Reversible leukoencephalopathy caused by 5-fluorouracil derivatives, presenting as akinetic mutism.

Two cancer patients are reported, who presented with altered consciousness 2 and 3 months, respectively, after the administration of 5-fluorouracil derivatives, and progressed to a state of akinetic mutism. At first a presumptive diagnosis of metastatic brain tumor was made. However, the result of a cerebrospinal fluid cytology for malignancy was negative, and computed tomography (CT) scanning revealed diffuse decreased attenuation of the cerebral white matter, indicative of leukoencephalopathy, without association of mass lesion. Upon discontinuing the drugs, both patients made significant recovery and the decreased attenuation on the CT also disappeared. The significance of the early diagnosis of this pathology is emphasized.