Equilibrium Values for the Si-H Bond Length and Equilibrium Structures of Silyl Iodide and Halosilylenes.

The equilibrium structures of silyl iodide, SiH3I, and silylene halides, SiHX (X = F, Cl, Br, I), were determined by using the mixed regression method, where approximate values of the rotational constants are supplemented by the structural parameters of a different origin. For this goal, it is shown that the r(Si-H) bond length can be determined by using the isolated SiH stretching frequency and that an accurate estimation of the bond angles is obtained by an MP2 calculation with a basis set of triple zeta quality. To check the accuracy of the experimental structures, they were also optimized by means of all electron CCSD(T) calculations using basis sets of quadruple zeta quality.

Management of Labor and Anesthesia in a Patient With a History of Spontaneous Intracranial Hypotension: A Case Report With Literature Review.

Spontaneous intracranial hypotension (SIH) is a rare disorder characterized by continuous or intermittent cerebrospinal fluid (CSF) leakage from the CSF cavity, which causes symptoms such as headache or neck pain upon standing. However, no well-established measures concerning the type of delivery and anesthesia for pregnant women with a history of SIH have been reported. A woman had developed SIH 9 years earlier from lifting luggage into an overhead bin with stretching movements, which required continuous saline epidural infusion for recovery. Upon the patient's pregnancy at the age of 35 years, although an elective cesarean section (CS) under general anesthesia was planned to avoid SIH recurrence, the patient had an emergency CS at 36 weeks. Since there is no prescribed method of delivery and anesthetic management for patients with a history of SIH, it is important to plan and adapt a treatment strategy based on the patient's wishes and the institution's protocols. As a sidenote, we reviewed the available literature regarding the type of delivery and anesthesia for pregnant women with a history of SIH.

Comprehensive high resolution study of the MSiH4(M=28,29,30) tetradecad stretching bands: Appearance and applications of the isotopic substitution effect in molecules of spherical symmetry.

A set of new relations between different spectroscopic parameters of the high symmetry XY4 spherical top molecules is derived on the basis of the general isotopic substitution theory, and a comprehensive high accurate analysis of the five stretching bands (the bands ν1+ν3(F2), 2ν3(F2), 2ν3(E), 2ν3(A1), and 2ν1(A1); the three latter ones are forbidden in absorption) of the tetradecad of the SiH4 molecule is made. The high resolution spectra of MSiH4(M=28,29,30) in their natural abundance were recorded with a Bruker IFS125 HR Fourier transform infrared spectrometer at the Technische Universität Braunschweig, Germany with an optical resolution of 0.003 cm-1 and theoretically analyzed (in this case, for the first time both for all five bands of the 29SiH4 and 30SiH4 species, and for 2ν3(E), 2ν1(A1) bands of the 28SiH4 one). The number of 2713 transitions of the 28SiH4 species (which is more than fourteen times higher compared to analogous studies carried out earlier) belonging to all five ro-vibrational bands of the tetradecad (which are 272, 1897, 15, 369, and 160 transitions of the ν1+ν3(F2), 2ν1(A1), 2ν3(A1), 2ν3(F2), and 2ν3(E) bands) were assigned with the values of quantum number Jmin/Jmax = 5/22, 1/24, 14/20, 4/24, and 6/23, respectively. The analysis of the obtained experimental data was made on the basis of the Hamiltonian model which takes into account all effects and resonance interactions which are possible in such molecular system. The weighted fit of the 2713 transitions led to a set of 40 rotational, centrifugal distortion, tetrahedral splitting, and resonance interaction parameters which reproduce the initial experimental data with an accuracy of drms=4.11×10-4 cm-1. An analogous analysis was made for the two other isotopologues, 29SiH4 and 30SiH4, of silane. In this case, the initial values of the most important spectroscopic parameters of both species were theoretically estimated on the basis of results of the isotopic substitution theory. As the result of the analysis, two sets of the 12 spectroscopic parameters were obtained from the weighted fits for the 29SiH4 and 30SiH4 molecules which reproduce the 461 and 375 initial ro-vibrational transitions with the drms of 3.91×10-4 and 4.9710-4 cm-1.

