5-Fluorouracil (5-FU) is a commonly used chemotherapeutic agent. However, its neurotoxicity is rare and not well recognized. We report a case of 5-FU neurotoxicity with organic brain syndrome and progression to multifocal leukoencephalopathy in a 44-year-old male patient having malignant gast- rointestinal stromal tumor. 5-FU-induced neurotoxicity should, therefore, be considered as an important differential diagnosis in cancer patients with neurological abnormality and history of chemotherapy.
Adult ; Brain/*pathology ; Case Report ; Electroencephalography ; Fluorouracil/*adverse effects/therapeutic use ; Gastrointestinal Neoplasms/drug therapy ; Human ; Leukoencephalopathy, Progressive Multifocal/diagnosis/etiology ; Magnetic Resonance Imaging ; Male ; Neurotoxicity Syndromes/diagnosis/*etiology

In a patient receiving 5-fluorouracil and levamisole, neurologic deficits suggest the cerebral demyelinating syndrome as a differential diagnosis. The authors report a patient diagnosed as multifocal inflammatory leukoencephalopathy for which thallium-201 ((201)Tl) single photon emission computed tomography (SPECT) and proton magnetic resonance spectroscopy (MRS) were employed as noninvasive diagnostic tools. (201)Tl SPECT study was negative and proton MRS showed an increase of choline and lactate and well preserved N-acetylaspartate. These findings support histopathologic findings of multifocal inflammatory leukoencephalopathy revealing demyelination with relative axonal sparing in the patient.
Adjuvants, Immunologic/adverse effects/therapeutic use ; Antimetabolites, Antineoplastic/adverse effects/therapeutic use ; Aspartic Acid/*analogs & derivatives/metabolism ; Axons/pathology ; Biopsy ; Brain/pathology ; Brain Neoplasms/secondary ; Choline/metabolism ; Colorectal Neoplasms/drug therapy/pathology ; Diagnosis, Differential ; Fluorouracil/adverse effects/therapeutic use ; Human ; Lactic Acid/metabolism ; Leukoencephalopathy, Progressive Multifocal/*diagnosis/etiology ; Levamisole/adverse effects/therapeutic use ; Magnetic Resonance Spectroscopy/*methods ; Male ; Middle Aged ; Neoplasm Metastasis ; Thallium Radioisotopes/*diagnostic use ; Tomography, Emission-Computed, Single-Photon/*methods