Interventions for idiopathic intracranial hypertension

Coupling of CSF and sagittal sinus pressure in adult patients with pseudotumour cerebri

OBJECTIVE

Pseudotumour cerebri syndrome (PTCS including idiopathic intracranial hypertension) is characterised by the symptoms and signs of raised cerebrospinal fluid pressure (CSFp) in the absence of ventricular dilatation or an intracranial mass lesion. Its aetiology is unknown in the majority of cases but there is much evidence for impaired CSF absorption. Traditionally, sagittal sinus pressure has been considered to be independent of CSF pressure in adults. However, the discovery of stenoses of intracranial venous sinuses and introduction of venous sinus stenting has highlighted the importance of the venous drainage in PTCS. In this study, we have explored the relationship between CSFp and SSp before and during a CSF infusion test and during CSF drainage.

MATERIALS AND METHODS

Ten patients (9 females:1 male) with PTCS underwent infusion studies in parallel with direct retrograde cerebral venography. Both SSp and CSFp were recorded at a baseline and during CSFp elevation in a course of a CSF infusion test. The drainage of CSF after the CSF infusion was performed in 7 patients. In 5 cases, jugular venous pressure was also measured.

RESULTS

CSFp and SSp including their amplitudes correlated significantly and strongly both at baseline (R = 0.96; p = 0.001) and during infusion (R = 0.92; p = 0.0026). During drainage, this correlation was maintained until SSp reached a stable value, whereas CSFp continued to decrease.

CONCLUSIONS

In this series of ten patients with PTCS, CSFp and SSp were coupled, both at baseline and during infusion. The implications of such coupling for the calculation of CSF outflow resistance are discussed.

Surgical Outcomes and Postoperative Management in Spontaneous Cerebrospinal Fluid Rhinorrhea

Background  The etiology of spontaneous cerebrospinal fluid (CSF) rhinorrhea remains unknown, though emerging evidence suggests that this likely represents a variant of idiopathic intracranial hypertension. Long-term success rates for repair and postoperative management strategies remain variable. Methods  Retrospective review of patients undergoing surgical management of spontaneous CSF rhinorrhea was conducted over a 5-year period. Analysis was performed to correlate recurrence with demographics and perioperative variables. Lumbar puncture usage and neuro-ophthalmological examinations in clinical management were also assessed. Results  Forty-eight patients were included in the study. The mean age was 51.4 years with 94% females. Leaks were most commonly located in the sphenoid (43.8%) and cribriform region (33.3%). The most common findings on magnetic resonance imaging were empty sella (48%) and Meckel's cave diverticula (24%). Nine patients (18.8%) had recurrent CSF leaks. Six occurred >1 month postoperatively. Three had repeat endoscopic repairs, two received ventriculoperitoneal shunts, and one was managed with a lumbar drain, with overall success rate of 93.8%. Acetazolamide was utilized in 19 cases (39.6%) postoperatively. Overall, 59% of patients had elevated opening pressures on postoperative lumbar puncture ( n  = 32). Neuro-ophthalmology evaluated 28 patients; 25% had visual field deficits, and 7.1% had papilledema. Conclusions  Management of spontaneous CSF leaks remains a significant challenge. Endoscopic repair is successful in most patients with little morbidity; however, postoperative management remains inconsistent, and further studies are warranted to establish consensus on post-surgical care. The association with elevated intracranial pressure and visual field deficits/papilledema suggests opening pressures, and neuro-ophthalmologic evaluation should be considered in the treatment algorithm.

Understanding idiopathic intracranial hypertension: mechanisms, management, and future directions

Idiopathic intracranial hypertension is a disorder characterised by raised intracranial pressure that predominantly affects young, obese women. Pathogenesis has not been fully elucidated, but several causal factors have been proposed. Symptoms can include headaches, visual loss, pulsatile tinnitus, and back and neck pain, but the clinical presentation is highly variable. Although few studies have been done to support evidence-based management, several recent advances have the potential to enhance understanding of the causes of the disease and to guide treatment decisions. Investigators of the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT) reported beneficial effects of acetazolamide in patients with mild visual loss. Studies have also established weight loss as an effective disease-modifying treatment, and further clinical trials to investigate new treatments are underway. The incidence of idiopathic intracranial hypertension is expected to increase as rates of obesity increase; efforts to reduce diagnostic delays and identify new, effective approaches to treatment will be key to meeting the needs of a growing number of patients.

