and Measures

Likelihood of a spinal CSF leak based on the proposed diagnostic score.

Results

A total of 152 participants (101 female [66.4%]; mean [SD] age, 46.1 [14.3] years) were studied. These included 56 with SIH and a spinal CSF leak, 16 with orthostatic headache without a CSF leak, 60 control participants, and 20 patients in the validation cohort. Six imaging findings were included in the final scoring system. Three were weighted as major (2 points each): pachymeningeal enhancement, engorgement of venous sinus, and effacement of the suprasellar cistern of 4.0 mm or less. Three were considered minor (1 point each): subdural fluid collection, effacement of the prepontine cistern of 5.0 mm or less, and mamillopontine distance of 6.5 mm or less. Patients were classified into groups at low, intermediate, or high probability of having a spinal CSF leak, with total scores of 2 points or fewer, 3 to 4 points, and 5 points or more, respectively, on a scale of 9 points. The discriminatory ability of the proposed score could be demonstrated in the validation cohort.

Conclusions and Relevance

This 3-tier predictive scoring system is based on the 6 most relevant brain MRI findings and allows assessment of the likelihood (low, intermediate, or high) of a positive spinal imaging result in patients with SIH. It may be useful in identifying patients with SIH who are leak positive and in whom further invasive myelographic examinations are warranted before considering targeted therapy.

Recurrent Bilateral Chronic Subdural Hematoma After Interventional Embolization Combined With Drilling and Drainage Treatment

The main treatment for chronic subdural hematoma (CSDH) is surgical drilling and drainage. Meanwhile, the most accepted treatment strategy for bilateral CSDHs (bCSDHs) is unilateral evacuation only on the larger or symptomatic side because the contralateral hematoma is generally either small or asymptomatic. However, the probability of recurrence is high. To effectively reduce this recurrence rate, embolization has been proposed. Because middle meningeal artery embolization may effectively block the blood supply of the CSDH, its combination with drilling and drainage could be an effective treatment strategy for addressing unilateral CSDH (uCSDH). In addition, the recurrence mechanism of bCSDH may be not completely same as that of the uCSDH. Hence, the authors need find a more effective treatment for it.

Cerebrospinal Fluid Leakage at the Lumbar Spine: A Unique Cause of Delayed Neurologic Deterioration in a Traumatic Acute Subdural Hematoma Patient

We present a rare case of traumatic acute subdural hematoma (SDH) in which intracranial hypotension (IC) secondary to cerebrospinal fluid (CSF) leakage at the lumbar spine caused delayed neurological deterioration. A 70-year-old male sustained a head injury after ground-level fall and was brought to our institution. A brain computed tomography (CT) showed a thin acute SDH with mild brain shift, and conservative management was initiated. He exhibited neurological deterioration on the 9^th hospital day, however, and a brain CT showed a change in CT density and marked an increase in hematoma volume and brain shift. It was thought that conversion from acute to subacute SDH was associated with the deterioration, and emergency hematoma evacuation was performed. Despite the surgery, neither clinical nor radiographical improvement occurred. The lack of improvement pointed to the presence of underlying IC, and a CT myelography revealed the dural sleeve of the right L2 nerve root as the source of the CSF leakage. An epidural blood patch therapy was performed on the 12^th hospital day to seal the CSF leakage. The postprocedural course was uneventful, and the patient was discharged free of symptoms on the 20^th hospital day. Spinal CSF leakage should be considered as a cause of delayed neurological deterioration in patients with traumatic acute SDH which exhibits conversion to subacute SDH.

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.

The depth of catheter in chronic subdural haematoma: does it matter?

