OBJECTIVES: Persistent oscillating vertigo that occurs after entrainment to periodic motion is known as Mal de Débarquement Syndrome (MdDS). Down-modulation of this oscillating vertigo is associated with reduction in long-range resting-state functional connectivity between fronto-parieto-occipital regions. In order to determine the association between this oscillating vertigo and hypersynchrony as measured by the auditory steady-state response (ASSR), we investigated the differences in ASSR between individuals with MdDS and healthy controls as well as the change in ASSR in individuals with MdDS before and after treatment with transcranial alternating current stimulation (tACS).
MATERIALS AND METHODS: Individuals with treatment refractory MdDS lasting at least six months received single administrations of fronto-parieto-occipital tACS in an "n-of-1" double-blind randomized design: alpha-frequency in-phase, alpha-frequency antiphase, and gamma frequency antiphase control. The treatment protocol that led to the most acute reduction in symptoms and improved balance was administered for 10-12 sessions given over three days (each session 20-min at 2-4 mA).
RESULTS: Twenty-four individuals with MdDS participated (mean age 53.0 ± 11.8 years [range: 22-66 years, median: 57.0 years]; mean duration of illness 38.6 ± 53.4 months [range: 6-240 months, median: 18.0 months]). Individuals with MdDS had elevated ASSR compared to healthy controls at baseline (t 11 = 5.95, p < 0.001). There was a significant decrease in the 40 Hz-ASSR response between responders compared to nonresponders to tACS (t-test, t 15 = -2.26, p = 0.04). Both in-phase and anti-phase alpha tACS lead to symptom improvement but only antiphase alpha-tACS led to a significant decrease of 40 Hz-ASSR (t-test, t 12 = -9.6, p < 0.001).
CONCLUSIONS: Our findings suggest that tACS has the potential to reduce network-level hypersynchrony and pathological susceptibility to entrainment by sensory input. To the best of our knowledge, this is the first successful demonstration of desynchronization by noninvasive brain stimulation leading to reduced vertigo. Other disease states associated with pathological functional coupling of neuronal networks may similarly benefit from this novel approach.
Bibliographical noteFunding Information:
Source(s) of financial support: This work was supported by the Laureate Institute for Brain Research, the William K. Warren Foundation, the MdDS Balance Disorders Foundation (Y.H.C.), the Springbank Foundation (Y.H.C.), NIH/NIGMS P20 GM121312 (Y.H.C.), the Springbank Foundation (Y.H.C.), and NSF RII Track‐2 #1539068 (Y.HC.), NIH/NIMH R01 MH111889 (F.F.), and NIH/NIMH R33 MH105574 (F.F.). This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2020R1G1A1099733). The funding sources had no role in the overall design or analysis of the study.
© 2021 International Neuromodulation Society.
- Auditory steady-state response
- Mal de Débarquement Syndrome
- persistent oscillating vertigo
- transcranial alternating current stimulation
- Transcranial Direct Current Stimulation
- Middle Aged
- Occipital Lobe
PubMed: MeSH publication types
- Randomized Controlled Trial
- Journal Article