Visual loss in pseudotumor cerebri. Incidence and defects related to visual field strategy

The Relationship between Lumbar Puncture Opening Pressure and Retinal Nerve Fiber Layer Thickness in the Diagnosis of Idiopathic Intracranial Hypertension: Is a Lumbar Puncture Always Necessary?

OBJECTIVES

Idiopathic intracranial hypertension (IIH), is characterized by elevated intracranial pressure (ICP) without an identified cause. Today, lumbar puncture (LP) is the most common method used for diagnosis by measuring cerebrospinal fluid (CSF) pressure to reflect intracranial pressure. This invasive examination has significant disadvantages, such as complications and negative experiences for patients. Therefore, noninvasive methods for ICP measurement are desired. Optical coherence tomography (OCT) is widely used for the diagnosis and follow-up of IIH patients as it reflects papilledema. The aim of this study is to investigate the relationship between CSF pressure and OCT parameters and the ability of OCT in the diagnostic approach.

METHODS

In our study, patients who were followed up with a diagnosis of IIH with complete neuro-ophthalmological examinations, including visual acuity (VA), visual field, and OCT imaging within 24 hours before lumbar puncture, were retrospectively evaluated. CSF pressure, visual acuity LogMAR, mean deviation of visual fields, retinal nerve fiber layer (RNFL) thickness measured by OCT, and treatment protocols were obtained from our hospital data system.

RESULTS

A total of 42 eyes of 21 patients were enrolled in the study. A statistically significant positive and moderate correlation was found between CSF pressure values and average RNFL thickness ( r =0.507; P =0.001). The same relationship was demonstrated in all 4 quadrants: inferior, superior, nasal, and temporal.

CONCLUSIONS

Increased peripapillary RNFL thickness in optic nerve head OCT may be correlated with increased ICP in IIH patients. A larger number of patients are needed to better understand the correlation between OCT parameters and CSF pressure in patients with IIH.

The Utility of Quantitative D-Dimer Assay as a Biomarker in the Diagnosis and Exclusion of Cerebral Venous Sinus Thrombosis

The utility and sensitivity of quantitative D-Dimer assay to rule out the diagnosis of deep vein thrombosis is well established. We extrapolated this principle to evaluate the utility of D-Dimer assay in exclusion of cerebral venous sinus thrombosis (CVST). As advanced imaging modalities required for the diagnosis of CVST might not be available everywhere, it is important to have a sensitive biomarker and a clinical decision rule which can assist in the diagnosis. Patients undergoing CT/MR Venography of the brain with the suspicion of CVST were enrolled. Quantitative D-Dimer assay was performed in those who had CVST on CT/MR Venography and was compared with those who did not. A Clinical decision rule for the diagnosis of CVST was formulated using logistic regression analysis. Receiver operating characteristic analysis evaluating the diagnostic accuracy of D Dimer for patients with CVST as compared to those who did not revealed an AUROC of 0.694. D-Dimer levels of < 300 ng/mL had a sensitivity of 90% for the exclusion of CVST. After logistic regression analysis, a clinical decision rule with a total score of 16 and individual components of Female gender (2 points), Headache (7 points), D-Dimer levels of ≥ 792 ng/mL (7 points) was proposed. D-Dimer had a poor diagnostic accuracy for differentiation of patients who had CVST from those who did not, however, had a high sensitivity at values < 300 ng/mL. The proposed clinical decision rule with a score of ≥ 9 had a good diagnostic accuracy in prediction of CVST (AUROC = 0.809).

Papilledema: A review of etiology, pathophysiology, diagnosis, and management

Papilledema is optic nerve head edema secondary to raised intracranial pressure (ICP). It is distinct from other causes of optic disk edema in that visual function is usually normal in the acute phase. Papilledema is caused by transmission of elevated ICP to the subarachnoid space surrounding the optic nerve that hinders axoplasmic transport within ganglion cell axons. There is ongoing controversy as to whether axoplasmic flow stasis is produced by physical compression of axons or microvascular ischemia. The most common cause of papilledema, especially in patients under the age of 50, is idiopathic intracranial hypertension (IIH); however, conditions that decrease cerebrospinal fluid (CSF) outflow by either causing CSF derangements or mechanically blocking CSF outflow channels, and rarely conditions that increase CSF production, can be the culprit. When papilledema is suspected clinically, blood pressure should be measured, and pseudopapilledema should be ruled out. Magnetic resonance imaging of the brain and orbits with venography sequences is the preferred neuroimaging modality that should be performed next to look for indirect imaging signs of increased ICP and to rule out nonidiopathic causes. Lumbar puncture with measurement of opening pressure and evaluation of CSF composition should then be performed. In patients not in a typical demographic group for IIH, further investigations should be conducted to assess for underlying causes of increased ICP. Magnetic resonance imaging of the neck and spine, magnetic resonance angiography of the brain, computed tomography of the chest, complete blood count, and creatinine testing should be able to identify most secondary causes of intracranial hypertension. Treatment for patients with papilledema should be targeted toward the underlying etiology. Most patients with IIH respond to weight loss and oral acetazolamide. For patients with decreased central acuity and constricted visual fields at presentation, as well as patients who do not respond to treatment with acetazolamide, surgical treatments should be considered, with ventriculoperitoneal shunting being the typical procedure of choice.

