Fluorouracil-induced leukoencephalopathy mimicking neuroleptic malignant syndrome: a case report

Abstract

Background Fluorouracil-induced leukoencephalopathy is a rare complication and has been reported to present as confusion, oculomotor abnormality, ataxia, and parkinsonism; however, there is no previous report of a presentation mimicking neuroleptic malignant syndrome. Acute cerebellar syndrome may occur, which can be explained by the extremely high accumulation of the drug in the cerebellum. However, presentation mimicking neuroleptic malignant syndrome similar to our case has never been reported. Case presentation Here, we describe a 68-year-old Thai male presenting with advanced-stage cecal adenocarcinoma, as well as symptoms and signs indicative of neuroleptic malignant syndrome. He received two doses of intravenous metoclopramide 10 mg 6 hours before his symptoms occurred. Magnetic resonance imaging scan revealed signal hyperintensity within the bilateral white matter. Further evaluation showed that his thiamine level was extremely low. Thus, he was diagnosed with fluorouracil-induced leukoencephalopathy mimicking neuroleptic malignant syndrome. The concomitant fluorouracil-induced thiamine deficiency eventually leads to rapid depletion of thiamine and was considered a risk factor for fluorouracil-induced leukoencephalopathy. Conclusion Fluorouracil-induced leukoencephalopathy is believed to be caused by insult causing mitochondrial dysfunction. However, the exact mechanism remains unknown, but our finding suggests that thiamine deficiency plays a crucial role in fluorouracil-induced leukoencephalopathy. Diagnosis is usually delayed due to a lack of clinical suspicion and results in significant morbidity requiring unnecessary investigations.

5-Fluorouracil-induced acute leukoencephalopathy: Case report and literature review

“…Several clinical signs of 5-FU neurotoxicity have been described, such as headache, dysarthria, cerebellar syndrome, oculomotor disorders, confusion, cognitive disorders, Parkinson's syndrome, seizure, and coma [5] , [6] , [7] . Diagnosis of TL is based on a number of arguments, including the onset of symptoms after taking 5-FU, and the exclusion of other etiologies that may explain the neurological signs [8] .…”

“…Corticosteroids and antioxidants may be prescribed, as well as thiamine infusion and plasma exchange [ 2 , 10 ]. Uridine triacetate is a 5-FU antidote that can also be administered during the first 96 hours if available [5] .…”