Absence of CSF flow within the cerebral aqueduct in spontaneous intracranial hypotension: a report of two cases

Spontaneous intracranial hypotension (SIH) is a potentially debilitating condition resulting from a low cerebrospinal fluid (CSF) volume secondary to spinal CSF leakage. Characteristic clinical and radiological imaging findings are helpful in diagnosis. Herein, we present and discuss the magnetic resonance imaging (MRI) and CSF flow study of two patients with SIH and no CSF flow within the cerebral aqueduct, which is extremely rare in the literature.

Pediatric post-dural puncture headache and paraplegia

A cerebrospinal fluid (CSF) leak developed in a 14-year-old girl and a 12-year-old boy following a diagnostic lumbar puncture. Two days and sixteen years later, respectively, paraplegia developed due to a functional disorder. Imaging revealed an extensive extradural CSF collection in both patients and digital subtraction myelography was required to pinpoint the exact site of a ventral dural puncture hole where the lumbar spinal needle had gone "through and through" the dural sac. The CSF leak was complicated by cortical vein thrombosis in one patient. Both patients underwent uneventful surgical repair of the ventral dural puncture hole with prompt resolution of the paraplegia. Iatrogenic ventral CSF leaks may become exceptionally long standing and may be complicated by paraplegia on a functional basis both in the acute and chronic phases.

A hidden pathophysiology of endolymphatic hydrops: case report of a patient with spontaneous intracranial hypotension presenting with sudden sensorineural hearing loss with vertigo

Spontaneous intracranial hypotension (SIH) is characterized by decreased cerebrospinal fluid (CSF) volume due to leakage through the dural membrane. We present the case of a patient with SIH manifested by fluctuating low-frequency hearing loss, tinnitus, and vertigo. In this patient, endolymphatic hydrops in the cochlea and saccule were visualized by means of a special sequence of inner ear magnetic resonance imaging scans, with a gadolinium-based contrast agent administered intravenously. Endolymphatic hydrops is a potential underlying pathophysiology of SIH-associated hearing impairment. We hypothesize that SIH may be a rare cause of endolymphatic hydrops.

Headache associated with intracranial hypotension: diagnostic challenges and difficulties in everyday neurological practice

Low pressure of cerebrospinal fluid (CSF) is a rare cause of headache, except when the patient undergoes a lumbar puncture. Headache associated with a low CSF pressure i.e. intracranial hypotension causes diagnostic difficulties. Headaches related to spontaneous intracranial hypotension (SIH) pose a significant diagnostic challenge in everyday neurological practice. Patients with headaches due to SIH are usually diagnosed only after a long delay. Diagnostic problems may result in unnecessary invasive diagnostic procedures, or even neurosurgical operations. Diagnosing headaches attributed to SIH requires the consideration of several clinical scenarios, and the disease's features causing primary or secondary disturbances. In this review, we discuss the differential diagnosis of SIH-related headaches with reference to accumulated knowledge, including meta-analyses, guidelines, casuistry, and the applicable criteria of the International Classification of Headache Disorders. In addition, we discuss head and spine magnetic resonance imaging abnormalities, which may indicate intracranial hypotension.

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.

Fluctuating hearing loss secondary to spontaneous intracranial hypotension: A case report and review of the literature

OBJECTIVE

Fluctuating sensorineural hearing loss (SNHL) has multiple etiologies, most commonly Ménière's disease (MD), recurrent sudden SNHL, and autoimmune inner ear disorders. Fluctuating SNHL has rarely been described as a symptom of spontaneous intracranial hypotension (SIH).

PATIENT

A 39-year-old previously healthy female presented with "Ménière's like" symptoms responsive to steroid treatment, which worsened during the day and improved in the supine position. Conservative treatment for MD consisting of low salt and caffeine diet and betahistine medication yielded no improvement. Secondary revision of brain imaging scans showed signs indicative of SIH, and a spinal cerebrospinal fluid leak was ultimately found and treated by a novel technique of transvenous fistula embolization by means of Onyx® glue, leading to gradual clinical improvement and near-complete resolution of symptoms.

