Diagnostics and Group Therapy in Patients with Persistent Postural-Perceptual Dizziness and Anxiety Disorder: Biomarkers and Neurofunctional Correlates of Underlying Treatment Effects.

: There is a certain degree of overlap between persistent postural-perceptual dizziness (PPPD) (ICD-11) and anxiety disorders (ANX) with regard to the phenomenological, pathological and neurobiological characteristics of both conditions. The implementation of an integrative psychotherapy programme may potentially result in the generation of synergistic effects across both patient groups. : This study assessed (1) whether psychological mechanisms similarly influence symptom severity in PPPD and ANX group, (2) the effectiveness of psychotherapy, and (3) potential neurofunctional biomarkers. : Patients with PPPD (n = 14) and ANX (n = 20) underwent an integrative psychotherapy programme with balance training and mindfulness-based interventions. Emotional and neutral pictures were presented during MRI scans before and after therapy, with healthy controls (HC = 29) for comparison. Clinical and psychological questionnaires were administered, and brain activity was analysed in key regions. : The only diagnostic difference in the direct comparison between patients with PPPD and with ANX were the vertigo intensity values before and after therapy. PPPD with comorbid anxiety disorder had significantly more fear of physical symptoms than patients without comorbid anxiety disorder. PPPD showed no change regarding vertigo intensity (VSS), anxiety, or depression scores, but reported decreased impact of vertigo on social functioning (VHQ), and improved personal control after therapy (IPQ). By contrast, anxiety, dizziness, depression, alexithymia, and IPQ scores were significantly reduced after therapy in the ANX group. Neuroimaging revealed decreased activity in the hippocampus and superior temporal gyri (STG) in the PPPD group post-therapy as compared to the pre-therapy measurement, while the ANX group showed reduced activity in the insula, thalamus, hippocampus, and inferior frontal gyrus. Compared to the ANX and HC groups, patients with PPPD showed increased activity in the supramarginal gyrus and STG, both of which could serve as biomarkers for PPPD patients but need to be further validated. : Anxiety and vertigo may reinforce each other in PPPD, as symptoms persisted post-therapy, whereas ANX patients improved significantly. Nevertheless, there is some evidence for a successful management of symptoms in the PPPD group. Findings are limited by small sample size and require further research.