A cerebral demyelinating disease developed in 3 patients during adjuvant therapy with 5‐fluorouracil and levamisole for adenocarcinoma of the colon. None of the patietns had evidence of metastatic disease or prior neurological disease. The duration of chemotherapy before onset of neurological symptoms ranged from 15 to 19 weeks. The total dose of 5‐fluorouracil was 9.7 to 15.7 gm. The total dose of levamisole was 2.7 to 3.75 gm. Two patietns presented with a subacute (2–3 weeks) progressive decline in mental status and ataxia. The third patient had two unexplained episodes of loss of consciousness. In each, magnetic resonance imaging with gadolinium demostrated prominent multifocal enhancing white matter lesions. Cerebral biopsy was performed stereotaxically in 2 patietns. The morphological features were those of active demyelinating disease. The myelin loss was associated with numerous dispersed as well as vasocentric macrophages, sparing of axons, and pervisacular lymphocytic inflammation. Electron microscopy confirmed the light microscopic findings. All 3 patients improved after cessation of chemotherapy and a short course of corticosteroid therapy. Our patients represent the first reported examples of an inflammatory leukoencephalopathy associated with the administration of 5‐fluorouracil and levamisole. This syndrome may represent the pathological basis for 5‐fluorouracil neurotoxicity, although we cannot completely exclude the role of levamisole.
ASJC Scopus subject areas
- Clinical Neurology