Diffusion-weighted magnetic resonance imaging in acute reversible toxic leukoencephalopathy: A report of two cases

Chemotherapy-Induced Leukoencephalopathy Revealed by Seizure and Alteration of the Mental Status

Leukoencephalopathy is progressive demyelination of the white matter, induced by a variety of factors. Among the causes of leukoencephalopathy, chemotherapy is an uncommon cause that generates potentially reversible lesions. The clinical presentation is classically made of alterations in mental status, hallucinations, hypertension, seizures, and acute visual changes. Imaging plays an important role in the diagnosis of this entity, especially by conventional and diffusion-weighted magnetic resonance imaging which enables an accurate diagnosis by identifying symmetric white matter lesions, especially in the parietal and occipital lobes. Herein, we report a 54-year-old female patient, newly diagnosed with non-metastatic moderately differentiated adenocarcinoma of the cecum. The patient received her first cancer chemotherapy (5-fluorouracil at 300 mg/m²). Five days later she was admitted to the intensive care unit for confusion following two generalized seizures. Conventional and diffusion-weighted magnetic resonance imaging was performed and showed diffuse white matter lesions of the parietal and occipital lobes. A diagnosis of 5-fluorouracil-induced leukoencephalopathy was established. The diagnosis of leukoencephalopathy should be considered in patients receiving cancer chemotherapy with alterations in mental status and seizures.

MRI in Chemotherapy induced Leukoencephalopathy: Report of Two Cases and Radiologist's Perspective

Leukoencephalopathy is a progressive white matter disease primarily caused due to myelin damage by a variety of factors. Chemotherapy for oncological treatment is an uncommon but important cause of potentially reversible leukoencephalopathy. In current radiological setting, conventional and diffusion weighted MRI play a significant role in early and accurate detection of this entity. We are hereby presenting MRI evaluation of two cases of methotrexate and 5-fluorouracil induced toxic leukoencephalopathy.

Posterior reversible encephalopathy syndrome in malignant hypertension secondary to focal segmental glomerulosclerosis

Posterior reversible encephalopathy syndrome (PRES) is a neurological condition that occurs secondary to a variety of causes like autoimmune diseases, uncontrolled hypertension and immunosuppressive agents. We report an unusual association of PRES and malignant hypertension secondary to focal segmental glomerulosclerosis in a young woman, presenting with sudden loss of vision and seizures. She had uncontrolled hypertension and a Glasgow Coma Scale of 6/15. Brain MRI revealed high signals in cortical and subcortical white matter and some involvement of the periventricular areas. She improved dramatically with antihypertensive and antiepileptic medications and was discharged home in a stable condition. It is important to have a high clinical suspicion for this uncommon condition in an appropriate clinical setting, because a timely intervention can prevent long-term complications.

Chlorfenapyr-Induced Toxic Leukoencephalopathy with Radiologic Reversibility: A Case Report and Literature Review

Chlorfenapyr is a widely used, moderately hazardous pesticide. Previous reports have indicated that chlorfenapyr intoxication can be fatal in humans. We reported the first non-fatal case of chlorfenapyr-induced toxic leukoencephalopathy in a 44-year-old female with resolution of extensive and abnormal signal intensities in white matter tracts throughout the brain, brain stem, and spinal cord on serial magnetic resonance imaging.

Posterior Reversible Encephalopathy Syndrome (PRES): Restricted Diffusion does not Necessarily Mean Irreversibility

Background

Restricted diffusion is the second most common atypical presentation of PRES. This has a very important implication, as lesions with cytotoxic edema may progress to infarction. Several studies suggested the role of DWI in the prediction of development of infarctions in these cases. Other studies, however, suggested that PRES is reversible even with cytotoxic patterns. Our aim was to evaluate whether every restricted diffusion in PRES is reversible and what factors affect this reversibility.

Material/Methods

Thirty-six patients with acute neurological symptoms suggestive of PRES were included in our study. Inclusion criteria comprised imaging features of atypical PRES where DWI images and ADC maps show restricted diffusion. Patients were imaged with 0.2-T and 1.5-T machines. FLAIR images were evaluated for the severity of the disease and a FLAIR/DWI score was used. ADC values were selectively recorded from the areas of diffusion restriction. A follow-up MRI study was carried out in all patients after 2 weeks. Patients were classified according to reversibility into: Group 1 (reversible PRES; 32 patients) and Group 2 (irreversible changes; 4 patients). The study was approved by the University’s research ethics committee, which conforms to the declaration of Helsinki.

Results

The age and blood pressure did not vary significantly between both groups. The total number of regions involved and the FLAIR/DWI score did not vary significantly between both groups. Individual regions did not reveal any tendency for the development of irreversible lesions. Similarly, ADC values did not reveal any significant difference between both groups.

Conclusions

PRES is completely reversible in the majority of patients, even with restricted diffusion. None of the variables under study could predict the reversibility of PRES lesions. It seems that this process is individual-dependent.