CONCLUSION

SIH should be considered as part of the differential diagnosis of fluctuating SNHL. Clinical and radiological features should be known and sought. We suspect that early diagnosis and treatment can lead to cure and prevent permanent auditory damage.

Efficacy of transvenous embolization of CSF-venous fistula in spontaneous intracranial hypotension: Case-series

BACKGROUND

Spontaneous intracranial hypotension is a debilitating neurological condition which can be caused by a cerebrospinal fluid-venous fistula. Transvenous embolization is a promising technique to provide minimally invasive yet durable treatment.

METHODS

A retrospective single-center case series was performed on all patients who underwent transvenous embolization of a cerebrospinal fluid (CSF)-venous fistula. Clinical and radiographic parameters, including Bern score, were reported preoperatively and at 3-month follow-up.

RESULTS

Six patients underwent embolization of a CSF-venous fistula. All fistulae were located in the thoracic spine and technical success was achieved in all cases. Three patients had symptom resolution, two had significant improvement, and one had stable symptoms on follow-up. The mean Bern score was 6.83 (SD = 1.47) preoperatively and 1.83 (SD = 1.64) postoperatively with a mean improvement in Bern score of 5.0 (SD = 1.9, p = 0.0013).

CONCLUSIONS

CSF-venous fistulas are an increasingly recognized clinical entity which may be treated with transvenous embolization. This case series serves to further validate this technique and suggests it can be performed with similar outcomes in lower volume centers.

Reversible cerebral vasoconstriction syndrome following intracranial hypotension in a postpartum patient: a case report and literature review

Introduction

Reversible cerebral vasoconstriction syndrome (RCVS) is a potentially life-threatening neurological disorder, rarely linked to intracranial hypotension. The presentation showed a patient with intracranial hypotension after peridural anesthesia who experienced RCVS during the early postpartum period, suggesting a potential involvement of intracranial hypotension in RCVS occurrence.

Case report

A young female of 29 years of age initially developed an orthostatic headache after undergoing a painless delivery with lumbar epidural anesthesia. Intracranial hypotension was considered the underlying cause. Her headache was partially resolved after intravenous fluid therapy and strict bed rest. After 2 days, the patient had a new onset thunderclap headache with generalized seizures, cortical blindness, and elevated blood pressure. An MRI scan revealed high signal intensity within the temporal, parietal, and occipital lobes, left caudate nucleus, and right cerebellum on T2-FLAIR imaging with vasogenic edema. MR angiography indicated multifocal, segmental, diffuse narrowing affecting the cerebral arteries that are large and medium. An RCVS2 score was six, and the patient was diagnosed with RCVS. She was managed conservatively, quickly improving her symptoms. After 10 days, a follow-up MRI indicated a significant reduction in the abnormal signal, and a substantial resolution of the constriction of the cerebral artery constriction was confirmed by MR angiography.

Conclusion

Intracranial hypotension could potentially lead to RCVS in postpartum patients, and it may be triggered by cerebral vasospasm secondary to intracranial hypotension.

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.

Bilateral Sensorineural Hearing Loss Related to a Skull Base Spontaneous Cerebrospinal Fluid Leak: A Case Report and Literature Review

Spontaneous intracranial hypotension (SIH) is a rare condition characterized by orthostatic headache, pulsatile tinnitus, vertigo, nausea, and fluctuating hearing loss; this latter seems to be due to the development of cochlear endolymphatic hydrops following negative cerebrospinal fluid (CSF) pressure transmitted to the perilymphatic space through a patent cochlear aqueduct. We here describe a case of bilateral progressive sensorineural hearing loss (SNHL) due to intracranial hypotension caused by an undiagnosed spontaneous CSF leak from a skull base defect in a middle-aged woman. To the best of our knowledge, this is the first report describing a SNHL in a patient affected by SIH secondary to sphenoidal CSF leak.

