5-FU-induced leukoencephalopathy with reversible lesion of splenium of corpus callosum in a patient with colorectal cancer

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

Toxic leukoencephalopathy (TL) refers to damage to the brain white matter following exposure to toxic agents. Multiple agents are incriminated in this condition, including chemotherapy drugs. 5-Fluorouracil, widely used in oncology, is responsible for neurotoxicity in less than 5% of cases. We report the case of a 54-year-old male patient who presented with neurological symptoms following 5-FU-based chemotherapy for gastric adenocarcinoma, and whose MRI scan revealed signs suggestive of toxic leukoencephalopathy. We also report on the evolution of the abnormalities described on his MRI after 1 year.

FOLFIRI-bevacizumab-induced acute toxic leukoencephalopathy

INTRODUCTION

Acute toxic leukoencephalopathy (ATL) is a rare complication of cancer treatment, with symptoms varying from mild cognitive impairment to coma. Recognition and management of ATL are important because in most cases, the cessation of the responsible agent is essential.

CASE REPORT

We report a case of a 57-year-old male with relapsed right colon cancer who had multiple steps of chemotherapy, admitted to the emergency department (ED) with confusion and inability to talk, 4 days after FOLFIRI and bevacizumab treatment. To exclude cerebrovascular events cranial computed tomography and diffusion-weighted magnetic resonance imaging were evaluated. There was bilateral and symmetric diffusion restriction on white matter, which was consistent with ATL.

MANAGEMENT AND OUTCOME

Supportive treatment such as optimization of blood pressure and metabolic control was applied since there is no specific treatment for ATL other than cessation of the responsible agents. 12 days after the admission to the ED his neurologic symptoms were normalized and there was no diffusion restriction on control imaging.

DISCUSSION

ATL is a rare complication of cancer treatment and responsible agents are increasing in number due to the development of cancer treatment. ATL is associated with drugs that are used frequently such as 5-fluorouracil. ATL is mostly reversible, but the progression of neurologic symptoms was also reported. The diagnosis and cessation of the responsible agent are important in management.

Drug-induced hyperammonaemia

Hyperammonaemia (HA) as a consequence of numerous primary or secondary causes, gives rise to clinical manifestations due to its toxic effects on the brain. The neurological consequences broadly reflect the ammonia level, duration and age, with paediatric patients being more susceptible. Drug-induced HA may arise due to either decreased ammonia elimination or increased production. This is associated most frequently with use of valproate and presents a dilemma between ongoing therapeutic need, toxicity and the possibility of an alternative cause. As there is no specific test for drug-induced HA, prompt discussion with a metabolic physician is recommended, as the neurotoxic effects are time-dependent. Specific guidelines for managing drug-induced HA have yet to be published and hence the treatment approach outlined in this review reflects that outlined in relevant urea cycle disorder guidelines.

Diagnosis and management of 5-fluorouracil (5-FU)-induced acute leukoencephalopathy: lessons learnt from a single-Centre case series

Background

The administration of 5-fluorouracil (5FU) in the treatment of gastrointestinal (GI) malignancies is associated with common side effects such as mucositis, diarrhoea, and myelosuppression, which are easily managed with supportive measures and dose adjustments. Cardiotoxicity and neurotoxicity are rare but reversible side effects of 5-FU and are treated with withdrawal of the drug and conservative measures. The presenting symptoms of 5-FU-induced leukoencephalopathy are often confusing and pose a diagnostic dilemma in routine clinical practice.

Methods

We report a series of five patients with GI malignancies who developed 5-FU-induced leukoencephalopathy.

Results

All (n = 5) had Naranjo scores of 6–7, predictive of 5-FU-related adverse effects, with clinical and radiological findings suggestive of 5-FU-induced encephalopathy as described in prior literature. The median time to onset of symptoms from initiation of 5FU was 3 days (range: 2–4 days). All patients improved after conservative management with complete neurological recovery.

Conclusion

Prompt recognition of this rare yet severe adverse effect of 5-FU-based chemotherapy aids early withdrawal of the offending agent (5-FU) and timely initiation of supportive measures and helps plan alternative oncological interventions.

A unique presentation of 5-fluorouracil (5-FU) induced cerebral encephalopathy

5-Fluorouracil (5-FU), a commonly used antimetabolite and antineoplastic agent, has been approved for the treatment of various cancers. It is associated with systemic side-effects such as gastrointestinal problems, neutropenia. 5-FU-related encephalopathy is very rarely reported. Imaging with computed tomography (CT) and magnetic resonance imaging (MRI) plays a key role in diagnosing and monitoring the changes. Since the prognosis of cerebral involvement is usually good if recognized and treated in time, the reporting radiologist and treating physician should be familiar with them. We present a rare case of 5-FU-induced encephalopathy that was diagnosed based on her clinical and MRI findings and managed successfully.

The splenium of the corpus callosum: embryology, anatomy, function and imaging with pathophysiological hypothesis

BACKGROUND AND PURPOSE

The splenium of the corpus callosum is the most posterior part of the corpus callosum. Its embryological development, anatomy, vascularization, function, imaging of pathology, possible pathophysiological mechanisms by which pathology may develop and the clinical consequences are discussed.

METHODS

A literature-based description is provided on development, anatomy and function. MR and CT images are used to demonstrate pathology. The majority of pathology, known to affect the splenium, and the clinical effects are described in three subsections: (A) limited to the splenium, with elaboration on pathophysiology of reversible splenial lesions, (B) pathology in the cerebral white matter extending into or deriving from the splenium, with special emphasis on tumors, and (C) splenial involvement in generalized conditions affecting the entire brain, with a hypothesis for pathophysiological mechanisms for the different diseases.

RESULTS

The development of the splenium is preceded by the formation of the hippocampal commissure. It is bordered by the falx and the tentorium and is perfused by the anterior and posterior circulation. It contains different caliber axonal fibers and the most compact area of callosal glial cells. These findings may explain the affinity of specific forms of pathology for this region. The fibers interconnect the temporal and occipital regions of both hemispheres reciprocally and are important in language, visuospatial information transfer and behavior. Acquired pathology may lead to changes in consciousness.

CONCLUSION

The development, location, fiber composition and vascularization of the splenium make it vulnerable to specific pathological processes. It appears to play an important role in consciousness.