Rebound Intracranial Hypertension.

PURPOSE OF REVIEW: Rebound intracranial hypertension (RIH) is a post-procedural treatment complication in patients with spontaneous intracranial hypotension (SIH) characterized by transient high-pressure headache symptoms. This article reviews the epidemiology, clinical features, risk factors, and treatment options for RIH. RECENT FINDINGS: This article discusses how changes in underlying venous pressure and craniospinal elastance can explain symptoms of RIH, idiopathic intracranial hypertension (IIH), and SIH. The pathophysiology of RIH provides a clue for how high and low intracranial pressure disorders, such as IIH and SIH, are connected on a shared spectrum.

Popping the balloon: Abrupt onset of a spinal CSF leak and spontaneous intracranial hypotension in idiopathic intracranial hypertension, a case report.

OBJECTIVES: Spontaneous intracranial hypotension (SIH) is a debilitating neurologic condition that is often thought of as separate from idiopathic intracranial hypertension (IIH). The unique case presented here details a spontaneous spinal cerebrospinal fluid (CSF) leak that developed abruptly following a CSF pressure elevating maneuver in a patient with pre-existing intracranial hypertension, raising the possibility of a causative link between the two conditions. RESULTS: A 40-year-old woman with symptomatic IIH developed a dural tear of a thoracic spinal nerve root sleeve during an episode of Valsalva maneuver leading to a CSF leak and development of symptomatic SIH. This was successfully treated with epidural blood and fibrin glue patch and the patient is now symptom-free. DISCUSSION: The implication of a possible causative link between elevated CSF pressure and subsequent development of dural rupture and SIH raises important questions regarding the pathophysiology of SIH in some cases. Furthermore, it suggests that there could be a potential prophylactic benefit of CSF pressure lowering medications in preventing the development of SIH in patients with IIH.

A Review of Spontaneous Intracranial Hypotension.

PURPOSE OF REVIEW: Spontaneous intracranial hypotension (SIH) is an underdiagnosed phenomenon predominantly presenting with low cerebrospinal fluid (CSF) pressure and postural headache in setting of CSF leak. The goal of this paper is to provide updates on the pathology, diagnosis, and management of SIH. The utility of multiple imaging modalities and the use of epidural blood patches and fibrin glue polymers are explored. RECENT FINDINGS: In regard to diagnosis, new non-invasive modalities in detection of SIH including transorbital ultrasound and serum biomarkers are found. In addition, increased efficacy of large volume and repeated placement of multiple epidural blood patches (EBP) are seen. In addition, the management of refractory SIH using fibrin glue polymers has proved efficacious in recent case series. While the diagnosis may be challenging for clinicians, future research in SIH is leading to more rapid detection methods. Future studies may target optimal use of EBP in comparison to fibrin glue polymers, in addition to new developments in increased understanding of SIH physiology and phenotype.

A clinical analysis on 40 cases of spontaneous intracranial hypotension syndrome.

OBJECTIVE: To investigate clinical and imaging features of 40 patients with spontaneous intracranial hypotension (SIH). METHODS: 40 cases of spontaneous intracranial hypotension (SIH) diagnosed in our hospital from June 2013 to September 2017 were collected and retrospectively analyzed. RESULTS: In our study, the male to female ratio was 2:3. The average age of onset was 43.0 ± 15.0 years. There were 12 (30.0%) patients with clear incentives, mostly catching cold. The average length of hospital stay was 11.2 ± 6.3 days. All the patients showed orthostatic headaches, 62.5% patients with nausea or vomiting, 40.0% patients with neck stiffness, 17.5% patients with dizziness and vertigo, 10.0% patients with numbness and weakness of limbs, 5% patients with neck discomfort, and 2.5% patients with visual symptoms (visual impairment, photophobia, diplopia). 24 patients underwent CT scans which showed no abnormalities in 20 cases (83.3%), subdural fluid accumulation in 3 cases (12.5%), and subdural haematoma in 1 case (2.5%). Cranial contrast-enhanced MR scans showed diffuse pachymeningeal enhancement (95.83%, 23/24), signs of pituitary hyperaemia in 5 cases (20.8%), subdural fluid accumulation and subdural hematoma in 4 cases (16.7%), sagging of the brain in 3 cases (12.5%), and engorgement of venous structures in 1 case (4.1%). Six patients underwent plain and contrast-enhanced spinal MR scans which showed varying degrees of dural thickening and enhanced performance in all the patients. 92.5% (37/40) of patients had cerebrospinal fluid pressure <60 mmH2O on lumbar puncture. 97.5% of patients underwent conservative treatment with drugs and had a good outcome. CONCLUSION: Orthostatic headache and cranial MRI diffuse pachymeningeal enhancement are characteristic features of SIH. Cranial contrast-enhanced MR scan is recognized as the first and non-invasive investigation in the diagnosis of SIH. Most patients had cerebrospinal fluid pressure <60 mmH2O. The vast majority of patients improved with fluid replacement.

