TRANSSYNAPTIC DEGENERATION OF LATERAL GENICULATE BODIES IN BLIND-CHILDREN - IN-VIVO MR DEMONSTRATION

PURPOSE: To investigate signal alterations in the thalamic lateral gen iculate bodies of blind patients compatible with transsynaptic degener ation of these nuclei caused by pregeniculate or postgeniculate interr uption of the visual pathway. METHODS: Six patients were selected from a group of blind children in our care. Four had cerebral palsy caused by periventricular leukomalacia, one had infantile neuroaxonal dystro phy, and one had Chiari I malformation and hydrocephalus, which was wo rsened by bilateral ischemic lesions of the occipital lobes. MR examin ations (obtained at 0.5 T) were reviewed retrospectively by two neuror adiologists, with particular attention to the visual pathway. RESULTS: Symmetric, focal areas of T2 prolongation were found at the precise s ite of the lateral geniculate bodies. CONCLUSION: Anterograde (pregeni culate) and retrograde (postgeniculate) transsynaptic degeneration of the second neurons of the visual pathway produce alterations in MR sig nal.