Sensitivity and specificity of neuroimaging signs in patients with idiopathic intracranial hypertension

BACKGROUND

The primary role of neuroimaging in idiopathic intracranial hypertension (IIH) is to exclude secondary causes of raised intracranial pressure. Recently, a few imaging markers have been described which may suggest diagnosis of IIH in atypical cases. We carried out this study to assess the prevalence and accuracy of these neuroimaging signs in predicting the diagnosis of IIH.

METHODS

Eighty treatment-naive patients with IIH and 30 controls were recruited as per a predefined criterion. Magnetic resonance imaging (MRI) brain with detailed sella imaging was done in all patients.

RESULTS

The most common abnormality noted was optic nerve tortuosity in 82.5% of patients, followed by posterior scleral flattening in 80%, perioptic subarachnoid space (SAS) dilatation in 73.8% and partial empty sella in 68.8% of patients. The presence of optic nerve tortuosity was the most sensitive sign on neuroimaging, though the highest specificity was seen for posterior scleral flattening and perioptic SAS dilatation. The presence of more than three neuroimaging features correlated with severity of vision loss.

CONCLUSION

In suggestive clinical scenarios, posterior scleral flattening, perioptic SAS dilatation and optic nerve tortuosity are highly sensitive and specific signs in IIH. This study also highlights the utility of MRI as a valuable tool for prognosis of visual outcome in patients with IIH.

Outcomes measures in idiopathic intracranial hypertension

Introduction: Idiopathic intracranial hypertension is a condition characterized by raised intracranial pressure, papilledema, and normal neuroimaging (aside from radiological signs of raised intracranial pressure). Symptoms of idiopathic intracranial hypertension include chronic headaches and for some, visual loss. New treatments are unmet clinical needs.Areas covered: The aim of this review is to present the evidence base and considered opinion on outcome measures to determine successful management of idiopathic intracranial hypertension.Expert opinion: Less invasive measures of disease activity such as optical coherence tomography will continue to grow in this field, both as a measure of papilledema, and potentially as a surrogate for intracranial pressure and visual function. As a highly disabling aspect of the disease is headache, treatment outcomes for headache morbidity need to be appropriately chosen and standardized to allow comparison between trials.

Space Flight-Associated Neuroocular Syndrome, Idiopathic Intracranial Hypertension, and Pseudotumor Cerebri: Phenotypic Descriptions, Pathogenesis, and Hydrodynamics

Recent data from astronauts who have returned to Earth from a long-duration space flight have unequivocally distinguished spaceflight-associated neuro-ocular syndrome (SANS) from idiopathic intracranial hypertension (IIH) and pseudotumor cerebri (PTC). We review the semiology and pathogenesis of these three entities, noting that optic disc edema is what unites them, and this where the similarities between SANS and IIH/PTC end. We distinguish between PTC and IIH and between SANS and IIH/PTC and review the medical and surgical therapy of IIH/PTC. The key to understanding the phenomenon of optic disc edema is the geometry of the optic nerve sheath, which is a simulacrum of an inverted Venturi tube. This allows us to theoretically study the hydrodynamics of the optic nerve sheath by applying simple physical laws, including the Venturi effect, Poiseuille’s law, and Reynold’s number, and we speculate on nature’s design and the correlation of form and function in understanding how cerebrospinal fluid (CSF) circulates in the optic nerve sheath as it approaches the optic nerve head. Recent spectacular data on the histology of the blood nerve-barrier of the optic nerve disc and the glymphatic system of the optic nerve sheath will also help us understand the development of optic disc edema due to the microgravity-induced cephalad shift of CSF in SANS. We will explore the role of the sodium/potassium adenosine triphosphatase (ATPase) pump on choroid plexus epithelial cells and the aquaporin-4 water receptors located on astrocyte end-feet and their complex interactions with the tetracyclines, mineralocorticoids, and therapeutic agents with carbonic anhydrase activity. We also adumbrate the complex interactions between obesity, vitamin A, and 11-beta-hydroxysteroid dehydrogenase and how the aquaporin-4 receptor relates to these interactions.

Evaluation of cerebrovascular hemodynamics in patients with idiopathic intracranial hypertension using transcranial Doppler

Background

Idiopathic intracranial hypertension (IIH) is a disorder of increased intracranial pressure without a clear cause and can have serious visual effects. Previous research work suggests that transcranial Doppler measurements of pulsatility index correlate accurately with elevated intracranial pressure.

Objective

To assess the cerebrovascular hemodynamic changes in patients with IIH using transcranial Doppler before and after lumbar puncture and CSF withdrawal.