Isolated Abducens Nerve Palsy Following Spinal Anesthesia

A healthy 28-year-old lady, para 1, presented to the emergency department with persistent frontal headache, nausea, and vomiting following an emergency cesarean section four days ago. She experienced difficulties with six failed attempts of spinal anesthesia intrapartum before conversion to general anesthesia. A 25-gauge Whitacre needle was utilized for administering spinal anesthesia under a sitting position. The anesthetist noticed a loss of resistance upon needle insertion, but only a negligible amount of cerebrospinal fluid was obtained upon removing the stylet. The patient underwent an emergency cesarean section due to fetal distress, and she was not in labor during the attempts of spinal anesthesia. Otherwise, the cesarean section lasted for an hour and was uneventful. No intrapartum eclampsia or pre-eclampsia. She was diagnosed with post-dural puncture headache, and her symptoms improved after receiving intravenous hydration, oral caffeine, and non-steroidal anti-inflammatory drug (NSAIDs). However, on the sixth day after the spinal anesthesia, she suddenly developed double vision. Examination showed bilateral visual acuity was measured at 6/7.5. No proptosis or ptosis was noted. The relative afferent pupillary defect was negative with no anisocoria. Both eyes were orthophoria with normal head posture. Extraocular muscles revealed a right abduction restriction of -1 with the patient complaining of binocular horizontal diplopia at the right gaze, consistent with right abducens nerve palsy. Systemic neurological findings were normal, and imaging results were unremarkable. Diagnosis of right abducens nerve palsy post-dural puncture was made clinically. The patient was keen on conservative management instead of blood patch therapy. Hence, she was treated supportively via uni-ocular patching to relieve diplopia. Spontaneous complete recovery of the right abducens nerve palsy was observed after three weeks. Cranial nerve palsy is a rare complication reported following spinal anesthesia, with the abducens nerve being the commonest nerve involved. Although it is not always benign, the presented case showed spontaneous complete recovery of the right abducens nerve palsy after three weeks. Awareness of this uncommon complication will avoid unnecessary distress and investigative burden to both the patient and the doctor.

Intracranial Hypotension Syndrome: The Importance of Neurointensive Care

Surgical procedures involving the spine can result in various complications, including vascular, nerve root and dura mater injury, surgical wound infection, and hematoma formation. Unintentional durotomy is a frequent complication of these procedures (up to 17%). Two clinical cases are reported in which the occurrence of epileptiform activity in the form of generalized tonic-clonic seizures after instrumentation of the dorsal and lumbar spine raised suspicion of cerebrospinal fluid (CSF) fistula. In both cases, the diagnostic suspicion and early approach allowed for the adoption of a timely medical and surgical plan, with the aim of reducing the volume of lost CSF as well as the potential neurological dysfunction resulting from this surgical complication.

Comparing two techniques of performing an epidural catheter-assisted epidural blood patch using a 20 ml syringe versus a 5 ml syringe and its effect on clotting time, the strength of clot retraction and haemolysis - A prospective in vitro study (EC-EBP study)

Background and Aims

Epidural blood patch (EBP) is performed by injecting autologous blood into the epidural space using a Tuohy needle. Certain clinical scenarios mandate an epidural catheter (EC)-assisted EBP. Collecting blood in a 20-ml versus 5-ml syringe appears to influence the quality of the clot. This in vitro study compared the techniques of performing the EC-assisted EBP using 20-ml versus 5-ml syringe on clotting time (CT), clot retraction (CR) and haemolysis.

Methods

This in vitro study was performed in a haematology laboratory. Five consented adult healthy male volunteers donated blood. In the 5-ml syringe technique, blood was injected through an EC, and as it flowed out of the tip, it was collected at the beginning and the end of 1 min. With the 20-ml technique, blood was collected at the beginning and end of the first, second and third minute. The samples were tested for CT, CR and haemolysis by measuring the plasma-free haemoglobin (PFHb).

Results

Five injections were made using a 5-ml syringe, and another five with a 20-ml syringe. Injection time was shorter in the 5-ml technique (80.80 ± 5.89 vs. 272 ± 28.4 s, P < 0.0001). With the 20-ml technique, CT progressively increased (>15 min), whereas, with the 5-ml syringe, the CT was normal. Both techniques caused mild, insignificant haemolysis (PFHb >0.005 g/dl), without affecting the quality of CR.

