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Background: The diagnosis of spontaneous or post-traumatic intracranial hypotension (IH) mainly relies on clinical features and neuro-imaging. However, the results of brain and spine magnetic resonance imaging are not always contributive. There is an interest for other non-invasive procedures, able to confirm or refute the diagnosis. The use of oto-acoustic emissions (OAE) was previously reported on isolated cases of IH associated with endolymphatic hydrops (ELH). The aim of this study was to assess the real-life utilization of this electrophysiological method in a larger population of suspected IH., Methods: A retro-prospective cohort study was conducted from November 2013 to July 2022 in patients with a suspected or doubtful diagnosis of IH. They were assessed for ELH by recording bilateral distortion product of oto-acoustic emissions (DPOAE) in sitting then in supine position., Results: Among the 32 patients assessed, the diagnostic of IH was confirmed in 18 patients. An ELH was shown in 15 of them (83%), but also in seven other patients. They had several differential diagnoses: chronic migraine, Chiari malformation, rebound intracranial hypertension and perilymph fistula., Conclusions: This procedure seems to be insufficient to exclude differential diagnosis when intracranial hypotension is suspected., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

One of the latest diagnoses that need to be considered when evaluating patients with persistent headache is spontaneous (postural) intracranial hypotension (SIH). The diagnosis can be clinched by magnetic resonance imaging (MRI) findings of subdural collections, meningeal enhancement and tonsillar descent. Cerebrospinal fluid leak has been postulated as the cause, and both medical and surgical treatment options have been documented. The treatment of choice is, however, an epidural blood patch. Here we discuss two cases of SIH treated successfully with epidural blood patch.

Introduction: Marfan syndrome is an autosomal dominant, multi-systemic connective tissue di sorder of different presentations. Dural ectasia is a common, but little known complication that can be associated with intracranial hypotension syndrome (IHS)., Objective: To present a case of severe headache secondary to IHS in order to warn about this rare complication, which must be considered in children carriers of connective tissue diseases, especially Marfan syndrome., Clinical Case: 13-year- old female carrier of Marfan syndrome, clinically diagnosed according to the 2010 Ghent criteria, who consulted due to a 6-months history of severe orthostatic headache. Head magnetic resonance imaging (MRI) showed multiple signs of intracranial hypotension, while whole-spine MRI showed dural ectasia that caused the thecal sac dilation and subsequent remodeling of vertebral bodies, es pecially the sacral ones. Treatment with an autologous epidural blood patch was administered with good clinical response., Conclusions: Dural ectasia, frequent in Marfan syndrome, is a predisposing cause of cerebrospinal fluid (CSF) leakage, which could cause orthostatic headache secondary to IHS.

Spontaneous intracranial hypotension (SIH) is a clinical syndrome that is increasingly recognized as an important and treatable secondary cause of headaches. Insight into the condition has evolved significantly over the past decade, resulting in a greater understanding of the underlying pathophysiology, development of new diagnostic imaging tools, and a broadening array of targeted treatment options. This article reviews the clinical presentation and pathogenesis of SIH, discusses the important role of imaging in diagnosis, and describes how imaging guides treatment., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: The aim of this study is to analyze the lamina cribrosa depth and to study the optic nerve in patients with spontaneous intracranial hypotension., Methods: A total of 10 eyes of the patients with spontaneous intracranial hypotension with unknown etiology (study group) and 10 eyes of healthy patients without any ophthalmological or neurological pathologies (control group) were included. The subjects were submitted to ophthalmological examination with the evaluation of visual acuity, spherical equivalent, applanation tonometry, pachymetry, axial length, retinography, computerized static perimetry (Humphrey 30-2 SITA-Standard), and OCT Spectralis with enhanced depth image, to calculate the depth of the anterior surface of the lamina cribrosa and to measure the nerve fiber layer thickness of the optic nerve. All of these parameters were compared between the two groups., Results: Mean anterior surface of the lamina cribrosa depth was 447.96 ± 118.51 (313.30-632.0) μm for the spontaneous intracranial hypotension group and 292.56 ± 40.71 (247-387) μm for the control group, with a statistically significant difference between them (p = 0.001). The thickness of the nerve fiber layer did not differ significantly in the temporal (p = 0.94), nasal (p = 0.173), superior (p = 0.41), central (p = 0.36) or inferior (p = 0.5) sectors. Four eyes of patients with spontaneous intracranial hypotension showed a marked reduction in the temporal nerve fiber layer. Pachymetry (p = 0.16), axial length (p = 0.71), and intraocular pressure (p = 0.6) did not differ significantly between groups, whereas spherical equivalent (p = 0.03) was significantly different. Visual fields were normal in both groups., Conclusion: The translaminar gradient is determinant in the structure of the lamina cribrosa. Low intracranial pressure associated with a high translaminar gradient leads to an increased lamina cribrosa depth similar to that observed in glaucoma patients.