Objective: To investigate the appropriate depth of drainage catheter in the patients with chronic subdural haematoma (CSDH). Methods: We retrospectively analysed the data of 190 patients with CSDH undergoing single parietal burr-hole evacuation and drainage. Results: According to the depth of catheter (DC), 190 patients were divided into three groups: shallow group (DC <4.3 cm), middle group (DC 4.3 ~ 5.4 cm) and deep group (DC > 5.4 cm). During postdischarge 6 months, two, six and nine patients had recurrences in shallow, middle and deep groups, respectively. The recurrence rate in shallow or middle group was significantly lower than that in deep group. No significant difference in preoperative haematoma volume (PHV) was observed in three groups. While the residual subdural space (RSS) in shallow group was significantly smaller than those in the other two groups. The duration of drainage in shallow, middle and deep groups increased successively, and the differences were statistically significant. The total drainage volume (TDV) in shallow group showed no significant difference when compared with the other two groups. Conclusion: The depth of catheter may affect the outcome of CSDH. Inserting drainage catheter shallowly might be a preferred choice in patients with CSDH undergoing burr-hole evacuation and drainage.

Sonography of the optic nerve sheath diameter before and after microsurgical closure of a dural CSF fistula in patients with spontaneous intracranial hypotension - a consecutive cohort study

OBJECTIVE

Spontaneous intracranial hypotension is caused by spinal cerebrospinal fluid leakage. Patients with orthostatic headaches and cerebrospinal fluid leakage show a decrease in optic nerve sheath diameter upon movement from supine to upright position. We hypothesized that the decrease in optic nerve sheath diameter upon gravitational challenge would cease after closure of the leak.

METHODS

We included 29 patients with spontaneous intracranial hypotension and refractory symptoms admitted from 2013 to 2016. The systematic workup included: Optic nerve sheath diameter sonography, spinal MRI and dynamic myelography with subsequent CT. Microsurgical sealing of the cerebrospinal fluid leak was the aim in all cases.

RESULTS

Of 29 patients with a proven cerebrospinal fluid leak, one declined surgery. A single patient was lost to follow-up. In 27 cases, the cerebrospinal fluid leak was successfully sealed by microsurgery. The width of the optic nerve sheath diameter in supine position increased from 5.08 ± 0.66 mm before to 5.36 ± 0.53 mm after surgery ( p = 0.03). Comparing the response of the optic nerve sheath diameter to gravitational challenge, there was a significant change from before (-0.36 ± 0.32 mm) to after surgery (0.00 ± 0.19 mm, p < 0.01). In parallel, spontaneous intracranial hypotension-related symptoms resolved in 26, decreased in one and persisted in a single patient despite recovery of gait.

CONCLUSIONS

The sonographic assessment of the optic nerve sheath diameter with gravitational challenge can distinguish open from closed spinal cerebrospinal fluid fistulas in spontaneous intracranial hypotension patients. A response to the gravitational challenge, that is, no more collapse of the optic nerve sheath while standing up, can be seen after successful treatment and correlates with the resolution of clinical symptoms. Sonography of the optic nerve sheath diameter may be utilized for non-invasive follow-up in spontaneous intracranial hypotension.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Coma

Objective

To review our experience with patients with spontaneous intracranial hypotension (SIH) and coma because, although disorders of consciousness may complicate SIH, no comprehensive study of such patients has been reported.

Methods

Using a prospectively maintained registry, we identified all patients with SIH in whom coma developed. Patients or their caregivers/families were contacted for follow-up. Patients were compared to a cohort of patients with SIH without coma.

Results

The mean age of the 12 men and 3 women with SIH was 56.2 years (range 34–72 years) at the time of onset of coma. In one-third of patients, coma developed after craniotomy for subdural hematomas or for an unrelated intracranial pathology. Imaging showed brain sagging, including bilateral temporal lobe herniation, in all 15 patients and brainstem edema in 8 patients (53%). Overall, coma was reversible in 7 of 15 patients treated with epidural blood patches, in 2 of 4 treated with percutaneous glue injections, and in 6 of 6 treated surgically. Only 1 patient had residual neurologic deficit related to coma (Glasgow Outcome Scale score 4 [moderate disability]). Compared to patients with SIH without coma (n = 568), those with coma were older, more often were male, and more often underwent surgery.

