J Clin Neurol.  2012 Sep;8(3):238-240. 10.3988/jcn.2012.8.3.238.

Medial Temporal Activation in Mal de Debarquement Syndrome Revealed by Standardized Low-Resolution Brain Electromagnetic Tomography

• Jeong SH
• Jung KY
• Kim JM
• Kim JS

• KMID: 2287598
• DOI: http://doi.org/10.3988/jcn.2012.8.3.238

Abstract

BACKGROUND
Mal de debarquement (MdD) literally means "sickness of disembarkation", and refers to the illusion of movement perceived as an after-effect of traveling on a boat, train, or airplane. The pathophysiology of MdD is currently unknown.
CASE REPORT
A 20-year-old man presented with dizziness and swaying sensation for 3 days after a boat trip. Compared with the follow-up EEG without symptoms, the EEG recorded while having MdD symptoms disclosed a significantly decreased alpha-band current source density at the precentral gyrus of the left frontal lobe and increased beta-2 activity at the parahippocampal gyrus of right mesial temporal region.
CONCLUSIONS
Our results provide evidence of deranged cortical activity in MdD. To the best of our knowledge this is the first study to document cortical correlates of MdD using an EEG source-localization method.

Keyword

vertigo; mal de debarquement; temporal lobe; EEG; sLORETA

MeSH Terms

Aircraft
Brain
Dizziness
Electroencephalography
Follow-Up Studies
Frontal Lobe
Humans
Illusions
Magnets
Motion Sickness
Parahippocampal Gyrus
Sensation
Ships
Temporal Lobe
Vertigo
Young Adult
Motion Sickness

Figure

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  Fig. 1 Voxel-based nonparametric statistical map of sLORETA images. Ten artifact-free, 1.5-s epochs were selected from each EEG recording, made with the subject's eyes closed. Cross-spectra were computed for six frequency bands [delta (1-3 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta-1 (13-18 Hz), beta-2 (19-21 Hz), and beta-3 (22-30 Hz)]. sLORETA was subsequently used to estimate the three-dimensional intracerebral current source density distribution in the frequency domain directly from the average cross-spectral matrix for each frequency band. Voxel-wise statistical nonparametric mapping was used to evaluate differences in sLORETA power between two conditions. Compared with the EEG performed after resolution of the symptoms, the EEG recorded while experiencing MdD symptoms exhibited a significant decrease in alpha activity at the precentral gyrus (Brodmann area 6) of the left frontal lobe (A) and an increase in beta-2 activity at the parahippocampal gyrus (Brodmann areas 27, 30, 35, and 36) of the right mesial temporal region (B). The red color indicates a significant increase and the blue color denotes a significant decrease in current density at a 5% significance level after corrections for multiple comparisons. MdD: Mal de debarquement, sLORETA: standardized low-resolution brain electromagnetic tomography.

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