Cerebral Responses to Stationary Emotional Stimuli Measured by fMRI in Women with Persistent Postural-Perceptual Dizziness

Abstract

Introduction Persistent postural-perceptual dizziness (PPPD) is a functional vestibular disorder characterized by chronic dizziness, unsteadiness, and hypersensitivity to motion. Preexisting anxiety disorders and neurotic personality traits confer vulnerability to PPPD. High anxiety during acute vertigo or dizziness incites it. A functional magnetic resonance imaging (fMRI) study of chronic subjective dizziness found unexpectedly hypoactive responses to vestibular stimulation in cortical regions that integrate threat assessment and spatial perception. Objective This fMRI study used non-moving, but emotionally charged visual stimuli to investigate the brain's activity of PPPD patients and control subjects. Methods The participants included 16 women with PPPD and 16 age-matched women who recovered completely from acute episodes of vertigo or dizziness capable of triggering PPPD. Brain responses to positive, neutral, and negative figures from the International Affective Picture System were measured with fMRI and compared between the groups. Dizziness handicap, anxiety, and depression were assessed with validated questionnaires. Results Between group analyses: Participants with PPPD showed reduced activity in anterior cingulate cortex and increased activity in left angular gyrus in response to negative versus positive stimuli, which was not observed in recovered individuals. Within group analyses: Participants with PPPD had increased activity in visuospatial areas (parahippocampal gyrus, intraparietal sulcus) in negative versus positive and negative versus neutral contrasts, whereas recovered individuals had increased activity in anxiety regions (amygdala, orbitofrontal cortex). Conclusion Patients with PPPD may be more attuned to spatial elements than to the content of emotionally charged visual stimuli.

Brain Correlates of Persistent Postural-Perceptual Dizziness: A Review of Neuroimaging Studies

“…However, this response is increased by depression [ 74 ], which was likely higher in patients with respect to controls. An fMRI study by von Söhsten Lins et al [ 54 ] directly assessing the brain response of patients with PPPD vs. controls to pictures with negative vs. positive affective value showed increased response to aversive stimuli in a posterior parietal area corresponding to the angular gyrus (PGa) and, contrarily to Popp et al [ 48 ], decreased response in the subgenual cingulate cortex [ 54 ]. The posterior parietal cortex is involved in the response to visual threat to self as the relay between visual information and motor cortex to produce defensive movements [ 75 ].…”

“…However, that study controlled for depression but not for anxiety or body vigilance, two psychological factors that are more relevant than depression for PPPD and habituation to noxious stimuli. von Söhsten Lins et al addressed the question of whether patients with PPPD respond more strongly than controls to generic aversive visual stimuli that do not possess provocative features specific to PPPD using the International Aversive Picture System [ 54 ]. Between-group comparisons showed that the angular gyrus responded more to negatively than positively valenced stimuli in patients with PPPD compared to controls, whereas within-group analysis found an unexpectedly absent amygdalar response in patients with PPPD, despite them having higher mean ratings of anxiety than comparison patients who had recovered from acute vestibular syndromes.…”

“…Popp et al [ 48 ] found increased response in the subgenual cingulate cortex (s24, s32) in patients with PPV both during visual motion stimulation and motion aftereffect. von Söhsten Lins et al [ 54 ] found increased response in the left PGa angular gyrus in patients with PPPD in response to negative vs. positive pictures. Passamonti et al [ 47 ] considered the effect of neuroticism after matching the control group for neuroticism and found increased response in neurotic patients in response to vertical vs. horizontal stimulation in left BA45.…”

The impact of disease duration in persistent postural-perceptual dizziness (PPPD) on the quality of life, dizziness handicap and mental health

“…As physical examination, clinical laboratory testing and vestibular evaluation may be normal in PPPD [21,22], advances in neuroimaging have provided new insights in patients with PPPD illustrating the delicate changes in functional activity and internetwork connectivity involving the vestibular, visual and emotion processing centers [10,12,13,24,26]. However, the functional MRI is not easily available and diagnosis relies heavily on clinical history [21].…”

“…Studies have since shown that PPPD is more often seen in females and middle aged [1,4,26,27], interferes with the way individuals experience their personal, social and work life [20] and treatment is patient centric that begins with communication and education regarding the disorder [16]. However, there has not been studies that investigated the impact of disease duration in an already chronic ailment.…”