Background: Spontaneous intracranial hypotension is uncommon. There is a lack of understanding of its exact pathophysiology along with significant variability in its clinical management., Case Description: The authors report the case of a previously well man with cervicogenic headache associated with magnetic resonance imaging features of intracranial hypotension. The salient features of this case include the details of various treatments prescribed for his condition and the therapeutic difficulties encountered., Conclusion: Owing to the infrequency of the diagnosis, the challenges of clinical management for this patient are discussed in relationship to current literature. Next, the highlights of this unusual case in an individual add to the growing body of literature reports for better understanding of this disease., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objective: To compare brainstem acoustic evoked potentials (BAEP) and magnetic resonance imaging (MRI) in the differential diagnosis of intracranial hypotension (IH), Chiari malformation (CM) and sensorineural hearing loss (SNHL)., Methods: BAEP were recorded in 18 IH, 18 CM, 20 SNHL patients and 52 controls. MRI were acquired in all IH and CM patients., Results: Abnormal BAEP were observed in 94% of IH patients, in 33% of CM and 70% of SNHL patients. After recovery from IH, BAEP abnormalities disappeared. Internal auditory canal (IAC) MRI abnormalities were described in 88% of IH patients. MRI signs of IH were observed in 33-78% in IH patients, but the most frequent MRI sign was 8th nerve T2 hyperintensity, with contrast enhancement in T1 sequences. This finding, combined with wave I latency, yielded highest specificity and sensitivity for IH diagnosis., Conclusions: Our study points out how IH can be effectively distinguished from CM and SNHL through the contribution of neurophysiology and MRI; in particular, evaluation of the 8th nerve achieves a high sensitivity and specificity in patients with IH. Further studies are required to examine the combined use of BAEP recordings ad MRI in diagnosis and monitoring of patients affected by IH., (Copyright © 2019 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

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.

Objectives: Several brain and spinal magnetic resonance imaging signs have been described in spontaneous intracranial hypotension. Their correlations are not fully studied. This study aimed to explore potential mechanisms underlying cerebral neuroimaging findings and to examine associations among spinal and brain magnetic resonance imaging signs., Methods: We conducted a retrospective review of magnetic resonance myelography and brain magnetic resonance imaging records of patients with spontaneous intracranial hypotension. Categorical principal component analysis was employed to cluster brain neuroimaging findings. Spearman correlation was employed to analyze associations among different brain neuroimaging findings and between brain and spinal neuroimaging findings., Results: In patients with spontaneous intracranial hypotension (n = 148), categorical principal component analysis of brain neuroimaging signs revealed two clusters: Cerebral venous dilation and brain descent. Among all brain magnetic resonance imaging signs examined, only midbrain-pons angle associated with anterior epidural cerebrospinal fluid collection length (surrogate spinal cerebrospinal fluid leak severity) (n = 148, Spearman's ρ = -0.38, p < .001). Subgroup analyses showed that the association between midbrain-pons angle (within brain descent cluster) and spinal cerebrospinal fluid leak severity was presented in patients with convex margins of the transverse sinuses (n = 122, Spearman's ρ = -0.43, p < .001), but not in patients without convex margins (n = 26, Spearman's ρ = -0.19, p = .348). The association between severity of transverse sinus distension and spinal cerebrospinal fluid leak severity was only presented in patients without convex margins (n = 26, Spearman's ρ = 0.52, p = .006)., Conclusion: This study indicates that there are two factors behind the brain neuroimaging findings in spontaneous intracranial hypotension: Cerebral venous dilation and brain descent. Certain brain neuroimaging signs correlate with spinal cerebrospinal fluid leakage severity, depending on different circumstances.

Background Intracranial structural dislocation in spontaneous intracranial hypotension (SIH) can be measured by various intracranial angles and distances. We aimed to identify the clinical significance of structural dislocation in relation to treatment outcome in patients with SIH. Methods In this retrospective analysis, we identified patients with SIH who received an epidural blood patch (EBP) at Samsung Medical Center from January 2005 to March 2015. Structural dislocation in pretreatment MRIs of SIH patients was assessed by measuring tonsillar herniation, mamillopontine distance, the angle between the vein of Galen and straight sinus (vG/SS angle), the pontomesencephalic angle, and the lateral ventricular angle. After the first EBP, poor response was defined as the persistence of symptoms that prompted a repeat EBP. Results Out of the 95 patients included, 31 (32.6%) showed poor response. Among the radiological markers of structural dislocation, the vG/SS angle was associated with poor response (49.82 ± 16.40° vs 66.58 ± 26.08°, p = 0.002). Among clinical variables, premorbid migraine ( p = 0.036) was related to poor response. In multivariate analysis, reduced vG/SS angle was independently associated with poor response (OR 1.04 [95% CI 1.01 - 1.07] per 1° decrease, p = 0.006). In 23 patients who underwent MRI after successful treatment, the vG/SS angle significantly increased after the EBP ( p < 0.001, by paired t-test), while two patients with aggravation or recurrence showed a further reduction of their vG/SS angles. Conclusions Intracranial structural dislocation, measured by the vG/SS angle, is associated with poor response to the first EBP in patients with SIH. Successful treatment can reverse the structural dislocation.

