What is new about idiopathic intracranial hypertension? An updated review of mechanism and treatment

Neuroimaging and other investigations in patients presenting with headache

Headache is very common. In the United Kingdom, it accounts for 4.4% of primary care consultations, 30% of referrals to neurology services and 0.5-0.8% of alert patients presenting to emergency departments. Primary headache disorders account for the majority of patients and most patients do not require investigation. Warning features (red flags) in the history and on examination help target those who need investigation and what investigations are required. This article summarizes the typical presentations of the common secondary headaches and what neuroimaging and other investigations are appropriate for each headache type.

A 43-year-old woman on triptorelin presenting with pseudotumor cerebri: a case report

Introduction

To the best of our knowledge, this is the first time triptorelin has been reported to cause benign intracranial hypertension.

Case presentation

A 43-year-old Caucasian woman who suffered from chronic menorrhagia was started on triptorelin, a gonadotrophin-releasing hormone analogue. Three days later, she developed gradually worsening headaches accompanied by bilateral visual disturbance. Examination revealed bilateral papilledema and enlarged blind spots on her visual fields. A diagnosis of benign intracranial hypertension was made and confirmed on magnetic resonance imaging.

Conclusion

We recommend that patients at high risk (women who are overweight and of reproductive age) who are using any gonadotrophin-releasing hormone analogue (for example, triptorelin) should be periodically monitored for the possible development of benign intracranial hypertension.

Aquaporin-4 antibodies are not present in patients with idiopathic intracranial hypertension

OBJECTIVES

We aimed to investigate anti-aquaporin-4 (AQP-4) water channel antibodies, affecting cerebrospinal fluid (CSF) secretion and absorption, in idiopathic intracranial hypertension (IIH) patients.

METHODS

Patients fulfilling the modified Dandy's diagnostic criteria for IIH were included and their clinical features and CSF findings were reviewed. Their serum samples and control groups were investigated by immunofluorescence and a cell-based assay for anti-AQP-4 antibodies and by immunohistochemistry for IgG binding patterns.

RESULTS

Twenty-nine patients diagnosed with IIH were investigated. We could not detect any anti-AQP-4 antibodies in our series. However, we identified different serum IgG binding patterns in 11 IIH patients.

CONCLUSION

There is only one report investigating the anti-AQP4 antibodies in IIH. Our study with a larger sample confirmed the results of this report and indicated that AQP4 antibodies did not have a primary role in IIH pathogenesis, but provided some support for the contribution of inflammatory mechanisms in IIH.

[Treatment and prognosis of idiopathic intracranial hypertension in children. Retrospective study (1995-2009) and literature review]

AIM

Idiopathic intracranial hypertension (IIH) may cause severe visual loss due to the optic nerve damage. Routine management involves mainly medical treatment. The aim of this study was to improve diagnosis and management of IIH in children.

METHODS

The medical records of all patients with definite IIH seen at the children's hospital of Toulouse between 1995 and 2009 were reviewed. Cases of secondary intracranial hypertension were included because they did not present any cerebral lesions and underwent a similar therapeutic approach. The clinical and ophthalmological data at the beginning and at the end of their treatment was collected.

RESULTS

Eighteen children were included in this study. The average age was 10 years and the sex-ratio was equal to 1. There were 3 cases of secondary idiopathic intracranial hypertension in this pediatric group. The main features encountered were headache (15 children) and diplopia (8 children). Abnormal neurological examination was found for 11 patients with abducens nerve paresis in 8 cases, rachialgia in 6 cases, and neurogenic pains (neuralgia, dysesthesia, paresthesia, hyperesthesia) in the other cases. Papilledema was noted in 16 patients. At the initial phase, loss of visual acuity was documented in 6 patients and altered visual field in nine patients. All patients had a medical treatment. When recurrence occurred, each new treatment was documented, for a total of 23 treatments analyzed. Lumbar puncture was the only treatment for 2 patients. In 16 cases, first-line treatment was acetazolamide and it was the second choice in 1 case, with an average dosage of 11.2mg/kg and a mean duration of 2.5 months (15 treatments could be analyzed). This treatment was effective in 11 cases out of 15. Steroids were the initial treatment in 4 cases and second-line treatment in 4 cases (after failed acetazolamide therapy). The dosage was 1.5-2mg/kg for a mean duration of 1.5 months (6 treatments could be analyzed). This treatment was effective in 5 patients out of 6. One patient had dual therapy. No surgical procedure was necessary in this pediatric cohort. Three patients presented relapses of IIH. The outcome was good with no residual visual impairment in the 13 patients analyzed. One patient was still under medication.