Methods

An interventional study conducted on 40 patients (31 females and 9 males) fulfilling the modified Dandy criteria for diagnosis of idiopathic intracranial hypertension, MRI brain, and MRV was done to the patients. Lumbar puncture was done for all included patients to measure intracranial pressure and CSF withdrawal. Transcranial Doppler was performed for all included before and after lumbar puncture and CSF withdrawal and the following parameters were measured: peak systolic velocity (PSV), end diastolic velocity (EDV), resistivity index (RI), and pulsatility index (PI).

Results

Significant relation was found between grades of papilledema and PSV, RI, and PI (p value 0.012, 0.025, 0.016) but no significant relation was found between grades of papilledema and EDV (0.102). Significant changes occurred in parameters of TCD pre- and post-CSF withdrawal including PSV, EDV, and PI (p value 0.001, 0.015, 0.019) denoting a significant change in cerebral hemodynamics after CSF withdrawal which denotes a decrease in intracranial pressure.

Conclusion

Increased intracranial pressure significantly affects cerebral blood flow. A normalization of transcranial Doppler parameters occurs following lowering of intracranial pressure through lumbar puncture and CSF withdrawal.

Idiopathic Intracranial Hypertension

PURPOSE OF REVIEW

Idiopathic intracranial hypertension is a syndrome of increased intracranial pressure of unclear etiology that most often occurs in obese women of childbearing age but can also occur in men, children, and older adults. This article reviews the diagnostic criteria, clinical features, neuroimaging findings, differential diagnosis, and management options for this condition.

RECENT FINDINGS

Recent population studies have found that the annual incidence of idiopathic intracranial hypertension is increasing in association with obesity rates, whereas recent scientific studies indicate a possible role for androgen sex hormones and adipose tissue in the pathogenesis of the disease. Prospective clinical trials have demonstrated a role for weight loss, acetazolamide, and topiramate in the management of mild disease. A recently begun randomized multicenter trial of surgical interventions will provide insight into the indications for surgical intervention, optimal timing and choice of intervention, and long-term outcomes.

SUMMARY

Idiopathic intracranial hypertension is a disorder producing symptoms and signs of increased intracranial pressure in the absence of an alternative cause. The main goals of treatment are to preserve visual function and alleviate symptoms, which can usually be achieved with a combination of weight loss, medical therapies, and surgical interventions depending on the severity of symptoms and vision loss, response to treatment, and subsequent clinical course.

Idiopathic Intracranial Hypertension (Pseudotumor Cerebri): Descriptive Epidemiology, Clinical Features, and Visual Outcome in Parma, Italy, 1990 to 1999

Purpose

To ascertain the annual incidence rate and the clinical features, other than visual outcome, of idiopathic intracranial hypertension (IIH) in Parma, northern Italy.

METHODS

Neurologic care of people living in the Parma area is entirely provided by one private and two public hospitals. Medical records related to IIH were retrospectively reviewed for all Parma residents from 1990 through 1999.

Results

Ten patients (8 women and 2 men) were identified as having IIH according to modified Dandy criteria. Their age ranged from 16 to 53 years with a mean of 36 years at diagnosis. The annual age-adjusted rate per 100,000 is 0.28 for the total population. For women in reproductive age, the annual incidence rate is 0.65/100,000. For overweight women in reproductive age, the annual incidence rate is 2.7/100,000.

CONCLUSIONS

The incidence rate found in this study is lower than the incidence reported in previous US and Libyan studies. A significant difference in overweight distribution is observed comparing percentage of body weight between US and Parma populations. As overweight and obesity are important factors contributing to IIH development, it is possible that their low percentage in the Parma population may, at least partially, explain the low IIH incidence observed.

Electroretinography in idiopathic intracranial hypertension: comparison of the pattern ERG and the photopic negative response

PURPOSE

To evaluate the relationship between electrophysiological measures of retinal ganglion cell (RGC) function in patients who have idiopathic intracranial hypertension (IIH).

METHODS

The pattern electroretinogram (pERG) and photopic negative response (PhNR) were recorded from 11 IIH patients and 11 age-similar controls. The pERG was elicited by a contrast-reversing checkerboard. The PhNR, a slow negative component following the flash ERG b-wave, was recorded in response to a long-wavelength flash presented against a short-wavelength adapting field. The PhNR was elicited using full-field (ffPhNR) and focal macular (fPhNR) stimuli. Additionally, Humphrey visual field mean deviation (HVF MD) was measured and ganglion cell complex volume (GCCV) was obtained by optical coherence tomography.

RESULTS

The ffPhNR, fPhNR, and pERG amplitudes were outside of the normal range in 45, 9, and 45% of IIH patients, respectively. However, only mean ffPhNR amplitude was reduced significantly in the patients compared to controls (p < 0.01). The pERG amplitude correlated significantly with HVF MD and GCCV (both r > 0.65, p < 0.05). There were associations between ffPhNR amplitude and HVF MD (r = 0.58, p = 0.06) and with GCCV (r = 0.52, p = 0.10), but these did not reach statistical significance. fPhNR amplitude was not correlated significantly with HVF MD or GCCV (both r < 0.40, p > 0.20).