Spontaneous Intracranial Hypotension: 10 Myths and Misperceptions.

OBJECTIVE: To discuss common myths and misperceptions about spontaneous intracranial hypotension (SIH), focusing on common issues related to diagnosis and treatment, and to review the evidence that contradicts and clarifies these myths. BACKGROUND: Recognition of SIH has increased in recent years. With increasing recognition, however, has come an increased demand for management by neurologists and headache specialists, some of whom have little prior experience with the condition. This dearth of practical experience, and lack of awareness of recent investigations into SIH, produces heterogeneity in diagnostic and treatment pathways, driven in part by outdated, confusing, or unsubstantiated conceptions of the condition. We sought to address this heterogeneity by identifying 10 myths and misperceptions that we frequently encounter when receiving referrals for suspected or confirmed SIH, and to review the literature addressing these topics. METHODS: Ten topics relevant to diagnosis and treatment SIH were generated by the authors. A search for studies addressing SIH was conducted using PubMed and EMBASE, limited to English language only, peer reviewed publications from inception to 2018. Individual case reports were excluded. The resulting studies were reviewed for relevance to the topics in question. RESULTS: The search generated 557 studies addressing SIH; 75 case reports were excluded. Fifty-four studies were considered to be of high relevance to the topics addressed, and were included in the data synthesis. The topics are presented in the form of a narrative review. CONCLUSIONS: The understanding of SIH has evolved over the recent decades, leading to improvements in knowledge about the pathophysiology of the condition, diagnostic strategies, and expanded treatments. Awareness of these changes, and dispelling outdated misconceptions about SIH, is critical to providing appropriate care for patients and guiding future investigations going forward.

Chest Pain as a Manifestation of Intracranial Hypotension: Report of Four Cases.

BACKGROUND: Chest pain has not been recognized as a manifestation of intracranial hypotension secondary to cerebrospinal fluid leakage. CASE REPORT: We report on 4 patients with intracranial hypotension diagnosed by the pattern of headaches, temporal proximity to dural puncture, magnetic resonance imaging findings, and resolution of symptoms after epidural blood patch who presented with chest pain. The chest pain was episodic, located in the sternal and interscapular region for the first 3 patients, with no radiation to any other region and no clear relationship to exertion. The fourth patient had episodic chest pain located in the subclavicular and suprascapular region. Two patients reported dyspnea with chest pain. Underlying coronary artery ischemia was excluded using a combination of the electrocardiogram and cardiac enzyme assays. The pain resolved after epidural blood patch treatment. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Clinicians should be aware of chest pain that can be seen with intracranial hypotension and cerebrospinal leakage to ensure appropriate diagnostic tests and treatment.

Granulomatosis With Polyangiitis-Associated Hypertrophic Pachymeningitis Mimicking Spontaneous Intracranial Hypotension: A Case Report.

BACKGROUND: Dural enhancement is a characteristic finding in both spontaneous intracranial hypotension and hypertrophic pachymeningitis. Positional headache is the most important feature that distinguishes the two diseases. We report a patient with granulomatosis with polyangiitis (formerly Wegener's granulomatosis) who initially manifested like spontaneous intracranial hypotension. CASE PRESENTATION: We report here the case of a 63-year old man who presented with severe positional headache. The patient had typical symptoms, symmetric dural enhancement, and a recent history of nontraumatic subdural hygroma which led to the diagnosis of spontaneous intracranial hypotension, but was finally diagnosed as granulomatosis with polyangiitis-associated secondary hypertrophic pachymeningitis. Cyclophosphamide therapy was effective for the maintenance of remission. CONCLUSIONS: Hypertrophic pachymeningitis associated with granulomatosis with polyangiitis can present with positional headache and subdural hygroma, mimicking spontaneous intracranial hypotension. Granulomatosis with polyangiitis should be suspected when patients with spontaneous intracranial hypotension or hypertrophic pachymeningitis show atypical features.

Association of Cerebral Venous Thrombosis and Intracranial Hypotension: Review of 3 Cases.

