Ocular Findings During Vestibular Testing in Vestibular Migraine: Systematic Review.

ImportanceVestibular migraine (VM) is diagnosed using limited consensus-based criteria and presents with symptoms that overlap those of other vestibular disorders. Accurate diagnosis of VM is important to facilitate adequate and timely symptom management as well as to avoid mismanagement.ObjectiveTo characterize ocular findings during vestibular testing in adults with VM.DesignSystematic review.SettingThis systematic review was completed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Database searches of Embase, MEDLINE, and Cochrane Library were conducted.ParticipantsStudies evaluating participants with a diagnosis of definite or probable VM and no concomitant vestibular disorders were included.Intervention or ExposuresPositioning tests, positional tests, caloric testing, and video head impulse testing (vHIT).Main Outcome MeasuresPositioning and positional testing of nystagmus, caloric testing for unilateral weakness, as well as vHIT gain and saccades.ResultsThis review included 31 studies. Positioning testing nystagmus was present in 2% to 100% of patients during Dix-Hallpike (DH) and in 7.9% to 37.5% of patients during the supine head roll testing (SHRT). Nystagmus direction, when present during DH and SHRT, included horizontal, vertical, and torsional nystagmus. Positional testing nystagmus was present in 0% to 100% of patients during upright positional testing and in 42.1% to 95.5% of patients during supine positional testing. Horizontal, vertical, and torsional nystagmus in upright positional testing and direction-changing nystagmus in supine positional testing were observed. Unilateral weakness was present in 0% to 100% of patients; however, most studies reported a rate of <50% of unilateral weakness in tested patients. During vHIT, both abnormal gain and corrective saccades were observed, with the latter being more common.Conclusion and RelevanceVM can present with ocular movement patterns seen in both central nervous system disorders and peripheral vestibular system disorders on vestibular testing. Future studies should focus on further describing the characteristics of nystagmus and associated symptoms experienced during vestibular testing in VM.