Visually induced postural sway in anxiety disorders

Abstract

Postural sensitivity to moving visual environments in patients with anxiety disorders was studied. We hypothesized that patients with anxiety disorders would have greater sway in response to a moving visual environment compared to healthy adults, especially if they have space and motion discomfort (SMD). Twenty one patients with generalized anxiety without panic (NPA), and 38 patients with panic and agoraphobia (PAG) were compared to 22 healthy controls. SMD was evaluated in all subjects via questionnaire. Subjects stood on a force platform that was either fixed or rotating with the subject (i.e. sway referenced) during exposure to a sinusoidally moving visual surround. Center of Pressure (COP) data were computed from force transducers in the platform as a measure of sway. Results showed that patients swayed significantly more in response to the moving visual scene compared to control subjects, with no differences between the NPA and PAG groups. SMD was a predictor of sway response in the patients: patients with high SMD swayed significantly more than both Controls and anxiety patients with low SMD. These results indicate that patients with anxiety disorders, particularly those with SMD, are more visually dependent for balance. This subgroup of patients may be amenable to treatment used for patients with balance disorders (i.e. vestibular rehabilitation) that focuses on sensory re-integration processes that address visual sensitivity.

Deconstructing acrophobia: physiological and psychological precursors to developing a fear of heights

“…[39] Our results also support the claim that patients with anxiety and SMD rely more heavily on visual cues for postural control. [8] Jacob and coworkers [14] also found that disorientation sensitivity was related to postural instability, and it is likely that postural instability precedes body symptoms, in a process similar to that seen in motion sickness. [40] BODY SYMPTOMS Postural control relies on multisensory processing and motor responses that seem to be automatic and occur without conscious awareness.…”

“…[8] Unfortunately, the tendency to regard these disorders as related has lead to patients with differing specific disorders being lumped together, making it difficult to ascertain the selective effects of factors such as balance control. There are, in fact, several good reasons for thinking that acrophobics may struggle with postural control.…”

Visual field dependence is associated with reduced postural sway, dizziness and falls in older people attending a falls clinic

“…Visual-vestibular conflict and optokinetic stimulation have been used as intervention strategies for vestibular rehabilitation [38,39,40,4]. However, in this study optokinetic stimulation conditions did not trigger augmented destabilising effects, therefore exposure to optokinetic stimulation may not be an appropriate intervention in rehabilitation for older people at increased risk of falls.…”

“…It increases with age [1] and is prevalent not only in older people [2] but also in those with vestibular and anxiety disorders [3,4].…”

“…Moving visual environments can cause postural changes [8], disequilibrium, and motion sickness in healthy adults, and in patients with balance disorders these effects can be even greater [9]. 4 To date no studies have reported the prevalence of VFD or have examined the relationship between VFD and sway in older people at increased risk of falls, such as those who attend a falls clinic. This information could be valuable for understanding fall risk and guiding the treatment and clinical rehabilitation in this group.…”