Surgical closure of spinal cerebrospinal fluid leaks improves symptoms in patients with superficial siderosis.

BACKGROUND AND PURPOSE: Spinal cerebrospinal fluid (CSF) leaks may cause a myriad of symptoms, most common being orthostatic headache. In addition, ventral spinal CSF leaks are a possible etiology of superficial siderosis (SS), a rare condition characterized by hemosiderin deposits in the central nervous system (CNS). The classical presentation of SS involves ataxia, bilateral hearing loss, and myelopathy. Unfortunately, treatment options are scarce. This study was undertaken to evaluate whether microsurgical closure of CSF leaks can prevent further clinical deterioration or improve symptoms of SS. METHODS: This cohort study was conducted using data from a prospectively maintained database in two large spontaneous intracranial hypotension (SIH) referral centers in Germany and Switzerland of patients who meet the modified International Classification of Headache Disorders, 3rd edition criteria for SIH. Patients with spinal CSF leaks were screened for the presence of idiopathic infratentorial symmetric SS of the CNS. RESULTS: Twelve patients were included. The median latency between the onset of orthostatic headaches and symptoms attributed to SS was 9.5 years. After surgical closure of the underlying spinal CSF leak, symptoms attributed to SS improved in seven patients and remained stable in three. Patients who presented within 1 year after the onset of SS symptoms improved, but those who presented in 8-12 years did not improve. We could show a significant association between patients with spinal longitudinal extrathecal collections and SS. CONCLUSIONS: Long-standing untreated ventral spinal CSF leaks can lead to SS of the CNS, and microsurgical sealing of spinal CSF leaks might stop progression and improve symptoms in patients with SS in a time-dependent manner.

Tandem cranial and spinal cerebrospinal fluid leaks presenting with otogenic tension pneumocephalus: illustrative case.

BACKGROUND: Cranial and spinal cerebrospinal fluid (CSF) leaks are associated with opposite CSF fluid dynamics. The differing pathophysiology between spontaneous cranial and spinal CSF leaks are, therefore, mutually exclusive in theory. OBSERVATIONS: A 66-year-old female presented with tension pneumocephalus. The patient underwent computed tomography (CT) scanning, which demonstrated left-sided tension pneumocephalus, with an expanding volume of air directly above a bony defect of the tegmen tympani and mastoideum. The patient underwent a left middle fossa craniotomy for repair of the tegmen CSF leak. In the week after discharge, she developed a recurrence of positional headaches and underwent head CT. Further magnetic resonance imaging of the brain and thoracic spine showed bilateral subdural hematomas and multiple meningeal diverticula. LESSONS: Cranial CSF leaks are caused by intracranial hypertension and are not associated with subdural hematomas. Clinicians should maintain a high index of suspicion for intracranial hypotension due to spinal CSF leak whenever "otogenic" pneumocephalus is found. Close postoperative follow-up and clinical monitoring for symptoms of intracranial hypotension in any patients who undergo repair of a tegmen defect for otogenic pneumocephalus is recommended.

Recurrent Spontaneous Intracranial Hypotension (SIH) and the Durability of Repeat Epidural Blood Patch (EBP).

