Effect of canalith repositioning on resting-state brain functional connectivity in patients with benign paroxysmal positional vertigo.
Frontiers in neurology – January 01, 2025
Source: PubMed
Summary
The brain's functional connectivity changes significantly with benign paroxysmal positional vertigo (BPPV). Using functional near-infrared spectroscopy (fNIRS) during resting-state, 50 BPPV patients initially displayed elevated functional connectivity between key brain regions compared to 50 healthy individuals. Following a canalith repositioning maneuver, patients experienced a 23.4% reduction in dizziness scores, and their whole-brain functional connectivity decreased. Specific connections also normalized, demonstrating how the canalith repositioning maneuver effectively restores brain network activity. This suggests fNIRS can objectively track BPPV's neural impact.
Abstract
To compare the characteristics of resting-state functional connectivity (FC) before and after repositioning therapy in patients with benign paroxysmal positional vertigo (BPPV) using functional near-infrared spectroscopy (fNIRS). Fifty BPPV patients and fifty healthy controls were enrolled. Oxygenated hemoglobin (HbO) concentration changes during resting-state were recorded using fNIRS. The experimental group underwent Dizziness Handicap Inventory (DHI), Visual Analogue Scale (VAS) assessments, and 10-min resting-state fNIRS scans before and after repositioning therapy; the control group received baseline scans only. FC strength of the whole brain and specific regions of interest (ROIs) was analyzed using correlation coefficients. fNIRS analysis revealed significantly elevated FC strength between the middle temporal gyrus (MTG) and both the motor cortex (MC) and somatosensory cortex (SC) in BPPV patients at baseline compared to healthy controls (p < 0.05); after canalith repositioning, the whole-brain average FC strength in patients significantly decreased. Connectivity strength decreased synchronously in the following ROI pairs: prefrontal cortex (PFC)-occipital cortex (OC), PFC-MTG, PFC-MC, OC-MC, OC-SC, MTG-MC, and MTG-SC, and brain network parameters returned to normal levels post-repositioning. Clinical indicators improved simultaneously: the total DHI score decreased by 23.4% (p < 0.05), and the VAS score showed a significant reduction. BPPV involves compensatory enhancement of the vestibulo-sensorimotor network. Canalith repositioning eliminates abnormal vestibular input and restores pathologically enhanced FC to normal levels. This supports fNIRS as a potential objective neuroimaging biomarker for evaluating BPPV neural mechanisms and treatment efficacy.