Akinetic mutism as a classification criterion for the diagnosis of Creutzfeldt-Jakob disease.

OBJECTIVES Among the classification criteria for the diagnosis of Creutzfeldt-Jakob disease, akinetic mutism is described as a symptom which helps to establish the diagnosis as possible or probable. Akinetic mutism has been anatomically divided into two forms--the mesencephalic form and the frontal form. The aim of this study was to delimit the symptom of akinetic mutism in patients with Creutzfeldt-Jakob disease from the complex of symptoms of an apallic syndrome and to assign it to the individual forms. METHODS Between April and December 1996, 25 akinetic and mute patients with Creutzfeldt-Jakob disease were consecutively examined. The patients were classified according to the definition of akinetic mutism by Cairns and secondly in accordance with the features constituting the complete picture of an appalic syndrome (defined by Gerstenbrand). RESULTS From 25 patients with definite Creutzfeldt-Jakob disease, 24 patients showed impoverishment of speech and, after a mean duration of four (range 1.1-11.2) months, almost complete absence of voluntary movements and speech. Seven patients were classified as being mute and akinetic and assigned to the mesencephalic form whereas 13 patients were classified as apallic. One patient was mute without being akinetic and four patients were comatose. CONCLUSION Diffuse brain damage underlies akinetic mutism in patients with Creutzfeldt-Jakob disease. The term can be used as a classification criterion for the diagnosis of Creutzfeldt-Jakob disease; however, it should be applied very carefully and delimited clearly from the apallic syndrome.