Sleep apnea, daytime somnolence, and idiopathic dizziness--a novel association

To determine if an association exists between sleep apnea, daytime somnolence, and chronic idiopathic dizziness.

Case-control study of new patients presenting to a tertiary neuro-otologic practice. A total of 46 subjects with idiopathic dizziness (ID), 20 positive controls with dizziness (benign paroxysmal positional vertigo [BPV]), and 69 negative controls with hearing loss (HL) but no dizziness were enrolled.

Participants who were patients diagnosed with the above conditions and who met all other inclusion criteria completed a sleep questionnaire and had a complete physical exam and investigations to establish or exclude a neuro-otologic diagnosis. They were subsequently evaluated for risk of symptomatic sleep disturbance based on the Epworth Sleepiness Scale (ESS), the Berlin Questionnaire, and the Multivariable Apnea Risk Index (MAP). Statistical analysis was carried out using SPSS (SPSS Inc., Chicago, IL).

There was no significant demographic difference among the groups in terms of age, sex, body mass index, neck size, alcohol consumption, or smoking. Using a cutoff of both 10 and 12 on the ESS, the ID were more likely to have significant daytime somnolence than the HL group, with a likelihood ratio (LR) of 7.8 for the ESS 12 score (P = .021) and 7.1 for the ESS 10 score (P = .029). Using the MAP score, a statistically significant difference between the ID group and both the BPV group (LR 3.99, P = .046) and the HL group (LR 5.46, P = .019) was found.

This study suggests that a previously undescribed link between idiopathic dizziness, daytime somnolence, and sleep apnea might exist. Prospective investigation is warranted to determine whether treatment of any sleep issues resolves symptoms of idiopathic dizziness.