EP 50. Correlation between oculomotor changes and atlas-based volumetry in patients with different neurodegenerative Parkinson syndromes

Abstract

Background Characteristically impaired oculomotor functions are recognized in Parkinsonian syndromes including idiopathic Parkinson disease (PD), Multiple System Atrophy (MSA), Progressive Supranuclear Palsy (PSP) ( Pinkhardt and Kassubek, 2011 ). Atrophy of specific brain structures has been reported in Parkinsonian syndromes ( Brenneis et al., 2007 , Focke et al., 2011 ). The aim of this study was to investigate possible relationships between oculomotor alterations and volumetric alterations in PD, PSP and MSA. Methods Forty-two PD, 18 MSA, and 32 PSP patients together with 26 healthy controls underwent standardized video-oculographic testing and MRI at a clinical 1.5T scanner. Whole-brain based T1-weighted MRI-images were analyzed using atlas-based volumetry ( Kassubek et al., 2011 ). Data of 5 brain structures (forebrain, brainstem, cerebellum, midbrain, pons) and 5 oculomotor parameters (smooth pursuit gain, peak eye velocity, rate of saccadic intrusions, anti-saccade errors) were used for group comparisons in PD, MSA and PSP with healthy controls. Oculomotor parameters were correlated with regional brain volumes in the patients. Results PD patients compared with control showed a significantly increased rate of saccadic intrusions (p). Conclusions The worse the oculomotor performance the lower the regional brain volume, suggesting a relationship between regional brain atrophy and cerebral oculomotor network disturbances. Deficits in eye movement control in PD appear to be characterized by executive abnormalities, whereas oculomotor dysfunctions in MSA and PSP were associated with impaired pontine and midbrain pathways.