Cochrane systematic reviews and co-publication: dissemination of evidence on interventions for ophthalmic conditions

BACKGROUND

Systematic reviews of interventions provide a summary of the evidence available on intervention effectiveness and harm. Cochrane systematic reviews (CSRs) have been published electronically in the Cochrane Database of Systematic Reviews (CDSR) since 1994, and co-publication (publication of a Cochrane review in another journal) has been allowed since that time, as long as the co-publishing journal has agreed to the arrangement. Although standards for co-publication were established in 2008, the frequency of co-publication and adherence to the standards have remained largely unexamined. Our objective was to examine the frequency of co-publication of Cochrane Eyes and Vision Group (CEVG) reviews, adherence to the co-publication policy, the relative numbers of citations of the two modes of publishing, and differences in times cited in CSRs with and without a co-publication.

METHODS

We identified all CEVG reviews published by May 30, 2014 in The Cochrane Library. Using keywords from the title, author names, and "Cochrane Eyes and Vision Group", we searched Google Scholar, Web of Science, Scopus, and PubMed databases to identify possible co-publications. We also emailed contact authors of all identified CEVG reviews to ask them whether they had published their CSR elsewhere. We compared each co-publication to the corresponding CEVG review for adherence to the Cochrane Policy Manual (dated June 10, 2014). We recorded the number of times each CEVG review and each co-publication had been cited by others according to Google Scholar, Web of Science, and Scopus, as of June 11, 2014.

RESULTS

We identified 117 CEVG reviews;19 had been co-published in 22 articles. Adherence to Cochrane policy on co-publication was moderate, with all authors complying with at least one of four requirements we addressed. Co-publications were cited more often than the corresponding CEVG reviews; CEVG reviews with at least one co-publication were cited approximately twice as often as CEVG reviews without a co-publication. The number of citations varied considerably depending on whether the CEVG review had a co-publication or not.

CONCLUSIONS

The findings support encouraging co-publication while maintaining the primacy of the Cochrane systematic review. Support for co-publication may be tempered by other factors such as the possibility that CEVG reviews with a co-publication covered more clinically important and timely topics than those without a co-publication. Assuming that citations are a valid measure of dissemination effectiveness, the 15-year CEVG experience with co-publication of systematic reviews suggests that Cochrane authors should be encouraged to co-publish in traditional medical journals.

Interventions for idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) has an estimated incidence of one to three people per 100,000 people per year, and occurs most commonly in obese, young women. IIH is associated with severe morbidity, notably due to a significant threat to sight and severe headache. Several different management options have been proposed. Conservative measures centre on weight loss. Pharmacological therapy includes use of diuretics. Refractory and sight-threatening cases demand surgical intervention, most often in the form of cerebrospinal fluid (CSF) diversion or optic nerve sheath fenestration. Other treatments include venous sinus stenting and bariatric surgery.

OBJECTIVES

To assess the effects of any intervention for IIH in any patient group.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015 Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to July 2015), EMBASE (January 1980 to July 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 22 July 2015.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) in which any intervention was compared to placebo, or to another form of treatment, for people with a clinical diagnosis of IIH.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the search results for trials to be included in the review. We resolved any discrepancies by third party decision.