COMMENTS

Therapeutic management of IIH in a pediatric population is essentially medical, in some cases limited to lumbar puncture. The first-line treatment is acetazolamide, but this study shows that low doses and short duration are usually chosen. Doses must be increased and treatment prolonged to avoid the use of corticosteroids as a second-line treatment and prevent possible relapses that require close monitoring of visual function.

CONCLUSION

The visual prognosis is generally better for this age group compared to adults and no risk factors for visual sequelae were identified. A standardized protocol for management of IIH was proposed.

Magnetic resonance "flip-flop" in idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a headache syndrome with raised CSF pressure in the absence of an intracranial mass lesion. Though earlier confined to excluding intracranial lesions, magnetic resonance imaging (MRI) in recent years has been shown to identify intracranial changes from prolonged raised CSF pressure, suggestive of IIH. We present the MRI and TOF (time-of-flight) venography findings involving the orbit, sella tursica and cerebral venous structures in a 45-year-old lady with IIH and illustrate their reversibility ("flip-flop") following CSF drainage. Our case highlights the role of imaging in evaluation and follow-up of patients with IIH, without the need for repeated lumbar punctures to monitor pressures.

MR imaging findings in patients with secondary intracranial hypertension

BACKGROUND AND PURPOSE

IH can alter the configuration of anatomic structures of the central nervous system. We determined the sensitivity and specificity of MR imaging to detect these changes in patients with secondary IH.

MATERIALS AND METHODS

Patients (n = 36) with IH were prospectively investigated with MR imaging and were matched to 36 controls. MR images were evaluated for elongation and edema of the optic nerves, protrusion of the optic disc, flattening of the posterior sclera, height of the pituitary gland, and width of the optic nerve sheath. On MRV, we recorded venous sinus abnormalities and measured the luminal width of the superior ophthalmic veins. A grading score was introduced to define cranial venous outflow obstruction.

RESULTS

Cranial venous outflow obstruction and ONS hydrops were the most valid signs indicating IH with a sensitivity of 94% and 92% and a specificity of 100% and 89%, respectively. Sensitivities and specificities were 56% and 97% for reduced pituitary height, 64% and 78% for flattening of the posterior sclera, 31% and 97% for widening of the superior ophthalmic veins, 33% and 100% for optic disc protrusion, 14% and 100% for optic nerve edema, and 6% and 100% for elongation of the optic nerve. At least 2 MR imaging findings could be demonstrated in each patient but in none of the controls. The number of positive MR imaging findings correlated with CSF pressure (r = 0.62, P = .01).

CONCLUSIONS

The combination of cranial and orbital MR imaging and MRV can be highly sensitive and specific in the diagnosis of patients with IH.

The entire dural sinus tree is compressed in patients with idiopathic intracranial hypertension: a longitudinal, volumetric magnetic resonance imaging study

INTRODUCTION

The objective of this study was to explore the volumetric alterations of dural sinuses in patients with idiopathic intracranial hypertension (IIH).

METHODS

Standardized cranial magnetic resonance imaging (MRI) was used in 17 patients prior to and following treatment of IIH and in seven controls. Magnetic resonance venographies (MRV) were employed for (a) judgement of circumscript dural sinus stenoses and (b) computation of sinus volumes. Cross-sectional areas (CSA) of the superior sagittal sinuses (SSS) were measured on T2-weighted images. Results of the initial MRIs were compared to those on follow-up MRIs and to results of controls.

RESULTS

Stenoses of the transverse sinuses (TS) resulting in cranial venous outflow obstruction (CVOO) were present in 15/17 (88%) patients, normalizing in 7/15 cases (47%) after treatment of IIH. CVOO was not detected in the control group. Segmentation of MRV revealed decreased dural sinus volumes in patients with IIH as compared to controls (P = 0.018). Sinus volumes increased significantly with normalization of intracranial pressure independent from disappearing of TS stenoses (P = 0.007). The CSA of the SSS were normal on the initial MRIs of patients with IIH and increased on follow-up after treatment (P < 0.001). However, volumetries displayed overlap in patients and controls.

