TY - JOUR
T1 - Altered insular and occipital responses to simulated vertical self-motion in patients with persistent postural-perceptual dizziness
AU - Riccelli, Roberta
AU - Passamonti, Luca
AU - Toschi, Nicola
AU - Nigro, Salvatore
AU - Chiarella, Giuseppe
AU - Petrolo, Claudio
AU - Lacquaniti, Francesco
AU - Staab, Jeffrey P.
AU - Indovina, Iole
N1 - Publisher Copyright:
© 2017 Riccelli, Passamonti, Toschi, Nigro, Chiarella, Petrolo, Lacquaniti, Staab and Indovina.
PY - 2017/10/17
Y1 - 2017/10/17
N2 - Background: Persistent postural-perceptual dizziness (PPPD) is a common functional vestibular disorder characterized by persistent symptoms of non-vertiginous dizziness and unsteadiness that are exacerbated by upright posture, self-motion, and exposure to complex or moving visual stimuli. Recent physiologic and neuroimaging data suggest that greater reliance on visual cues for postural control (as opposed to vestibular cues-a phenomenon termed visual dependence) and dysfunction in central visuo-vestibular networks may be important pathophysiologic mechanisms underlying PPPD. Dysfunctions are thought to involve insular regions that encode recognition of the visual effects of motion in the gravitational field. Methods: We tested for altered activity in vestibular and visual cortices during self-motion simulation obtained via a visual virtual-reality rollercoaster stimulation using functional magnetic resonance imaging in 15 patients with PPPD and 15 healthy controls (HCs). We compared between groups differences in brain responses to simulated displacements in vertical vs horizontal directions and correlated the difference in directional responses with dizziness handicap in patients with PPPD. Results: HCs showed increased activity in the anterior bank of the central insular sulcus during vertical relative to horizontal motion, which was not seen in patients with PPPD. However, for the same comparison, dizziness handicap correlated positively with activity in the visual cortex (V1, V2, and V3) in patients with PPPD. Conclusion: We provide novel insight into the pathophysiologic mechanisms underlying PPPD, including functional alterations in brain processes that affect balance control and reweighting of space-motion inputs to favor visual cues. For patients with PPPD, difficulties using visual data to discern the effects of gravity on self-motion may adversely affect balance control, particularly for individuals who simultaneously rely too heavily on visual stimuli. In addition, increased activity in the visual cortex, which correlated with severity of dizziness handicap, may be a neural correlate of visual dependence.
AB - Background: Persistent postural-perceptual dizziness (PPPD) is a common functional vestibular disorder characterized by persistent symptoms of non-vertiginous dizziness and unsteadiness that are exacerbated by upright posture, self-motion, and exposure to complex or moving visual stimuli. Recent physiologic and neuroimaging data suggest that greater reliance on visual cues for postural control (as opposed to vestibular cues-a phenomenon termed visual dependence) and dysfunction in central visuo-vestibular networks may be important pathophysiologic mechanisms underlying PPPD. Dysfunctions are thought to involve insular regions that encode recognition of the visual effects of motion in the gravitational field. Methods: We tested for altered activity in vestibular and visual cortices during self-motion simulation obtained via a visual virtual-reality rollercoaster stimulation using functional magnetic resonance imaging in 15 patients with PPPD and 15 healthy controls (HCs). We compared between groups differences in brain responses to simulated displacements in vertical vs horizontal directions and correlated the difference in directional responses with dizziness handicap in patients with PPPD. Results: HCs showed increased activity in the anterior bank of the central insular sulcus during vertical relative to horizontal motion, which was not seen in patients with PPPD. However, for the same comparison, dizziness handicap correlated positively with activity in the visual cortex (V1, V2, and V3) in patients with PPPD. Conclusion: We provide novel insight into the pathophysiologic mechanisms underlying PPPD, including functional alterations in brain processes that affect balance control and reweighting of space-motion inputs to favor visual cues. For patients with PPPD, difficulties using visual data to discern the effects of gravity on self-motion may adversely affect balance control, particularly for individuals who simultaneously rely too heavily on visual stimuli. In addition, increased activity in the visual cortex, which correlated with severity of dizziness handicap, may be a neural correlate of visual dependence.
KW - Chronic subjective dizziness
KW - Functional magnetic resonance imaging
KW - Insula
KW - Persistent postural-perceptual dizziness
KW - Rollercoaster simulation
KW - Vestibular system
UR - http://www.scopus.com/inward/record.url?scp=85032210563&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85032210563&partnerID=8YFLogxK
U2 - 10.3389/fneur.2017.00529
DO - 10.3389/fneur.2017.00529
M3 - Article
AN - SCOPUS:85032210563
SN - 1664-2295
VL - 8
JO - Frontiers in Neurology
JF - Frontiers in Neurology
IS - OCT
M1 - 529
ER -