Idiopathic Intracranial Hypertension and Anemia: A Matched Case–Control Study

Comparison of Idiopathic Intracranial Hypertension Patients With and Without Anemia

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition of elevated intracranial pressure without an identifiable cause. It mostly affects young obese women but has been reported in individuals newly diagnosed with anemia or with chronic anemia. The relationship between anemia and IIH is not well elucidated. This study aims to characterize the course of IIH in anemic patients.

METHODS

Consecutive patients with IIH were recruited from neuro-ophthalmology clinics. Subsequent retrospective chart review obtained information on symptoms, complete blood counts (CBCs), visual acuity, visual fields, and optic disc edema at baseline and follow-up. Anemia was diagnosed by hemoglobin <120 g/L (women) and <130 g/L (men).

RESULTS

One hundred twenty-three patients with IIH were recruited for this study, and 22.8% (28/123) had anemia. More anemic individuals had mild-to-moderate visual acuity impairment (logarithm of minimum angle of resolution 0.3-1, P = 0.01) and worse automated mean deviation ( P = 0.048). The median follow-up time was 47.4 weeks (interquartile range:20.1-91.8). Fifteen of 28 patients with anemia received anemia treatment and showed a trend toward increased hemoglobin. At follow-up, there were no differences in the visual acuity, but patients with anemia had worse automated mean deviation on visual fields ( P = 0.045).

CONCLUSIONS

IIH patients with anemia had worse visual function at presentation and worse final visual field parameters. This suggests that CBCs should be obtained for patients with papilledema because it may influence final visual outcome.

Anemia and Spaceflight Associated Neuro-Ocular Syndrome (SANS)

Spaceflight associated neuro-ocular syndrome (SANS) is a collection of distinct findings seen in some astronauts following prolonged spaceflight and is characterized by: optic disc edema, globe flattening, and choroidal folds. In this manuscript, we describe the potential mechanisms linking anemia and SANS. Future research aimed at understanding the relationship between these conditions may help to develop countermeasures and mitigation efforts for SANS.

Anemia and Idiopathic Intracranial Hypertension: A Case-Control Study

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition that mostly affects obese women of childbearing age but has been reported to be temporally related to new diagnoses of anemia. Despite these reports, the association between anemia and IIH remains controversial. The present study aimed to understand the strength of association between anemia and IIH through a case-control design.

METHODS

Consecutive IIH patients were recruited from neuro-ophthalmology clinics and matched by age and sex to consecutive patients attending neuro-ophthalmology clinics with diagnoses other than IIH. Complete blood counts (CBCs) were reviewed within 6 months of neuro-ophthalmology presentation, and anemia was diagnosed by hemoglobin of <120 g/L in women and <130 g/L in men. Anemia was classified as microcytic (mean corpuscular volume (MCV) < 80 fL), normocytic (MCV 80-100 fL), and macrocytic (MCV > 100 fL) as well as mild (hemoglobin >110 g/L), moderate (hemoglobin 80-109 g/L), and severe (hemoglobin <80 g/L).

RESULTS

One hundred twenty-three IIH patients and 113 controls were included in the study. More IIH patients than controls had anemia (22.8%, 28/123 vs 10.6%, 12/113, P = 0.01) with an odds ratio of 2.48 (95% CI: 1.19, 5.16). There were no differences in severity of anemia or MCV between IIH patients and controls, with anemia most often being mild (57.1%, 16/28 vs 75%, 9/12) and normocytic (50.0%, 14/28 vs 50.0%, 6/12). However, 17.9% (5/28) of IIH patients had severe anemia compared with zero in the control group. IIH patients had a higher mean platelet count than controls ( P < 0.001), and there were no differences on leukocyte counts.

CONCLUSION

Idiopathic intracranial hypertension patients have a higher prevalence of anemia compared with non-IIH neuro-ophthalmology patients. The anemia was mostly mild and may be explained by other factors related to worse health status and obesity, including low socioeconomic status, poor nutrition, and polycystic ovary syndrome. However, as a CBC is a widely available test and anemia may influence the IIH disease course, we propose that this test be obtained in all patients with new papilledema.

Management of idiopathic intracranial hypertension in pregnancy

Idiopathic intracranial hypertension is more common among women of reproductive age and is often encountered in pregnancy, either pre-existing and exacerbated by pregnancy-associated weight gain and hormonal changes or arising de novo. We report the case of a 33-year-old woman with progressive visual loss and intractable headache from 20 weeks' gestation requiring ventriculoperitoneal shunting during pregnancy. The risk of permanent maternal vision loss raises complex management dilemmas, when this must be balanced with the fetal and neonatal risks of treatment and possible premature delivery.

