A selective thalamic degeneration is described in a 21-year-old Chinese female patient. Clinical history was characterized by a 3-year evolution of severe memory loss, progressive dementia, amenorrhea, emaciation, and short terminal coma. Neuronal losses were maximal in the thalamic anterior and medialis formations, but they were also noted in the pulvinar, the nuclei ventralis anterior, reticularis polaris, and dorsalis superficialis. The microneurons were generally spared. All other thalamic nuclei and the rest of the central nervous system were intact but for discrete changes in the bulbar olives. The clinical features and the classification of this case of selective thalamic atrophy are discussed.