CONCLUSIONS

Patients with IIH not only exhibit bilateral stenoses of the TS as has been reported, but volume changes of their entire dural sinus system also occur. The potential etiopathological and diagnostic roles of these changes are discussed.

Graves' disease presenting as pseudotumor cerebri: a case report

Introduction

Pseudotumor cerebri is an entity characterized by elevated intracranial pressure with normal cerebrospinal fluid and no structural abnormalities detected on brain MRI scans. Common secondary causes include endocrine pathologies. Hyperthyroidism is very rarely associated and only three case reports have been published so far.

Case presentation

We report the case of a 31-year-old Luso-African woman with clinical symptoms and laboratory confirmation of Graves' disease that presented as pseudotumor cerebri.

Conclusion

This is a rare form of presentation of Graves' disease and a rare cause of pseudotumor cerebri. It should be remembered that hyperthyroidism is a potential cause of pseudotumor cerebri.

Familial idiopathic intracranial hypertension with variable phenotype

Familial occurrence of Idiopathic intracranial hypertension has been rarely reported in the literature. Idiopathic intracranial hypertension, both with and without papilloedema is only described in two families before, though one had a probable diagnosis. We report a family of mother and her two daughters. A 37 year old woman was diagnosed with idiopathic intracranial hypertension. Her 7 year old, younger daughter presented a year later with similar symptoms. She did not respond to medical treatment and required Lumbo-peritoneal shunt, Ventriculo-peritoneal shunt and bilateral sub-temporal decompression. Her elder daughter later presented with headaches and idiopathic intracranial hypertension without papilloedema was diagnosed at the age of 13 years. Further insight into the patterns of inheritance is required and other family members should be offered screening, even if papilloedema is not present.

A case of Gitelman syndrome associated with idiopathic intracranial hypertension

An 18-year-old woman with Gitelman syndrome (GS) associated with idiopathic intracranial hypertension (IIH) is described. She was obese and showed a 10 kg gain in body weight over a period of 8 months. She presented with headache, vomiting, and diplopia. She had bilateral papilledema, and right abducens palsy. CSF examination demonstrated high pressure (over 320 mmH(2)O) with normal cytochemistry. Brain MRI was normal. She showed mild alkalosis, hypokalemia, hypomagnesemia, increased plasma renin activity, and normal blood pressure. Two heterozygous mutations in the SLC12A3 gene were identified. Therefore, she was diagnosed as GS with IIH. We should keep in mind the possible occurrence of IIH in GS.

Idiopathic intracranial hypertension in children: a review and algorithm

This updated review of pediatric idiopathic intracranial hypertension focuses on epidemiology, clinical presentations, diagnostic criteria, evaluation, clinical course, and treatment. General guidelines for the clinical management of idiopathic intracranial hypertension are discussed. A new algorithm outlines an efficient management strategy for the initial diagnostic evaluation of children with signs or symptoms of intracranial hypertension. This algorithm provides a systematic approach to initial evaluation and management, and identifies important decision-making factors. The risk of permanent visual loss with idiopathic intracranial hypertension necessitates a prompt, thorough collaborative approach in the management of patients. Although idiopathic intracranial hypertension has been recognized for over a century, the need remains for prospectively collected data to promote a better understanding of the etiology, risk factors, evaluative methods, and effective treatments for children with this syndrome.

"Idiopathic" intracranial hypertension caused by venous sinus thrombosis associated with contraceptive usage

BACKGROUND

Cerebral venous sinus thrombosis (CVST) is a life-threatening condition that may present with symptoms and signs identical to idiopathic intracranial hypertension (IIH). Both conditions consist of increased intracranial pressure (ICP); however, IIH shows no evidence of contributory intracranial pathology. Oral hormonally based contraceptive usage has been associated with both conditions as well. Because disc edema often occurs in CVST, and IIH and is evident in other sight- and life-threatening conditions such as intracranial mass lesions, neuroimaging and other ancillary testing must be conducted for definitive diagnosis.