Conclusions

Coma in SIH is rare, reversible, and invariably associated with brain sagging. Coma due to SIH may be refractory to the usual percutaneous procedures, and surgical closure of the CSF leak may be required to regain consciousness.

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

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

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.

Impact of low coagulation factor XIII activity in patients with chronic subdural hematoma associated with cerebrospinal fluid hypovolemia: A retrospective study

Background:

Cerebrospinal fluid hypovolemia (CSFH) is sometimes associated with chronic subdural hematomas (CSHs). Affected patients often develop enlargement and recurrence of the CSH, even if appropriate treatments such as epidural blood patch (EBP) and/or burr-hole surgery for the CSH are performed. This situation may lead to subclinical coagulopathy, including low coagulation factor XIII (CFXIII) activity. We retrospectively analyzed whether CFXIII activity was involved in the development of CSHs and post-treatment exacerbation of CSHs in patients with CSFH.

Methods:

We diagnosed CSFH by radioisotope (RI), magnetic resonance imaging (MRI) and computed tomography (CT) findings, and CSH by CT and/or MRI findings. The plasma CFXIII activity was assessed on admission. All patients with CSFH initially received conservative treatments. When these treatments were ineffective, the patients underwent EBP and/or CSH surgery according to previously reported therapeutic strategies.

Results:

Among 206 patients with CSFH, 19 developed CSHs. Fourteen patients with a thin hematoma underwent EBP and three with a thick hematoma underwent CSH surgery immediately after EBP on the same day. We were unable to diagnose two patients with CSFH at the time of admission, and one of these two patients underwent repeated CSH surgery before obtaining the correct diagnosis. Seven patients (36.8%) developed CSH exacerbation after the treatment. The CFXIII activity was significantly lower in patients with than without a CSH (42.1% vs. 12.8%, respectively; P = 0.003). The CFXIII activity was significantly lower in patients with than without post-treatment CSH exacerbation (P = 0.046). All five patients with low CFXIII activity who developed CSH exacerbation received intravenous injection of CFXIII and had no recurrence of CSH after the additional treatment.

Conclusion:

In patients with CSFH, low CFXIII activity is one of the risk factors for both the development of a CSH and the post-treatment exacerbation CSH.

Misdiagnosis of Spontaneous Intracranial Hypotension as a Risk Factor for Subdural Hematoma

OBJECTIVE

This study aimed to evaluate the association between misdiagnosis of spontaneous intracranial hypotension (SIH) and subdural hematoma development.

BACKGROUND

Although SIH is more prevalent than expected and causes potentially life-threatening complications including subdural hematoma (SDH), the association between misdiagnosis of SIH and SDH development is not yet evaluated.

METHODS

Retrospective observational study was conducted between January 1, 2005, and December 31, 2014. Adult patients with spontaneous intracranial hypotension (age ≥ 18 years) were enrolled.

RESULTS

Of the 128 patients with SIH, 111 (86.7%) were in no SDH group and 17 (13.3%) were in SDH group. Their clinical presentation did not show significant different between the two groups, except age, the days from symptom onset to correct diagnosis, and the number of misdiagnoses. Age (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.07-1.23) and the number of times SIH was misdiagnosed (OR, 1.82; 95% CI, 1.03-3.21) were independent risk factors for the development of SDH in SIH patients by multivariate logistic analysis. The clinical outcomes, including length of hospital stay and revisit rate, were similar in the two groups.

CONCLUSIONS

The number of times SIH was misdiagnosed was associated with the later development of SDH perhaps because of delay in correct diagnosis of SIH. Clinicians would prevent the later complication of SDH in SIH patients by increasing the awareness and a high index of suspicion of SIH.

