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Updated: Aug 30, 2026
Diffusion Tensor Magnetic Resonance Imaging in Chronic Spinal Cord Compression
Published on: May 7, 2019
Neurotoxicity of intrathecal methotrexate: MR imaging findings
Claudio Sandoval1, Martin Kutscher, Somasundaram Jayabose
1Department of Pediatrics, New York Medical College, Valhalla, New York 10595, USA.
Abstract:
We report a case of intrathecal methotrexate neurotoxicity manifesting as left arm weakness and aphasia. Diagnostic imaging showed restricted diffusion and fluid-attenuated inversion recovery imaging findings were normal at presentation. Three weeks later, diffusion abnormalities resolved, and T2-weighted studies showed increased signal intensity of prolonged T2 changes in areas of prior restricted diffusion. We attribute the clinical and radiographic findings to cytotoxic edema secondary to intrathecal methotrexate.
Insights
Intrathecal methotrexate can cause neurotoxicity, leading to weakness and speech difficulties. Imaging revealed temporary restricted diffusion, later replaced by prolonged T2 changes, indicating cytotoxic edema.
Area of Science:
- Neuroscience
- Radiology
- Oncology
Background:
- Intrathecal chemotherapy is used for CNS malignancies.
- Methotrexate is a common chemotherapeutic agent administered intrathecally.
- Neurotoxicity is a potential adverse effect of intrathecal methotrexate.
Observation:
- A patient presented with left arm weakness and aphasia.
- Initial MRI showed restricted diffusion in affected areas.
- FLAIR imaging was normal at the time of presentation.
Findings:
- Restricted diffusion abnormalities resolved over three weeks.
- T2-weighted imaging subsequently demonstrated increased signal intensity.
- These findings indicate prolonged T2 changes in previously affected regions.
Implications:
- The case highlights cytotoxic edema as a cause of neurotoxicity from intrathecal methotrexate.
- Understanding these imaging patterns is crucial for accurate diagnosis and management.
- This emphasizes the importance of serial neuroimaging in evaluating methotrexate-induced neurotoxicity.