Abstract
This paper describes abnormal argyrophilic swellings and rings in the dentate nucleus of the cerebellum in 46 cases of various human pathological conditions. The swellings represent accumulations of neurofilaments in the terminal parts of Purkyně cell axons. They may be evidence of disturbed functions of the Purkyně cell terminals due to different causes and common to many pathological conditions. These are as varied as acute ischaemic cerebellar cortical lesions, liver failure, and chronic nervous system degenerations, such as progressive supranuclear palsy and Friedreich's ataxia, and include transmissible ones like Creutzfeldt-Jakob disease.