Phenotyping non-idiopathic pseudotumor cerebri syndrome - A prospective cohort study

OBJECTIVE

To identify the most frequent causes of secondary pseudotumor cerebri syndrome and compare phenotype, clinical presentation, and symptoms of secondary pseudotumor cerebri syndrome to the primary form of pseudotumor cerebri syndrome, idiopathic intracranial hypertension.

METHODS

The study was a prospective cohort study including patients with new-onset pseudotumor cerebri syndrome. Diagnostic work up was standardized. Patients were diagnosed with secondary pseudotumor cerebri syndrome or idiopathic intracranial hypertension according to the revised Friedman criteria. Secondary pseudotumor cerebri syndrome patients were categorized into five causes: medication, systemic causes, sleep apnea, cerebrovascular causes, and several competing causes. Phenotype, clinical presentation, symptoms and neuroimaging were compared between groups.

RESULTS

Out of 278 cases, 28 secondary pseudotumor cerebri syndrome and 120 idiopathic intracranial hypertension patients were included. The most frequent causes of secondary pseudotumor cerebri syndrome were medication (n  =  8, 28.6%) and systemic causes (n = 8, 28.6%), followed by sleep apnea (n = 5, 17.9%), cerebrovascular causes (n = 4, 14.3%) and several competing causes (n = 3, 10.7%). Secondary pseudotumor cerebri syndrome and idiopathic intracranial hypertension patients were phenotypically alike and predominately female, premenopausal, and obese. Symptoms and objective findings at disease onset were similar between groups.

CONCLUSION

Secondary pseudotumor cerebri syndrome should be considered in all patients with suspected pseudotumor cerebri syndrome as secondary pseudotumor cerebri syndrome and idiopathic intracranial hypertension patients are phenotypically and clinically alike. A thorough diagnostic workup is needed as treatment of idiopathic intracranial hypertension and secondary pseudotumor cerebri syndrome is markedly different.

Papilledema and Anemia: A Rare Association

Papilledema is the swelling of the optic disc due to the transmission of intracranial pressure through the optic nerve. It can occur as a symptom of various intracranial pathologies that elevate the intracranial pressure. Even though anemia has been described as an association with raised intracranial pressure, the exact causal relationship between the two has not been well established in the literature. We present one such unusual case wherein a 21-year-old female patient, who complained of headaches, was found to have papilledema and severe anemia. After an unyielding workup for secondary causes, the rare association between papilledema and anemia was considered and prompt hemoglobin correction was ensued. Subsequently, resolution of papilledema and improvement in the visual acuity of the patient was observed. Although the causal relationship between anemia and papilledema has not been thoroughly explained, appropriate workup and correction of anemia play an integral role in the management of patients with papilledema and the prevention of long-term ocular complications.

Anemia and Idiopathic Intracranial Hypertension: A Systematic Review and Meta-analysis

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition typically affecting young, obese women. Although anemia is recognized as a risk factor of IIH from case reports, their relationship remains controversial as several comparative studies showed no significant association. This study aimed to examine the relationship between anemia and IIH.

METHODS

MEDLINE, Embase, Cochrane Library, and grey literature were searched to September 2020. Primary studies on patients with diagnoses of anemia of any kind and IIH were included. Primary outcomes included the total number of cases of anemia and IIH. A meta-analysis on the prevalence of anemia in IIH compared with control patients was conducted. Grading of Recommendations, Assessment, Development and Evaluations (GRADE) was used to rate the quality of evidence.

RESULTS

Overall, 62 cases and 5 observational or case-control studies were included. Pooled incidence of anemia in patients with IIH was 195/1,073 (18.2%). Patients with IIH (n = 774) had a significantly higher prevalence of anemia compared with controls (n = 230,981) (RR 1.44 [95% confidence interval 1.08-1.92]). Patients were 67.7% females and had a mean age of 22.4 years. The mean opening pressure was 37.9 cmH2O. Anemia was most commonly caused by iron deficiency (51.6%) and aplastic anemia (19.4%). Most patients (59.7%) showed improvement or resolution with anemia treatment only without intracranial pressure-lowering therapy. Evidence was limited because of high risk of reporting bias from the large number of case reports and case-control studies.

CONCLUSIONS

Anemia is significantly more common in IIH compared with control patients, and case reports suggest a direct relationship. Complete blood counts should be considered in all patients with papilledema, particularly in atypical presentations (male, nonobese, nonperipapillary retinal hemorrhages, prominent risk factor for anemia) or in treatment-refractory IIH.

