TY - JOUR T1 - Abnormal Microstructure of the Atrophic Thalamus in Preterm Survivors with Periventricular Leukomalacia JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 185 LP - 191 DO - 10.3174/ajnr.A2243 VL - 32 IS - 1 AU - A.C. Nagasunder AU - H.C. Kinney AU - S. Blüml AU - C.J. Tavaré AU - T. Rosser AU - F.H. Gilles AU - M.D. Nelson AU - A. Panigrahy Y1 - 2011/01/01 UR - http://www.ajnr.org/content/32/1/185.abstract N2 - BACKGROUND AND PURPOSE: The neuroanatomic substrate of cognitive deficits in long-term survivors of prematurity with PVL is poorly understood. The thalamus is critically involved in cognition via extensive interconnections with the cerebral cortex. We hypothesized that the thalamus is atrophic (reduced in volume) in childhood survivors of prematurity with neuroimaging evidence of PVL and that the atrophy is associated with selective microstructural abnormalities within its subdivisions. MATERIALS AND METHODS: We performed quantitative volumetric and DTI measurements of the thalamus in 17 children with neuroimaging evidence of PVL (mean postconceptional age, 5.6 ± 4.0 years) who were born prematurely and compared these with 74 term control children (5.7 ± 3.4 years). RESULTS: The major findings were the following: 1) a significant reduction in the overall volume of the thalamus in patients with PVL compared with controls (P < .0001), which also correlated with the severity of PVL (P = .001); 2) significantly decreased FA (P = .003) and increased λ⊥ (P = .02) in the thalamus overall and increased axial, radial, and mean diffusivities in the pulvinar (P < .03), suggesting injury to afferent and efferent myelinated axons; and 3) a positive correlation of pulvinar abnormalities with those of the parieto-occipital white matter in periventricular leukomalacia, suggesting that the pulvinar abnormalities reflect secondary effects of damaged interconnections between the pulvinar and parieto-occipital cortices in the cognitive visual network. CONCLUSIONS: There are volumetric and microstructural abnormalities of the thalamus in preterm children with PVL, very likely reflecting neuronal loss and myelinated axonal injury. The selective microstructural damage in the pulvinar very likely contributes to abnormal cognitive visual processing known to occur in such survivors. A= anterior, ADC or Davapparent diffusion coefficient or mean diffusivityANOVAanalysis of varianceCVIcognitive visual impairmentDTIdiffusion tensor imagingFAfractional anisotropyFLAIRfluid attenuated inversion recoveryLlateralλ‖axial diffusivityλ1eigenvalue 1λ2eigenvalue 2λ3eigenvalue 3λ⊥radial diffusivityMmedial dorsalPpulvinarPCApostconceptional agePVLperiventricular leukomalaciaRPearson correlationRArelative anisotropyVRvolume ratio ER -