TY - JOUR T1 - Thalamic Projection Fiber Integrity in de novo Parkinson Disease JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. DO - 10.3174/ajnr.A3178 AU - P.J. Planetta AU - E.T. Schulze AU - E.K. Geary AU - D.M. Corcos AU - J.G. Goldman AU - D.M. Little AU - D.E. Vaillancourt Y1 - 2012/07/05 UR - http://www.ajnr.org/content/early/2012/07/05/ajnr.A3178.abstract N2 - BACKGROUND AND PURPOSE: Postmortem studies of advanced PD have revealed disease-related pathology in the thalamus with an apparent predilection for specific thalamic nuclei. In the present study, we used DTI to investigate in vivo the microstructural integrity of 6 thalamic regions in de novo patients with PD relative to healthy controls. MATERIALS AND METHODS: Forty subjects (20 with early stage untreated PD and 20 age- and sex-matched controls) were studied with a high-resolution DTI protocol at 3T to investigate the integrity of thalamic nuclei projection fibers. Two blinded, independent raters drew ROIs in the following 6 thalamic regions: AN, VA, VL, DM, VPL/VPM, and PU. FA values were then calculated from the projection fibers in each region. RESULTS: FA values were reduced significantly in the fibers projecting from the AN, VA, and DM, but not the VPL/VPM and PU, in the PD group compared with the control group. In addition, there was a reduction in FA values that approached significance in the VL of patients with PD. These findings were consistent across both raters. CONCLUSIONS: The present study provides preliminary in vivo evidence of thalamic projection fiber degeneration in de novo PD and sheds light on the extent of disrupted thalamic circuitry as a result of the disease itself. Abbreviations ANanterior nucleusDMdorsomedial nucleusFAfractional anisotropyPDParkinson diseasePUpulvinarSNsubstantia nigraVAventral anterior nucleusVLventral lateral nucleusVPLventral posterior lateral nucleusVPMventral posterior medial nucleus ER -