A 47-year-old man presented with a 9-year history of a hypoalert hypoactive behaviour syndrome, caused by the deep brain swelling variant of spontaneous intracranial hypotension. Along with apathy with retained cognition, he had stable ataxia, impaired upgaze and episodes of central apnoea. MRI brain showed a sagging brainstem, pointed ventricles and reduced angle between the vein of Galen and the straight sinus, but no meningeal enhancement or subdural collections. A dopamine transporter scan showed preganglionic dopamine receptor deficiency; a fluorodeoxy glucose positron emission tomography scan showed bilateral hypothalamic hypometabolism. This variant of spontaneous intracranial hypotension may alter deep brain functioning within the basal ganglia and thalamus, causing the hypoactive-hypoalert behaviour phenotype., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

There is evidence that patients with multiple sclerosis (MS) and hydrocephalus share some common pathophysiological mechanisms. Alterations in CSF pressure are known to affect cerebral venous sinus geometry. To further explore these mechanisms, we measured the superior sagittal sinus (SSS) cross-sectional area 3 cm above the torcular using T2 images in 20 MS, 10 spontaneous intracranial hypotension (SIH), 21 hydrocephalus and 20 idiopathic intracranial hypertension (IIH) patients and compared with 20 matched controls. The SSS area was reduced by 25% in hydrocephalus (p = 0.0008), increased by 22% (p = 0.037) in SIH and unchanged in IIH compared to matched controls. In MS there was a 16% increase in SSS area (p = 0.01).The findings suggest that changes in SSS cross-sectional are common between MS and SIH patients, while in hydrocephalus and IIH these are different.

Competing Interests: Competing interests: None declared.

Objective: The objective of our study was to determine whether the presence of individual imaging signs of spontaneous intracranial hypotension (SIH) is correlated with increasing duration of headache symptoms. Of particular interest is the relationship of symptom duration to dural enhancement because it is the most commonly identified imaging sign in patients with SIH., Materials and Methods: Eighty-nine patients with SIH who underwent pretreatment brain MRI and total-spine CT myelography and whose medical record included data on the duration of clinical symptoms were included in this cross-sectional retrospective study. Brain imaging was reviewed for the presence of dural enhancement, brain sagging, and the "venous distention" sign. CT myelograms were assessed for CSF leak. If present, a leak was subcategorized as a high-flow or low-flow leak. Differences in headache duration between subjects with and those without individual imaging signs were compared., Results: Subjects without dural enhancement on brain MRI had a longer average duration of symptoms than those with dural enhancement present (average symptom duration: 45.3 ± 59.0 [SD] vs 15.1 ± 33.0 weeks, respectively; p = 0.002). No difference in symptom duration was observed between subjects whose MRI studies showed and those whose MRI studies did not show brain sagging (p = 0.10) or the venous distention sign (p = 0.21). The presence of a CSF leak on CT myelography was not associated with symptom duration (p = 0.56) except in the subgroup of patients with low-flow leaks., Conclusion: Increasing symptom duration in SIH is associated with decreased prevalence of abnormal dural enhancement on brain MRI. Because dural enhancement is considered a hallmark imaging feature of this condition, its absence may exacerbate the problem of underdiagnosis in chronic cases of SIH.

Objectives To determine the proportion of patients with spontaneous intracranial hypotension (SIH) who had a cerebrospinal fluid (CSF) pressure >6 cm H 2 O and to investigate the clinical and imaging variables associated with CSF pressure ( P CSF ) in this condition. Methods We retrospectively reviewed 106 patients with SIH. P CSF was measured by lumbar puncture prior to treatment. Clinical and imaging variables - including demographic data, brain imaging results, symptom duration, and abdominal circumference - were collected. Univariate and multivariate analyses were performed to determine the correlation of these variables with P CSF . Results Sixty-one percent of patients had a P CSF between 6 and 20 cm H 2 O; only 34% had a P CSF ≤6 cm H 2 O. The factors associated with increased P CSF included abdominal circumference ( p < 0.001), symptom duration ( p = 0.015), and the absence of brain magnetic resonance imaging findings of SIH ( p = 0.003). A wide variability in P CSF was observed among all patients, which was not completely accounted for by the variables included in the model. Conclusions Normal CSF pressure is common in patients with SIH; the absence of a low opening pressure should not exclude this condition. Body habitus, symptom duration, and brain imaging are correlated with P CSF measurements, but these factors alone do not entirely explain the wide variability in observed pressures in this condition and this suggests the influence of other factors.