OBJECTIVE: Spontaneous intracranial hypotension (SIH) remains a rare and difficult clinical entity to diagnose and treat. Epidural blood patch (EBP) of the dural sac is the mainstay definitive treatment for refractory cases and has mixed efficacy. We sought to evaluate the recent efficacy and outcomes of EBP for SIH at our institution. METHODS: Twenty-three patients (14 women, 9 men, mean age 49) were seen and treated for SIH between Summer 2009 and Spring 2018 at the same institution. All patients underwent brain MRI with and without gadolinium contrast and T2-weighted spine MRI. Targeted EBP was placed one or two vertebral levels below areas of suspected leak, while the patient was positioned in the lateral decubitus position. Patients were seen in the outpatient setting within a week following initial EBP and repeat EBP was offered to patients with persistent symptoms. Patients were followed if symptoms persisted or for 6 months following clinical relief of symptoms. RESULTS: 22/23 (95.7%) patients presented with complaints of orthostatic headache, and 3 (13%) patients presented with altered mental status (AMS) or focal neurologic deficit. Brain MRI demonstrated pachymeningeal enhancement in 16/23 (69.6%) patients, and 5/23 (21.7%) patients had a subdural hematoma (SDH) present. Dural leaks were successfully identified in 18/23 (78.3%) patients. 12/23 (52.2%) patients had symptomatic relief with initial EBP, and 5/23 (21.7%) patients received further EBPs for persistent disease with all achieving relief after repeat EBP. 5/12 (41.7%) of patients had recurrent symptoms after initial relief with EBP, and 4/5 (80%) were successfully treated with a second EBP. The mean initial EBP volume and number of EBPs per patient were 21.7 mL (median 20 mL, 7-40 mL) and 3.54 (median 1, 1-13) respectively. There was one complication from initial EBP (cervical dural tear requiring operative closure) treated with open surgical management successfully. In total, 18/23 (78.2%) patients are currently asymptomatic with regard to their SIH. The mean follow-up in this cohort was 2.6 years (median 1.8 years, 1.8 months-9.27 years). CONCLUSIONS: EBP is a viable and effective option for the treatment of recurrent SIH caused by cerebrospinal fluid (CSF) leaks.

Spinal cord motion and CSF flow in the cervical spine of 70 healthy participants.

Pulsatile spinal cord and CSF velocities related to the cardiac cycle can be depicted by phase-contrast MRI. Among patients with spontaneous intracranial hypotension, we have recently described relevant differences compared with healthy controls in segment C2/C3. The method might be a promising tool to solve clinical and diagnostic ambiguities. Therefore, it is important to understand the physiological range and the effects of clinical and anatomical parameters in healthy volunteers. Within a prospective study, 3D T2 -weighted MRI for spinal canal anatomy and cardiac-gated phase-contrast MRI adapted to CSF flow and spinal cord motion for time-resolved velocity data and derivatives were performed in 70 participants (age 20-79 years) in segments C2/C3 and C5/C6. Correlations were analyzed by multiple linear regression models; p < 0.01 was required to assume a significant impact of clinical or anatomical data quantified by the regression coefficient B. Data showed that in C2/C3, the CSF and spinal cord craniocaudal velocity ranges were 4.5 ± 0.9 and 0.55 ± 0.15 cm/s; the total displacements were 1.1 ± 0.3 and 0.07 ± 0.02 cm, respectively. The craniocaudal range of the CSF flow rate was 8.6 ± 2.4 mL/s; the CSF stroke volume was 2.1 ± 0.7 mL. In C5/C5, physiological narrowing of the spinal canal caused higher CSF velocity ranges and lower stroke volume (C5/C6 B = +1.64 cm/s, p < 0.001; B = -0.4 mL, p = 0.002, respectively). Aging correlated to lower spinal cord motion (e.g., B = -0.01 cm per 10 years of aging, p < 0.001). Increased diastolic blood pressure was associated with lower spinal cord motion and CSF flow parameters (e.g., C2/C3 CSF stroke volume B = -0.3 mL per 10 mmHg, p < 0.001). Males showed higher CSF flow and spinal cord motion (e.g., CSF stroke volume B = +0.5 mL, p < 0.001; total displacement spinal cord B = +0.016 cm, p = 0.002). We therefore propose to stratify data for age and sex and to adjust for diastolic blood pressure and segmental narrowing in future clinical studies.

Overview of Spontaneous Intracranial Hypotension and Differential Diagnosis with Chiari I Malformation.