MAIN RESULTS

We identified two completed RCTs (enrolling a total of 211 participants and conducted in the UK and US) and two ongoing trials that met the inclusion criteria. Both completed trials compared acetazolamide to placebo, in conjunction with a weight loss intervention in both groups. Attrition bias was a problem in both trials with high loss to follow-up, in one study this loss to follow-up occurred particularly in the acetazolamide arm. One trial was unmasked and we judged it to be at risk of performance and detection bias.In these studies, change in visual acuity was similar in the treatment and control groups as measured by logMAR acuity. In one study people in the acetalomazide group had a similar change in logMAR acuity compared to the placebo group between baseline and 12 months in the right eye (MD 0.04 logMAR, 95% CI -0.08 to 0.16) and left eye (MD 0.03 logMAR, 95% CI -0.09 to 0.15). In the other study people in the acetalomazide group had a similar change in vision over six months compared with people in the placebo group (mean difference in change in letters read was 0.01 (95% CI -1.45 to 1.46). One study reported no cases of visual loss in 21 people treated with acetalomazide compared to 2/20 cases in the placebo group (odds ratio 0.17, 95% CI 0.01, 3.82).The prespecified outcome for this review was reduction in CSF pressure to normal levels which was not reported by the two trials. One trial reported that, in a subsample of 85 participants who agreed to lumbar puncture at 6 months, people in the acetalomazide group on average had a greater reduction in CSF pressure (MD -59.9 mmH(2)O, 95% CI -96.4, -23.4).In one study, people in the acetalozamide group on average experienced a greater reduction in papilloedema as assessed by fundus photographs MD -0.70 (95% CI -1.00 to -0.40) and by clinical grading MD -0.91 (95% CI -1.27 to -0.54) between baseline and six months in the study eye.Headache was recorded as present/absent in one study at 12 months (OR 0.42, 95% CI 0.12,1.41, 41 participants). Both studies reported headache on visual analogue scales (different ones) but results were inconclusive (MD for change in headache score measured on 10-point visual analogue scale at 12 months was 1.0 (-1.80, 3.70, 41 participants) and MD for change in headache score on a 6 point scale measured at 6 months was -0.45 (-3.5,2.6, number of participants unclear).In one study, a similar proportion of people in the acetalomazide group were in remission (however, the trial authors did not state their definition of this term) at 12 months compared to the placebo group. However, the 95% CIs were wide and there is considerable uncertainty as to the effect (OR 1.13 (95% CI 0.32 to 3.90, 41 participants).In one study of 185 participants, people in the acetalomazide group had an increased risk of decreased CO2, diarrhoea, dysgeusia, fatigue, nausea, paresthesia, tinnitus and vomiting compared to people in the placebo group. In general, the estimates of effect were uncertain with wide 95% CIs. Adverse effects were not reported in the other study.One study reported that quality of life was better in acetazolamide-treated patients based on the visual quality of life (VFQ-25) (MD 6.35, 95% CI 2.22 to 10.47) and the physical (MD 3.02, 95% CI 0.34 to 5.70) and mental (MD 3.45, 95% CI 0.35 to 6.55) components of the 36-Item Short Form Health Survey tool at six months. Costs were not reported in either study.We judged the evidence to be low certainty (GRADE) downgrading for imprecision and risk of bias.

AUTHORS' CONCLUSIONS

Although the two included RCTs showed modest benefits for acetazolamide for some outcomes, there is insufficient evidence to recommend or reject the efficacy of this intervention, or any other treatments currently available, for treating people with IIH. Further high-quality RCTs are required in order to adequately assess the effect of acetazolamide therapy in people with IIH.

Pseudotumor cerebri

INTRODUCTION

Pseudotumor cerebri is a condition characterized by raised intracranial pressure, normal CSF contents, and normal brain with normal or small ventricles on imaging studies. It affects predominantly obese women of childbearing age; however, its incidence seems to be increasing among adolescent and children. While among older children the clinical picture is similar to that of adults, younger children present demographic and clinical peculiarities. Different diagnostic criteria for adults and pre-pubertal children have been proposed. Etiology and pathogenesis are still unclear, particular concerning the role of obstruction to venous outflow.

METHODS

An extensive literature review concerning all the aspects of pseudotumor cerebri has been performed, both among adults and pre-pubertal children.

CONCLUSION

Pseudotumor cerebri is an avoidable cause of visual loss, both in adults and children. Few diagnostic measures are usually sufficient to determine the correct diagnosis. Since pseudotumor cerebri is a diagnosis of exclusion, the differential diagnosis work out is of special importance. Modern neuroimaging techniques, especially magnetic resonance imaging and magnetic resonance venography may clarify the role of obstruction to venous outflow in each case. Various therapeutic options are available: medical, surgical, and endovascular procedures may be used to prevent irreversible visual loss. Treatment is usually effective, and most patients will experience complete resolution of symptoms without persistent deficits.