Cerebrospinal fluid outflow resistance as a diagnostic marker of spontaneous cerebrospinal fluid leakage

OBJECTIVE Spinal CSF leakage causes spontaneous intracranial hypotension (SIH). The aim of this study was to characterize CSF dynamics via lumbar infusion testing in patients with and without proven spinal CSF leakage in order to explore possible discriminators for the presence of an open CSF leak. METHODS This analysis included all patients with suspected SIH who were treated at the authors' institution between January 2012 and February 2015. The gold standard for "proven" CSF leakage is considered to be extrathecal contrast accumulation after intrathecal contrast injection. To characterize CSF dynamics, the authors performed computerized lumbar infusion testing to measure lumbar pressure at baseline (opening pressure) and at plateau, as well as pulse amplitude, CSF outflow resistance (R_CSF), craniospinal elastance, and pressure-volume index. RESULTS Thirty-one patients underwent clinical imaging and lumbar infusion testing and were included in the final analysis. A comparison of the 14 patients with proven CSF leakage with the 17 patients without leakage showed a statistically significantly lower lumbar opening pressure (p < 0.001), plateau pressure (p < 0.001), and R_CSF (p < 0.001) in the group with leakage. Sensitivity, specificity, and positive and negative predictive values for an R_CSF cutoff of ≤ 5 mm Hg/(ml/min) were 0.86, 1.0, 1.0, and 0.89 (area under the curve of 0.96), respectively. The median pressure-volume index was higher (p = 0.003), and baseline (p = 0.017) and plateau (p < 0.001) pulse amplitudes were lower in patients with a proven leak. CONCLUSIONS Lumbar infusion testing captures a distinct pattern of CSF dynamics associated with spinal CSF leakage. R_CSF assessed by computerized lumbar infusion testing has an excellent diagnostic accuracy and is more accurate than evaluating the lumbar opening pressure. The authors suggest inclusion of R_CSF in the diagnostic criteria for SIH.

Neurocritical Care of Acute Subdural Hemorrhage

Although urgent surgical hematoma evacuation is necessary for most patients with subdural hematoma (SDH), well-orchestrated, evidenced-based, multidisciplinary, postoperative critical care is essential to achieve the best possible outcome. Acute SDH complicates approximately 11% of mild to moderate traumatic brain injuries (TBIs) that require hospitalization, and approximately 20% of severe TBIs. Acute SDH usually is related to a clear traumatic event, but in some cases can occur spontaneously. Management of SDH in the setting of TBI typically conforms to the Advanced Trauma Life Support protocol with airway taking priority, and management breathing and circulation occurring in parallel rather than sequence.

Clinical characteristics of 15 cases of chronic subdural hematomas due to spontaneous intracranial hypotension with spinal cerebrospinal fluid leak

The etiology of chronic subdural hematoma (CSDH) in patients is diverse. The primary objective of this article was to discuss one of the causes, spontaneous intracranial hypotension with spinal cerebrospinal fluid (CSF) leak, which is usually neglected by the neurosurgeon. All the consecutive 15 patients who underwent operation for CSDHs between June 2012 and June 2014 at Sir Run Run Shaw Hospital of Zhejiang University were included in this retrospective cohort study. The clinical and imaging data of these patients with CSDHs due to spinal CSF leak were retrospectively studied. Fifteen patients, with a mean age of 53.8 ± 8.3 years, underwent operations for CSDH. Hematomas were unilateral in 4 patients and bilateral in 11 patients. Among these patients, eight patients had recurrence of hematomas after operation due to neglect of spinal CSF leak. All patients had fully recovery. Spinal CSF leak is a cause of cSDH, which is overlooked by the doctor.

Management of spontaneous intracranial hypotension - Transorbital ultrasound as discriminator

OBJECTIVE

Spontaneous intracranial hypotension (SIH) is most commonly caused by cerebrospinal fluid (CSF) leakage. Therefore, we hypothesised that patients with orthostatic headache (OH) would show decreased optic nerve sheath diameter (ONSD) during changes from supine to upright position.

