Functional Dizziness as a Spatial Cognitive Dysfunction.

Abstract: ABSTRACT Background Two chronic forms of dizziness—bilateral vestibulopathy (BVP) with a loss of vestibular input, and functional dizziness with normal vestibular function—present with the key symptom of postural and gait imbalance. In BVP, this is associated with spatial disorientation. Here, we investigated whether persistent postural–perceptual dizziness (PPPD) in patients with normal vestibular function also affects spatial orientation, because there is evidence that central multisensory misintegration plays a crucial role in PPPD. Methods Thirty‐two patients with BVP (mean age 52.44 ± 12.00 years; 17 females), 43 patients with PPPD (mean age 45.93 ± 11.72 years; 25 females), and 32 healthy controls (HC, mean age 44.78 ± 14.40 years; 15 females) participated in a clinical bedside test investigating spatial orientation abilities (three‐dimensional real‐world pointing task, 3D‐RWPT). This test includes a cognitive (mental rotation) and a vestibular paradigm (body rotation around yaw axis with eyes closed). Participants reported their perceived spatial abilities and levels of spatial anxiety /orientation‐related discomfort through standardized questionnaires. Results Patients with BVP and PPPD showed significantly lower accuracy (i.e., larger angular deviations) in the 3D‐RWPT compared to HC (BVP: 9.62° ± 3.21°, PPPD: 9.16° ± 3.85°, HC: 7.77° ± 2.86°; p = 0.03), especially in the subtasks that rely on vestibular function (BVP: 8.11° ± 5.51°, PPPD: 6.62° ± 4.46°, HC: 4.45° ± 2.33°; p < 0.01). All cohorts had comparable levels of self‐assessed spatial abilities, while both BVP and PPPD patients showed higher levels of spatial orientation discomfort. Conclusions This impairment of spatial orientation in PPPD patients with normal vestibular function could be a sign of (potentially anxiety‐driven) central suppression of vestibular input, which is required for the continuous updating of the internal representation of body motion and position relative to the environment.

TL;DR: This cross-sectional study of 164 participants found that anxiety, cognitive fusion, and justice appraisal significantly mediate symptoms of Persistent Postural-Perceptual Dizziness (PPPD), suggesting psychological variables are crucial for diagnosis and treatment.

TL;DR: Developments of an open-field water-maze procedure in which rats learn to escape from opaque water onto a hidden platform are described, suggesting that they may lend themselves to a variety of behavioural investigations, including pharmacological work and studies of cerebral function.

TL;DR: A fundamental misconception about this issue is that the minimum sample size required to obtain factor solutions that are adequately stable and that correspond closely to population factors is not the optimal sample size.

TL;DR: The final version of the DHI was administered to 106 consecutive patients and demonstrated good internal consistency reliability, with the exception of the physical subscale, the mean values for DHI scale scores increased significantly with increases in the frequency of dizziness episodes.