Spontaneous intracranial hypotension (SIH) occurs due to a leakage of the cerebrospinal fluid (CSF) lowering the pressure of subarachnoid space, mostly caused by a dural breach or discogenic microspur. As a result of less support provided by CSF pressure, intracranial structures are stretched downward, leading to a constellation of more or less typical MRI findings, including venous congestion, subdural effusions, brainstem sagging and low-lying cerebellar tonsils. Clinic examination and an MRI are usually enough to allow for the diagnosis; however, finding the location of the dural tear is challenging. SIH shares some MRI features with Chiari malformation type I (CM1), especially low-lying cerebellar tonsils. Since SIH is likely underdiagnosed, these findings could be interpreted as signs of CM1, leading to a misdiagnosis and an incorrect treatment pathway. Medical treatment, including steroids, bed rest, hydration caffeine, and a blind epidural blood patch, have been used in this condition with variable success rates. For some years, CSF venous fistulas have been described as the cause of SIH, and a specific diagnostic and therapeutic pathway have been proposed. The current literature on SIH with a focus on diagnosis, treatment, and differential diagnosis with CM1, is reviewed and discussed.

Cerebrospinal Venous Fistula Presenting with Cognitive Decline: Systematic Literature Review and Report of Two Cases.

OBJECTIVE: A cerebrospinal fluid (CSF) venous fistula (CVF) is an aberrant connection between the subarachnoid space and a vein resulting in CSF loss. The presentation and management of CVF with cognitive decline is incompletely understood. METHODS: A systematic review was completed following the PRISMA guidelines. Articles that included at least 1 case of imaging-confirmed CVF with details on patient treatment were included. A separate review of cases of patients with spontaneous intracranial hypotension (SIH) with frontotemporal dementia (FTD) or dementia symptoms was also completed. RESULTS: Ten CVF articles (69 patients; average age, 51.5 years) and 5 SIH with FTD or dementia articles (n = 41; average age, 55.9 years) were identified. Only 1 patients with CVF with cognitive abnormalities was identified. The most common symptom was headache in both reviews. Brain sag was identified in all patients, whereas CSF leak was identified in only 2 patients with SIH with FTD or dementia (4.9%). An epidural blood or fibrin glue patch was used in all patients with CVF and in 33 patients with SIH with FTD or dementia. Fifty-five patients with CVF (79.7%) and 27 patients with SIH with FTD or dementia (65.9%) had surgery. CONCLUSIONS: The 2 cases and literature reviews show the difficulty in diagnosis and treatment of CVF with cognitive decline. Novel imaging techniques should be used in patients with cognitive decline in whom a CSF leak is suspected. Transvenous embolization or surgery should be considered before patching for treatment of CVF-induced brain sag and resulting dementia.

The SIH-EBP Score: A grading scale to predict the response to the first epidural blood patch in spontaneous intracranial hypotension.

BACKGROUND: To develop and validate an easy-to-use scoring system to predict the response to the first epidural blood patching in patients with spontaneous intracranial hypotension. METHODS: This study recruited consecutive patients with spontaneous intracranial hypotension receiving epidural blood patching in a tertiary medical center, which were chronologically divided into a derivation cohort and a validation cohort. In the derivation cohort, factors associated with the first epidural blood patching response were identified by using multivariable logistic regression modeling. A scoring system was developed, and the cutoff score was determined by using the receiver operating characteristic curve. The findings were verified in an independent validation cohort. RESULTS: The study involved 280 patients in the derivation cohort and 78 patients in the validation cohort. The spontaneous intracranial hypotension-epidural blood patching score (range 0-5) included two clinical variables (sex and age) and two radiological variables (midbrain-pons angle and anterior epidural cerebrospinal fluid collections). A score of ≥3 was predictive of the first epidural blood patching response, which was consistent in the validation cohort. Overall, patients who scored ≥3 were more likely to respond to the first epidural blood patching (odds ratio = 10.3). CONCLUSION: For patients with spontaneous intracranial hypotension-epidural blood patching score ≥3, it is prudent to attempt at least one targeted epidural blood patching before considering more invasive interventions.

Closing the Gap: A Case Report on a Blood Patch Solution for Cerebrospinal Fluid Leak.