CASE

An 18-year-old white woman with IIH previously diagnosed presented with headaches and severe visual loss in the left eye. Bilateral disc edema with macular edema in the left eye (O.S.) was present. Threshold perimetry found bilaterally enlarged blind spots as well as a central scotoma O.S. Her medical history was significant for a right transverse, sigmoid and jugular siphon thrombosis secondary to a hypercoagulable state and associated with her use of oral birth control medication. Subsequent magnetic resonance venography (MRV) found the presence of CVST. Despite anticoagulation therapy and acetazolamide, she had severe, nonresolving papilledema. Treatment with oral prednisone was initiated. She recovered full visual fields and excellent visual acuity.

CONCLUSION

Because of the similarity in clinical presentation of CVST and IIH, it is important to differentiate distinguishing characteristics of these diseases for correct diagnosis and prompt treatment.

Static and pulsatile intracranial pressure in idiopathic intracranial hypertension

OBJECTIVE

The aim of this observational study was to characterize the static and pulsatile intracranial pressure (ICP) in conservatively (medically) treated idiopathic intracranial hypertension (IIH) patients in need of shunt surgery, and also in patients with chronic daily headache (CDH) without visual disturbances.

METHODS

The material includes 14 IIH patients and 7 CDH patients in whom ICP was monitored continuously over-night. Static ICP was characterized by mean ICP, pulsatile ICP was characterized by the wave amplitude, rise time, and rise time coefficient.

RESULTS

In the IIH group all 14 had headache and visual disturbances. Mean ICP was high (> 15 mmHg) in only 7 patients (50%), while mean ICP wave amplitude was high (≥ 4 mmHg) in all 14 (100%). All IIH patients were shunted and improved clinically thereafter (i.e., relief from visual disturbances and/or headache). None in the CDH group had high mean ICP or mean ICP wave amplitude, and none were shunted.

CONCLUSIONS

In this cohort of 14 conservatively treated IIH patients with lasting and shunt-responsive headache and visual disturbances, the mean ICP wave amplitude was elevated (≥ 4 mmHg) in all patients despite normal mean ICP (< 15 mmHg) in 7 patients (all but one on medication). Therefore, the pulsatile ICP may be more relevant than the static ICP in the diagnostic setting for patients with IIH. Further prospective standardized approaches are warranted.

Incidence of papilledema and obesity in children diagnosed with idiopathic ''benign'' intracranial hypertension: case series and review

Idiopathic intracranial hypertension is an important cause of headaches in the pediatric population and can lead to permanent blindness if not diagnosed in a timely manner. The aim of this study was to characterize the incidence of papilledema and obesity in children with idiopathic intracranial hypertension. We retrospectively analyzed 27 patients followed at The University of Texas Houston Pediatric Neurology Clinic. Papilledema was absent in 13 (48%) patients. The majority of our patients were nonobese (70%). Our results are contrary to the current medical practice of associating papilledema and obesity with idiopathic intracranial hypertension in childhood and highlight the importance of revised diagnostic criteria in this population needed to detect and manage this condition.

Disease activity in idiopathic intracranial hypertension: a 3-month follow-up study

Idiopathic intracranial hypertension (IIH) is a disorder of raised intracranial pressure (ICP) in the absence of identifiable pathology. The purpose of this study was to evaluate the clinical presentation and monitor a 3-month course using frequent optical coherence tomography (OCT) evaluations, visual field testings and lumbar opening pressure measurements. A longitudinal study of 17 patients with newly diagnosed IIH and 20 healthy overweight controls were included in the study. Peripapillary retinal nerve fiber layer thickness (RNFLT) and retinal thickness (RT) measurements (Stratus OCT-3, fast RNFL 3.4 protocol), and Humphrey visual field testing were evaluated at regular intervals. Repeat lumbar puncture was performed at final visit (n = 13). The diagnostic delay was 3 months and initial symptoms were headache (94%), visual blurring (82%) and pulsatile tinnitus (65%). Complete clinical remission was achieved in 65%, partial in 29% and unchanged symptoms in 6%. Total average RNFLT and RT decreased significantly during the follow-up period (p < 0.0001 and p < 0.0001, respectively). Changes in RNFLT and RT correlated with improvements in visual field mean deviation (MD) (RNFLT: p = 0.006; RT: p = 0.03) and pattern standard deviation (PSD) (RNFLT: p = 0.002; RT: p = 0.003). In patients with weight-loss >3.5% of BMI, ICP decreased significantly (p = 0.0003). In patients with weight-loss <3.5% of BMI, changes in ICP were insignificant (p = 0.6). OCT combined with visual field testing may be a valuable objective tool to monitor IIH patients and the short term IIH outcome is positive. Weight-loss is the main predictor of a favorable outcome with respect to CSF pressure.

