Contribution of Otoacoustic Emissions for Diagnosis of Atypical or Recurrent Intracranial Hypotension. A Cases Series.

BACKGROUND: The diagnosis of spontaneous or post-traumatic intracranial hypotension mainly rely on clinical features and neuroimaging. In atypical presentations, other non-invasive tests are missing to support the diagnosis of intracranial hypotension. The assessment of otoacoustic emissions (OAE) shown interest to monitor intracranial pressure mainly in cases of intracranial hypertension. This non-invasive method was also assessed in response to pressure change after lumbar puncture. A few reports showed abnormal results of distortion product otoacoustic emissions (DPOAE) in cases of spontaneous or post-traumatic intracranial hypotension. We describe additional results in a series of intracranial hypotension cases. We discuss the interest of DPOAE assessment in atypical presentations of intracranial hypotension. We review the other non-invasive tests reported in literature. METHODS: We studied 4 atypical or recurrent cases of spontaneous or post-traumatic intracranial hypotension by recording OAE in sitting then supine position. RESULTS: Unilateral or bilateral abnormal changes of DPOAE were recorded in all cases, in response to postural test. These changes were present even in the absence of vestibular symptoms. CONCLUSION: The study of OAE may be a non-invasive tool for the diagnosis of spontaneous intracranial hypotension.

Cerebrospinal Fluid Refill Test as a Novel Diagnostic Tool for Cerebrospinal Fluid Hypovolemia: Preliminary Result.

OBJECTIVE: Cerebrospinal fluid (CSF) hypovolemia presents with orthostatic headaches due to CSF leakage. However, a direct association between the lack of CSF and clinical symptoms has not been found. CSF hypovolemia can be improved by refilling CSF. Therefore, we assessed the validity of a CSF refill test. METHODS: From November 2019 to August 2021, we included 10 patients (≥18 years old) with potential CSF hypovolemia, clear orthostatic headaches, and a CSF opening pressure <10 cmH2O. In the CSF refill test, 10 mL of artificial CSF was injected intrathecally. The primary outcome was improvement in orthostatic headache assessed using a visual analog scale (VAS), while the secondary outcomes were the 10-m walk time and adverse events. When the symptoms temporarily improved after intrathecal injection, the patients underwent radiologic imaging to identify the CSF leak, and an epidural blood patch was proposed accordingly. RESULTS: All patients showed post-test improvements in the VAS score (median [interquartile range], pretest 63.0 [50.3-74.3] vs. post-test 1.5 [0.0-26.0]). The 10-m walk time also significantly improved (9.5 [8.5-10.2] s vs. 8.2 [7.9-8.7] s). One patient experienced temporary right leg numbness associated with a lumbar puncture. After radiologic investigation, 9 patients underwent epidural blood patches, of which 6 were completely cured, and 3 revealed partial improvement. CONCLUSIONS: The cerebrospinal fluid (CSF) refill test was safe and effective in demonstrating the direct association between the lack of CSF and clinical symptoms and may help predict the outcome of an epidural blood patch.

Research productivity on spontaneous intracranial hypotension: A bibliometric analysis.

Introduction: Spontaneous intracranial hypotension (SIH) is an important cause of devastating headaches and caused by CSF-leaks in the spine. Research question: The aim of this analysis was to gain an overview of the progress of research on SIH over time. The global publication landscape relating to SIH was analyzed and comparisons between regions were made. Material and methods: A bibliometric analysis was performed by searching for research articles on SIH in PubMed published between 1983 and 2022. Countries responsible for the publications were ranked by the sum of citations. An average annual growth rate was calculated and the density of SIH publications per 100 000 physicians was determined. Results: We identified 974 articles. In 1983 only one SIH patient was reported; in 2021 the number of patients had increased to 4230. The average annual growth rate of SIH publications during this period was 12.7%. The most common publication type were case reports (n = 570). The most common medical specialty of the first author was neurology (n = 251) followed by neurosurgery (n = 250) and radiology (n = 191). Although most publications originated from the United States of America (USA), South Korea had the highest density of SIH investigators (37.86 publications per 100 000 medical doctors). The most cited paper (296 citations) was published in 2006 in JAMA (USA). Discussion and conclusion: Research on SIH has increased exponentially over the past four decades. The international community of SIH researchers is growing, and with it the opportunities for global networks involved in research, treatment, and patient education.

Spontaneous low pressure, low CSF volume headaches: spontaneous CSF leaks.

