Supranuclear gaze palsy in familial Creutzfeldt-Jakob disease.

Seven affected individuals from three generations in a kindred having over 250 members were identified as having possible, probable, or definite Creutzfeldt-Jakob disease. Spongiform encephalopathy was found at postmortem examination in two cases. Detailed inpatient neurological examinations were performed on four of the subjects, three of whom were first observed with supranuclear gaze paralysis, gait ataxia, and rapidly progressive dementia. Supranuclear gaze paresis can be seen as an early feature of Creutzfeldt-Jakob disease, although it has been regarded as a late sign. In this, the largest reported kindred of Creutzfeldt-Jakob disease, most of the affected patients were farmers. Possible modes of infection are discussed.