Conclusion

EC-assisted EBP using a 5-ml syringe technique shortens the injection time and deposits fresh blood quickly without affecting CT and CR.

Postoperative Diabetes Insipidus Mimicking Radiological Findings and Symptoms of Intracranial Hypotension: A Case Report

Endocrine disturbances such as diabetes insipidus (DI) and syndrome of inappropriate antidiuretic hormone secretion (SIADH) are recognized complications of craniopharyngioma surgery, which occur due to damage to structures that produce or store antidiuretic hormone (ADH). Intracranial hypotension is a clinical syndrome that presents with headache and typical radiological features and can occur due to a leak of cerebral spinal fluid (CSF) in operations that involve the opening of the arachnoid (e.g., craniopharyngioma surgery). We describe a patient presenting with headache, radiological evidence of intracranial hypotension, and chronic DI after craniopharyngioma surgery. This occurred in the absence of evidence of a CSF leak. The headache and radiological findings resolved after the identification and treatment of DI. Intracranial hypotension may have occurred secondary to dehydration in chronic DI. A 48-year-old woman presented with progressive visual field loss due to cystic recurrence of a craniopharyngioma. She underwent redo (second) extended endoscopic transsphenoidal surgery, having previously undergone an uncomplicated debulking procedure two years prior. Her redo operation was uneventful, and her vision improved postoperatively. A lumbar drain was placed preoperatively to protect the skull base repair and was removed after 48 hours. In the initial postoperative period, she developed a clinical (polyuria) and biochemical picture consistent with DI, subsequently reverting to a SIADH, after which fluid and sodium homeostasis appeared to normalize, and she was discharged. Two months after discharge, she re-presented with new headaches eased by lying flat. Magnetic resonance imaging (MRI) brain showed bilateral convexity subdural effusions and diffuse pachymeningeal enhancement, suggesting intracranial hypotension and raising concern for postoperative CSF leak. MRI spine did not show a CSF fistula at the site of the previous lumbar drain. Transsphenoidal examination under anesthesia showed a well-healed skull base repair and no evidence of CSF leak. She concurrently reported polyuria and polydipsia. A formal water deprivation test confirmed central DI. Treatment with desmopressin improved her headache, and a follow-up MRI brain showed resolution of the previous stigmata of intracranial hypotension. This case report reminds physicians and neurosurgeons that systemic disorders (such as dehydration) can cause intracranial hypotension.

Post Dural Puncture Subdural Hematoma: A Rare Iatrogenic Complication of Neuraxial Anesthesia

Although post-dural puncture headache is a well-known complication of neuraxial anesthesia, subdural hematoma following epidural injection is a rare but potentially under-recognized complication. The following is the case of a young female patient with no significant past medical history who developed a persistent and severe headache following the introduction of epidural anesthesia for labor induction. Imaging demonstrated multiple small subdural hematomas with findings concerning intracranial hypotension. She eventually underwent a blood patch and reported immediate relief from her headache.

ACR Appropriateness Criteria® Headache: 2022 Update

Headache is an ancient problem plaguing a large proportion of the population. At present, headache disorders rank third among the global causes of disability, accounting for over $78 billion per year in direct and indirect costs in the United States. Given the prevalence of headache and the wide range of possible etiologies, the goal of this document is to help clarify the most appropriate initial imaging guidelines for headache for eight clinical scenarios/variants, which range from acute onset, life-threatening etiologies to chronic benign scenarios. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

A False Pituitary Tumor

A false pituitary tumor describes pituitary enlargement due to intracranial hypotension. Reported previously primarily in the neurological literature, we present this case referred to endocrinology for evaluation of a pituitary mass. A 24-year-old male was referred to endocrinology for evaluation of pituitary enlargement without a hypo-enhancing lesion on magnetic resonance imaging (MRI). The main symptom reported was headache that was worse in the standing position and in the afternoon. He had no symptoms or signs of pituitary mass-effect, or hormone excess or deficiencies. Past medical history was relevant for a history of nerve schwannoma status post resection with subsequent spinal fusion. Biochemical evaluation of pituitary hormones was normal. Upon review of his pituitary MRI, other abnormalities seen were suggestive of intracranial hypotension. Based on his history and imaging findings, he was diagnosed with intracranial hypotension causing a "false pituitary tumor" rather than pituitary enlargement or abnormality. Further evaluation revealed multiple spinal leaks that were patched. His symptoms subsided within a few days of repair. Endocrinologists should be aware of the possible misdiagnosis of a pituitary mass due to intracranial hypotension.