CONCLUSIONS

Although the fPhNR is generally normal in IIH, other electrophysiological measures of RGC function, the ffPhNR and pERG, are abnormal in some patients. These measures provide complementary information regarding RGC dysfunction in these individuals.

Remote Cerebellar Hemorrhage Following Lumboperitoneal Shunt Insertion: A Rare Case Report

Idiopathic intracranial hypertension is characterized by high intracranial pressure without hydrocephalus or intracranial mass. Surgical treatment includes optic nerve fenestration and insertion of ventriculoperitoneal and lumboperitoneal (LP) shunts. For decreasing intracranial pressure, cerebrospinal fluid (CSF) LP shunt is widely used for the surgical management; it also carries complications such as shunt migration, venous sinus thrombosis, subarachnoid hemorrhage, and subdural and intracerebral hematoma. A 52-year-old man was admitted to the neurosurgery clinic with severe headache, retro-orbital pain, and blurred vision. Lumbar puncture demonstrated that the CSF opening pressure was 32 cm H ₂ O. A nonprogrammable LP shunt with two distal slit valves was inserted. Shortly after the surgery, his condition deteriorated and he became comatose. Immediate computed tomography scan revealed cerebellar hemorrhage and acute hydrocephalus. Development of remote cerebellar hemorrhage following LP shunt is rare. We discuss this rare event and the applicable literature.

Cerebrospinal Fluid Rhinorrhea Secondary to Idiopathic Intracranial Hypertension: Long-term Outcomes of Endoscopic Repairs

Background

Endoscopic endonasal repair of cerebrospinal fluid (CSF) rhinorrhea secondary to idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri or benign intracranial hypertension, has varying success rates, from 25–87%, with minimal morbidity. However, often these series have a relatively short-term follow-up. Given the pathophysiology of IIH, long-term follow-up is necessary to identify true CSF leak recurrence rates. Our investigation aimed to evaluate long-term outcomes in endoscopically repaired CSF leaks.

Methods

A retrospective chart review of all the patients with CSF rhinorrhea due to IIH who met inclusion criteria between 1996 and 2009. Outcome measures included the following: demographics, intracranial pressure, location of skull base defect, presence of encephalocele and/or meningoencephalocele, surgical repair technique, treatment with acetazolamide, whether a ventriculoperitoneal shunt was inserted, location of recurrence, history of meningitis or previous sinus surgery, and duration of follow-up.

Results

Thirty-two patients with a total of 44 skull base defects were reviewed over a mean follow-up of 10.2 years. The mean body mass index and intracranial pressure were 36.8 kg/m2 and 27.7 cm H2O, respectively. Seven patients (18%) required revision surgery at the same site or a distant site. We found no statistical significance that identified the recurrence risk in the outcome measurements most likely due to our small failure rate. However, early recurrences were noted to recur at the same repair site, whereas late recurrences were noted to recur at a distant site along the skull base.

Conclusion

IIH is an increasingly recognized entity treated by otorhinolaryngologists. We present the first long-term IIH CSF leak repair series. Long-term follow-up is necessary because delayed CSF leaks occur in this population.

The Pupillary Light Reflex in Idiopathic Intracranial Hypertension

Purpose

To evaluate the effects of idiopathic intracranial hypertension (IIH) on rod-, cone-, and melanopsin-mediated pupillary light reflexes (PLRs).

Methods

Pupillary light reflexes elicited by full-field, brief-flash stimuli were recorded in 13 IIH patients and 13 normal controls. Subjects were dark-adapted for 10 minutes and the PLR was recorded in response to short-wavelength flashes (0.001 cd/m²: rod condition; 450 cd/m²: melanopsin condition). Subjects were then exposed to a rod-suppressing field and 10 cd/m² long-wavelength flashes were presented (cone condition). Pupillary light reflexes were quantified as the maximum transient constriction (rod and cone conditions) and the post-illumination pupil constriction (melanopsin condition), relative to the baseline pupil size. Diagnostic power was evaluated using receiver operating characteristic (ROC) analysis.

Results

The IIH patients had significantly smaller PLRs under the melanopsin (P < 0.001) and rod (P = 0.04) paradigms; a trend for reduced cone-mediated PLRs was also found (P = 0.08). Receiver operating characteristic analysis indicated areas under the curves (AUC) of 0.83 (melanopsin-meditated; P = 0.001), 0.71 (rod-mediated; P = 0.07), and 0.77 (cone-mediated; P = 0.02). The AUC (0.90, P < 0.001), sensitivity (85%), and specificity (85%) were high for ROC analysis performed on the mean of the rod, cone, and melanopsin PLRs.

Conclusions

Pupillary light reflex reductions in IIH patients indicate compromised RGC function. PLR measurement, particularly under rod- and melanopsin-mediated conditions, may be a useful adjunct to standard clinical measures of visual function in IIH.