Spontaneous intracranial hypotension typically results from spontaneous cerebrospinal fluid (CSF) leak, often at spine level and only rarely from skull base. Once considered rare, it is now diagnosed far more commonly than before and is recognized as an important cause of headaches. CSF leak leads to loss of CSF volume. Considering that the skull is a rigid noncollapsible container, loss of CSF volume is typically compensated by subdural fluid collections and by increase in intracranial venous blood which, in turn, causes pachymeningeal thickening, enlarged pituitary, and engorgement of cerebral venous sinuses on magnetic resonance imaging (MRI). Another consequence of CSF hypovolemia is sinking of the brain, with descent of the cerebellar tonsils and brainstem as well as crowding of the posterior fossa noted on head MRI. The clinical consequences of these changes include headaches that are often but not always orthostatic, nausea, occasional emesis, neck and interscapular pain, cochleovestibular manifestations, cranial nerve palsies, and several other manifestations attributed to pressure upon or stretching of the cranial nerves or brain or brainstem structures. CSF lymphocytic pleocytosis or increase in CSF protein concentration is not uncommon. CSF opening pressure is often low but can be within normal limits. Stigmata of disorders of connective tissue matrix are seen in some of the patients. An epidural blood patch, once or more, targeted or distant, at one site or bilevel, has emerged as the treatment of choice for those who have failed the conservative measures. Epidural injection of fibrin glue of both blood and fibrin glue can be considered in selected cases. Surgery to stop the leak is considered when the exact site of the leak has been determined by neurodiagnostic studies and when less invasive measures have failed. Subdural hematomas sometimes complicate the CSF leaks; a rebound intracranial hypertension after successful treatment of a leak is not rare. Cerebral venous sinus thrombosis as a complication is fortunately less common, and superficial siderosis and bibrachial amyotrophy are rare. Short-term recurrences are not uncommon, and long-term recurrences are not rare.

Cerebrospinal Fluid Leaks: A Case Series of Sinus Opacification on Computed Tomography (CT) Imaging.

Introduction: Cerebrospinal fluid (CSF) leaks occur when fluid seeps through a dural or skull base defect, typically in the nose or ear. CSF leaks commonly are identified and diagnosed by use of computed tomography (CT) and CT cisternogram. CT findings suggestive of a CSF leak include a skull-based bone defect along with opacification of the contiguous sinus. This study examined a series of CSF leaks on CT imaging to document imaging findings. Methods: A single-institution retrospective review of cases of CSF leak diagnosed by CT maxillofacial or CT cisternogram from January 1, 2008 to March 12, 2018 was performed. Patient demographics, history, imaging findings, and treatment were recorded. Results: Thirty-nine patients met the inclusion criteria for the study. The average age was 51, and a large majority were female (76.9%). Among the 25 patients in which it was reported, the mean size of skull base defect was 0.472 cm. Of the 39 total cases, 27 patients (69.2%) presented with sinus opacification on CT imaging. Conclusions: Radiologists should be aware of the possibility of notable sinus opacification observable on CT when investigating a potential CSF leak. Opacification may vary in both location and size depending on the nature and location of a CSF leak. Further research is needed to draw a correlation between sinus opacification seen on CT scan and the diagnosed origin of a CSF leak.

Middle meningeal artery embolization for chronic subdural hematoma with cerebrospinal fluid hypovolemia: A report of 2 cases.

BACKGROUND: Chronic subdural hematoma (CSDH) with cerebrospinal fluid hypovolemia syndrome (CHS) remains refractory to standard treatment with hematoma drainage by burr hole and irrigation and/or epidural blood patch. Previously, we reported the utility of middle meningeal artery (MMA) embolization for intractable CSDH. In this study, we present the usefulness of MMA embolization as a treatment for CSDHs with CHSs. CASES: We present two cases of CSDHs with CHSs occurring in patients, 1 treated with burr hole craniotomy and irrigation, and the other treated with the epidural blood patch. Both patients exhibited similar-appearing bilateral relatively-thin hematomas, hyperplasia, and enhanced contrast effects in the dura mater, and extradural hygroma in the cervical portion on enhanced magnetic resonance imaging scans. Also, to reviewing prior literature and imaging findings, they had already undergone conventional treatment. We added MMA embolization treatment and they followed a good course. RESULTS: Despite the known intractable outcomes of patients with CSDHs with CHSs, MMA embolization worked well in the current case series. CONCLUSION: MMA embolization might be considered as a preferred therapeutic option for CSDHs with CHSs in order to buy time before the epidural blood patch starts working.