Background and Purpose: Atypical clinical presentations of spontaneous intracranial hypotension include obtundation, memory deficits, dementia with frontotemporal features, parkinsonism, and ataxia. The purpose of this study was to compare clinical and imaging features of spontaneous intracranial hypotension with typical-versus-atypical presentations., Materials and Methods: Clinical records and neuroimaging of patients with spontaneous intracranial hypotension from September 2005 to August 2014 were retrospectively evaluated. Patients with classic spontaneous intracranial hypotension (n = 33; mean age, 41.7 ± 14.3 years) were compared with those with intracranial hypotension with atypical clinical presentation (n = 8; mean age, 55.9 ± 14.1 years) and 36 controls (mean age, 41.4 ± 11.2 years)., Results: Patients with atypical spontaneous intracranial hypotension were older than those with classic spontaneous intracranial hypotension (55.9 ± 14.1 years versus 41.7 ± 14.3 years; P = .018). Symptom duration was shorter in classic compared with atypical spontaneous intracranial hypotension (3.78 ± 7.18 months versus 21.93 ± 18.43 months; P = .015). There was no significant difference in dural enhancement, subdural hematomas, or cerebellar tonsil herniation. Patients with atypical spontaneous intracranial hypotension had significantly more elongated anteroposterior midbrain diameter compared with those with classic spontaneous intracranial hypotension (33.6 ± 2.9 mm versus 27.3 ± 2.9 mm; P < .001) and shortened pontomammillary distance (2.8 ± 1 mm versus 5.15 ± 1.5 mm; P < .001). Patients with atypical spontaneous intracranial hypotension were less likely to become symptom-free, regardless of treatment, compared with those with classic spontaneous intracranial hypotension (χ(2) = 13.99, P < .001)., Conclusions: In this sample of 8 patients, atypical spontaneous intracranial hypotension was a more chronic syndrome compared with classic spontaneous intracranial hypotension, with more severe brain sagging, lower rates of clinical response, and frequent relapses. Awareness of atypical presentations of spontaneous intracranial hypotension is paramount., (© 2016 by American Journal of Neuroradiology.)

Objective: This study aimed to assess the utility of dural thickening of the internal auditory canal (IAC) in patients with spontaneous intracranial hypotension (SIH) syndrome and determined the sensitivity and specificity of this image finding., Methods: Magnetic resonance images were evaluated for 22 cases of definite SIH and 16 cases of unlikely SIH. On contrast-enhanced magnetic resonance imaging, pachymeningeal enhancement and dural thickening of the IAC were assessed., Results: Pachymeningeal enhancement was observed in 21 of 22 patients in the definite SIH group and 1 of 16 patients in the unlikely SIH group (sensitivity, 95.5%; specificity, 93.8%). Dural thickening of the IAC was observed in 15 of 22 patients in the definite SIH group and 0 of 16 patients in the unlikely SIH group (sensitivity, 68.2%; specificity, 100%)., Conclusions: Dural thickening of the IAC showed 100% specificity for SIH syndrome and can increase the accuracy of diagnosis of SIH syndrome.

Objective: Spontaneous spinal CSF leaks are an important cause of new-onset headaches. Such leaks are reported to be particularly common at the cervico-thoracic junction. The authors undertook a study to determine the significance of these cervico-thoracic CSF leaks., Methods: The patient population consisted of a consecutive group of 13 patients who underwent surgery for CSF leak repair based on CT myelography showing CSF extravasation at the cervico-thoracic junction but without any evidence of an underlying structural lesion., Results: The mean age of the 9 women and 4 men was 41.2 years. Extensive extrathecal longitudinal CSF collections were demonstrated in 11 patients. At surgery, small leaking arachnoid cysts were found in 2 patients. In the remaining 11 patients, no clear source of CSF leakage could be identified at surgery. Resolution of symptoms was achieved in both patients with leaking arachnoid cysts, but in only 3 of the 11 patients with negative intraoperative findings. Postoperative spinal imaging was performed in 9 of the 11 patients with negative intraoperative findings and showed persistence of the longitudinal intraspinal extradural CSF. Further imaging revealed the site of the CSF leak to be ventral to the thoracic spinal cord. Five of these patients underwent microsurgical repair of the ventral CSF leak with resolution of symptoms in all 5 patients., Conclusions: Cervico-thoracic extravasation of dye on myelography does not necessarily indicate the site of the CSF leak. Treatment directed at this site should not be expected to have a high probability of sustained improvement of symptoms., (© 2015 American Academy of Neurology.)