Ultrasound evaluation of internal jugular valve incompetence (IJVI) in Egyptian patients with idiopathic intracranial hypertension (IIH)

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a clinical syndrome with no identified causative factor. Internal jugular valve incompetence (IJVI) has been linked to many neurological disorders such as idiopathic intracranial hypertension (IIH), transient global amnesia and cough-induced headache. Intact valves prevent efficiently retrograde flow into the internal jugular vein.

AIM

The aim of this study is to evaluate the competence of the jugular vein valves and its relationship to age, BMI, opening CSF pressure and MRV findings in IIH patients.

SUBJECTS AND METHODS

Twenty-five Egyptian female patients diagnosed with IIH according to the modified Dandy criteria, and 24 female controls, matched for age and BMI, were included and examined using color-coded duplex for IJVI during the Valsalva maneuver. The patients underwent lumbar puncture to measure the opening pressure, MRV, ophthalmic examination and laboratory work-up.

RESULTS

There was no statistically significant difference in the proportion of IJVI among the patients and controls (P=0.7). There was a statistically significant increase in the opening pressure and proportion of MRV abnormalities in the patients with IJVI compared to the patients without IJVI (P=0.03 and 0.007, respectively), but there were no statistically significant difference with regard to age, BMI, grade of papilledema and perimetry findings.

CONCLUSION

This study showed that there is no relationship between IJVI and IIH; thus, IJVI would be a rather normal finding. Further studies are recommended to confirm or rule out a possible relationship.

Papilledema: epidemiology, etiology, and clinical management

Papilledema is optic disc swelling due to high intracranial pressure. Possible conditions causing high intracranial pressure and papilledema include intracerebral mass lesions, cerebral hemorrhage, head trauma, meningitis, hydrocephalus, spinal cord lesions, impairment of cerebral sinus drainage, anomalies of the cranium, and idiopathic intracranial hypertension (IIH). Irrespective of the cause, visual loss is the feared morbidity of papilledema, and the main mechanism of optic nerve damage is intraneuronal ischemia secondary to axoplasmic flow stasis. Treatment is directed at correcting the underlying cause. In cases where there is no other identifiable cause for intracranial hypertension (ie, IIH) the available options include both medical and surgical modalities. Weight loss and diuretics remain the mainstays for treatment of IIH, and surgery is typically reserved for patients who fail, are intolerant to, or non-compliant with maximum medical therapy.

The importance of visual field testing in idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a disease of unknown cause typically affecting obese women in the childbearing years. Although headache is the most common symptom, the major morbidity of IIH is visual loss, with 5% to 10% of patients progressing to blindness. While about 95% of patients with IIH have visual loss documented by perimetry, only about one-third notice their visual loss because most loss occurs in the peripheral visual field. Since treatment decisions in IIH are made primarily by changes in visual field function, serial perimetry is the most critical test to obtain when following patients with IIH. This article describes the role of visual field testing in the monitoring of IIH patients in clinical practice, including its importance in communication among providers.

Baseline visual field findings in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT)

PURPOSE

To characterize visual field (VF) loss at the baseline visit and to evaluate VF quality control (QC) procedures in the Idiopathic Intracranial Hypertension Treatment Trial (IIHTT).

METHODS

The Visual Field Reading Center (VFRC) evaluated 660 baseline VFs (1320 hemifields) from 165 enrolled patients. Three readers independently classified each superior and inferior hemifield and identified any abnormalities. A subset (20%) of the hemifields was reread to evaluate within- and between-reader agreements. The QC system addressed test parameters, patient data, and shipment errors.

RESULTS

The majority (60%) of the baseline hemifields consisted of localized nerve fiber bundle-type VF loss. Approximately one-third (31.5%) of all the classifications consisted of partial arcuate defects combined with an enlarged blind spot, making this the most common type of hemifield classification. Inferior hemifield loss was greater than superior loss for both study and nonstudy eyes. Reader agreements were >90% for both inferior and superior hemifields for two out of three readers. Test-retest reliability agreement for individual readers was 95% for both hemifields. There were few QC errors with only 5.48 error points per 100-point VF.

CONCLUSIONS

The most common type of IIHTT baseline hemifield abnormality was a localized nerve fiber bundle-like defect. Localized inferior hemifield loss was more common than superior hemifield loss. Quality control and within- and between-reader agreement were excellent for the IIHTT (ClinicalTrials.gov number, NCT01003639).

Macular thickness measurements with frequency domain-OCT for quantification of axonal loss in chronic papilledema from pseudotumor cerebri syndrome

PURPOSE

To evaluate the ability of frequency domain-optical coherence tomography (FD-OCT)-measured macular thickness parameters to differentiate between eyes with resolved chronic papilledema and healthy eyes and to evaluate the correlation between FD-OCT measures and visual field (VF) loss on standard automated perimetry (SAP).

METHODS

Fifty-two eyes from 29 patients suffering from pseudotumor cerebri syndrome (PTC) and 62 eyes from 31 normal controls underwent FD-OCT scanning and ophthalmic evaluation including VF with SAP. All patients had previously been submitted to treatment of PTC and had clinically resolved papilledema and stable VF for at least 6 months before the study. Macular and peripapillary retinal nerve fiber layer (RNFL) thickness measurements were determined for both groups. Comparisons were made using Generalized Estimated Equations. Correlations between FD-OCT and VF measurements were verified.