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.

Cerebrospinal Fluid Hypovolemia: A Case Report of a Red Herring.

Mild intracranial hypotension can lead to classically recognizable symptoms such as positional headaches, nausea, vomiting, and occasionally blurred vision. Less commonly, severe cerebrospinal fluid (CSF) hypovolemia can lead to a life-threatening condition that mimics intracranial hypertension, including transtentorial herniation and subsequent rapid neurologic decline. In this report we present a unique case of severe intracranial hypotension from a thoracic tumor resection that led to symptoms initially mistaken for intracranial hypertension, however ultimately correctly diagnosed as severe CSF hypovolemia that improved with dural repair. Additionally, we describe a rare angiography finding associated with CSF hypovolemia, kinking of the basilar artery. Here we report a 47-year-old female with neurofibromatosis Type 2 found to have a T3 intradural extramedullary tumor. She initially presented with urinary incontinence and gait/balance difficulty. She underwent thoracic laminectomies at T3 and T4 for the excision of the lesion. She was discharged on postoperative day 4. On postoperative day 9, she was noted to have nausea, vomiting, and decreased consciousness. Head computed tomography (CT) demonstrated acute downward herniation. She was transferred to our institution from a community facility obtunded and was intubated for airway protection. She was placed in the Trendelenburg position with immediate improvement, and declined every time her head was raised. Angiogram showed significant kinking of her basilar artery. A CT myelogram revealed a CSF leak from her recent thoracic surgery. She underwent exploration of her thoracic wound, and a ventral durotomy was repaired. Following this, she began to tolerate the head of bed elevations and recovered back to her neurologic baseline. A postoperative head CT angiography obtained before discharge showed improvement of her basilar kink. Mild intracranial hypotension is a common finding in patients who undergo procedures that enter the CSF space. Severe intracranial hypotension can easily be missed diagnosed as the signs on the exam are similar to patients with signs of intracranial hypertension. It is of paramount importance that the clinician recognizes brain sag, as the treatment algorithms are vastly different from that of intracranial hypertension leading to transtentorial herniation.

Management of spontaneous cerebrospinal fluid hypovolemia-associated massive chronic subdural hematoma with reinforced restriction of physical activity: report of three cases.

Spontaneous cerebrospinal fluid hypovolemia (SCFH) is an uncommon entity in neurosurgical practice. Without early recognition and management, some patients with SCFH can develop chronic subdural hematoma (CSDH). Generally, management of patients with SCFH without CSDH is relatively straightforward. However, this circumstance becomes more complicated in patients with concurrent CSDH. Treatment measures simply based on the respective management principles of SCFH and CSDH are insufficient or even disastrous. Our previous study showed that reinforced restriction of physical activity was a promising strategy in managing CSDH in the general population. We applied this strategy in three consecutive patients with SCFH and massive CSDH. All of the patients experienced complete resolution of CSDH. This study not only enriches the basic theory of formation and progression of CSDH, but also demonstrates that reinforced restriction of physical activity could be treated as an alternative or adjuvant management of CSDH secondary to SCFH.

Cerebrospinal Fluid Hypovolemia and Posterior Reversible Encephalopathy Syndrome.

Posterior reversible encephalopathy syndrome (PRES) is a reversible neuroradiological syndrome characterized by reversible vasogenic edema. The pathophysiological mechanism is still unclear, but PRES may be triggered by various etiologies. To date, only a few PRES cases linked to cerebrospinal fluid (CSF) hypovolemia were reported. The association between PRES and CSF hypovolemia needs to be explored. We presented a case of PRES with CSF hypovolemia as a result of an inadvertent dural puncture and reviewed the literature to identify the clinical characterization and pathophysiological mechanism of PRES following CSF hypovolemia. A total of 31 cases of PRES-CSF hypovolemia was included for analysis. The median age was 33 years, with a notable female predominance (87.1%). Fifteen patients (48.4%) didn't have either a history of hypertension nor an episode of hypertension. The most common cause of CSF hypovolemia was epidural or lumbar puncture (n = 21), followed by CSF shunt (n = 6). The median interval between the procedure leading to CSF hypovolemia and PRES was 4 days. Seizure, altered mental state, and headache were the most frequent presenting symptom. The parietooccipital pattern was most frequent (71.0%). Conservative management remains the mainstay of treatment with excellent outcomes. Three patients had a second episode of PRES. CSF hypovolemia is a plausible cause of PRES via a unique pathophysiologic mechanism including arterial hyperperfusion and venous dysfunction. Patients with CSF hypovolemia is more susceptible to PRES, which is potentially life-threatening. Given that CSF hypovolemia is a common complication of anesthetic, neurological, and neurosurgical procedures, PRES should be early considered for prompt diagnosis and appropriate management.