Detection of nerve fiber atrophy in apparently effectively treated papilledema in idiopathic intracranial hypertension

BACKGROUND

Since papilledema in idiopathic intracranial hypertension is a passive event not primarily affecting the visual tract, resolution with restitution ad integrum is expected if intracranial pressure is rebalanced. Retinal nerve fiber swelling due to papilledema in the acute phase and possible axon loss after long-lasting elevated intracranial pressure was investigated in a controlled cross-sectional study by scanning laser polarimetry.

METHODS

A cohort of 23 patients with idiopathic intracranial hypertension according to the modified Dandy diagnostic criteria, and 23 controls matched for age and gender were investigated. All patients received neurological and ophthalmologic examination including scanning laser polarimetry (GDx VCC). Patients were divided into groups depending on the presence of a papilledema (group 1) or the regression of the papilledema after initiation of therapy (group 2). Therapy was based on recommendations of the German Society of Neurology.

RESULTS

Scanning laser polarimetry showed an increase of nerve fiber thickness in group 1, and a decrease of the nerve fiber thickness in group 2 compared to controls. Ten of 13 patients showed signs of a regional axon loss in the deviation map of the GDx report, and six had a Nerve Fiber Index above 30. All patients with regressive papilledema and coincidence of visual field damage and pale optic disc appearance had a pathologic result in the GDx examination, but only four of ten patients with a pathologic GDx examination showed coincidence of pale optic disc appearance and visual field damage as sign of underlying optic disc atrophy.

CONCLUSION

In patients with apparently effective treatment of clinical symptoms and a regression of papilledema in idiopathic intracranial hypertension, a retinal axon loss was detected by scanning laser polarimetry. Axon loss was even present in patients without clinical evidence of optic nerve atrophy.

Cerebrospinal fluid markers of idiopathic intracranial hypertension: is the renin-angiotensinogen system involved?

BACKGROUND

The causes underlying idiopathic intracranial hypertension (IIH) are poorly understood.

METHODS

To identify disease-related biomarkers that could offer a new insight into IIH pathology, we analyzed the cerebrospinal fluid (CSF) of 18 patients with IIH and 18 controls using two-dimensional fluorescence differential in-gel electrophoresis (2-D DIGE).

RESULTS

We found six proteins that were upregulated in IIH (sterol regulatory element-binding protein 1, zinc-alpha-2-glycoprotein, immunoglobulin heavy constant alpha 1 [IGHA1], alpha-1-antitrypsin [SERPINA1], serotransferrin, haptoglobin) and four proteins that were downregulated (hemopexin, angiotensinogen, vitamin-D-binding protein, transthyretin). The validity of our approach was confirmed for one candidate protein (angiotensinogen). To account for a dependency from blood-CSF barrier function, the ratio of angiotensinogen and albumin CSF-to-serum quotients (Qang/Qalb) was determined, which confirmed the downregulation of angiotensinogen in IIH (p = .04).

CONCLUSION

Previous studies showed the intrinsic renin-angiotensin system (RAS) to regulate choroid plexus blood flow and CSF production. Altered levels of angiotensinogen could indicate an imbalance of the RAS in IIH that may provide new targets for therapeutic intervention.

Prolonged Intracranial Hypertension after Recombinant Growth Hormone Therapy due to Impaired CSF Absorption

We experienced a case of a Japanese boy who developed intractable idiopathic intracranial hypertension (IIH) during growth hormone (GH) treatment. At the age of 4 yr, the boy was diagnosed with idiopathic growth hormone deficiency, and recombinant human GH replacement was initiated. Nine months after initiation of the GH therapy, he began to complain of headache, but papilledema was not observed. His headache persisted thereafter, and right esotropia occurred 10 mo after the initiation of GH therapy, at which time papilledema was detected. No other neurological abnormalities were detected, and the findings of computed tomography and magnetic resonance imaging were normal. In a cerebrospinal fluid (CSF) examination, the pressure was markedly elevated to 450 mmH₂O, but no other abnormality was recognized. Impaired CSF absorption was detected using the pressure-volume index technique. The CSF levels of GH and insulin-like growth factor I were not increased. GH therapy was withdrawn after it was suggested that the IIH was associated with the GH therapy, but the headache persisted. The intracranial hypertension did not respond to diuretics, and prednisolone was only transiently effective. Although the funduscopic findings were normalized, increased CSF pressure was still observed. For over 2 yr, repeated lumbar puncture was necessary to protect against visual defect. IIH is an uncommon adverse event during GH therapy, but it must be considered carefully.