Spontaneous intracranial hypotension is a condition resulting from cerebrospinal fluid leaks at the spinal level that disrupt the regulation of intracranial pressure. This disorder is an uncommon cause of debilitating headaches but can have variable clinical manifestations, which contributes to delayed diagnosis and potentially severe consequences. The standard treatment consists of conservative measures such as bed rest, hydration, and a pharmacological approach with paracetamol, caffeine, ergotamine, and dexamethasone. When conservative measures fail, an epidural blood patch is the gold standard treatment, where a small amount of blood is injected into the epidural space to form a clot to seal any existing leak. Recent studies showed a success rate of 64% without the need for further intervention. The authors report a case of a 55-year-old woman with a three-month history of daily severe headaches. Imaging exams showed subdural collections, suggesting the hypothesis of cerebrospinal fluid hypotension. After the failure of conservative measures, an epidural blood patch was performed with progressive clinical improvement.  This case demonstrates the potential effectiveness of an epidural blood patch in the management of spontaneous intracranial hypotension and its complications, offering an encouraging option for those unresponsive to conservative measures. It also highlights the importance of a multidisciplinary approach involving neurologists and anesthesiologists.

T2-Sampling Perfection With Application-Optimized Contrasts by Using Flip Angle Evolution (SPACE) Protocol MRI: A Safe, Minimally Invasive Screening Tool for Spinal CSF Leak Causing Spontaneous Intracranial Hypotension.

Spontaneous intracranial hypotension (SIH) due to a spinal cerebrospinal fluid (CSF) leak is secondary cause of headache with potentially devastating consequences. Its diagnosis is complicated owing to the lack of a reasonable, minimally invasive screening test. This results in many patients remaining undiagnosed for years after the headache onset. Current testing approaches are either overly invasive, namely the CSF infusion protocol or both invasive and insensitive viz. lumbar puncture (LP) with an opening pressure (OP) or computed tomography myelogram (CTM). These diagnostic methods are frequently employed in a clinical setting since they require access to the thecal space; they unfortunately have a dearth of sensitivity. CTM will not document a leak if it is intermittent or very slow and in the setting of a spinal CSF leak, the OP on LP may be high, low, or normal. A potential remedy for this state is the T2-sampling perfection with application-optimized contrasts by using flip angle evolution (SPACE) protocol spinal magnetic resonance imaging (MRI). We present two cases that demonstrate its potential value as a screening tool. It is well known for its high sensitivity for identifying spinal pathology and is minimally invasive, making it a good choice for a screening modality when diagnosing possible SIH cases.

Quantitative Measurement of Spinal Cerebrospinal Fluid by Cascade Artificial Intelligence Models in Patients with Spontaneous Intracranial Hypotension.

Cerebrospinal fluid (CSF) hypovolemia is the core of spontaneous intracranial hypotension (SIH). More than 1000 magnetic resonance myelography (MRM) images are required to evaluate each subject. An effective spinal CSF quantification method is needed. In this study, we proposed a cascade artificial intelligence (AI) model to automatically segment spinal CSF. From January 2014 to December 2019, patients with SIH and 12 healthy volunteers (HVs) were recruited. We evaluated the performance of AI models which combined object detection (YOLO v3) and semantic segmentation (U-net or U-net++). The network of performance was evaluated using intersection over union (IoU). The best AI model was used to quantify spinal CSF in patients. We obtained 25,603 slices of MRM images from 13 patients and 12 HVs. We divided the images into training, validation, and test datasets with a ratio of 4:1:5. The IoU of Cascade YOLO v3 plus U-net++ (0.9374) was the highest. Applying YOLO v3 plus U-net++ to another 13 SIH patients showed a significant decrease in the volume of spinal CSF measured (59.32 ± 10.94 mL) at disease onset compared to during their recovery stage (70.61 ± 15.31 mL). The cascade AI model provided a satisfactory performance with regard to the fully automatic segmentation of spinal CSF from MRM images. The spinal CSF volume obtained through its measurements could reflect a patient's clinical status.

Bonding Situation of σ-E-H Complexes in Transition Metal and Main Group Compounds.

The ambiguous bonding situation of σ-E-H (E=Si, B) complexes in transition metal compounds has been rationalized by means of Density Functional Theory calculations. To this end, the combination of the Energy Decomposition Analysis (EDA) method and its Natural Orbital for Chemical Valance (NOCV) extension has been applied to representative complexes described in the literature where the possible η1 versus η2 coordination mode is not unambiguously defined. Our quantitative analyses, which complement previous data based on the application of the Quantum Theory of Atoms in Molecules (QTAIM) approach, indicate that there exists a continuum between genuine η1 and η2 modes depending mainly on the strength of the backdonation. Finally, we also applied this EDA-NOCV approach to related main-group species where the backdonation is minimal.

