Derealization during utricular stimulation

Abstract

In healthy subjects, unilateral centrifugation provokes DD symptoms. The results support that distorted vestibular signals may create a misleading frame of reference which mismatch with the other senses, giving rise to 'unreal' perceptions.

Magnitude Estimates Orchestrate Hierarchal Construction of Context-Dependent Representational Maps for Vestibular Space and Time: Theoretical Implications for Functional Dizziness

“…In turn, the BCSM's ability to properly scale estimates of displacement and duration is altered, thereby throwing off internal predictions of space and time, which in turn impairs accurate assessment of errors between predicted and actual motion, resulting in sensations of disconnectedness from self and surroundings (mild depersonalization and derealization). These minor dissociative symptoms are consistently experienced by patients with chronic dizziness, including functional dizziness, and by normal individuals exposed to strong vestibular stimuli (Jáuregui-Renaud et al, 2008;Aranda-Moreno and Jáuregui-Renaud, 2016). Such sensations of foggy headedness or indistinct feelings of not being well planted in space disrupt normal reflexive processes.…”

The Growing Evidence for the Importance of the Otoliths in Spatial Memory

“…These symptoms include feelings of déjà vu, of time passing slowly, being “spaced out,” difficulty concentrating, thoughts seeming blurred, one’s body feeling strange and not feeling in control of one’s self. In an experimental study, Aranda-Moreno and Jáuregui-Renaud (2016) used unilateral centrifugation in order to stimulate the utricle of 100 healthy subjects, who then completed a depersonalization/derealization (DD) questionnaire. The subjects reported symptoms such as “Body feels strange or different in some way” (56%) and “Time seems to pass very slowly” (55%).…”

“…This, in turn, is critical for the vestibular contribution to cognitive processes such as spatial memory (see Besnard et al, 2016; Smith, 2017 for reviews), the body representation of the self (see Mast et al, 2014; Lopez et al, 2015 for reviews), and even social cognition (see Deroualle and Lopez, 2014 for a review). Any role that the otoliths have in these processes is especially important since: aging is associated with reduced otolith function (e.g., Agrawal et al, 2012; Zu Eulenburg et al, 2017); impaired vestibular function and specifically otolithic function, has been recently associated with an increased risk of cognitive impairment and dementia (Aranda-Moreno and Jáuregui-Renaud, 2016; Harun et al, 2016; Wei et al, 2017, 2019; Xie et al, 2017; Kamil et al, 2018, in press; see Agrawal et al, 2019, in press, for a review); and otolithic lesions can occur in humans independently of lesions of the semi-circular canals (e.g., Manzari et al, 2014). In addition to other forms of dysfunction that can occur in the vestibular system (e.g., benign paroxysmal positional vertigo, vestibular migraine, Meniere’s disease, vestibular vertigo, vestibular neuritis, vestibular schwannomas, etc.…”

Persistent Postural-Perceptual Dizziness (PPPD) from Brain Imaging to Behaviour and Perception

“…Patients often report feelings of disconnectedness from the self and their surroundings (mild depersonalisation and derealisation). Such low-level but mostly persistent dissociative symptoms are very commonly reported by patients with PPPD, but also experienced by healthy individuals who are exposed to a strong vestibular stimulus [ 24 , 25 , 26 ], suggesting such cognitive perceptions are indeed engendered by vestibular symptoms. The character of dissociative symptoms includes a feeling of brain fog or non-specific sensations of disorientation, together with a range of more specific cognitive symptoms that include short-term memory loss, difficulty concentrating, and impairments in multi-tasking ( Figure 1 ) [ 27 ].…”