Cerebral venous thrombosis is a rare complication of intracranial hypotension. We describe 3 cases in which this phenomenon occurred, as a result of a lumbar puncture or due to a spontaneous cerebrospinal fluid leak. We emphasize the importance of early detection of the intracranial hypotension syndrome, the most common clinical manifestation being orthostatic headache. It is not an innocent condition as it is associated with other potential complications such as subdural hygroma/hematoma, cranial nerve palsies, cerebellar tonsillar descent, and even brainstem manifestations. Any change in the typical features of the syndrome should lead to further investigation. Repeat cerebral imaging is important in that situation, including ruling out cerebral venous thrombosis.

Reversible alterations of the neuronal activity in spontaneous intracranial hypotension.

AIM: The aim of this article is to investigate the pathophysiology underlying the alternation of the cognitive function and neuronal activity in spontaneous intracranial hypotension (SIH). METHODS: Fifteen patients with SIH underwent resting-state functional magnetic resonance imaging and working-memory (WM) test one day before and one month after a surgical operation. Alternation of the cognitive function and spontaneous neuronal activity measured as amplitude of the low-frequency fluctuations (ALFF) and the functional connectivity of the default-mode network (DMN) and frontoparietal networks (FPNs) were evaluated. RESULTS: WM performance significantly improved post-operatively. Whole-brain linear regression analysis of the ALFF revealed a positive correlation between cognitive performance change and ALFF change in the precuneus while a negative correlation was found in the bilateral orbitofrontal cortices (OFCs) and right medial frontal cortex (MFC). The ALFF changes normalised with the WM performance improvement post-operatively. The FPN activity in the right OFC was also increased pre-operatively. Partial correlation analysis revealed a significant correlation between WM performance and right OFC activity controlled for right FPN activity. CONCLUSIONS: The abnormal activity of the OFCs and MFC that is not originating from the synchronous intrinsic network activity, together with the decreased activity of the central node of the DMN, could lead to cognitive impairment in SIH that is reversible through restoration of the cerebrospinal fluid.

How common is normal cerebrospinal fluid pressure in spontaneous intracranial hypotension?

Objectives To determine the proportion of patients with spontaneous intracranial hypotension (SIH) who had a cerebrospinal fluid (CSF) pressure >6 cm H2O and to investigate the clinical and imaging variables associated with CSF pressure ( PCSF) in this condition. Methods We retrospectively reviewed 106 patients with SIH. PCSF 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 PCSF. Results Sixty-one percent of patients had a PCSF between 6 and 20 cm H2O; only 34% had a PCSF ≤6 cm H2O. The factors associated with increased PCSF 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 PCSF 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 PCSF 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.

Sex- and Age-Related Differences in the Clinical and Neuroimaging Characteristics of Patients With Spontaneous Intracranial Hypotension: A Records Review.

BACKGROUND: The significance of sex- and age-related differences in the clinical course of spontaneous intracranial hypotension (SIH) was investigated. METHODS: We retrospectively studied 40 consecutive patients (female:male = 28:12, median age 41.5 years) treated under clinical diagnoses of SIH satisfying the International Classification of Headache Disorders 3rd edition criteria, including 37 patients (92.5%) with diffuse pachymeningeal enhancement. The patients were divided into two groups by age and sex, and the clinical and neuroimaging findings in each group were investigated. RESULTS: Acute onset (female:male = 82.1%:50.0%, P = .042), severe headache (75.0%:41.7%, P = .045) occurred with higher frequency in females than in males, and SDH occurred with lower frequency in females than in males (28.6%:75.0%, P = .006). Duration until the consultation (2:14 days, P = .022), SDH thickness (0:7.1 mm, P = .001), and iter displacement (1.6:7.1 mm, P = .004) was greater in males. Acute onset (Younger [≤40 years]: older [>40 years] = 94.1%:56.5%, P = .012), occurred with higher frequency in younger patients, and duration until the consultation (1:5 days, P = .001), frequency of SDH (17.7%:60.9%, P = .010), SDH thickness (0:5.9 mm, P = .003), in older patients. All nine patients with thunderclap headache were female, with median age of 37 years. CONCLUSIONS: More severe clinical symptoms with acute onset were observed in females and younger patients of SIH. Comparatively rare subdural hygroma/hematoma on magnetic resonance imaging might result from the shorter duration to diagnosis in females and younger patients. KEY WORDS: spontaneous intracranial hypotension, sex, age, magnetic resonance imaging, thunderclap headache.

The quantitative evaluation of intracranial pressure by optic nerve sheath diameter/eye diameter CT measurement.

