Effects of Kampo medicine hangebyakujutsutemmato on persistent postural-perceptual dizziness: A retrospective pilot study

BACKGROUND Persistent postural-perceptual dizziness (PPPD) is a functional disorder, typically preceded by acute vestibular disorders. It is characterized by a shift in processing spatial orientation information, to favor visual over vestibular and somatosensory inputs, and a failure of higher cortical mechanisms. To date, no therapies for PPPD have been approved. Kampo medicine hangebyakujutsutemmato (HBT) has been reported to alleviate disturbances of equilibrium. We hypothesized that HBT would be a beneficial treatment for PPPD. AIM To examine the efficacy of HBT for the treatment of PPPD. METHODS Patients with PPPD were enrolled and divided into two groups: The HBT group (n = 24) and the non-HBT group (n = 14). The participants completed questionnaire surveys [Niigata PPPD questionnaire (NPQ), dizziness handicap inventory, hospital anxiety and depression scale (HADS), orthostatic dysregulation questionnaire, pittsburg sleep quality index (PSQI), and motion sickness scores] before and after HBT treatment. Additionally, to identify HBT responders, multivariate regression analysis was performed using the results of the questionnaire surveys and equilibrium tests; including stabilometry, and caloric, vestibular evoked myogenic response, and head-up tilt tests. RESULTS Thirty-eight outpatients were included in this study, of which 14 patients (3 men, 11 women; mean age, 63.5 +/- 15.9 years) received treatment without HBT, and 24 (1 man, 23 women; mean age, 58.2 +/- 18.7 years) received combination treatment with HBT. Following HBT treatment, NPQ scores decreased significantly (baseline 40.1 +/- 10.0 vs 2 mo 24.6 +/- 17.7, P < 0.001). No statistically significant changes were observed in the NPQ scores in the non-HBT group (baseline 38.6 +/- 12.2 vs 2 mo 39.4 +/- 14.4, P = 0.92). Multivariable regression analysis revealed that the results of stabilometry (P = 0.02) and the caloric (P = 0.03), and head-up tilt tests (P < 0.001), HADS (P = 0.003), and PSQI (P = 0.01) were associated with HBT responsiveness in PPPD patients. CONCLUSION HBT may be an effective adjunct therapy for PPPD. Patients with autonomic dysfunction, unstable balance, semicircular canal paresis, anxiety, and poor sleep quality may be high responders to HBT.