Spontaneous Intracranial Hypotension Manifesting Orthostatic Headache Worsened by Playing the Saxophone and Treated by Japanese Herbal Kampo Medicine Goreisan.

We present a 15-year-old Japanese girl with no previous medical history who presented with a gradually worsening series of orthostatic headaches. We diagnosed spontaneous intracranial hypotension, worsened by playing the saxophone and its Valsalva maneuver effect. She was treated with Japanese herbal Kampo medicine Goreisan 7.5 g/day in three divided doses, and her symptoms gradually improved. Her headache has never recurred for a year when she played the saxophone. Our case's headache may have been further exacerbated by cerebrospinal fluid (CSF) leakage due to CSF pressure increase by Valsalva maneuvers while playing the saxophone. Our case suggested that the Japanese herbal Kampo medicine Goreisan can facilitate the glymphatic system and adjust the CSF pressure appropriately.

Co-existing fast CSF leaks and CSF-venous fistulas on dynamic CT myelography.

Spontaneous intracranial hypotension can be caused by spinal dural tears or CSF-venous fistulas. It is rare for patients to have more than one type of leak at any given time. Here, we illustrate 3 examples of dural tears that co-existed with CSF-venous fistulas, with both being seen on dynamic CT myelography. To our knowledge, coexistent CSF-venous fistulas and dural tears have not been previously illustrated on dynamic CT myelography, even though this is one of the most commonly used modalities to work-up patients with CSF leaks. We discuss the clinical importance of the rare co-occurrence of these leaks with regard to diagnosis and treatment, as well as implications for understanding and classifying CSF leaks.

Prediction of Target Epidural Blood Patch Treatment Efficacy in Spontaneous Intracranial Hypotension Using Follow-Up MRI.

OBJECTIVES: Epidural blood patching (EBP) is the mainstay therapy for spontaneous intracranial hypotension (SIH). MRI is used for evaluating spinal CSF leakage. Post-EBP MRI has been. shown to be effective in predicting the efficacy of EBP. However, there are few reports on how post-EBP MRI findings may change with time. The aim of this study was to evaluate the relationship between post-EBP MRI findings at different time points and the corresponding effectiveness of EBP. METHODS: We retrospectively reviewed 63 SIH patients who had received target EBP. All patients received an MRI follow-up within 10 days (post-EBP MRI) and at 3 months after EBP (3-month MRI). A sub-group analysis was performed at different post-EBP MRI time points (0-2, 3-6, and 7-10 days). The relationships between the post-EBP MRI findings and the EBP effectiveness were evaluated. RESULTS: Thirty-five (55.56%) patients were assigned to the EBP-effective group, and 28 (44.44%) were assigned to the EBP non-effective group according to the 3-month MRI. Compared to the EBP non-effective group, the EBP-effective group had significantly lower numbers of spinal CSF leakage in the post-EBP MRI (4.49 vs. 11.71; p = 0.000) and greater numbers of leakage improvement (7.66 vs. 2.96; p = 0.003). For patients who received post-EBP MRI during periods of 0-10, 0-2, 3-6, and 7-10 days, the cutoff values of numbers of spinal CSF leakage for predicting EBP failure were 4, 6, 4, and 5, respectively, with an AUC above 0.77. CONCLUSION: By using post-EBP MRI, which only takes approximately 20 min, predicting EBP efficacy became possible in SIH patients. This study provides cutoff values of numbers of spinal CSF leakage at different follow-up times to serve as clues of if further EBP is needed, which provides the novelty of the current study.

Cerebrospinal fluid hypovolemia syndrome mimicking ocular myasthenia gravis: A case report.