Bilateral oculomotor palsy secondary to pseudotumor cerebri

Idiopathic intracranial hypertension is the syndrome of elevated intracranial pressure without clinical, laboratory, or imaging evidence of intracranial pathology. The classic symptoms include headache, nausea, and vomiting. It may also be associated with blurry vision, diplopia, stiff neck, increasing head size, photophobia, anorexia, retro-orbital pain, lightheadedness, myalgia, and head tilt. Sixth nerve palsy is documented in 10-40% of patients with pseudotumor cerebri, in most series, but third nerve palsy is very rarely associated with pseudotumor cerebri. Described here is the novel case of a pseudotumor cerebri patient who had bilateral partial oculomotor palsy with sparing of the pupillary fibers.

Idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a condition which affects predominantly overweight women and is characterized by raised intracranial pressure without any identifiable pathology in the brain and with normal cerebrospinal fluid (CSF) composition. The cause of IIH is unclear and as such it remains a diagnosis of exclusion. Although the pathophysiology of IIH remains elusive, some observations have recently been added to our understanding of this, including the presence of transverse sinus stenosis on many patients and the possible role of leptin and inflammation in the disease pathogenesis. Headache is the most common symptom and papilloedema is the major clinical finding. Choices of medical treatment are limited to the use of diuretics particularly acetazolamide and encouragement of weight loss. Surgical therapies such as CSF diversion procedures and fenestration of the optic nerve may be necessary in some cases with persistent symptoms or progressive visual deterioration. While not life-threatening, IIH has a significant morbidity with up to 25% of patients developing visual impairment from optic atrophy. Visual surveillance is therefore vital. Long-term follow-up is recommended as the disease may worsen after an initial period of stability.

The importance of toxoplasma gondii infection in diseases presenting with headaches. Headaches and aseptic meningitis may be manifestations of the Jarisch-Herxheimer reaction

Worldwide, approximately 2 billion people are chronically infected with T. gondii with largely unknown consequences. This review presents clinical symptoms, differential diagnosis, triggering factors, treatment, and pathomechanisms responsible for idiopathic intracranial hypertension, pseudotumor cerebri, and aseptic meningitis. Literature cited in this work illustrates that immune state and other biologic mediator imbalances due to various endogenous and exogenous triggering factors may markedly affect latent central nervous system T. gondii infection/inflammation intensity, and cause reactivation of cerebral toxoplasmosis (CT). Irregularities in pro- and anti-inflammatory processes may markedly disturb the host and/or T. gondii defense mechanisms important for immune control of the parasite thereby manifesting as a wide range of neurologic symptoms and signs observed in some patients with migraine, epilepsy, celiac disease, Henoch-Schönlein purpura, and other brain disorders. This is consistent with reactivation of CT in mice after treatment with dexamethasone associated with depression of type T(H)1 immune response, and development of CT after administration of etanercept or other bioproducts. It seems that various types of headaches, epilepsy, aseptic meningitis, systemic adverse reactions to drugs or other substances represent the Jarisch-Herxheimer reaction due to apoptosis of T. gondii tachyzoites. Also development of some brain tumors, such as ependymoma and glioma may be associated with a chronic course of CT. Thus, all these patients should be tested for T. gondii infection.

Headache attributed to non-vascular intracranial disorder

This chapter deals with non-vascular intracranial disorders resulting in headache. Headache attributed to high or low cerebrospinal fluid pressure is separated into headache attributed to idiopathic intracranial hypertension (IIH), headache attributed to intracranial hypertension secondary to metabolic, toxic, or hormonal causes, headache attributed to intracranial hypertension secondary to hydrocephalus, post-dural puncture headache, cerebrospinal fluid (CSF) fistula headache, headache attributed to spontaneous (or idiopathic) low CSF pressure. Headache attributed to non-infectious inflammatory disease can be caused by neurosarcoidosis, aseptic (non-infectious) meningitis or lymphocytic hypophysitis. Headache attributed to intracranial neoplasm can be caused by increased intracranial pressure or hydrocephalus caused by neoplasm or attributed directly to neoplasm or carcinomatous meningitis. Other causes of headache include hypothalamic or pituitary hyper- or hyposecretion and intrathecal injection. Headache attributed to epileptic seizure is separated into hemicrania epileptica and post-seizure headache. Finally headache attributed to Chiari malformation type I (CM1) and the syndrome of transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) are described.