RESULTS

In eyes with resolved papilledema, the macular thickness parameters corresponding to the inner and outer superior, temporal, inferior and nasal segments, average macular thickness and most RNFL thickness measurements were significantly reduced when compared with controls. The discrimination ability was similar for macular thickness measurements and RNFL thickness measurements. Both sets of OCT measurements correlated well with VF sensitivity loss.

CONCLUSIONS

Eyes with resolved chronic papilledema show a significant reduction in macular thickness, which is well correlated with the severity of VF loss. Macular thickness measurements can potentially be used to estimate and monitor the amount of ganglion cell loss in eyes with papilledema from patients with PTC.

Weight and visual field deficits in women with idiopathic intracranial hypertension

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a disorder of elevated intracranial pressure (ICP) with no identifiable cause, associated with papilledema, vision loss, and headache. Previous studies have observed a relationship between weight gain and vision loss in women with IIH. We retrospectively examined a population of women with IIH to determine an association between weight gain in the year before diagnosis and the presence of visual field deficits.

METHODS

This cross-sectional study included women who enrolled in the Intracranial Hypertension Registry (IHR) between 2003 and 2005 and met study criteria for IIH. Data were obtained from mailed questionnaires and review of registrant medical charts. Prevalence ratios were used to assess the relationship between weight measures during the year before diagnosis and abnormal visual field findings at diagnosis.

RESULTS

The study population consisted of 159 females aged 13-64. The mean weight of the study population 1 year before diagnosis was 92 kg (standard deviation [SD] 27 kg). Mean weight gain was 5 kg (SD 13 kg) over the year before diagnosis. Visual field findings at diagnosis were abnormal in 84% (n = 122) of study subjects. There was no association between visual field deficits and body mass index (BMI), weight gain, or percent change in ideal body weight (IBW).

CONCLUSIONS

Weight change over the year before diagnosis was not associated with visual field deficits at diagnosis in this registry population of women with IIH.

Long-term visual outcome in idiopathic intracranial hypertension

Objective:

To characterize the course, outcome, and risk of relapse or late worsening in a clearly defined cohort of idiopathic intracranial hypertension (IIH) over a long period of follow-up.

Materials and Methods:

Retrospective chart review of patients with definite IIH was evaluated at the Sree Chitra Tirunal Institute for Medical Sciences and Technology between 1998 and 2006. Patients’ demographic data, clinical, neuro-ophthalmic examinations, and treatment details were abstracted. Patients were further categorized into three groups based on whether they improved, worsened, or relapsed on follow-up. Final visual outcome of each patient was defined according to grading of the worse eye at the last visit. Statistical analysis included t test to compare group means and chi-square test to compare proportions.

Results:

Of the 43 women included, visual impairment was observed in 80 eyes (93%) at presentation and it was moderate to severe in 14%. The mean CSF opening pressure at presentation did not differ significantly in those with visual impairment compared to those with normal vision. Those having early severe visual impairment had significantly higher (P = 0.015) likelihood of severe visual impairment on last follow-up. Of the total, 34 patients (79%) improved, 4 (9.3%) relapsed on follow-up after period of stability, and 5 (11.6%) worsened over 56 months follow-up (range, 26-132 months). The groups were comparable, except those who improved were younger (P<0.05). At last examination, 9% had significant vision loss.

Conclusion:

IIH patients can have delayed worsening or relapses and about tenth of patients can have permanent visual loss early or late in the course of the disease. All patients with IIH need to be kept under long-term follow-up, with regular monitoring of visual functions.

Electromagnetic stereotactic ventriculoperitoneal csf shunting for idiopathic intracranial hypertension: a successful step forward?

OBJECTIVE

The optimal management of medically refractory idiopathic intracranial hypertension (IIH) remains a point of debate. The senior author's practice evolved after a review of our units' practice in placing lumboperitoneal shunts revealed an unacceptably high rate of complication and revision. We now preferentially perform custom-designed electromagnetic (EM) image-guided ventriculoperitoneal shunt placement instead of lumboperitoneal shunting in treating medically refractory IIH and present our outcome data with this technique.

PATIENTS AND METHODS

Retrospective case note review was carried out with prospective follow-up of 17 patients treated consecutively over a 3-year period.

OUTCOME MEASURES

The article aims to assess the implication of using EM image-guided tracking technology in ventricular catheter placement in patients with IIH and to assess outcome.

RESULTS

All of the patients improved clinically at the last follow-up compared to their preoperative condition. None of the patients experienced intra- or perioperative complications. All patients underwent ventriculoperitoneal shunt placement using EM guidance navigation. All patients in the EM subgroup were cannulated with a single pass, and satisfactory catheter placement was confirmed on a postoperative CT scan with concordant patient symptom improvement.