Depression and generalized anxiety symptoms in idiopathic intracranial hypertension: Prevalence, under-reporting and effect on visual outcome

BACKGROUND

Patients with idiopathic intracranial hypertension (IIH) have been reported to have high prevalence of co-existent mood disorders. We investigated the frequency of symptoms of depression and anxiety in a large cohort of patients with IIH without a known psychiatric diagnosis and compared it with the age- and gender-matched control group. We also studied whether the presence and severity of co-existing mood disorder was related to visual outcome in patients with IIH.

METHODS

The Patient Health Questionnaire-8 (PHQ-8) for depression symptoms and the Generalized Anxiety Disorder-7 (GAD-7) questionnaire for symptoms of generalized anxiety were administered via telephone survey to 100 patients with known diagnosis of IIH and 100 control subjects (matched for age and gender) who did not report a history of anxiety or depression during their prior in-person consultations. All participants were also asked whether they had ever been previously diagnosed with a mood disorder during this telephone assessment. Administered questionnaire results were correlated with final visual outcome in IIH cohort.

RESULTS

34 IIH patients and 36 controls self-reported anxiety and/or depression when specifically asked if they had ever been diagnosed with these conditions although this was not reported on clinic intake questionnaires. Mean PHQ-8 depression scale score was 6.5 ± 0.6 in control group and 7.6 ± 0.6 in IIH group (p = 0.18). Mean GAD-7 score was 6.3 ± 0.5 in control group and 7.7 ± 0.6 in the IIH group (p = 0.06). In multivariable regression, scores on both scales were correlated with higher body mass index (BMI), younger age and presence of headache, but not with IIH diagnosis. In the IIH cohort, visual outcomes were not related to GAD-7 or PHQ-8 scores but were predicted by mean deviation on visual fields at presentation.

CONCLUSIONS

Pre-existing diagnosis of anxiety and depression are highly under-reported. Symptoms of anxiety and depression are very common in young women with elevated BMI and headache, however, there was no statistical difference in frequency of these symptoms between IIH and control groups. Presence and severity of mood disorder symptoms did not correlate with the final visual outcome in patients with IIH.

A national Swedish case-control study investigating incidence and factors associated with idiopathic intracranial hypertension

OBJECTIVE

To study the incidence of idiopathic intracranial hypertension in Sweden and to explore whether previously proposed risk factors are associated with idiopathic intracranial hypertension by investigating the odds of exposure one year prior to diagnosis in patients compared to controls.

METHODS

Using Swedish health care registers and validated diagnostic algorithms, idiopathic intracranial hypertension patients diagnosed between 2000-2016 were compared with randomly selected matched controls, five from the general population and five with obesity.

RESULTS

We identified 902 idiopathic intracranial hypertension patients and 4510 matched individuals in each control group. Mean incidence among inhabitants ≥18 years of age was 0.71 per 100,000; rising from 0.53 in 2000-2005 to 0.95 in 2012-2016. There were increased odds for idiopathic intracranial hypertension patients compared to general population for exposure to: kidney failure (odds ratio =13.2 (4.1-42.0)), arterial hypertension (odds ratio =17.5 (10.5-29.3)), systemic lupus erythematosus (odds ratio =13.8 (4.3-44.7)), tetracyclines, sulphonamides, lithium, and corticosteroids. In obese controls, odds ratios were also significantly increased for these exposures. Hormonal contraceptive use and exposure to pregnancy did not appear to be associated factors for idiopathic intracranial hypertension development.

CONCLUSIONS

The incidence of idiopathic intracranial hypertension in Sweden is lower relative to reports from other countries but is on the rise. This case-control study confirms several previously reported risk factors associated with idiopathic intracranial hypertension.

Abortion and Fulminant Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH) causes visual involvement secondary to papilledema but rarely presents with acute gross diminution of vision. Anemia is associated with IIH. Acute hemorrhage-related anemia causing severe sudden onset bilateral visual loss due to IIH has not been previously reported. A 28-year-old female attempted the first-trimester abortion by self-administration of oral drugs. She presented with bleeding per vaginum, followed by bilateral visual loss. Symptoms pertaining to intracranial hypertension were mild. Examination revealed pallor, normal hemodynamic parameters, bilaterally dilated pupils, bilateral lateral rectus palsy, and only perception of light in both eyes. Lumbar puncture demonstrated high pressures; neuroimaging was noncontributory. Blood transfusion and supportive therapy in the form of acetazolamide and pulse methylprednisolone improved her vision in the right eye to six of 24; optic nerve sheath fenestration was performed in the left eye. During follow-up, her vision improved to six of 24 (right) and two of 60 (left), respectively. The IIH can present with severe acute onset bilateral visual loss even if features of raised intracranial pressure are minimal or absent. Immediate correction of anemia and supportive measures may significantly improve visual outcomes in fulminant IIH without the necessity of surgery.