METHODS

Transorbital B-mode ultrasound was performed employing a high-frequency transducer for ONSD measurements in the supine and upright positions. Absolute values and changes of ONSD from supine to upright were assessed. Ultrasound was performed in 39 SIH patients, 18 with OH and 21 without OH, and in 39 age-matched control subjects. The control group comprised 20 patients admitted for back surgery without headache or any orthostatic symptoms, and 19 healthy controls.

RESULTS

In supine position, mean ONSD (±SD) was similar in patients with (5.38±0.91 mm) or without OH (5.48±0.89 mm; p=0.921). However, in upright position, mean ONSD was different between patients with (4.84±0.99 mm) and without OH (5.53±0.99 mm; p=0.044). Furthermore, the change in ONSD from supine to upright position was significantly greater in SIH patients with OH (-0.53±0.34 mm) than in SIH patients without OH (0.05±0.41 mm; p≤0.001) or in control subjects (0.01±0.38 mm; p≤0.001; area under the curve: 0.874 in receiver operating characteristics analysis).

CONCLUSIONS

Symptomatic patients with SIH showed a significant decrease of ONSD, as assessed by ultrasound, when changing from the supine to the upright position. Ultrasound assessment of the ONSD in two positions may be a novel, non-invasive tool for the diagnosis and follow-up of SIH and for elucidating the pathophysiology of SIH.

Treatment strategy for cerebral hypotension caused by spontaneous cerebrospinal fluid leaks

OBJECTIVE

Spontaneous spinal cerebrospinal fluid (CSF) leaks are rare (5 per 100,000 per year). Treatment generally consists of conservative therapy or interventional therapy with epidural blood patching. Surgical treatment is conducted rarely, usually in cases when conservative or interventional treatment has failed. The aim of our case series was to assess the clinical outcome after surgery.

METHODS

Our clinical database was reviewed for patients with spontaneous spinal CSF leaks who underwent surgical exploration between 2010 and 2013. Etiology, symptoms, preoperative imaging, type of required surgical method, intraoperative findings, and clinical outcome were reported.

RESULTS

We identified five patients with a mean age of 62 years with spontaneous spinal CSF leaks who were treated surgically. Two patients received surgery after failure of interventional treatment. The origin of the CSF leak could be identified intraoperatively in three cases. Surgical technique in all cases consisted of an interlaminar fenestration or hemilaminectomy and a complete foraminotomy to explore the thecal sack and the exiting nerve roots and identify the CSF leak. After surgery, the preoperative symptoms improved in all patients. In one case, there was a relapse after 4 weeks.

CONCLUSIONS

Preoperative identification of a CSF leak with MRI was positive in only one case. In all other cases, a post-myelography CT had to be performed. In all cases, the preoperative symptoms improved after surgery. Surgical treatment is an effective treatment of spontaneous cerebrospinal fluid leaks in cases of refractory symptoms after failed conservative or interventional treatment.

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.

Delayed chronic intracranial subdural hematoma complicating resection of a tanycytic thoracic ependymoma

Background:

To demonstrate that the diagnosis of an intracranial subdural hematoma should be considered for patients presenting with acute or delayed symptoms of intracranial pathology following resection of a spinal tumor.

Case Description:

We present a case of a 57-year-old woman found to have a chronic subdural hematoma 1 month following resection of a thoracic extramedullary ependymoma. Evacuation of the hematoma through a burr hole relieved the presenting symptoms and signs. Resolution of the hematoma was confirmed with a computed tomography (CT) scan.

Conclusion:

Headache and other symptoms not referable to spinal pathology should be regarded as a warning sign of an intracranial subdural hematoma, and a CT scan of the head should be obtained. The mechanism of the development of the hematoma may be related to the leakage of cerebrospinal fluid with subsequent intracranial hypotension leading to an expanding subdural space and hemorrhage.

Dural diverticulum with a symptomatic cerebrospinal fluid leak

A case report of a 63-year-old female patient with a cervical spinal dural diverticulum and intracranial hypotension secondary to a symptomatic CSF leak after minor trauma. The patient responded well after the cervical approach epidural blood patch procedure.