Altered Neuromagnetic Activity in Persistent Postural-Perceptual Dizziness: A Multifrequency Magnetoencephalography Study.

Objective:The aim of our study was to investigate abnormal changes in brain activity in patients with persistent postural-perceptual dizziness (PPPD) using magnetoencephalography (MEG). Methods:Magnetoencephalography recordings from 18 PPPD patients and 18 healthy controls were analyzed to determine the source of brain activity in seven frequency ranges using accumulated source imaging (ASI). Results:Our study showed that significant changes in the patterns of localization in the temporal-parietal junction (TPJ) were observed at 1-4, 4-8, and 12-30 Hz in PPPD patients compared with healthy controls, and changes in the frontal cortex were found at 1-4, 80-250, and 250-500 Hz in PPPD patients compared with controls. The neuromagnetic activity in TPJ was observed increased significantly in 1-4 and 4-8 Hz, while the neuromagnetic activity in frontal cortex was found increased significantly in 1-4 Hz. In addition, the localized source strength in TPJ in 1-4 Hz was positively correlated with DHI score (r = 0.7085, p < 0.05), while the localized source strength in frontal cortex in 1-4 Hz was positively correlated with HAMA score (r = 0.5542, p < 0.05). Conclusion:Our results demonstrated that alterations in the TPJ and frontal cortex may play a critical role in the pathophysiological mechanism of PPPD. The neuromagnetic activity in TPJ may be related to dizziness symptom of PPPD patients, while the neuromagnetic activity in frontal lobe may be related to emotional symptoms of PPPD patients. In addition, frequency-dependent changes in neuromagnetic activity, especially neuromagnetic activity in low frequency bands, were involved in the pathophysiology of PPPD.