Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension: a series.

Spontaneous intracranial hypotension (SIH) is a relatively uncommon cause of headache, which usually presents as orthostatic cranial pain and is relieved by recumbency. The precise cause of spontaneous spinal cerebrospinal fluid leakage related SIH remains unknown. We report the case of a 32-year-old man who presented with an orthostatic headache. Brain magnetic resonance imaging (MRI) revealed typical pachymeningeal enhancement. Radionuclide cisternography revealed leakages in the cervicothoracic and upper cervical areas. The patient was successfully treated by lumbar epidural blood patch (EBP). The diagnosis of SIH involves the assessment of the characteristic clinical presentations and non-invesive neuroimaging studies. The latest diagnostic criteria with more broadened spectrum due to variable manifestations are discussed. EBP is an effective treatment for SIH if conservative management fails.

Cerebrospinal fluid-venous fistulas (CVFs) are a major cause of spontaneous intracranial hypotension (SIH) and are best detected with lateral decubitus-CT myelography (LD-CTM) and lateral decubitus-digital subtraction myelography (LD-DSM). On LD-CTMs, we have often noticed an accessory dural sleeve (ADS) separate from the nerve root sleeve, a previously underrecognized imaging finding. The purpose of this study is to describe the imaging appearance of the ADS and its relationship to CVFs. Retrospective single-center review of LD-CTM examinations performed between August/2019 and December/2025 for suspected CVF, evaluated for: 1) Presence, location, size and morphology of an ADS; 2) Visibility of a radicular vein in relationship to the ADS; 3) relationship of ADSs to CVFs (when present). ADSs were defined as independent dural projections separate from nerve root sleeves. Morphologic classification (infundibular, linear, diverticular) was based on objective length and diameter criteria. Associations between ADS presence, clinical status, and CVF location were assessed using descriptive statistics, chi-square testing, and permutation-based simulation. 91 LD-CTMs from 59 patients were analyzed. 53 ADSs were identified in 33 patients (55.9%; 95% CI, 43.3%-67.9%), most commonly in the thoracic spine. A radicular vein was seen traversing the ADS in 49.1% of cases. Regarding morphology, 22 were infundibular (41.51%), 18 linear (33.96%) and 13 diverticular (24.53%). Only in 2 cases, the CVF originated from the ADS (6% of CVFs). Co-occurrence of ADS and CVF at the same level and side occurred more often than expected by chance with approaching statistical significance (p = 0.059), but ADS location demonstrated limited predictive value for CVF localization. ADSs are a common anatomic variant encountered on LD-CTMs that may mimic CSF leaks, particularly CVFs, and only rarely represent true CVFs. Recognition of ADS morphology and reliance on dynamic contrast behavior are essential to avoid false-positive diagnoses. Linear and diverticular morphologies were more likely to resemble fistulas. ADS: accessory dural sleeve; CSF: cerebrospinal fluid; CVF: cerebrospinal fluid-venous fistula; ICHD-3: International Classification of Headache Disorders, Third Edition; LD-CTM: lateral decubitus CT myelography; LD-DSM: lateral decubitus-digital subtraction myelography; SIH: spontaneous intracranial hypotension.

IntroductionDiscogenic microspurs are calcified outgrowths from the intervertebral disc which can perforate the dura, causing a leak of cerebrospinal fluid (CSF). Spontaneous leaks of the CSF present a recognized cause of spontaneous intracranial hypotension (SIH). Moreover, subdural hematomas (SDH) are a potentially severe complication of SIH. Research questionWe present a case of a bilateral subdural hematoma without orthostatic headaches caused by a discogenic microspur protruding from the T1-2 intervertebral disc. The microspur is conjectured to be the culprit of the leak by ventrally perforating the dura and catalyzing the causal chain leading to the formation of the subdural hemorrhage. Material and methodsA 79-year woman noticed a progressive gait disturbance accompanied by a decline of short-term memory over several months without experiencing orthostatic headaches. Magnetic resonance imaging (MRI) showed extensive bilateral subdural fronto-parietal hematoma, signs of CSF hypotension (dilated venous compartments), and computed tomography (CT) myelography revealed a CSF leak originating at the T1-2 level. ResultsThe leakage site was treated with microsurgical duraplasty leading to a regression of the symptoms and complete resolution of the subdural hematomas within five postoperative months. Discussion and conclusionDiscogenic microspurs can perforate the dura causing a CSF leak, leading to spontaneous intracranial hypotension, finally resulting in a bilateral subdural hematoma. This constellation of symptoms does not necessarily induce orthostatic headaches and can be treated with microsurgical duraplasty.