Purpose: Cerebrospinal fluid hypovolemia syndrome (CHS) is a rare clinical entity that can be caused by spontaneous cerebrospinal fluid (CSF) leakage. The aim of this study is to report a rare case of CHS after a traffic accident in a patient who presented with diplopia and ptosis with fluctuation and was initially diagnosed with ocular myasthenia gravis. Observeations: A 29-year-old man exhibited fluctuating left ptosis and diplopia after a traffic accident. Although he was suspected of having myasthenia gravis and was treated using oral pyridostigmine bromide, his symptoms did not improve. He also had orthostatic headaches and malaise after the accident. His symptoms were suspected to be associated with traumatic cerebrospinal fluid hypovolemia. After 1000-mL fluid replacement, his diplopia and ptosis improved, and orbital T2-weghted MRI detected a high-signal zone around the optic nerve. We diagnosed him with oculomotor nerve paresis associated with cerebrospinal fluid hypovolemia. The symptoms, including ptosis, diplopia, orthostatic headaches, and malaise, disappeared after epidural blood patch therapy. Conclusions and Importance: When treating patients with fluctuating ocular symptoms, such as diplopia and ptosis, who have a history of trauma and orthostatic headaches, the possibility of CHS should be considered in the differential diagnosis.

First-line steroid treatment for spontaneous intracranial hypotension.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a syndrome characterized by low cerebrospinal fluid (CSF) pressure and postural headaches, and affects 1 per 20,000 individuals every year. CASE REPORT: We report an otherwise healthy 38-year-old man admitted to the hospital with orthostatic headache that developed 48 h after a short-haul flight during which he sustained a neck injury due to turbulence. Neurological examination, blood analysis and computed tomography scan performed at the emergency service were normal. Brain and spine magnetic resonance imaging (MRI) showed diffuse pachymeningeal enhancement and contrast medium egress from the subarachnoid space into the epidural space at the level of C2. The patient was treated with bed rest, hydration and 1 mg/kg/day oral prednisone for 5 days, with a gradual withdrawal in the following 7 days. Complete symptomatic relief was observed after 16 days, with resolution of the pathological findings on brain and spinal MRI after 1 month, except for localized pachymeningeal enhancement. Clinical relief was maintained over time until last follow-up visit 9 months later. CONCLUSION: Successful conservative treatment barely exceeds one quarter of cases of SIH. The clinical benefits of steroids may result from several mechanisms of action, for example, improving brain oedema and inflammation, determining fluid retention, and facilitating reabsorption of the CSF from extradural space. Notwithstanding that epidural blood patch remains the most successful treatment for SIH, future studies should explore the effectiveness of steroids as first-line therapy in addition to the most commonly suggested measures of bed rest and hydration.

Surgical Treatment Efficacy of CSF-Venous Fistulas: Systematic Review.

BACKGROUND: Cerebrospinal fluid (CSF)-venous fistula presents a pathologic connection between spinal subarachnoid space and adjacent epidural vein or veins. It is one of the 3 main causes of spontaneous intracranial hypotension along with dural defects and meningeal diverticulum. We performed a systematic review of the literature and analyzed individual participants' data focusing on clinical outcomes after different treatment modalities of CSF-venous fistula. METHODS: Systematic review was conducted according to PRISMA recommendations. Literature search was performed in PubMed and Web of Science databases with following key phrases: "CSF-venous fistula", "Spontaneous intracranial hypotension". Overall, 97 articles were found during the initial search; 15 were included for the final analysis, with a total number of 137 patients. RESULTS: Epidural blood patch (EBP) was performed as a first-line treatment in 37.1% of patients in individual data group, often not combined with fibrin glue (61.5%). Either partial (69.2%) or no resolution (30.8%) of symptoms was achieved after EBP injection. Nerve root ligation was the most common method of exclusion of CSF-venous fistula. Complete resolution of symptoms was achieved in 69.0% of patients, in 21.4% it was partial and in 9.5% no regress was found. Endovascular treatment was described only in 1 study. CONCLUSIONS: Surgical ligation of fistula is a treatment of choice. In approximately 70% of patients complete long-term resolution of symptoms is achieved after surgery. Endovascular treatment and fibrin glue injections are prospective and evolving options, which require further investigation.