2023 Volume 55 Issue 1 Pages 48-51
Methotrexate (MTX) -related leukoencephalopathy presents with encephalopathy symptoms and white matter lesions on brain MRI after administration of MTX. Most of the patients show transient symptoms and MRI findings. However, there are no reports of detailed functional evaluation of this condition. Herein, we report a case of MTX-related leukoencephalopathy that was functionally evaluated with SPECT during the acute and convalescent phases. The patient had received anticancer drug treatment for lymphoma at his ago of 14 years. At age 15, he developed dysarthria and bilateral upper limb paresis 5 days after intrathecal administration of MTX. He was diagnosed with MTX-related leukoencephalopathy due to the high signal intensity in the left centrum semiovale on brain MRI. Since the symptoms disappeared within 2 weeks, additional intrathecal MTX was administered. However, he showed dysarthria and paresis of the left upper limb on the 23rd day and disturbance of consciousness, dysphagia, and tetraparesis on the 55th day. On the 65th day, ethyl cysteinate dimer (ECD) -SPECT demonstrated diffuse hypoperfusion in the bilateral cerebral cortex, while iomazenil (IMZ) -SPECT showed no decrease of benzodiazepine receptor accumulation. In 4 weeks, dysarthria, disturbance of consciousness, dysphagia, and tetraparesis disappeared with the recovery of cerebral blood flow in ECD-SPECT. IMZ-SPECT showed normal findings in the convalescent phase as well. We suspended the administration of MTX, and he achieved remission at the age of 19 without neurological sequelae. MTX-related leukoencephalopathy may show transient dysfunction of the central nervous system without loss of neuronal cells.
