IC-P1-068: Structural anatomy of environmental dependency syndrome in neurodegenerative disease

Environmental dependency syndrome (EDS) is a compulsive, involuntary, environmentally dependent behavior which occurs usually in patients with frontal lobe lesions. All of the previous studies for the anatomical localization of the EDS were based on the analysis of the lesion sites. This study investigates the neuroanatomical correlates of the EDS in patients with neurodegenerative disease with voxel-based morphometry (VBM) method. Severity of EDS was measured by the total score of the six items of the environment dependency category in modified Manchester Behavior Inventory. Sixty nine patients with Alzheimer's disease, frontotemporal lobar degeneration, corticobasal degeneration, and twenty two normal controls were evaluated. Total scores of the EDS were correlated with structural MRI gray matter volume using VBM. EDS was observed in 46 patients (67%). Voxels in the left inferior frontal gyrus, right medial and lateral superior fontal gyrus, left supplementary motor area, left inferior frontal gyrus, bilateral caudate and putamen, and right inferior temporal gyrus negatively correlated with total EDS scores (P<0.05, corrected) . EDS is a frequently observed abnormal behavior in patients with neurodegenerative disease. The results suggest that the bilateral frontal and subcortical structures are important in regulating EDS. VBM analysis can reveal the neural basis of the EDS using correlative analytic methods.