Left Entorhinal Cortex and Amygdala Hypermetabolism in Mal de Debarquement Syndrome (P02.248)

Abstract

Objective: To determine whether patients with mal de debarquement syndrome (MdDS) exhibit differences in resting state brain metabolism. Background Patients with MdDS experience a persistent sense of internal motion described as a rocking sensation triggered by prolonged exposure to passive motion, typically from sea travel. Structural brain imaging and vestibular function testing are normal in MdDS. Design/Methods: Twenty subjects with MdDS (15 female, mean age: 43.4 yrs) with symptoms ranging from 3 months to 20 years underwent resting state 18F FDG PET and structural MRI scans and were compared to 20 controls (15 female, mean age 43.0 yrs). A bootstrapping method was used to identify peak voxels that were either more active in MdDS subjects or controls. An initial exploratory group of 10 MdDS subjects and 10 controls was first used to determine regions of differential activity. These coordinates were screened in a confirmatory group of 10 patients and 10 controls with a corrected family-wise-error of p Results: The area of maximum difference in activity greater in MdDS was in the left entorhinal cortex and amygdala (T= 4.01). Controls had more activity in the left middle temporal gyrus (T= 4.35) and left inferior temporal gyrus (T= 3.94). Conclusions: MdDS subjects exhibit higher resting state metabolic activity in the entorhinal cortex, a key area of spatial information processing before storage in the hippocampus. The entorhinal cortex has been previously shown to exhibit sustained activity in the absence of stimuli and has a function enhanced by concurrent amygdala activity. These data further the understanding of the anatomical correlates of sustained perceptions of self-motion. Supported by: NIDCD: R03DC010451. Disclosure: Dr. Cha has nothing to disclose. Dr. Chakrapani has nothing to disclose. Dr. Baloh has nothing to disclose.