Efficacy of endovascular stenting in dural venous sinus stenosis for the treatment of idiopathic intracranial hypertension

Multiple pathophysiological mechanisms have been proposed for the increased intracranial pressure observed in idiopathic intracranial hypertension (IIH). The condition is well characterized, with intractable headaches, visual obscurations, and papilledema as dominant features, mainly affecting obese women. With the advent of MR venography and increased use of cerebral angiography, there has been recent emphasis on the significant number of patients with IIH found to have associated nonthrombotic dural venous sinus stenosis. This has led to a renewed interest in endovascular stenting as a treatment for IIH. However, the assumption that venous stenosis leads to a high pressure gradient that decreases CSF resorption through arachnoid villi requires further evidence. In this paper, the authors analyze the published results to date of dural venous sinus stenting in patients with IIH. They also present a case from their institution for illustration. The pathophysiological mechanism in IIH requires further elucidation, but venous sinus stenosis with subsequent intracranial hypertension appears to be an important mechanism in at least a subgroup of patients with IIH. Among these patients, 78% had complete relief or improvement of their main presenting symptoms after endovascular stenting. Resolution or improvement in papilledema was seen in 85.1% of patients. Endovascular stenting should be considered whenever venous sinus stenosis is diagnosed in patients with IIH.

Optic nerve head drusen and idiopathic intracranial hypertension in a 14-year-old girl

A 14-year-old girl had a 3-month history of headache and blurred vision. Funduscopy showed bilateral optic disc edema. Findings on brain imaging were normal, and a diagnosis of idiopathic intracranial hypertension was confirmed after lumbar puncture showed an elevated opening pressure of 32 cm H(2)O. Optic nerve head drusen were noted on computed tomography scan and confirmed with B-scan ultrasound. After 2 years, resolution of symptoms coincided with variable compliance to treatment with acetazolamide and concomitant papilledema. In general, optic disc edema poses a clinical conundrum due to the more common occurrence of optic nerve head drusen, potentially resulting in delayed diagnosis and treatment of idiopathic intracranial hypertension.

Double adverse drug reaction: Recombinant human growth hormone and idiopathic intracranial hypertension - acetazolamide and metabolic acidosis: a case report

A 9-year-old girl, treated for growth hormone deficiency, developed bitemporal progressive headache, diplopia, acute comitant esotropia and visual loss 3 months after starting recombinant growth hormone. An increased intracranial pressure was revealed by examination of ocular fundus and lumbar puncture, and the absence of other causes, ruled out through a brain scan, led to the diagnosis of idiopathic intracranial hypertension.

Recombinant growth hormone was discontinued and acetazolamide started up to 30 mg/kg/die without any clinical improvement but developing metabolic acidosis. The switch to intravenous dexamethasone (0.4 mg/kg/die) led to a dramatic clinical improvement after only 1 day, then confirmed by examination of ocular fundus and visual evoked potentials. Currently, there are no evidence-based guidelines for the management of intracranial hypertension, and even though acetazolamide is recognized as the first-line drug, its efficacy and safety have not been proven: some patients might not respond and others will present unacceptable side-effects. Therefore we suggest the use of corticosteroids in intracranial hypertension when acetazolamide is inefficient or intolerable.

Iron deficiency masquerading as idiopathic intracranial hypertension

A 13-year-old female presented with complaints of headache, vomiting, diplopia and progressive blurring of vision developing sequentially over 1 month. Examination revealed marked pallor and bilateral lateral rectus palsy with a visual acuity of 6/12 and 6/36 in the left and the right eye, respectively. Fundus examination showed late stage papilloedema in both eyes. Investigation for anaemia revealed severe iron deficiency. MRI of the brain was normal. The cerebrospinal fluid opening pressure was markedly raised at 320 mm of water but fluid analysis did not reveal any abnormality. Thus, a diagnosis of iron deficiency anaemia with idiopathic intracranial hypertension was made. The patient responded dramatically to intravenous iron treatment. Physicians must be aware of this rare presentation of the common problem of iron deficiency, the rapid correction of which plays an instrumental role in salvaging the patient's vision and preventing a recurrence of disease.

