Anemia and Idiopathic Intracranial Hypertension: a Prospective Study

Authors: Amir R. Vosoughi¹, Irina Sverdlichenko², Edward Margolin³, Jonathan Micieli³. ¹Max Rady College of Medicine, University of Manitoba, ²Faculty of Medicine, University of Toronto, ³Department of Ophthalmology and Vision Sciences, University of Toronto.

Author Disclosures: Amir Vosoughi: None Irina Sverdlichenko: None Edward Margolin: None Jonathan Micieli: None 


Abstract Body: 

Purpose: Anemia has been temporally associated with idiopathic intracranial hypertension (IIH) in retrospective studies; however, this relationship is uncertain due to lack of prospective studies and as patients with IIH do not routinely have complete blood counts (CBC). Therefore, CBCs may have only been available in patients with significant comorbidities, higher risk factors, or symptoms from anemia. In addition, both IIH and anemia are common in young women with obesity, which creates further challenges in establishing an association between IIH and anemia. 

Study Design: Prospective cross‐sectional study. 

Methods: Consecutive patients with IIH referred to three neuro‐ophthalmology centres between March 2021 and September 2022. Inclusion criteria included presence of papilledema, normal neurologic exam excluding cranial nerve abnormalities, normal neuroimaging, age >18 years, and complete blood count available within 6‐ months of presentation. Anemia was defined as mild (110‐120 g/L), moderate (80‐109 g/L) and 
severe (<80 g/L). 

Results: A total of 143 patients were included, 113 patients had normal hemoglobin (Group‐1) and 30 patients had anemia (Group‐2). In Group‐2, the anemia was defined as mild (15/30, 50.0%), moderate (11/30, 36.7%) and severe (4/30, 13.3%). The anemia was most often microcytic (15/30, 50%) and normocytic (15/30, 50%). There was no difference in female sex (105/113 vs 29/30, p=0.453), age (31.5±9.2 vs 28.5±10.3, p=0.144), and BMI (35.2 ± 6.9 vs 38.0 ± 8.1, p=0.111). Group‐1 and Group‐2 did not differ in logMAR visual acuity (0.04±0.09 vs 0.07±0.15, p=0.377), RNFL thickness (174.5±68.4 vs 206.5±97.0, p=0.098), mean deviation (‐3.2±3.1 vs ‐3.9±3.4, p=0.180), and the need for medical (34/113 vs 8/30, p=0.715) and surgical treatment (3/113 vs 3/30, p=0.074). Patients with moderate‐severe anemia were significantly more likely to require surgical therapy compared to patients with normal hemoglobin (2/15 vs 3/113, p=0.045). 

Conclusions: Approximately one out of every five patients with Idiopathic Intracranial Hypertension has anemia and this is severe in over 10% of patients. Patients with moderate and severe anemia may require more invasive surgical treatment. Given the high incidence of anemia and the availability of a complete blood count, we recommend this test be obtained for all patients with suspected idiopathic intracranial hypertension.

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