Background: Experimental stroke studies use multiple techniques to evaluate histopathological damage. Unfortunately, sensitivity and reproducibility of these techniques are poorly characterized despite pivotal influence on results., Method: The present study compared several quantification methods to differentiate between two severities of global cerebral ischemia and reperfusion. Male Sprague-Dawley rats were randomized to moderate (10min) or severe (14min) ischemia by bilateral carotid occlusion (BCAO) with hemorrhagic hypotension. Neuronal cell count was determined in hippocampus at bregma -3.14mm and -3.8mm on day 3 and 28 post insult by counting neurons in the whole CA1 or in one to three defined regions of interest (ROI) placed in NeuN and Fluoro-Jade B stained sections., Results: In healthy rats hippocampal neurons were arranged uniformly, while distribution became inhomogeneous after ischemia. The number of NeuN and Fluoro-Jade B positive cells was dependent on localization. Differences between ischemia severities became more prominent at 28 days compared to 3 days. Fluoro-Jade B positive cell count increased at 28 days, staining rather injured not dying neurons., Comparison With Existing Methods: Placement of counting windows has a major influence on extent of differences between degree of neuronal injury and variations within groups., Conclusions: The investigated quantification methods result in inconsistent information on the degree of damage. To obtain consistent and reliable results observation period should be extended beyond 3 days. Due to inhomogeneous distribution of viable neurons in CA1 after ischemia neuronal counting should not be performed in a single ROI window, but should be performed in multiple ROIs or the whole CA1 band., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Spontaneous intracranial hypotension (SIH) is a syndrome of low pressure headache associated with low CSF pressure. The condition is generally considered benign but extreme cases of SIH can lead to changes in the level of consciousness. We describe a case in which alteration in the level of consciousness was prolonged and severe, and could not be explained solely by the presence of subdural collections. MRI of the brain showed evidence of impaired venous flow secondary to brain sagging causing distortion of deep venous structures., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

The specific aim of this review is to report the features of intracranial pressure changes [spontaneous intracranial hypotension (SIH) and idiopathic intracranial hypertension (IIH)] in children and adolescents, with emphasis on the presentation, diagnosis, and treatment modalities. Headache associated with intracranial pressure changes are relatively rare and less known in children and adolescents. SIH is a specific syndrome involving reduced intracranial pressure with orthostatic headache, frequently encountered connective tissue disorders, and a good prognosis with medical management, initial epidural blood patching, and sometimes further interventions may be required. IIH is an uncommon condition in children and different from the disease in adults, not only with respect to clinical features (likely to present with strabismus and stiff neck rather than headache or pulsatile tinnitus) but also different in outcome. Consequently, specific ICP changes of pediatric ages required specific attention both of exact diagnosis and entire management.

Low cerebrospinal fluid (CSF) pressure results in neurologic deficits, of which the most common manifestation is headache. Typically, the headache is postural - and specifically, orthostatic - in presentation. There are three hypotheses to explain the occurrence of headache associated with low CSF fluid. The first is traction on pain-sensitive intracranial and meningeal structures; the second is CSF hypovolemia; and the third is spinal loss of CSF resulting in increased compliance at the caudal end of the CSF space. Spontaneous intracranial hypotension (SIH), once believed to be rare, is now more commonly recognized. It is typically associated with orthostatic headache (although initially it may not be) and one or more other symptoms such as alterations in hearing, nausea, vomiting, neck stiffness, diplopia, and visual field cuts. Magnetic resonance imaging (MRI) of the brain with gadolinium is the first study of choice, which typically reveals diffuse pachymeningeal enhancement and, frequently, cerebellar tonsillar descent and posterior fossa crowding. Epidural blood patch (EBP) is the treatment of choice. Surgery and epidural fibrin glue injection are options for those who fail conservative therapy and/or EBP.

We report a case of diplopia during continuous epidural injection presumably caused by catheter migration. A 61-year-old woman underwent shoulder surgery under general anesthesia with cervical epidural anesthesia. The epidural catheter was placed in the C6-C7 epidural space with some difficulty before general anesthesia. The depth of the catheter placed under the skin was 10 cm. On POD 2, the patient noticed diplopia and developed dysarthria despite of good pain control so far. She complained of sudden headache after the rate of continuous epidural infusion was increased to relieve postoperative pain. Computed tomography and T2-weighted cerebral magnetic resonance imaging revealed an air image and surrounding edema in the pons. Diplopia and dysarthria disappeared after ceasing continuous epidural injection. A 15-cm-long mark under the skin and leak of colorless clear fluid from the puncture site were noted at removal of the catheter. On POD 13, diplopia recurred, which improved gradually. On the 9-month radiologic follow-up, we considered that the symptoms on POD 2 were caused by migration of the epidural catheter into the pons and that her later diplopia was induced by intracranial hypotension syndrome. One should be aware that such an unexpected migration of the catheter can occur following a difficult insertion.

A 72-year-old woman was admitted for elective L4/L5 laminectomy. The operative procedure was extradural, and a Jackson-Pratt (JP) drain was placed in the tissue bed and set to wall suction during skin closure. During closure, the patient developed a 15 s period of asystole. The patient was haemodynamically stable, but was comatose for 3 days postoperatively. Cardiac enzymes and EEG were unrevealing. Head CT showed traces of subarachnoid haemorrhage and signs suggestive of cerebral anoxia. JP drain at the incision produced 170-210 mL/day of fluid, positive for β-2 transferrin, indicating cerebrospinal fluid (CSF). The patient fully returned to baseline on hospital day 10. MRI on hospital day 8 normalised. The reversible coma and radiographic findings were most consistent with acute intracranial hypotension relating to acute loss of CSF. Because radiographic findings can mimic hypoxic-ischaemic injury, acute intracranial hypotension should be considered in the differential diagnosis of postoperative coma after cranial or spinal surgery.

