Atypical MRI findings in treatment-related leukoencephalopathy: case report

Multifocal leukoencephalopathy in a patient medicated with etanercept and methotrexate for rheumatoid arthritis

Methotrexate (MTX) and etanercept are commonly used in the treatment of rheumatoid arthritis (RA). Several important adverse events, including central nervous system lesions, have been reported during RA treatment. Among them, MTX-induced leukoencephalopathy is a recognized complication that is often observed following intrathecal or intravenous MTX administration. Herein, we report a case of a RA patient who was diagnosed with multifocal leukoencephalopathy during etanercept and MTX therapy. A 77-year-old Chinese woman with a 3-year history of RA had been taking subcutaneous etanercept and low-dose oral MTX since February 2021. Five months after the initial administration, she developed cognitive impairment and experienced a dropped attack. She was then admitted to our hospital in June 2021. T2-weighted magnetic resonance imaging (MRI) images revealed disseminated lesions in the white matter of the brain. Based on these MRI findings and extensive clinical investigation that excluded other possible causes of white matter lesions, she was suspected of having a demyelinating disorder. There was no evidence suggesting other neurological disorders. High-dose corticosteroid was administered, which resulted in improved cognitive impairment. This case report illustrates an important example of multifocal leukoencephalopathy induced by the combined use of etanercept and MTX, which resolved with high-dose corticosteroid. With the recent emphasis on various biologic agents for treatment of RA, our case highlights the importance of identifying leukoencephalopathy that may be induced by various biologics.

Disseminating Necrotizing Leukoencephalopathy Associated With Intra-CSF Methotrexate Chemotherapy: A Retrospective Observational Study

BACKGROUND AND OBJECTIVES

Leptomeningeal metastases (LMs) are neoplasms that proliferate to membranes lining the brain and spinal cord. Intra-CSF methotrexate (MTX) chemotherapy is a prevalent treatment option. However, resultant long-term neurotoxicity can lead to irreversible disseminated necrotizing leukoencephalopathy (DNL). This study aims to determine the incidence, characteristics, risk factors, and outcomes of DNL following intra-CSF MTX chemotherapy for LM.

METHODS

We retrospectively reviewed patients with LM who received intra-CSF MTX between 2001 and 2021 at the National Cancer Center of Korea. Patients with a follow-up duration of <3 months and those without follow-up MRI after MTX administration were excluded. The primary outcome was the development of DNL, evaluated based on the clinical and radiologic definitions of DNL. Logistic and Cox proportional regression models were used to assess the risk of DNL in patients with LM receiving intra-CSF MTX chemotherapy.

RESULTS

Of the 577 patients included in the DNL investigation, 13 (2.3%) were identified to have irreversible DNL. The MRI features of DNL typically include necrotic changes in the bilateral anterior temporal region, extensive white matter, and/or brainstem lesions. All patients with DNL experienced fatal clinical course despite MTX cessation. Logistic regression analysis revealed that a cumulative dose of MTX significantly affected DNL occurrence. Multivariable analysis showed that the factor of ≥10 MTX rounds was significant for DNL development after adjusting for route of MTX administration and prior brain radiotherapy (odds ratio 7.32, 95% CI 1.42-37.77 at MTX rounds ≥10 vs < 10). In the Cox proportional hazards model considering time to occurrence of DNL, ≥10 rounds of MTX were identified as an independent predictor of DNL (hazard ratio 12.57, 95% CI 1.62-97.28, p = 0.015), even after adjusting for the synergistic effect of brain radiotherapy.

DISCUSSION

DNL is a rare but fatal complication of intra-CSF MTX chemotherapy, and its progression cannot be prevented despite early recognition. The cumulative dose of intra-CSF MTX was an independent risk factor for DNL occurrence. Thus, intra-CSF MTX treatment for patients with LM should be administered with caution considering the possibility of the cumulative irreversible neurotoxicity.

Methotrexate induced leucoencephalopathy: A stroke mimic

With increasing usage of thrombolysis in the treatment of acute ischemic strokes within 4.5- hour window, it is becoming more important to recognize stroke mimics. Though the incidence of stroke mimics being thrombolysed is less than 3%, it is essential to diagnose them so as to avoid wrong thrombolytic treatment which carries potential complications of bleeding. We describe the case of a 17 year old girl with acute lymphoblastic leukemia, who developed stroke like episodes on two consecutive challenges with a chemotherapeutic regime which included intravenous and intrathecal methotrexate. She had MRI changes consistent with acute ischemic stroke on both occasions. Her deficits recovered completely and spontaneously, as did the MRI changes. She did not have any further episodes when methotrexate was excluded from the chemotherapeutic regime.

Leukoencephalopathy and disseminated necrotizing leukoencephalopathy following intrathecal methotrexate chemotherapy and radiation therapy for central nerve system lymphoma or leukemia

OBJECTIVE

Intrathecal methotrexate (MTX) therapy combined with whole brain radiotherapy (WBRT) is one of the major treatment modalities for leukemia and lymphoma involving the central nervous system (CNS). The purpose of this study was to retrospectively determine the incidences of leukoencephalopathy and disseminated necrotizing leukoencephalopathy (DNL) following intrathecal MTX therapy for CNS lymphoma or leukemia and to assess the potential risk factors.

METHODS

Between January 2000 and August 2009, 143 patients with CNS lymphoma or leukemia received intrathecal MTX therapy alone or in combination with WBRT at a single institution. Patients were followed up clinically and radiologically at regular two- or three-month intervals. Medical records were reviewed to obtain information regarding the patients' demographics, medical histories, radiologic characteristics, treatments, and clinical courses.