Incidence of spontaneous intracranial hypotension in Olmsted County, Minnesota: 2019-2021

BACKGROUND

As the myriad clinical and radiographic presentations of spontaneous intracranial hypotension are increasingly recognized, disease prevalence appears to rise. True incidence data remain insufficient. We sought to calculate the incidence of spontaneous intracranial hypotension among the residents of Olmsted County, Minnesota.

METHODS

Our institution is a quaternary care center for spontaneous intracranial hypotension evaluation and provides primary neurologic care for local residents. All patients who were evaluated at our institution from 2019 to 2021 for spontaneous intracranial hypotension were reviewed, and cases of spontaneous intracranial hypotension with advanced imaging work-up using digital subtraction myelography or dynamic computed tomography myelography were identified. Patients who were residents of Olmsted County were identified.

RESULTS

Fourteen patients with spontaneous intracranial hypotension were identified in Olmsted County during the study period, all of whom were adults and underwent our institution's standard spontaneous intracranial hypotension work-up. In Olmsted County, the incidence of spontaneous intracranial hypotension was 3.8 per 100,000 adult population, including 3.2 per 100,000 adult females and 2.5 per 100,000 adult males. Seven of 14 patients (50%) had a cerebrospinal fluid-venous fistula.

CONCLUSION

This study uniquely presents the incidence rate of spontaneous intracranial hypotension in the general population of Olmsted County, Minnesota. Spontaneous intracranial hypotension is more common in women than men and has an overall incidence roughly equivalent to that of aneurysmal subarachnoid hemorrhage in Olmsted County, a widely known neurologic condition. Approximately half the cases of spontaneous intracranial hypotension are due to cerebrospinal fluid-venous fistulas, which generally require specialty expertise for diagnosis and treatment.

Intracranial hypotension in a breast cancer patient treated with epidural blood patches

We report the case of a patient with metastatic breast cancer who presented with an orthostatic headache. After a comprehensive diagnostic workup including MRI and lumbar puncture, we maintained the diagnosis of intracranial hypotension (IH). The patient was therefore treated with two consecutive non targeted epidural blood patches, resulting in the remission of IH symptoms for 6 months. IH in cancer patients is a rarer cause of headache than carcinomatous meningitis. As the diagnosis can be made by standard examination and the treatment is relatively simple and effective, IH deserves to be better known by oncologists.

Does an Epidural Blood Patch (EBP) for Postdural Puncture Headache (PDPH) From a Lumbar Spinal Drain Necessitate a Distinct Approach?

An intentional or unintentional dural puncture puts patients at significant risk for a postdural puncture headache (PDPH). When conservative treatments fail, an epidural blood patch (EBP) is offered cautiously due to rare but devastating complications. The literature is abundant with reviews on the management of PDPH in obstetric patients, but there is a paucity of data on the management of PDPH and complications of EBP in patients post spinal drain placement. In this case report, we address the specific concerns that vascular patients may have about the outcomes of large needle sizes and suggest alternative approaches for non-obstetric patients.

Minimally invasive surgery for spinal cerebrospinal fluid leaks in spontaneous intracranial hypotension

OBJECTIVE

Spinal CSF leaks cause spontaneous intracranial hypotension (SIH). Surgical closure of spinal CSF leaks is the treatment of choice for persisting leaks. Surgical approaches vary, and there are no studies in which minimally invasive techniques were used. In this study, the authors aimed to detail the safety and feasibility of minimally invasive microsurgical sealing of spinal CSF leaks using nonexpandable tubular retractors.

METHODS

Consecutive patients with SIH and a confirmed spinal CSF leak treated at a single institution between April 2019 and December 2020 were included in the study. Surgery was performed via a dorsal 2.5-cm skin incision using nonexpandable tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach. The primary outcome was successful sealing of the dura, and the secondary outcome was the occurrence of complications.