Background: Spontaneous intracranial hypotension (SIH) is a neurologic condition with the prototypical symptom of orthostatic headache. We report a dramatic case of SIH with life-threatening bilateral hygroma and uncal herniation., Methods: Case report., Results: A 44-year-old male patient presenting with orthostatic headache and double vision was diagnosed with SIH. Diagnostic imaging showed meningeal enhancement and bilateral hygroma. A conservative treatment regime was initiated. The patient's condition rapidly deteriorated with progressive loss of consciousness. Cranial MRI showed beginning uncal herniation. As an emergency treatment measure, an intracranial pressure (ICP) probe was inserted and intrathecal lumbal saline infusion was initiated. This led to a stabilization of ICP and allowed further diagnostics and treatment., Conclusion: Intrathecal lumbal saline infusion in combination with ICP monitoring can be a life-saving treatment option in unstable SIH patients.

In children or young adults, the morphology of the skull can be altered by excessive drainage of CSF following placement of a ventriculoperitoneal (VP) shunt. In Sunken Eyes, Sagging Brain Syndrome, gradual enlargement of the orbital cavity occurs from low or negative intracranial pressure (ICP), leading to progressive bilateral enophthalmos. The authors report several heretofore unrecognized manifestations of this syndrome, which developed in a 29-year-old man with a history of VP shunt placement following a traumatic brain injury at the age of 9 years. Magnetic resonance imaging showed typical features of chronic intracranial hypotension, and lumbar puncture yielded an unrecordable subarachnoid opening pressure. The calvaria was twice its normal thickness, owing to contraction of the inner table. The paranasal sinuses were expanded, with aeration of the anterior clinoid processes, greater sphenoid wings, and temporal bones. The sella turcica showed a 50% reduction in cross-sectional area as compared with that in control subjects, resulting in partial extrusion of the pituitary gland. These new features broaden the spectrum of clinical findings associated with low ICP. Secondary installation of a valve to restore normal ICP is recommended to halt progression of these rare complications of VP shunt placement.

Objective: Intracranial hypotension is an uncommon cause of headaches that is often misdiagnosed. The classic MRI features of intracranial hypotension can be variable and subjective. The purpose of this study was to provide objective criteria in the MRI evaluation of intracranial hypotension by quantifying normal values for the pontomesencephalic angle, mamillopontine distance, and lateral ventricular angle., Materials and Methods: A retrospective review of patients with the clinical diagnosis of intracranial hypotension and a control group was performed with measurements of the pontomesencephalic angle, mamillopontine distance, and lateral ventricular angle. Qualitative evaluation of other MRI findings included dural enhancement, venous engorgement, subdural collections, brainstem slumping, and tonsillar herniation., Results: In 29 patients with intracranial hypotension, the mean pontomesencephalic angle, mamillopontine distance, and lateral ventricular angle were 41.2° (SD, ± 17.4°), 4.4 mm (SD, ± 1.8), and 130.1° (SD, ± 9.8°), respectively. In the control group, the mean pontomesencephalic angle, mamillopontine distance, and lateral ventricular angle were 65° (SD, ± 9.9°), 7.0 mm (SD, ± 1.3), and 132.2° (SD, ± 5.7°), respectively. The differences in the pontomesencephalic angle and mamillopontine distance values for the intracranial hypotension group versus the control group were statistically significant (p < 0.01). The difference in the lateral ventricular angle measurements was not statistically significant (p = 0.37). Cutoff points of a 5.5-mm mamillopontine distance and 50° pontomesencephalic angle were estimated using receiver operating characteristic curves., Conclusion: In patients with the clinical suspicion of intracranial hypotension, we found that cutoff values of 5.5 mm or less for the mamillopontine distance and 50° or less for the pontomesencephalic angle were sensitive and specific in strengthening the qualitative MRI findings. Therefore, quantitative assessments may provide a more accurate diagnosis.

Spontaneous intracranial hypotension was first described by Schalternbarn. Severe complications like cerebral venous thrombosis and subdural hemorrhage are seldomly seen. A 40-year-old man was examined for weakness of right arm started 9 months earlier and aggravated in last 3 months. He was undergo a lumbar punction because of a demyelinating plaque at C2 level in MRI. After 10 days of lumbar punction he experienced a generalised tonic clonic seizure. At cranial MRI and venography thrombosed superior sagittal and right transverse sinus and image of pachymeningitis, caused by intracranial hypotension were observed. Coincidence of these two situations together was seldomly found at literature. Thrombosis can both effect the sinuses and cortical veins. Spontaneous intracranial hypotension is a risk factor for CVT, but at only 2% CVT is seen as a complication. We think that our case can add addition to literature by having this coincidence.