The Cervical Spine as a Predominant Site of Cerebrospinal Fluid Leak: Preliminary Results Using the Overflow Leak Test.

BACKGROUND: Cerebrospinal fluid (CSF) hypovolemia is usually treated via an epidural blood patch (EBP). Accurate placement of the EBP at the site of CSF leakage is required for successful treatment of CSF hypovolemia. The thoracolumbar spine is evidently a common site of leakage, but because rates of detection of the leakage site via conventional imaging have historically not been high, there may be other common leakage sites. In this study, CSF leakage sites were identified via a combination of conventional imaging, a new method called the overflow leak test, and patient interviews. METHODS: CSF leakage sites were identified using computed tomography myelography, radioisotope cisternography, and the overflow leak test in 14 patients with CSF hypovolemia. The patients were also asked about their history with regard to potential trauma. EBP was performed, and the accuracy of leakage site identification was assessed. RESULTS: Conventional imaging identified a leakage site in 7 of 14 patients, and in most cases it was in the lumbar spine. In the remaining 7 cases, the overflow leak test and ascertaining a history of trauma facilitated identification of the cervical spine as a leakage site. The site of the EBP was the cervical spine in 10 patients and the lumbar spine in 4 patients. Complete recovery was observed in 13 of 14 patients. CONCLUSIONS: The cervical spine was a common leakage site in this study. Leakage in the cervical spine was undetectable via conventional imaging, suggesting that many cases of cervical spine leakage may remain undetected.

Cerebrospinal fluid hypovolemia syndrome after a traffic accident with abnormal eye movements: A case report.

PURPOSE: To describe a rare case of cerebrospinal fluid hypovolemia syndrome after a traffic accident with abnormal eye movements. OBSERVATIONS: A 19-year-old man was referred to our clinic after being hit by a car five months ago while riding a bicycle. After the accident, he sometimes noticed oscillopsia, and had postural headaches and reading difficulties. His eye movement recording revealed square wave jerks during fixation and decreased pursuit gain during horizontal smooth pursuit. MR myelography detected cerebrospinal fluid leakage and the patient was diagnosed with cerebrospinal fluid hypovolemia. After undergoing epidural blood patch therapy, the leakage disappeared, and his postural headaches improved immediately. Square wave jerks and decreased pursuit gain improved, and his oscillopsia and reading difficulty also improved after therapy. CONCLUSIONS AND IMPORTANCE: A patient with cerebrospinal fluid hypovolemia presented with square wave jerks and decreased pursuit gain. Epidural blood patch therapy was effective for the symptoms. When treating patients with oscillopsia and postural headaches, we should consider the possibility of cerebrospinal fluid hypovolemia syndrome in the differential diagnosis.

Ventral longitudinal intraspinal fluid collection: Rare presentation as brachial amyotrophy and intracranial hypotension.

CONTEXT: Ventral longitudinal intraspinal fluid collection (VLISFC) presenting as hand amyotrophy has been described only in a few cases and there are no reports on associated intracranial CSF hypovolemia (ICH). We describe the clinical and imaging findings of a case with combined brachial amyotrophy and ICH secondary to VLISFC. FINDINGS: A 31 year old man presented with severe positional neck discomfort, radiating pain, progressive asymmetrical wasting and weakness of distal upper limbs. Contrast Magnetic Resonance Imaging (MRI) of the spine demonstrated a ventral extradural intraspinal fluid collection extending from upper border of C6 to lower border of T3 vertebra with pockets of dorsal collection. Three-dimensional constructive interference in steady state (CISS 3D) used in spinal imaging for identification of CSF leak corroborated with the extent seen on T2 sagittal sections; however, the site of the leak was not identified. After a year he developed disturbing postural headache which was relieved in recumbent position. Follow up MRI of brain was normal while spine demonstrated significant cervical cord atrophy and bilateral cord white matter hyperintensities. Conclusion / Clinical Relevance: We report this unusual case where local compression by VLISFC located at the cervical and upper thoracic level not only caused distal bi-brachial amyotrophy mimicking Hirayama disease but also led to secondary intracranial hypotension. An early identification and intervention could possibly have prevented the onset of ICH.