RESULTS

Fifty-eight patients, 65.5% of whom were female (median age 46 years [IQR 36-55 years]), with 38 ventral leaks, 17 lateral leaks, and 2 CSF venous fistulas were included. In 56 (96.6%) patients, the leak could be closed, and in 2 (3.4%) patients the leak was missed because of misinterpretation of the imaging studies. One of these patients underwent successful reoperation, and the other patient decided to undergo surgery at another institution. Two other patients had to undergo reoperation because of insufficient closure and a persisting leak. The rate of permanent neurological deficit was 1.7%, the revision rate for a persisting or recurring leak was 3.4%, and the overall revision rate was 10.3%. The rate of successful sealing during the primary closure attempt was 96.6% and 3.4% patients needed a secondary attempt. Clinical short-term outcome at discharge was unchanged in 14 patients and improved in 25 patients, and 19 patients had signs of rebound intracranial hypertension.

CONCLUSIONS

Minimally invasive surgery with tubular retractors and a tailored interlaminar fenestration and, if needed, a transdural approach is safe and effective for the treatment of spinal CSF leaks. The authors suggest performing a minimally invasive closure of spinal CSF leaks in specialized centers.

Thunderclap headache revealing dural tears with symptomatic intracranial hypotension: Report of two cases

Cerebrospinal fluid (CSF) leakage is considered the cause of spontaneous intracranial hypotension (SIH), an important etiology for new daily persistent headaches and a potentially life-threatening condition. Minor traumatic events rarely lead to CSF leakage, contrasting with iatrogenic interventions such as a lumbar puncture or spinal surgery, which are commonly complicated by dural tears. Most meningeal lesions are found in the cervicothoracic region, followed by the thoracic region, and rarely in the lumbar region, and extremely rarely in the sacral region. We describe two patients admitted to our hospital for severe headaches aggravated in the orthostatic position, with a recent history of minor trauma and sustained physical effort, respectively. In the first case, a bone fragment pierced an incidental congenital meningocele creating a dural fistula. An extensive extradural CSF collection, spanning the cervicothoracic region (C4-T10), was described in the second case. In both patients, the clinical evolution was favorable under conservative treatment.

[Complicated course of the postoperative period with the development of epidural hygroma and intracranial hypotension after removal of cranio-orbital meningioma. Clinical case and literature review]

Surgical removal of cranio-orbital meningiomas is an effective method of treating this pathology. Modern surgical techniques and technologies make it possible to perform operations with a low risk of complications. Lumbar drainage or repeated lumbar punctures are often used intraoperatively or in the early postoperative period to prevent nasal CSF leak; this rarely leads to the development of significant neurological symptoms. We present a case of the development of severe intracranial hypotension with the formation of a subdural hygroma in the early postoperative period after removal of a cranio-orbital meningioma in a 41-year-old patient. The operation was performed using an individual model and molds for simultaneous reconstruction of the bone defect with an implant made of polymethyl methacrylate. On the 1st and 2nd days after surgery, lumbar punctures were performed. From the 2nd day there was a progressive deterioration with the development of symptoms characteristic of intracranial hypotension. Computed tomography revealed an increasing displacement of the midline structures of the brain and an increasing volume of epidural fluid accumulation in the area of surgical intervention. Magnetic resonance imaging revealed characteristic signs of intracranial hypotension. Conservative treatment (bed rest, active hydration) had no effect. On the 6th day after surgery, an epidural blood patch procedure was performed and closed external drainage of the epidural hygroma was performed, and a rapid regression of neurological symptoms was noted. Our experience and literature data indicate that it is necessary to remember the possibility of developing clinically significant intracranial hypotension even after a single lumbar puncture. The formation of hygromas in the surgical area is characteristic of intracranial hypotension, but in most cases does not require additional surgical intervention and does not have a negative impact on the outcome of treatment. Conservative treatment of intracranial hypotension is the first choice and often sufficient. If there is no effect and the patient's condition worsens, it is necessary to perform an epidural blood patch procedure.