CONCLUSION

Our series suggests that EM image-guided ventriculoperitoneal cerebrospinal fluid (CSF) shunting for IIH is a safe and effective procedure for ventricular cannulation and placement.

Visual fields in neuro-ophthalmology

Visual field assessment is important in the evaluation of lesions involving the visual pathways and should be performed at baseline and periodically in the follow-up. Standard automated perimetry has been shown to be adequate in neuro-ophthalmic practise and is now the technique of choice for a majority of practitioners. Goldman kinetic visual fields are useful for patients with severe visual and neurologic deficits and patients with peripheral visual field defects. Visual fields are useful in monitoring progression or recurrence of disease and guide treatment for conditions such as idiopathic intracranial hypertension (IIH), optic neuropathy from multiple sclerosis, pituitary adenomas, and other sellar lesions. They are used as screening tools for toxic optic neuropathy from medications such as ethambutol and vigabatrin. Visual field defects can adversely affect activities of daily living such as personal hygiene, reading, and driving and should be taken into consideration when planning rehabilitation strategies. Visual field testing must be performed in all patients with lesions of the visual pathway.

More than meets the eye? Redefining idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is a disease of unknown etiology associated with increased intracranial pressure, predominantly affecting obese females of childbearing age. The history of IIH is quite unique, featuring only limited advancements in evidenced-based treatments, but boasting literally countless changes in nomenclature, proposed etiology, and conceptual approach. Despite its elusive pathogenesis, an evolution of our approach to IIH can be traced sequentially through identifiable periods. Contemporary research suggests that we are approaching a new phase in IIH, redefining it as a global neurologic syndrome with more far-reaching effects than previously realized.

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

Idiopathic intracranial hypertension ((IIH) is characterized by increased cerebrospinal fluid pressure of unknown cause. It is predominantly a disease of women in the childbearing years. Although the cause of IIH remains obscure, it has become clear that loss of visual function is common and patients may progress to blindness if untreated. Diagnosis should adhere to the modified Dandy criteria and other causes of intracranial hypertension sought. IIH patient management should include serial perimetry and optic disc grading or photography. The proper therapy can then be selected and visual loss prevented or reversed. Although there are no evidence-based data to guide therapy, there is an ongoing randomized double-blind controlled treatment trial of IIH investigating diet and medical therapy.

Reversible benign intracranial hypertension in a child with hyperthyroidism

Endocrine dysfunction is a rare but known cause of benign intracranial hypertensio (BIH) in adults. Here we describe a rare case of BIH in the pediatric age group associated with autoimmune hyperthyroidism. A 12-year-old girl presented with a 3-month history of headaches. Ophthalmic examination revealed bilateral papilledema. The ocular findings were otherwise normal, with no exophthalmos. Cranial and orbital magnetic resonance imaging was unremarkable. Lumbar CSF opening pressure in recumbent and relaxed position was elevated (31 cm water). Thyroid hormones fT3 and fT4 were elevated while TSH was completely suppressed. As TSH receptor stimulating antibodies (TSHR-Ab) were elevated Graves' disease was diagnosed. Thyroid suppressive therapy with carbimazole was initiated and supplemented by propranolol. As hyperthyroidism improved over two weeks the headaches subsided and the papilledema slowly resolved over the next 2 months. This case illustrates that hyperthyroidism should be considered as a cause of BIH in children.

Mechanisms of visual loss in papilledema

The term "papilledema" indicates swelling of the optic discs secondary to increased intracranial pressure. Papilledema can be caused by an intracranial mass lesion or by other factors. Visual symptoms frequently accompany papilledema, which can lead to permanent visual loss if left untreated. Starting with an illustrative case, the authors review the pathophysiology of the visual signs and symptoms of papilledema. They also briefly review potential treatment options, focusing on the role of the neurosurgeon in the treatment of patients with papilledema.

Endoscopic endonasal management of pseudotumor cerebri: is it effective?

PURPOSE

To study the efficacy and safety of endoscopic endonasal optic nerve fenestration for the management of idiopathic intracranial hypertension (IIH).

DESIGN

A prospective study at a tertiary care center.

PATIENTS AND METHODS

All patients with a final diagnosis of IIH from July 2001 to March 2005 were included and subjected to detailed neuro-ophthalmologic examination and endoscopic endonasal optic nerve fenestration. Postoperative visual acuity and the perimetry was compared with the preoperative status, and the results were analyzed using the chi2 test.

RESULTS

: Of the 18 patients included in the study, 17 had improvement in vision postoperatively. Fifteen patients had visual deterioration in the other eye as well, and of these, 12 had improvement, obviating the need for surgery on the other side. Complications were minimal and in the form of synechiae in two of the cases.

DISCUSSION

A number of procedures have been described for the management of this entity, and each is associated with a significant morbidity; therefore, there was a need for a minimally invasive procedure. The procedure adopted in the series is minimally invasive and is associated with a 94.5% success rate and minimal morbidity.

