Sickle Cell Disease and Vestibular Dysfunction
Authors: Andresen Nicholas S , McIntyre Tiffany , Ward Bryan K , Nelson Melanie Dawn , Kheradmand Amir , Pecker Lydia H. , Lanzkron Sophie M. , Lance Eboni I. 
Published: November 2021

Abstract
Introduction: Sickle cell disease (SCD), a common genetic disease involving red blood cell structure and function, is associated with cerebral vasculopathy and increased risk of ischemic events that may also affect the inner ear. Individuals with SCD are at increased risk for hearing loss; however, little is known regarding the effects of SCD on the vestibular system or the relationship between hearing loss and vestibular symptoms in these patients. Vestibular dysfunction affects 15-20% of the general population can lead to significant morbidity through falls, fall-related injuries, missed work, and overall reduction in quality of life.
Methods: To assess the burden of vestibular dysfunction amongst individuals with SCD, we surveyed individuals with SCD who answered questions about symptoms of dizziness, imbalance, and hearing loss. The survey also captured demographic information, current symptoms of dizziness/imbalance, symptoms of hearing loss, and history of falls. Fisher's exact test was performed to test for associations between clinical characteristics including SCD genotype, hearing loss, dizziness or imbalance, and headache history.
Results: Twenty-six participants, ages 20 to 73 years (median 37.5 years) completed the survey. All participants were Black or African-American. Five participants (19.2%) were male, 15 (58%) had hemoglobin SS, 8 (32%) hemoglobin SC, and 3 (12%) S-β + thalassemia. Three (11.5%) participants reported hearing loss. Twelve (46.2%) participants reported dizziness or imbalance, of which 8 (66%) reported recent falls. Of the 12 participants experiencing dizziness, 9 (75%) reported having dizziness for 1 to 3 days a month, 2 reported having dizziness for 4 to 9 days a month, and 1 reported having dizziness for more than 15 days a month. Three participants reported their dizziness symptoms resolved within seconds, 7 within minutes, and 2 within hours. Eleven (42.3%) participants reported headaches. Self-reported dizziness or imbalance was not associated with hearing loss (X 2=0.57; p=0.45), SCD genotype (X 2=0.75; p=0.68), or sex (X 2=0.09; p=0.76). Headache history was associated with dizziness or imbalance (X 2=9.76; p=0.002).
Conclusions: In this small pilot study, 46% of individuals with SCD reported dizziness or imbalance, which is twice the rate reported amongst the general population. Headache history is associated with dizziness and imbalance amongst individuals with SCD. Further investigation is warranted to determine the specific effects of SCD on the vestibular end-organs.

Disclosures
Lanzkron: Imara: Research Funding; Pfizer: Current holder of individual stocks in a privately-held company; GBT: Research Funding; Shire: Research Funding; Teva: Current holder of individual stocks in a privately-held company; Novartis: Research Funding; Novo Nordisk: Consultancy; Bluebird Bio: Consultancy; CSL Behring: Research Funding. Lance: Novartis: Other: participated in research advisory board in 2020.