The effects of acute reduction in arterial blood pressure in severe anaphylactic shock (AS) on cerebral blood flow are of paramount importance to be investigated. We studied cerebral circulation and oxygenation in a model of severe AS and compared it with a pharmacologically induced arterial hypotension of similar magnitude. Anaphylactic shock was induced by 1 mg intravenous ovalbumin (OVA) in sensitized rats. Rats were randomized to three groups: (i) no resuscitation (OVA; n = 10) (ii) intravenous volume expansion (10 mL in 10 min after OVA injection) (OVA + VE; n = 10); (iii) control hypotension (100 μg of nicardipine followed by continuous infusion of 1 mg · 100 g · h intravenously; NICAR; n = 10). Mean arterial pressure (MAP), carotid blood flow (CBF), cardiac output, cerebral cortical blood flow (CCBF; estimated by laser Doppler technique), and cerebral tissue oxygen pressure (PtiO2) were recorded over the 15 min following AS induction in all three groups. Results are expressed as mean (SD). One minute after OVA or nicardipine injection, there was a rapid and significant 50% decrease in MAP from basal values. In the OVA group, AS severely altered systemic and cerebral hemodynamics in 5 min: 93% (SD, 4%) decrease in CBF, 66% (SD, 8%) in CCBF, and 44% (SD, 8%) in PtiO2; the decrease in CBF was significantly (P < 0.05) attenuated in the OVA + VE group; however, CCBF and PtiO2 were not statistically different in the OVA versus OVA + VE groups. On the contrary, nicardipine-induced hypotension had only a limited impact on CBF, cardiac output, CCBF, and PtiO2 for a similar MAP decrease. There was a linear relation between CCBF and blood pressure in the OVA (regression slope: 0.87 [SD, 0.06]; median r = 0.81) but not in the NICAR group (regression slope: 0.23 [SD, 0.32]; median r = 0.33). Anaphylactic shock resulted in severe impairment of cerebral blood flow and oxygenation, beyond what could be expected from the level of arterial hypotension.

Background: Spontaneous intracranial hypotension (SIH) is recognized with increasing frequency. A throbbing headache occurring or worsening in the upright position and improving after lying down, a so-called 'orthostatic headache', low cerebrospinal fluid (CSF) pressure, and diffuse pachymeningeal enhancement on brain magnetic resonance imaging (MRI) are the major features of the classic syndrome. These patients, who are admitted with fever, headache, and CSF findings revealing lymphocytic pleocytosis, elevated protein concentration, normal glucose levels, and negative culture results, are prone to be misdiagnosed with aseptic meningitis. The aims of this single-centre retrospective study were to determine the epidemiological, clinical, laboratory, and radiological features of patients initially evaluated as having aseptic meningitis but subsequently diagnosed with SIH, and to touch upon the key points of the differential diagnosis in daily infectious diseases practice., Methods: Patients referred to Cerrahpasa Medical School with a presumed diagnosis of aseptic meningitis or viral meningitis between 1 January 2006 and 1 January 2011 were reviewed. Epidemiological, clinical, laboratory, radiological, and follow-up data obtained from the hospital database were processed. Patients confirmed to have SIH syndrome were included for evaluation., Results: Eleven cases of SIH syndrome were diagnosed during the study period (8 male and 3 female, median age 30 y, range 21-44 y). All had headache, hearing changes, and nausea. Vomiting (10/11) and posterior neck pain (9/11) were also frequent. Seven had fever and 5 had a stiff neck. Four cases had lymphocytic pleocytosis, 4 cases had elevated CSF protein concentrations (> 1.5 times the upper limit of normal), and 2 cases had slightly lower CSF glucose levels. Polymerase chain reaction (PCR) analyses of the CSF for Mycobacterium tuberculosis complex, herpes simplex viruses 1 and 2, and enteroviruses were negative in all cases. MRI of the 11 cases revealed signs of spontaneous CSF leaks with diffuse pachymeningeal gadolinium enhancement (11/11), sagging of the brain (9/11), enlargement of the pituitary (6/11), engorgement of the venous structures (5/11), and subdural fluid collections (2/11). CSF leaks were demonstrated by intrathecal magnetic resonance or computed tomography myelography at different levels along the thoracic spine (7/11), cervico-thoracic junction (2/11), and thoraco-lumbar junction (2/11). Autologous blood injection into the spinal epidural space ('blood patch') was performed for treatment. Strict bed rest followed, and all patients recovered fully within a week; no recurrence or complication was observed during the follow-up periods, which ranged from 6 months to 5 y., Conclusions: Findings of fever, headache, and meningeal irritation are generally accepted as the clinical features of meningitis. When CSF findings are not characteristically compatible with bacterial meningitis and particularly when the headache is orthostatic in nature, SIH should also be included in the differential diagnosis. MRI findings are characteristic and clearly contribute to the differential diagnosis between viral meningitis and SIH.