Advancements in CT myelography (CTM) have improved visualization of CSF-venous fistulas (CVFs), a frequent cause of spontaneous intracranial hypotension (SIH). However, the relative impact of the timing of image acquisition and the contrast density in the subarachnoid space remain unclear. This study compared the effects of timing and contrast density in the ipsilateral subarachnoid space and assessed the impact of other technical factors on CVF conspicuity using a validated instrument to stratify diagnostic confidence. A retrospective review of International Classification of Headache Disorders, 3rd edition-confirmed patients with SIH with CVFs was performed. Only fistulas classified as definite by the Duke CSF-Venous Fistula Confidence Score (DCCS) were included. All available CTMs covering each index fistula site were reviewed, excluding examinations occurring after surgery or embolization for a definite CVF. We assigned a DCCS to each acquisition and recorded contrast density in the subarachnoid space ipsilateral to the known CVF and image acquisition time. Patient positioning and scanner type were also collected as potential confounders. Ordinal logistic regression was used to assess associations with CVF conspicuity. One hundred forty-four patients with 149 definite CVFs comprised the final cohort, from which 222 CTMs and 697 acquisitions were assessed. Both increased contrast density and reduced acquisition time were associated with increased CVF conspicuity in univariate analyses (P < .001). When adjusting for sex, scanner type, and patient positioning in the multivariate model, contrast density and time remained significant predictors of conspicuity (P < .001). Density had a 4-fold greater impact on conspicuity than time, with a 14.3% increase in likelihood of CVF detection per 100 Hounsfield unit (HU) increase in attenuation and an optimal target threshold at 836 HU. Both contrast density and time influence conspicuity of CVFs on CTM; however, the greater relative impact of density suggests that myelogram technique should prioritize maximization of contrast density for optimal visualization of CVFs. Positioning strategies to increase local contrast pooling may improve CVF detection more effectively than timing adjustments alone.

Background: Spontaneous intracranial hypotension (SIH) is caused by spinal leakage of cerebrospinal fluid (CSF) and it is characterized by an orthostatic headache without a history of trauma or dural puncture. SIH may lead to serious complications such as subdural haematoma (SDH), may lead to neurological deficits and can even be life-threatening. Lumbar epidural blood patching (EBP) has been regarded as the mainstay of therapy for SIH, often providing instantaneous relief of symptoms in 90% of cases regardless of the site of the leak. There is no conclusive evidence regarding the specific time from the onset of symptoms after which the epidural blood patch should not be tried. This report presents a case of SIH that was successful with lumbar EBP after 6 weeks of symptom onset.

Spontaneous intracranial hypotension (SIH) is often misdiagnosed, and can lead to severe complications. Conventional MR sequences show a limited ability to aid in this diagnosis. MR-based intracranial pressure (MR-ICP) may be able to detect changes of intracranial elastance and pressure. To determine whether MR-ICP is able to differentiate SIH patients from normal subjects, improve diagnostic sensitivity, and provide an insight into the pathophysiology. Prospective. Twenty-eight SIH cases with orthostatic headache and 20 healthy volunteers. Cine phase-contrast MRI on a 1.5T scanner. Intracranial elastance (IE) was derived from the ratio of the peak-to-peak cerebrospinal fluid (CSF) pressure gradient (PGcsf-pp ) and intracranial volume change, obtained by summing all flows before each sequential cardiac frame. Student's t-test was used to compare the MR-ICP indexes and flow parameters between SIH patients and healthy volunteers (P < 0.01). The SIH patients with cervical epidural venous dilatation (EVD) had an IE of 0.121 ± 0.027 mmHg/cm/ml, significantly higher than that of the normal volunteers (0.085 ± 0.027 mmHg/cm/ml; P = 0.002). In contradistinction, the EVD-negative SIH patients, including four with no sign of CSF leaks, had significantly lower IE (0.055 ± 0.012 mmHg/cm/ml) compared with the normal volunteers and the EVD-positive group (P = 0.001, P < 0.001). The EVD-negative patients had significantly lower PGcsf-pp (0.024 ± 0.007 mmHg/cm) compared with the normal volunteers and the EVD-positive group (0.035 ± 0.011 mmHg/cm, 0.040 ± 0.010 mmHg/cm; P = 0.003, P < 0.001). Additionally, the MRI flow study showed a significant decrease in transcranial inflow and outflow of SIH patients (P < 0.01). We found that the MR-ICP method is potentially more sensitive than morphological MRI in the early diagnosis of SIH. Also, contrary to common belief, our results suggest that an abnormal craniospinal elastance might be the cause of SIH, instead of CSF leak. 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:1255-1263.

CSF-venous fistulas (CVFs) are a common cause of spontaneous intracranial hypotension. Due to the more routine use of decubitus myelography and advancements in various imaging techniques, recognition of CVFs has increased in recent years. Most commonly, patients harbor only 1 fistula at the time of myelography (although additional de novo fistulas can arise after treatment). Occasionally, 2 synchronous CVFs may be seen on a single myelogram. The coexistence of more than 2 CVFs, however, is quite rare and has only been previously described in 2 instances. Here, we present a multi-institutional series of 16 patients with 3 or more concurrently discovered CVFs, representing the largest cohort of such patients to date. We describe their clinical features, imaging findings, treatment approaches, and outcomes.

CSF venous fistula (CVF) is a rare cause of spontaneous intracranial hypotension (SIH) which is estimated to be found in 2.5% of patients with orthostatic headaches.1 In patients with persistent...