Changes in weight, papilledema, headache, visual field, and life status in response to diet and metformin in women with idiopathic intracranial hypertension with and without concurrent polycystic ovary syndrome or hyperinsulinemia

The authors hypothesized that a metformin (MET)-diet would improve symptoms of idiopathic intracranial hypertension (IIH) in women who also had polycystic ovary syndrome (PCOS) or hyperinsulinemia without PCOS. Changes in weight, papilledema, headache, visual fields, and overall life status were prospectively assessed in response to 6 to 14 months on 2.25 g/day MET-diet or diet alone in 36 women with IIH, 23 with PCOS, selected by baseline body mass index (BMI) > or = 25, and no previous surgery for IIH. Overall life status was graded using a self-reported 1-5 scale (1 = well, normal activities; 2 = unwell, usual activities; 3 = poor, usual activities; 4 = poor, no usual activities; 5 = totally disabled). Conventional treatment for IIH was maintained unchanged during MET-diet intervention. The diet was hypocaloric (1500 calories/day), high protein (26% of calories), and low carbohydrate (44%). Of the 23 women with PCOS, 20 received MET-diet and 3 diet only (could not tolerate MET). Of the 13 women without PCOS, 7 were hyperinsulinemic and received MET-diet and 6 received diet alone. The 3 treatment groups (diet only [n = 9], PCOS-MET-diet [n = 20], and hyperinsulinemia-MET-diet [n = 7]) did not differ by median entry BMI (33.3, 37.6, and 35.7 kg/m(2)) or by duration of treatment (10.2, 11.4, and 10.9 months). Median percent weight loss was greatest in the PCOS-MET group (7.7%, P = 0.0015), was 3.3% in the diet only group, and 2.4% (P = 0.04) in the hyperinsulinemia-MET group. Papilledema significantly improved in the diet-alone group from 100% at baseline to 13% (P = 0.03), and in the PCOS-MET group from 95% to 30% (P = 0.002). If headache persisted on therapy, it was less intense-less frequent (P = 0.03) in the diet-only group and in the PCOS-MET group (P = 0.04). As many women with IIH have PCOS, and because weight loss is central to IIH treatment, diet-MET is a novel approach to treat IIH in women with concurrent PCOS or hyperinsulinemia without PCOS.

Idiopathic intracranial hypertension, polycystic-ovary syndrome, and thrombophilia

We studied thrombophilia, hypofibrinolysis, and polycystic-ovary syndrome (PCOS) in 65 women consecutively referred because of idiopathic intracranial hypertension (IIH) as a means of better understanding the origin of IIH, with the ultimate goal of developing novel medical therapies for IIH. Our hypothesis: IIH results in part from inadequate drainage of cerebrospinal fluid (CSF) resulting from thrombotic obstruction to CSF resorption-outflow, favored by thrombophilia-hypofibrinolysis. We conducted the polymerase chain reaction (PCR) and assessed serologic coagulation measures in 65 women (64 of them white) with IIH, PCR in 102 healthy white female controls (72 children, 30 age-matched adults), and serologic measures in the 30 adults. Of the 65 patients, 37 (57%) were found to have PCOS; 16 (43%) were obese (BMI > or = 30 to < 40), and 19 (51%) were extremely obese (BMI > or = 40). Of the 65 women with IIH, 25 (38%) were homozygous for the thrombophilic C677T MTHFR mutation, compared with 14% of controls (14/102) ( P = .0002). Thrombophilic high concentrations of factor VIII (>150%) were present in 9 of 65 (14%) IIH cases, compared with 0 of 30 controls (0%) (Fisher's p [p f ] = .053). An increased concentration of lipoprotein A (> or = 35 mg/dL), associated with hypofibrinolysis, was present in 19 of 65 IIH cases (29%), compared with 3 of 30 controls (10%) (p f = .039). IIH occurred in 18 of 65 IIH patients taking estrogen-progestin contraceptives (28%), in 6 patients taking hormone-replacement therapy (9%), and in 5 pregnant subjects (8%). We speculate that PCOS, associated with obesity and extreme obesity, is a treatable promoter of IIH. We also speculate that if thrombophilia-hypofibrinolysis and subsequent thrombosis are associated with reduced CSF resorption in the arachnoid villi of the brain, thrombophilia and hypofibrinolysis-often exacerbated by thrombophilic exogenous estrogens, pregnancy, or the paradoxical hyperestrogenemia of PCOS-are treatable promoters of IIH.