Pseudotumor cerebri in pediatric age: role of obesity in the management of neurological impairments

Pseudotumor cerebri occurs quite rarely in the pediatric population and its clinical features differ from adults in many ways. Intracranial hypertension with papilledema should obviously be treated promptly to avoid permanent visual damage, but various more or less invasive options have been proposed over the years, from bariatric surgery for obesity to optic nerve sheath fenestration. We report a prospective study on a group of 15 children, aged 3-16 years, with clinical and instrumental diagnosis of pseudotumor cerebri. All the patients were treated simply by external lumbar cerebrospinal fluid drainage with a mean volume of 10 ml/h for 3-5 days, with hypocaloric diet and with appropriate dosages of acetazolamide. All had immediate relief of headache, a considerable reduction in papilledema and marked improvement of both visual loss and cranial nerve palsies within 2 months. None of the patients relapsed during the follow-up period, ranging from 12-48 months.

[Benign intracranial hypertension: history, definition, and physiopathology]

Benign intracranial hypertension (BIH) is a rare condition in which the pathophysiology remains unclear. Multiple theories have been proposed in the past to explain BIH. Today it is widely accepted that the condition occurs in situations where alteration of cerebrospinal fluid (CSF) reabsorption is encountered. The venous system is therefore involved and may be the common denominator of the pathophysiological theories. A distinction must be made between idiopathic benign intracranial hypertension and BIH resulting from drugs, other pathological conditions, or toxics (secondary BIH), which are reported in this paper. We emphasize the crucial role of exhaustive clinical, biological, and neuroradiological investigations aiming to establish the diagnosis of BIH.

[Idiopathic intracranial hypertension without headache detected during a routine health check]

A 47-year-old woman was admitted to our hospital with an optic disc edema detected during a routine health check. On admission, she exhibited bilateral optic disc edema without headache and no visual disturbance. Her cerebrospinal pressure was 440 mmH2O, but we detected no abnormalities in the CSF, blood tests, brain MRI or MRV. Therefore, she was diagnosed with idiopathic intracranial hypertension (IIH). Treatment with acetazolamide reduced the cerebrospinal pressure. We suggest that examination of the optic fundi is sufficient to diagnose both IIH without headache and IIH with atypical symptoms.

Cluster-like headache and idiopathic intracranial hypertension: a case report

Cluster headache (CH) is a well-defined primary headache syndrome, but cases of symptomatic headache with clinical features of CH have been previously reported. Idiopathic Intracranial Hypertension (IIH) is a secondary headache disorder characterized by headache and visual symptoms, without clinical, radiological or laboratory evidence of intracranial pathology. Both papilloedema and IIH-related headache are typically bilateral, however asymmetrical or even unilateral localizations are described in literature. We report the case of a previously headache-free woman who presented cluster-like headache and asymmetrical papilloedema related to IIH. In our opinion the asymmetrical presentation supports, in this case, the hypothesis of cavernous sinus involvement in the IIH-related cluster-like headache pathogenesis.

Idiopathic intracranial hypertension with and without papilloedema in a consecutive series of patients with chronic migraine

Chronic migraine (CM) has been associated with idiopathic intracranial hypertension without papilloedema (IIHWOP), a significant percentage of these cases occurring in obese patients with intractable headache. A prospective study from February 2005 to June 2006 was made of 62 CM patients who fulfilled International Headache Society diagnostic criteria and had cerebral magnetic resonance venography (MRV) and lumbar puncture (LP) done. Two patients were excluded, six (10%) with elevated cerebrospinal fluid (CSF) open pressure (OP), five with body mass index (BMI) > 25. None of the patients had papilloedema or abnormal MRV. BMI and CSF OP were significantly correlated (r = 0.476, P < 0.001, Pearson's correlation test). Obesity (defined as BMI > 30) was a predictor of increase in intracranial pressure (defined as OP > 200 mmH(2)O) (f = 17.26, 95% confidence interval 6.0, 8.6; P < 0.001). From our study we strongly recommend that not only intractable CM patients with high BMI, but also first diagnosed patients with BMI > 30 should be systematically evaluated by a LP to rule out IIHWOP.