Procedural predictors of epidural blood patch efficacy in spontaneous intracranial hypotension.

BACKGROUND AND OBJECTIVE: Epidural blood patch (EBP) is a safe and effective treatment for spontaneous intracranial hypotension (SIH), but clinical and procedural variables that predict EBP efficacy remain nebulous. METHODS: This study is an institutional review board-approved retrospective case series with dichotomized EBP efficacy defined at 3 months. The study included 202 patients receiving 604 EBPs; iatrogenic cerebrospinal fluid leaks were excluded. RESULTS: Of the EBPs, 473 (78%) were single-level, 349 (58%) lumbar, 75 (12%) bilevel, and 56 (9%) multilevel (≥3 levels). Higher volume (OR 1.64; p<0.0001), bilevel (3.17, 1.91-5.27; p<0.0001), and multilevel (117.3, 28.04-490.67; p<0.0001) EBP strategies predicted greater efficacy. Only volume (1.64, 1.47-1.87; p<0.0001) remained significant in multivariate analysis. Site-directed patches were more effective than non-targeted patches (8.35, 0.97-72.1; p=0.033). Lower thoracic plus lumbar was the most successful bilevel strategy, lasting for a median of 74 (3-187) days. CONCLUSIONS: In this large cohort of EBP in SIH, volume, number of spinal levels injected, and site-directed strategies significantly correlated with greater likelihood of first EBP efficacy. Volume and leak site coverage likely explain the increased efficacy with bilevel and multilevel patches. In patients with cryptogenic leak site, and either moderate disability, negative prognostic brain MRI findings for successful EBP, or failed previous lumbar EBP, a low thoracic plus lumbar bilevel EBP strategy is recommended. Multilevel EBP incorporating transforaminal administration and fibrin glue should be considered in patients refractory to bilevel EBP. An algorithmic approach to treating SIH is proposed.

Central Herniation Induced by Craniotomy Prompting Air Replacement for Subdural Fluid Collection Due to Cerebrospinal Fluid Hypovolemia.

BACKGROUND: Chronic subdural hematoma (CSDH) often occurs in association with cerebrospinal fluid (CSF) hypovolemia. Many cases with CSDH due to CSF hypovolemia and treated by burr hole surgery have been reported to present with paradoxical deterioration. However, the mechanisms and pathology of deterioration after surgery for CSDH due to CSF hypovolemia remain obscure. CASE DESCRIPTION: We report herein a 62-year-old man with gait disturbance due to subdural fluid collection (SDFC) who underwent burr hole irrigation and additional craniotomy, in which postoperative deterioration resulted from rapidly progressing central herniation with a large amount of air accumulation. Epidural blood patch with saline infusion in the thoracic spine finally resolved central herniation. CONCLUSION: SDFC deteriorating after surgery has never been reported. SDFC has communication with CSF differing from mature CSDH composed of closed cavity surrounded by neomembrane. Under situations of CSF hypovolemia due to spinal dural tear, opening the cranium can prompt air replacement in the CSF space, which might represent a substantial risk for central herniation caused by a rapid loss of buoyancy force.

Early post-operative cerebrospinal fluid hypovolemia: Report of 7 cases.

Cerebrospinal fluid (CSF) hypovolemia is a common neurosurgical condition, which may be spontaneous or iatrogenic. At our institution, a substantial number of the reported cases of early post-operative CSF hypovolemia were identified to have unintentional or unrecognized post-operative continuous excessive CSF leakage. Cases who presented with post-operative CSF hypovolemia several days after uneventful intracranial surgeries without continuous CSF leakage were rarely reported. A retrospective review of the medical records of these patients was performed to identify those patients who developed early post-operative CSF hypovolemia without the presence of post-operative continuous CSF leakage. A total of 7 patients, 5 of which were males, were identified in this retrospective study. They experienced CSF hypovolemia between days 1 and 7 after emergency or scheduled intracranial surgeries. Ventricular collapse, cisternal effacement and midline shift are the most common radiological observations. With early diagnosis and management, 4 of the patients achieved a Glasgow Outcome Scale (GOS) score of 5, 1 achieved a GOS score of 4 and the remaining 2 had a GOS score of 3. No mortality was noted in this series. Although rare in incidence, early post-operative CSF hypovolemia may occur without the existence of post-operative continuous CSF leakage. When the diagnosis of CSF hypovolemia is reached, factors that may exacerbate CSF compensation should be promptly terminated. Trendelenburg position and sufficient intravenous hydration are practical and effective managements, and CSF hypovolemia may thereby be reversed in a substantial number of patients.

