ERDHEIM-CHESTER DISEASE AND SLOWLY PROGRESSIVE CEREBELLAR DYSFUNCTION

A 59 year old woman developed pronounced thirst, increased water intak e, and increased urinary output followed by slowly progressive cerebel lar symptoms. Brain MRI showed abnormal hyperintensity on T2 weighted studies in the region of both dentate nuclei without atrophy of the ce rebellum or the brainstem. A (TC)-T-99m diphosphonate bone scan showed bone lesions in the distal parts of both femurs as well as distal and proximal parts of both tibias. The diagnosis of Erdheim-Chester disea se was made by bone biopsy. This is the first case of Erdheim-Chester disease presenting as a slowly progressive cerebellar syndrome and dia betes insipidus, and also showing high signal lesions in deep cerebell ar nuclei on MRI. Skeletal surveys are indicated for patients with oth erwise unexplained slowly progressive cerebellar symptoms.