Cortical alterations in phobic postural vertigo – a multimodal imaging approach

Abstract

ObjectiveFunctional dizziness syndromes are among the most common diagnoses made in patients with chronic dizziness, but their underlying neural characteristics are largely unknown. The aim of this neuroimaging study was to analyze the disease‐specific brain changes in patients with phobic postural vertigo (PPV).MethodsWe measured brain morphology, task response, and functional connectivity in 44 patients with PPV and 44 healthy controls.ResultsThe analyses revealed a relative structural increase in regions of the prefrontal cortex and the associated thalamic projection zones as well as in the primary motor cortex. Morphological increases in the ventrolateral prefrontal cortex positively correlated with disease duration, whereas increases in dorsolateral, medial, and ventromedial prefrontal areas positively correlated with the Beck depression index. Visual motion stimulation caused an increased task‐dependent activity in the subgenual anterior cingulum and a significantly longer duration of the motion aftereffect in the patients. Task‐based functional connectivity analyses revealed aberrant involvement of interoceptive, fear generalization, and orbitofrontal networks.InterpretationOur findings agree with some of the typical characteristics of functional dizziness syndromes, for example, excessive self‐awareness, anxious appraisal, and obsessive controlling of posture. This first evidence indicates that the disease‐specific mechanisms underlying PPV are related to networks involved in mood regulation, fear generalization, interoception, and cognitive control. They do not seem to be the result of aberrant processing in cortical visual, visual motion, or vestibular regions.

Network changes in patients with phobic postural vertigo

“…Upon visual motion stimulation, the sensorimotor network of PPV patients became significantly more connected, while the cerebellar network became less connected compared to HC. Building on the previous study by Popp et al (2018), we also find different connectivity of cerebellum. The significant changes of network properties within the sensorimotor network during the two visual stimulation periods in PPV patients are particularly notable.…”

“…This study used the data from Popp et al (2018) to analyze differences in functional connectivity between PPV patients and HC. Overall, 34 patients and 37 HC were included in the original study (Popp et al, 2018). Patients were recruited from the Dizziness Clinic of the University Hospital Munich (German Center for Vertigo and Balance Disorders).…”

“…Conversely, decreased gray matter and connectivity were found in cerebellar vermis, posterior lobules, and the supramarginal gyrus. These results pointed to a higher weighting of cognitive‐based control of motor areas during a sensory task that induced dizziness in PPV patients (Popp et al, 2018).…”

“…Therefore, we examined the whole‐brain network architecture during episodes of visual motion, compared to a static visual stimulus. To this aim, we used a graph theoretical approach to extensively analyze the network properties of the whole brain in PPV patients using the data collected in Popp et al (2018). Six well‐known functional subnetworks were characterized in terms of their importance, segregation, and functional integration of the network (degree centrality [DC], clustering coefficient [CC], and eccentricity [ECC], respectively) (Bullmore & Sporns, 2009; Rubinov & Sporns, 2010).…”

DIZZYNET 2019: approaching the future of vestibular research

“…(2) Selfvideo recording of eye and body movements during vestibular attacks [2]. 3Refinement of imaging methods to depict pathological changes in the inner ear and central vestibular networks [3,4]. 4Increasing practical application of innovative therapeutic strategies (e.g., vestibular implants, stochastic galvanic vestibular stimulation, vestibulo-ocular reflex adaptation) [5].…”