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

Abstract

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.

New Onset Severe Anemia and Fulminant Idiopathic Intracranial Hypertension

“…3 Our group performed a systematic review of the literature and identified 74 cases of IIH reported in the literature that were associated with anemia, with only 16 of these patients reported to be obese. 4 The most common causes of anemia were iron deficiency. In 60% of cases, anemia treatment without ICP-lowering therapy was initiated and patients demonstrated improvement or resolution of symptoms.…”

Anemia and Idiopathic Intracranial Hypertension: A Case–Control Study

“…A cross-sectional study by Ardissino et al (7) found a statistically higher prevalence of anemia in IIH patients compared with controls. This finding was supported in a meta-analysis carried out by Yu et al (8) Despite the existing literature supporting the association between anemia and IIH, the relationship remains controversial. Age- and sex-matched case controls by Giuseffi et al (9).…”

“…The literature has previously documented variable prevalence of anemia in IIH patients, ranging from 7.5% to 32% (Table 2). A meta-analysis by Yu et al (8) reported a prevalence of 20.1%, which is similar to the 22.8% prevalence in the present study (8). Our finding that IIH patients have a higher likelihood of anemia than age-and sexmatched controls supports the findings of Yu et al (8) (RR 1.44, 95% CI 1.08, 1.92) and Ardissino et al (7) (OR 1.478, P , 0.0001).…”

Micronutrient Deficiencies Presenting with Optic Disc Swelling Associated with or without Intracranial Hypertension: A Systematic Review

“…Cases with co-existent morbidities known to cause optic disc swelling or IIH were excluded, e.g., ischemic optic neuropathy or Leber’s Hereditary Optic Neuropathy, even if they also had nutritional deficiencies. We also excluded cases with iron deficiency and/or severe anaemia (defined as haemoglobin < 8.0 g/dL) [ 13 ] as they are already established risk factors for IIH and have been reviewed elsewhere [ 11 , 14 ]. Reports of epidemic optic neuropathy, e.g., the Cuban epidemic, were not included as individual patient-level information was lacking and there is still some uncertainty about their etiology; these cases are considered in the discussion.…”