Clinical Spectrum of Positional Vertigo in an Outpatient Setting.

Objectives: To explore the clinical spectrum of positional vertigo (PV) and to study the causes of PV with atypical positional nystagmus (PN) and PV without PN.

Design: We retrospectively analyzed the registry (2425 cases) in a university hospital. Patients who actively reported PV as their main dizziness pattern were included. Candidates were divided into three groups according to their PN: (1) benign paroxysmal PV (BPPV); (2) PV with atypical PN; and (3) PV without PN. The diagnoses and reported symptoms in each group were analyzed.

Results: PV was the most commonly (n = 518, 28.3%) reported pattern in the registry. The two most common diagnoses of PV were BPPV (n = 146, 29.2%) and vestibular migraine (VM; n = 137, 27.4%). Fifty-seven (11.4%) patients had PV with atypical PN, the majority of which was caused by VM. Moreover, 297 (59.4%) patients had PV without PN. The two main diagnoses in this group were VM and functional dizziness, although the cause remained uncertain in 23.9% of the cases of PV without PN. The odds ratio of VM was 3.95 in patients with PV who reported headaches.

Conclusions: PV is the most common self-reported dizziness pattern and is predominantly caused by BPPV and VM. VM is the most common cause of PV with atypical PN and PV without PN. Clinicians often erroneously assume the presence of PN in those with PV. Managing PV without PN can be challenging because of the uncertainty surrounding this phenomenon. Structured patient-oriented questionnaires assist clinicians in making timely diagnoses and adjusting treatment goals accordingly.