Objective and Importance: A rare cause of intracranial hypotension is leakage of cerebrospinal fluid (CSF) through a dural breach from degenerative cervical spine pathology. To our knowledge there have been only four cases described in the English literature. Treatment is challenging and varies from case to case, with complete symptom resolution reported for only one patient. Herein we review the literature and describe our surgical management of a 46-year-old woman with symptomatic intracranial hypotension from the penetration of the cervical thecal sac., Clinical Presentation: The patient presented with a 3-month history of progressive orthostatic headaches. Magnetic resonance imaging demonstrated bilateral subdural hematomas and pachymeningeal gadolinium enhancement. An anterior epidural CSF collection commencing at a C4-5 calcified disc protrusion and osteophyte was evident on a computed tomography spinal myelogram., Intervention: After three unsuccessful lumbar blood patches, we elected to attempt surgical removal of the causative pathology with exposure and primary closure of the dural defect by anterior cervical discectomy as described previously. After resection of the disc-osteophyte complex and dural exposure, immediate high volume egression of CSF mixed with blood at the surgical site. The dural defect was not visible but CSF egression promptly ceased. Cervical corpectomy for greater exposure and primary repair of the defect has been described, but we considered this unwarranted and felt the intraoperative blood collection formed a local blood patch. A collagen dural substitute membrane was inserted through the discectomy space for reinforcement., Conclusion: Two months after this novel surgical blood patch procedure the patient was asymptomatic and follow-up imaging demonstrated complete resolution.

Purpose: To present an illustrative case study of a patient with spontaneous intracranial hypotension (SIH) and to increase awareness of this condition among nurse practitioners (NPs)., Data Sources: A literature search was conducted, and deidentified patient information forms the basis of this presentation. The authors' experience and appropriate images enhance the presentation of the case study., Conclusions: SIH is a condition that typically occurs without a traumatic event, although it can be associated with minor trauma. It occurs when cerebrospinal fluid (CSF) leaks through a focal weakness in the dural sac or meningeal diverticula, resulting in CSF hypovolemia. Patients usually present with an orthostatic headache. The most common brain magnetic resonance imaging findings are diffuse pachymeningeal enhancement, descent of the cerebellar tonsils, and subdural fluid collections. Treatment options range from management of symptoms to surgical repair of the leak., Implications for Practice: As NPs continue to provide care in a variety of settings, including emergency departments and urgent care areas, they must be familiar with the progression of symptoms that might indicate SIH and be prepared to make appropriate referrals to prevent iatrogenic morbidity., (©2012 The Author(s) Journal compilation ©2012 American Academy of Nurse Practitioners.)

Background and Purpose: Localization of spinal CSF leaks in CSF hypovolemia is critical in directing focal therapy. In this retrospective review, our aim was to determine whether GdM was helpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on a prior CTM., Materials and Methods: Forty-one symptomatic patients with clinical suspicion of SIH were referred for GdM after undergoing at least 1 CTM between February 2002 and August 2010. A retrospective review of the imaging and electronic medical records was performed on each patient., Results: In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously documented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for a suspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients (21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MR imaging, spine MR imaging, and CTM of the entire spine. Sixteen of 17 patients with previously identified leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%)., Conclusions: GdM is a useful technique in the highly select group of patients who have debilitating symptoms of SIH, a high clinical index of suspicion of spinal CSF leak, and no demonstrated leak on conventional CTM. Intrathecal injection of gadolinium contrast remains an off-label use and should be reserved for those patients who fail conventional CTM.

Spontaneous Intracranial Hypotension is a syndrome involving reduced intracranial pressure secondary to a dural tear which occurs mostly due to connective tissue disorders such as Marfans Syndrome, and Ehler Danlos Syndrome. Patients with dural ectasias leading to CSF leakage into the subdural or epidural space classically present with orthostatic headaches and cranial nerve deficits mostly seen in cranial nerves V-VIII. Diagnosis of SIH is confirmed with the aid of neuroimaging modalities of which Cranial MR imaging is most widely used. SIH can be treated conservatively or with epidural blood patches which are now widely being used to repair dural tears, and their effectiveness is being recognized. Recently epidural injection of fibrin glue has also been used which has been found to be effective in certain patients.

Spontaneous intracranial hypotension is a rare condition caused by spontaneous cerebrospinal fluid leak and volume depletion. It is initially misdiagnosed as a cause of an orthostatic headache, which is the most important symptom of the syndrome. It can be presented as one of four types: classic form, normal pressure form, normal pachymeninges form and acephalgic form. The diagnosis is made based on the clinical presentation, physical examination, typical cerebrospinal fluid and magnetic resonance imaging findings. We present a case of a 29-year-old woman with uncommon normal pressure form of the spontaneous intracranial hypotension, characterized by normal cerebrospinal fluid opening pressure, and typical clinical and magnetic resonance imaging findings, including the finding of pituitary gland enlargement with asymptomatic pituitary haemorrhage as an unusual complication.