Cerebellar dysfunction during high dose cytosine arabinoside therapy in a case of acute myelogenous leukaemia.

A case of persistent cerebellar toxicity following systemic high dose cytosine arabinoside (HDCA) treatment of acute myelogenous leukaemia is reported. The symptoms, which developed at a cumulative dose of 32 g/m2, subsided to some extent following discontinuation of the drug, but left signs of cerebellar dysfunction 10 months later. A review of previously published reports indicates that the cerebellar toxicity of HDCA, which has been ascribed to loss of Purkinje cells, usually occurs when the accumulated dose exceeds 36 g/m2. That it may occur at even lower doses is supported by the present case. In addition, available evidence of re-appearance or worsening of previously induced signs of toxicity following its repeated administration stresses the importance of immediate and permanent cessation of cytosine arabinoside therapy, when signs of cerebellar dysfunction develop.