BACKGROUND: The changes of the optic nerve sheath diameter (ONSD) have been used to assess changes of the intracranial pressure for 20 years. The aim of this research was to further quantify the technique of measuring the ONSD for this purpose. METHODS: Retrospective study of computed tomographic (CT) data of 1766 adult patients with intracranial hypotension (n=134) or hypertension (n=1632) were analyzed. The eyeball transverse diameter (ETD) and ONSD were obtained bilaterally, and the ONSD/ETD ratio was calculated. The ratio was used to calculate the normal ONSD for patients and to estimate the intracranial pressure of the patients before and after the onset of the pathology. Correlation analysis was performed with invasively measured intracranial pressure, the presence or absence of papilledema, sex, and age. RESULTS: In hypotension cases, the ONSD by CT was 3.4±0.7 mm (P=.03 against normative 4.4±0.8 mm). In cases with hypertension, the diameter was 6.9±1.3 (P=.02, with a cutoff value ˃5.5 mm). The ONSD/ETD ratio was 0.29±0.04 against 0.19±0.02 in healthy adults (P=.01). CONCLUSION: The ONSD and the ONSD/ETD ratio can indicate low intracranial pressure, but quantification is impossible at intracranial pressure less than 13 mm Hg. In elevated intracranial pressure, the ONSD and the ratio provide readings that correspond to readings in millimeters of mercury. The ONSD method, reinforced with additional calculations, may help to indicate a raised intracranial pressure, evaluate its severity quantitatively, and establish quantitative goals for treatment of intracranial hypertension, but the limitations of the method are to be taken into account.

Monitoring of Intracranial Pressure in Meningitis.

BACKGROUND: The literature on intracranial pressure (ICP) monitoring in meningitis is limited to case reports and a handful of descriptive series. The aim of this study is to investigate relationships among ICP, cerebral perfusion pressure (CPP), and outcome in meningitis and to identify whether ICP affected clinical decisions. METHODS: Between 1999 and 2011, a total of 17 patients with meningitis underwent ICP monitoring at the University Hospitals Leuven. Charts were reviewed for clinical history, ICP/CPP data, imaging findings, and Glasgow Outcome Scale score. Univariate correlations were computed for outcome and ICP/CPP variables, computed tomography characteristics, and Corticosteroid Randomization After Significant Head Injury outcome model variables. Treatment decisions were assessed regarding whether or not they were based on ICP. RESULTS: At drain placement, Glasgow Coma Scale scores showed a median of 8 (range 3-12). Six of 17 patients had either one or two nonreactive pupils. Significant correlations with outcome were found for the highest documented ICP value (r = -0.70), the number of episodes when CPP <50 mmHg (r =-0.50), the lowest documented CPP value (r = 0.61), and pupil reactivity (r = 0.57). Treatment was influenced by ICP in all patients. CONCLUSION: The results support the notion that in meningitis high ICP and low CPP represent secondary insults. The poor condition of the patients illustrates that the level of suspicion for increased ICP in meningitis may not be high enough.

Systematic review of decreased intracranial pressure with optimal head elevation in postcraniotomy patients: a meta-analysis.

AIM: To determine an optimal head elevation degree to decrease intracranial pressure in postcraniotomy patients by meta-analysis. BACKGROUND: A change in head position can lead to a change in intracranial pressure; however, there are conflicting data regarding the optimal degree of elevation that decreases intracranial pressure in postcraniotomy patients. DESIGN: Quantitative systematic review with meta-analysis following Cochrane methods. DATA SOURCES: The data were collected during 2014; three databases (PubMed, Embase and China National Knowledge Internet) were searched for published and unpublished studies in English. The bibliographies of the articles were also reviewed. The inclusion criteria referred to different elevation degrees and effects on intracranial pressure in postcraniotomy patients. REVIEW METHODS: According to pre-determined inclusion criteria and exclusion criteria, two reviewers extracted the eligible studies using a standard data form. RESULTS: These included a total of 237 participants who were included in the meta-analysis. (1) Compared with 0 degree: 10, 15, 30 and 45 degrees of head elevation resulted in lower intracranial pressure. (2) Intracranial pressure at 30 degrees was not significantly different in comparison to 45 degrees and was lower than that at 10 and 15 degrees. CONCLUSION: Patients with increased intracranial pressure significantly benefitted from a head elevation of 10, 15, 30 and 45 degrees compared with 0 degrees. A head elevation of 30 or 45 degrees is optimal for decreasing intracranial pressure. Research about the relationship of position changes and the outcomes of patient primary diseases is absent.

Chapter 5 cerebral perfusion pressure and intracranial pressure in traumatic brain injury.