RESULTS

On follow-up MR images, leukoencephalopathy was found in 95 of 143 patients (66.4%). The median time to develop leukoencephalopathy was 6.6 months. Among those with leukoencephalopathy, four patients showed seven extensive white-matter changes with strongly enhancing lesions demonstrating DNL. Histological confirmation was done in six lesions of three patients and radiological diagnosis alone in one patient. Four lesions spontaneously disappeared on MR images without any treatment, with a mean duration of 14 months before disappearance of DNL.

CONCLUSION

Leukoencephalopathy is a common phenomenon that occurs following intrathecal MTX therapy; however, DNL occurs at a very low incidence. For newly developed enhancing lesions, consideration for the occurrence of DNL should be taken to avoid unnecessary invasive procedures or therapies.

Disseminated necrotizing leukoencephalopathy following low-dose oral methotrexate

Leukoencephalopathy is a recognized complication with intrathecal or intravenous methotrexate (MTX). We report a 59-year-old lady who developed MTX leukoencephalopathy with long-term low-dose oral MTX. She developed posterior leukoencephalopathy (PLE) that initially was reversible on discontinuation of oral MTX. Four months later, she developed disseminated necrotizing leukoencephalopathy (DNL), and was left with devastating neurological deficits. The sequential conventional magnetic resonance imaging (MRI), diffusion weighted imaging (DWI), MR perfusion (MRP) and MR spectroscopic (MRS) changes are highlighted in this report. MRP and MRS showed more wide spread abnormalities than DWI. Stereotactic biopsy from the lesion revealed demyelination with macrophagic infiltration, pericapillary lymphomononuclear aggregation, fibrinoid changes in the capillaries and neovascularization. Of the two cases of PLE with oral MTX reported in literature, one reversed clinically and radiologically with the discontinuation of MTX. To the best of our knowledge, this is the first reported case of DNL following oral MTX in the world literature.

Disseminated necrotizing leukoencephalopathy following chemoradiation therapy for acute lymphoblastic leukemia

Disseminated necrotizing leukoencephalopathy (DNL) is a potentially fatal complication of treatment involving intrathecal administration of chemotherapeutic agents such as methotrexate (MTX) alone or in combination with cranial radiotherapy (RT). We describe a case of acute lymphoblastic leukemia (ALL) treated with high-dose intravenous and intrathecal methotrexate combined with craniospinal RT resulting in DNL. Typical MR imaging features of progressive deep white matter lesions showing a characteristic pattern of enhancement after contrast was seen in this case. Deep white matter lesions with ring-like enhancement and calcifications were seen on CT; it showed a mass effect at one stage, which is not typical for DNL. Long-term clinical and imaging follow-up were helpful for the diagnosis in this case.

MRI in methotrexate-related leukoencephalopathy: Disseminated necrotising leukoencephalopathy in comparison with mild leukoencephalopathy

We report two fatal cases of methotrexate (MTX)-induced disseminated necrotising leukoencephalopathy (DNL) in which MRI was repeated from the onset. Initial T2-weighted images showed multiple areas of high signal, mainly in deep cerebral white matter, which on follow-up, spread and coalesced to involve the entire white matter. Small irregular low-signal foci on T2-weighted images were seen within the high-signal lesions. Multiple areas of contrast enhancement corresponded to these low-signal foci. The condition of both patients deteriorated and they died. We compared their MRI findings with those of seven patients with mild MTX-related leukoencephalopathy, six of whom were asymptomatic; one had transient neurological symptoms. They showed no contrast enhancement, but rather mild-to-moderate diffuse high signal in deep white matter, which later disappeared. These findings suggest that multiple low-signal foci on T2-weighted images with contrast enhancement may be characteristic of DNL, and that contrast-enhanced imaging is useful to differentiate this condition from mild leukoencephalopathy.

Methotrexate treatment protocols and the central nervous system: significant cure with significant neurotoxicity

Methotrexate can influence the central nervous system through several metabolic toxic pathways. These effects can be categorized as immediate, acute to subacute, or chronic neurologic syndromes. The acute to subacute syndrome occurs frequently in acute lymphoblastic leukemia treatment protocols, generally manifesting with focal neurologic signs and changes seen on magnetic resonance imaging and single photon emission computed tomography. While in some patients the neurotoxicity is transient and benign and allows for continuation of chemotherapy, in others it can be quite severe and debilitating, leading to permanent neurologic deficits. The need to modify the treatment protocols when neurotoxicity appears is not fully established. It is also unknown whether the use of sufficient amounts of leucovorin can overcome the toxic effects of the drug.

Delayed methotrexate clearance in a patient with sickle cell anemia and osteosarcoma

A 15-year-old girl with homozygous sickle cell anemia (HbSS) and osteosarcoma is described. Delayed clearance of methotrexate (MTX) after the second course of high-dose MTX (HDMTX) led to the development of renal and hepatic toxicities. Rescue was accomplished with high-dose leucovorin, intravenous carboxypeptidase G2, and thymidine. Although the renal and hepatic abnormalities resolved, focal tonic-clonic seizures developed, accompanied by abnormal brain imaging. Four weeks after this episode, all clinical and biochemical abnormalities resolved. Preexistent end-organ damage associated with HbSS may compromise the ability to deliver high-dose chemotherapy with curative intent in patients with malignant disease.