CONCLUSIONS

Endoscopic endonasal optic nerve fenestration is a safe, minimally invasive, and extremely effective procedure for the management of IIH.

Idiopathic Intracranial Hypertension

The syndrome of intracranial hypertension without structural brain or cerebrospinal fluid abnormalities and without identifiable cause, now most appropriately termed idiopathic intracranial hypertension, was described over a century ago. Although the pathogenesis of this condition remains unknown, diagnostic and therapeutic developments during the past two decades have substantially advanced patient management.

Pseudotumor cerebri

Pseudotumor cerebri is a perplexing syndrome of increased intra-cranial pressure without a space-occupying lesion. The terminology for the disorder has changed over the years and the diagnostic criteria revised to reflect advances in diagnostic technology and insights into the disease process. The classification and nomenclature depend on the presence or absence of an underlying cause. When the diagnostic criteria are followed, a secondary etiology is unlikely. When no secondary cause is identified, the syndrome is termed "idiopathic intracranial hypertension."

Refractory idiopathic intracranial hypertension treated with stereotactically planned ventriculoperitoneal shunt placement

Object

Ventriculoperitoneal (VP) shunts have not been widely used for idiopathic intracranial hypertension (IIH) because of the difficulty of placing a shunt into normal or small-sized ventricles. The authors report their experience with stereotactic placement of VP shunts for IIH.

Methods

The authors reviewed the clinical records of all patients in whom stereotaxis was used to guide the placement of a VP shunt for IIH at their institution. All shunts were placed using stereotactic guidance to target the frontal horn of the lateral ventricle. Patients were contacted at a mean postoperative interval of 15.1 months. No patients were lost to follow up.

The authors identified 13 patients who underwent placement of a stereotactically guided VP shunt for IIH over a 6-year period. A trial of either acetazolamide or steroid therapy had failed in all patients. Prior surgical treatments included optic nerve sheath fenestrations in seven patients and cerebrospinal fluid diversionary procedures, other than stereotactic VP shunt procedures, in nine patients. Twelve patients reported excellent or good durable symptomatic relief at the time of follow up. No patient suffered progression of visual deficits. Four patients experienced persistent headaches following the procedure. Three patients required a revision of the VP shunt for technical failure.

Conclusions

Stereotactically guided VP shunt placement is an effective and durable treatment option in many cases of IIH that are refractory to more traditional medical and surgical approaches.

Use of scanning laser ophthalmoscopy to monitor papilloedema in idiopathic intracranial hypertension

AIMS

To determine the sensitivity of confocal scanning laser ophthalmoscopy (SLO) in detecting clinically significant changes in papilloedema secondary to idiopathic intracranial hypertension (IIH) and the correlation with visual field loss.

METHODS

Eight patients--three new, two recurrent, and three chronic cases of IIH--were examined over a 9 month period with SLO (Heidelberg retina tomograph) of optic nerve head and 30-2 Humphrey visual fields (six cases). Optic disc swelling (volume) was assessed in each eye using a circular contour line placed around the swollen optic nerve head on the mean image of three topographic images. Nine volume measurements from single images in each eye of every patient were performed on one occasion to assess repeatability.

RESULTS

In the five acute cases optic disc volumes (range 1-16 mm3) decreased with treatment to stable, normal levels. Three of these had mild, reproducible, field defects which resolved. Two chronic cases had stable or fluctuating disc volume with no detectable change in grade of papilloedema and mild field loss. In one case which underwent theco-peritoneal shunting both disc volume and field worsened, indicating therapeutic failure. Both improved postoperatively.

CONCLUSIONS

SLO has a high sensitivity for detecting small changes in disc volumes and correlates closely with visual field change in the short term. It can confirm therapeutic failure by detecting stable or increasing disc volume. Decreasing volume may indicate resolution of papilloedema or secondary optic atrophy, so accompanying funduscopy and visual fields remain essential.

Assessment of visual function in idiopathic intracranial hypertension: a prospective study

The visual function of 35 patients with a diagnosis of idiopathic intracranial hypertension was assessed prospectively over a 3 year period. In assessing the visual function of cases of idiopathic intracranial hypertension a number of tests were employed including visual field assessment with Humphrey and Goldmann perimeters and documentation of visual acuity and contrast sensitivity. Loss of visual function is the only serious complication and may occur early or late in the course of the condition. An appropriate and sensitive clinical assessment regime is therefore of importance in the outpatient situation. Visual field assessment was documented as the most sensitive to detection of visual loss, with statistically greater sensitivity in comparison with visual acuity and contrast sensitivity testing. Detection of asymptomatic visual loss indicates the necessity for visual monitoring to ensure detection of insidious visual loss. The types of visual field defects noted in this study were typical of anterior optic nerve pathology of raised intracranial pressure and commonly included arcuate defects, nasal steps and global constriction. Visual loss was noted at presentation and during follow-up in up to 87% of patients using Goldmann perimetry and up to 82% of patients using Humphrey perimetry. The visual status improved significantly throughout the follow-up period and the final visual outcome was excellent or good in 83% of patients.