Percutaneous Treatment and Post-treatment Management of CSF Leaks and CSF-Venous Fistulas in Spontaneous Intracranial Hypotension.

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. 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. 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). EBP is a viable and effective option for the treatment of recurrent SIH caused by cerebrospinal fluid (CSF) leaks.

INTRODUCTION: Spinal cerebrospinal fluid (CSF)-leaks cause spontaneous intracranial hypotension (SIH). In persisting symptoms despite treatment, surgical closure of spinal CSF-leaks is the treatment of choice. METHODS: Since April 2019 SIH patients were operated using the minimal invasive technique of tubular retractors. Leaks were sealed using an interlaminar dorsal access and if necessary a transdural route. Neuromonitoring was used for ventral leaks in the first 16 cases. The primary outcome was the benefit of surgery with respect to orthostatic symptoms; secondary outcome was the occurrence of complications. RESULTS: Between April 2019 and December 2020 we included 58 patients, mean age 46 years (IQR 36-55), 65% female, with the diagnosis of SIH. We treated 38 ventral leaks, 17 dorsal/lateral leaks, 2 CSF-venous fistulas. In all but two patients (96.6%) the leak could be approached, identified and closed via the tubular retractor. Leaks were visualized via a transdural approach, after cutting the dentate ligament and lateralization of the ventral dura. Microspurs were removed and leaks were closed by sandwich patch using a fibrin sealant patch (ventral leaks) or clipping of the respective nerve root (lateral leaks, CSF-venous fistula). At a median follow up of 21.5 months (IQR 16-28), eight patients were lost to follow up and 45 reported a benefit from surgery with respect to orthostatic symptoms. Mild permanent neurologic deficits occurred in 1.7%, the revision rate due to persisting or recurring leak was 3.4% and the overall revisioin rate was 10.3%. CONCLUSIONS: Minimally invasive surgery using tubular retractors of 18-20mm diameter can be safely and effectively performed for closure of spinal dural CSF-leaks in specialized centers.

The diagnosis of spontaneous intracranial hypotension or cerebrospinal fluid (CSF) hypovolemia syndrome requires a high index of suspicion and meticulous history taking, demonstration of low CSF pressure and/or neuroimaging features. A 31-year-old male, presented with subacute onset moderate occipital and sub-occipital headaches precipitated by upright posture and relieved on recumbency and neck pain for 2 years. There was no trauma, cranial/spinal surgery. Clinical examination was normal and CSF opening pressure and laboratory study were normal. Magnetic resonance imaging (MRI) brain showed thin subdural hygroma. Another patient, 41-year-old male presented with 1 month of subacute onset severe bifrontal throbbing orthostatic headaches (OHs). CSF opening pressure was normal. Contrast MRI brain showed the presence of bilateral subdural hygromas, diffuse meningeal enhancement, venous distension, sagging of the brain, and tonsillar herniation. We report two cases of “spontaneous OHs” with normal CSF pressures who were successfully treated with epidural blood patching after poor response to conservative management.

Rationale:Cerebrospinal fluid (CSF) leaks, arising from abnormal openings in the protective layers surrounding the spinal cord and brain, are a significant medical concern. These leaks, triggered by various factors including trauma, medical interventions, or spontaneous rupture, lead to the draining of CSF—an essential fluid safeguarding the nervous system. A classic symptom of CSF leaks is an incapacitating headache exacerbated by sitting or standing but relieved by lying down. Spontaneous intracranial hypotension (SIH) denotes the clinical condition marked by postural headaches due to spontaneous CSF leakage and hypotension, often misdiagnosed or underdiagnosed. While orthostatic headaches are the hallmark, SIH may manifest with an array of symptoms including nausea, tinnitus, hearing loss, visual disturbances, and dizziness. Treatment options encompass conservative measures, epidural blood patches (EBP), and surgery, with EBP being the primary intervention.Patient Concern:The patient did not express any specific concerns regarding their medical diagnosis. However, they did harbor apprehensions that their condition might necessitate surgical intervention in the future.Diagnosis:The patient had been treated with antibiotics with a pre-diagnosis of sinusitis and was admitted to the neurology department of our hospital when his symptoms failed to improve. Cranial magnetic resonance imaging was interpreted as thickening of the dural surfaces and increased contrast uptake, thought to be due to intracranial hypotension. Cranial MR angiography was normal. Full-spine magnetic resonance imaging revealed a micro-spur at the C2 to 3 level and the T1 to 2 level in the posterior part of the corpus.Interventions:The cervical EBP was performed in the prone position under fluoroscopic guidance. There were no complications.Outcomes:The patient was invited for follow-up 1 week after the procedure, and control examination was normal.Lessons:SIH poses a diagnostic challenge due to its diverse clinical presentation and necessitates precise imaging for effective intervention. Cervical EBP emerges as a promising treatment modality, offering relief and improved quality of life for individuals grappling with this condition. However, clinicians must carefully assess patients and discuss potential risks and benefits before opting for cervical blood patches.

Epidural Blood Patch as a Diagnostic and Therapeutic Intervention in Spontaneous Intracranial Hypotension: A Novel Approach to Management