Toxic Leukoencephalopathy: An unusual Presentation by 5-Fluorouracil Infusion

Toxic leukoencephalopathy predominantly affect white matter of the brain parenchyma. Patient presents either in acute, subacute or chronic phase. The clinical presentation may vary, ranging from mild cognitive impairment to severe neurological dysfunction. It can also mimic psychiatric illness.

A 50-year-old woman was diagnosed with locally advanced carcinoma buccal mucosa. She was planned for Neoadjuvant chemotherapy consisting of Docetaxel, Cisplatin, 5-FU (TPF). During 3rd day of 3rd cycle of 5-fluorouracil (5FU) infusion, patient developed hypoactive delirium and later became comatose state of drowsiness, with Glasgow Coma Scale (GCS) was 5. There was no previous history for the same. Hence, the infusion was stopped. Patient was evaluated with NCCT head. No abnormality was seen on CT scan. MRI brain was done and it showed diffusion restriction with T2 / FLAIR hyper intensities in bilateral centrum semiovale, white matter of bilateral parietal region and in corpus callosum. Patient received symptomatic care, nutrition by ryles tube during this period and she started to improve after 1st week of onset of symptoms. After 3 weeks, MRI was repeated and there was complete resolution of previous findings.

Development of neurological symptoms during 5FU infusion is a rare entity. Henceforth, occurrence of toxic leukoencephalopathy should be kept in mind. Diffusion weighted imaging play an important role in both acute episode of toxic encephalopathy and in follow up.