Benign paroxysmal positional vertigo (BPPV) is a common clinical disease characterized by self-limiting and easy recurrence. Manual reduction is effective but residual symptoms may occur in some patients after reduction. In recent years, there have been many studies focus on the influencing factors of therapeutic efficiency of BPPV, while the comparison among specific causes and factors influencing residual symptoms remain to be further investigated.

To analyze the clinical features of secondary BPPV, investigate the effect of etiological classification of BPPV on the recurrence rate, and clarify the risk factors of residual symptoms after BPPV reduction.

A total of 340 patients diagnosed with BPPV were enrolled in the vertigo clinic of the Department of Otorhinolaryngology Head and Neck Surgery and Otology Department of the First Hospital of Jilin University from April 2019 to April 2021, and all of them agreed to manual reduction. The included patients were divided into the primary BPPV (the primary group) and secondary BPPV (the secondary group) groups according to the presence or absence of primary disease. The secondary group was further divided into five subgroups according to different etiologies, including sudden sensorineural hearing loss (SSNHL), vestibular migraine (VM), Meniere disease (MD), vestibular neuritis (VN), and others (such as cranial and ear surgery, Hunt syndrome, temporal bone fracture, etc.). The clinical features and prognosis were compared between the primary group and the secondary group. Follow-up to 3 months after the first reduction, the patients were divided into the residual symptom group and non-residual symptom group according to the occurrence of residual symptoms. The differences were compared in clinical characteristics and scores of Self-rating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) at different periods (at diagnosis, 4 weeks after treatment, and 3 months after treatment) between the two groups, and the independent risk factors of residual symptoms after BPPV reduction were analyzed.

Among the 340 patients, 184 (54.1%) were in the primary group and 156 (45.9%) were in the secondary group. Compared with the primary group, the patients of the secondary group were younger, and the proportion of patients who underwent more than two reductions was higher, the success rate of the first reduction was lower; and the recurrence rate within 3 months, incidence of residual symptoms, SAS score at diagnosis, and SDS score at diagnosis in the primary group were higher than those in the secondary group, with significant differences (P<0.05). There were statistically significant differences in the age of patients with different etiologies of secondary BPPV (P<0.05), and the age of patients with other etiologies (such as cranial and ear surgery, Hunt syndrome, temporal bone fracture, etc.) was lower than that of patients with SSNHL, VM, MD, and VN groups (P<0.05). There were no significant differences in gender, semicircular canal involvement, number of reductions, success rate of the first reduction, recurrence rate within 3 months, incidence of residual symptoms, SAS and SDS scores at different times among different etiology groups of secondary BPPV (P>0.05). There were 133 patients in residual symptom group and 207 patients in the non-residual symptom group. The main residual symptoms were dizziness (59.40%, 79/133), instability (24.06%, 32/133) and head and neck discomfort (9.77%, 13/133), and 6.77% (9/133) had two or more symptoms. The proportion of secondary BPPV and more than two reductions in the residual symptom group was higher than that in the non-residual symptom group (P<0.05), and the proportion of recurrence was less, the SAS and SDS scores at diagnosis, 4 weeks after treatment, and 3 months after treatment were higher than those in the non-residual symptom group (P<0.01). The results of multivariate Logistic regression analysis showed that SAS score at diagnosis (OR=1.231, 95%CI=1.117-1.357, P<0.001) and SDS score at diagnosis (OR=1.209, 95%CI=1.113-1.314, P<0.001) were influencing factors for the occurrence of residual symptoms after reduction in BPPV patients.

Secondary BPPV is characterized by a high incidence of residual symptoms and recurrence rate after reduction. Anxiety and depression can affect the occurrence of residual symptoms after reduction.