This study aimed to explore clinical characteristics and treatment efficacy in patients with posterior canal benign paroxysmal positional vertigo and different sleep qualities.

Patients with posterior canal benign paroxysmal positional vertigo were divided into high and low sleep quality groups based on Pittsburgh Sleep Quality Index scores.

No significant baseline differences existed between low (n = 53) and high (n = 39) sleep quality groups. However, the proportion of cupulolithiasis was higher in the low sleep quality group (60.38 per cent vs. 35.90 per cent; p < 0.05). Additionally, the low sleep quality group had a longer median duration of upbeat nystagmus during the Dix-Hallpike test (63.50 seconds vs. 26.80 seconds; p < 0.05) and a lower cured rate in initial repositioning (9.43 per cent vs. 56.41 per cent) compared to high sleep quality group. Repositioning therapy significantly improved depressive and anxiety symptoms in all patients with posterior canal benign paroxysmal positional vertigo, with a more pronounced improvement in depressive symptoms in the low sleep quality group.

Poor sleep quality is associated with higher cupulolithiasis prevalence and treatment resistance, with residual symptoms mainly affecting social functioning.

Benign paroxysmal positional vertigo is classified into five subtypes according to the features of positional nystagmus: lateral canalolithiasis, lateral light cupula, lateral heavy cupula, posterior canalolithiasis and posterior heavy cupula.

The first aim of the study was to clarify whether the lateral canal type or posterior canal type was more common. The second aim of the study was to assess the aetiology of benign paroxysmal positional vertigo by investigating the onset time of each subtype.

The subjects were 512 consecutive patients with benign paroxysmal positional vertigo. The patients were prospectively aggregated, and interviews were used to evaluate onset time.

The lateral canal type (55.5 per cent) was more common than the posterior canal type (44.5 per cent). Time of awakening was the most common onset time in every subtype.

The incidence of lateral canal type is higher than that of posterior canal type. The aetiology of benign paroxysmal positional vertigo is closely related to sleep.