Excellent Outcomes of Large-Volume Epidural Blood Patch Using an Intravenous Catheter in 15 Consecutive Cases with Cerebrospinal Fluid Leak.

OBJECTIVE: The effects of large-volume epidural blood patch (EBP) remain unclear in patients with cerebrospinal fluid (CSF) leak. We report excellent outcomes from 15 consecutive CSF leak cases that underwent a large-volume EBP using an intravenous catheter from a single lumbar entry point, together with outcomes from 4 patients who underwent direct surgical closure or drip-and-rest therapy during the same period. METHODS: Nineteen patients with idiopathic CSF leaks were enrolled in this study since November 2011 (12 women; mean age, 43.3 ± 14.0 years). Patient demographic data, radiologic findings, symptoms, administrated therapies, complications, and clinical courses were investigated retrospectively. RESULTS: Different types of headache were observed, including typical orthostatic headache alone (n = 10), orthostatic headache with chronic subdural hematoma (CSDH) (n = 3), and posture-unrelated headache accompanied with CSDH (n = 6). Regarding treatments, in 1 case, direct surgical closure was performed. In 15 cases, large-volume EBPs were performed, and the volume of injected blood was 44.8 ± 21.6 mL. The other 3 cases were treated by simple drip infusion regardless of the drainage for CSDH. Out of 9 cases with accompanied CSDH, recurrence of subdural hematoma was completely prevented by the application of an EBP after drainage in 5 cases and without drainage in 3 cases, and by simple intravenous drip-and-rest therapy after drainage in 1 case. Among 10 patients suffering from typical orthostatic headache alone, symptoms disappeared completely in 7 cases and were relieved in 3 cases. CONCLUSIONS: We demonstrate here a perfect control of spinal CSF leaks with the administration of a large-volume EBP through an intravenous catheter.

Multilevel, ultra-large-volume epidural blood patch for the treatment of neurocognitive decline associated with spontaneous intracranial hypotension: case report.

Spontaneous intracranial hypotension (SIH) is a progressive clinical syndrome characterized by orthostatic headaches, nausea, emesis, and occasionally focal neurological deficits. Rarely, SIH is associated with neurocognitive changes. An epidural blood patch (EBP) is commonly used to treat SIH when conservative measures are inadequate, although some patients require multiple EBP procedures or do not respond at all. Recently, the use of a large-volume (LV) EBP has been described to treat occult leak sites in treatment-refractory SIH. This article describes the management of a patient with profound neurocognitive decline associated with SIH, who was refractory to conservative management and multiple interventions. The authors describe the successful use of an ultra-LV-EBP of 120 ml across multiple levels, the largest volume reported in the literature, and describe the technical aspects of the procedure. This procedure has resulted in dramatic and sustained symptom resolution.

Targeted Epidural Blood Patch Under O-Arm-Guided Stereotactic Navigation in Patients with Intracranial Hypotension Associated with a Spinal Cerebrospinal Fluid Leak and Ventral Dural Defect.

OBJECTIVE: Targeted epidural blood patch (EBP) at the site of a presumed cerebrospinal fluid leak reportedly has better outcomes than non-targeted EBP; however, it is associated with a higher risk of wrong-site injection, such as iatrogenic subarachnoid or intramuscular injections, which lead to reintervention because of the insufficient coverage of injected blood. METHODS: Eight patients with intracranial hypotension owing to a CSF leak diagnosed with myelographic computed tomography (CT) and thin-cut magnetic resonance imaging (MRI) received an epidural blood patch under O-arm-guided stereotactic navigation. RESULTS: The leak site was identified on the basis of myelographic CT findings of a micro-spur, epidural contrast medium extravasations, and MRI findings of a ventral dural defect. During the EBP procedure, no iatrogenic dural puncture or subarachnoid injection occurred because O-arm-guided stereotactic navigation provided real-time feedback on the needle trajectory. O-arm CT revealed the sufficient coverage of injected blood following the first injection in 6 of 8 patients. In the 2 remaining patients, a second injection was performed during the same session because of insufficient coverage at the previous site. In all patients, complete recovery from orthostatic headaches was achieved after a single session. CONCLUSIONS: O-arm-guided navigation facilitated EBP by enabling real-time observations of the needle trajectory and distribution of injected blood while simultaneously avoiding major complications, such as wrong-site injections or reintervention.