Nearly 300,000 children and adults are hospitalized annually with traumatic brain injury (TBI) and monitored for many vital signs, including intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Nurses use these monitored values to infer the risk of secondary brain injury. The purpose of this chapter is to review nursing research on the monitoring of ICP and CPP in TBI. In this context, nursing research is defined as the research conducted by nurse investigators or research about the variables ICP and CPP that pertains to the nursing care of the TBI patient, adult or child. A modified systematic review of the literature indicated that, except for sharp head rotation and prone positioning, there are no body positions or nursing activities that uniformly or nearly uniformly result in clinically relevant ICP increase or decrease. In the smaller number of studies in which CPP is also measured, there are few changes in CPP since arterial blood pressure generally increases along with ICP. Considerable individual variation occurs in controlled studies, suggesting that clinicians need to pay close attention to the cerebrodynamic responses of each patient to any care maneuver. We recommend that future research regarding nursing care and ICP/CPP in TBI patients needs to have a more integrated approach, examining comprehensive care in relation to short- and long-term outcomes and incorporating multimodality monitoring. Intervention trials of care aspects within nursing control, such as the reduction of environmental noise, early mobilization, and reduction of complications of immobility, are all sorely needed.

[The effectiveness of using HyperHAES hypertonic isooncotic plasma solution to achieve stable intracranial hypotension in endoscopic endonasal transsphenoidal adenomectomy as an alternative to the invasive external lumbar drainage].

The structure of surgery of pituitary adenomas has been fundamentally changed over the past decade. The transnasal transsphenoidal approach is currently used to resect more than 95% of adenomas. The wide use of endoscopy has changed the need for perioperative control of intracranial pressure. While controlled intracranial hypertension was previously used during microscopically controlled transnasal surgery to bring the suprasellar capsule and tumor remnants to the field of vision, endoscopically controlled tumor resection implies that controlled intracranial hypotension is required to achieve complete spreading of the suprasellar capsule. External lumbar drains inserted at least for the entire surgery duration are conventionally used to control intracranial pressure. We present the results of the study proving the effectiveness and safety of the HyperHAES hypertonic isooncotic plasma substitute in achieving stable intracranial hypotension according to a large body of clinical data. Our findings give grounds for claiming that the use of the HyperHAES hypertonic isooncotic plasma substitute during the standard adenomectomy allows one to abandon the use of invasive external lumbar drainage, while the surgery quality and risks remain at the same level.

High-pressure headaches, low-pressure syndromes, and CSF leaks: diagnosis and management.

BACKGROUND: Headache resulting from idiopathic intracranial hypertension (IIH) in a population of moderately to obese women of childbearing age. The causes overall remain unclear. With this review, we provide an overview of clinical treatment and management strategies. RESULTS: IIH management is dependent on the signs and symptoms presented. Symptomatic treatment should attempt to lower intracranial pressure, reduce pain, and protect the optic nerves. Consideration for lumbar puncture and draining fluid as an option for reducing pressure may be helpful; however, repeated treatment is not usually favored by patients. Traditional prophylactic medications used in migraine may help reduce the primary headache often induced by raised intracranial pressure. We suggested surgical intervention for patients experiencing visual loss or impending visual loss and not responding to medication therapy. CONCLUSION: In this review, we discuss headache associated with IIH and spontaneous intracranial hypotension. Much needs to be learned about treatment options for patients with cerebrospinal fluid leaks including methods to strengthen the dura.

Headache secondary to intracranial hypotension.

Intracranial hypotension is known to occur as a result of spinal cerebrospinal fluid (CSF) leaking, which may be iatrogenic, traumatic, or spontaneous. Headache is usually, but not always, orthostatic. Spontaneous cases are recognized more readily than in previous decades as a result of a greater awareness of clinical presentations and typical cranial magnetic resonance imaging findings. An underlying disorder of connective tissue that predisposes to weakness of the dura is implicated in spontaneous spinal CSF leaks. CT, MR, and digital subtraction myelography are the imaging modalities of choice to identify spinal CSF leakage. Spinal imaging protocols continue to evolve with improved diagnostic sensitivity. Epidural blood patching is the most common initial intervention for those seeking medical attention, and may be repeated several times. Surgery is reserved for cases that fail to respond or relapse after simpler measures. While the prognosis is generally good with intervention, serious complications do occur. More research is needed to better understand the genetics and pathophysiology of dural weakness as well as physiologic compensatory mechanisms, to continue to refine imaging modalities and treatment approaches, and to evaluate short- and long-term clinical outcomes.