Recurrent Reversible Stroke-Like Encephalopathy After 5-Fluorouracil (5-FU) Chemotherapy: A Case Report and Literature Review

BACKGROUND Chemotherapy based on 5-fluorouracil (5-FU) is a well-established treatment for solid cancers, including metastatic or advanced colon cancer. Despite its efficacy, 5-FU can cause rare but serious adverse events such as acute neurotoxicity, which presents as symptoms similar to stroke. CASE REPORT We report the case of a patient who was diagnosed with stage IV colorectal cancer and who underwent chemotherapy with a high dose of 5-FU as part of the FOLFIRI (Folinic Acid, Fluorouracil, Irinotecan) treatment plan. During the seventh, eighth, and ninth cycles of chemotherapy, the patient suffered from severe encephalopathy, and the cause of this condition was determined to the 46-hour continuous intravenous infusion of 5-FU, which was part of the FOLFIRI regimen. CONCLUSIONS 5-FU-induced hyperammonemic encephalopathy is a rare but serious adverse event that requires immediate recognition and treatment. The first step in managing this condition is to halt the 5-FU infusion and provide the patient with high volumes of fluid. Although most cases of 5-FU-induced encephalopathy resolve spontaneously, recurrence is possible if the drug is re-administered to the same patient. Therefore, it is crucial for healthcare providers to closely monitor patients receiving 5-FU chemotherapy and be aware of the signs and symptoms of hyperammonemic encephalopathy. Early intervention can prevent further complications and ensure the best possible outcome for the patient. It is important to note that while 5-FU-induced hyperammonemic encephalopathy is rare, it highlights the importance of closely monitoring patients receiving chemotherapy to identify and treat adverse events promptly. This can help improve patient outcomes and prevent serious long-term complications.