Methotrexate-Induced Stroke-Like Encephalopathy: Beware the Stroke Mimic

Area of Science:

• Neuroscience
• Oncology
• Radiology

Background:

• Acute lymphoblastic leukemia (ALL) treatment often involves methotrexate (MTX), a chemotherapy agent.
• Neurological complications can arise during cancer therapy, necessitating careful differential diagnosis.
• Stroke-like presentations require prompt and accurate identification to guide appropriate management.

Observation:

• An 18-year-old woman with ALL developed sudden neurological deficits mimicking a stroke.
• Brain MRI revealed diffusion-weighted imaging (DWI) hyperintensities with corresponding apparent diffusion coefficient (ADC) hypointensities.
• These characteristic MRI findings, typically seen in acute cerebral infarction, were noted.

Findings:

• The observed DWI/ADC changes in the patient did not follow typical vascular territories and spared the cerebral cortex.
• This pattern suggested a non-vascular etiology for the neurological deficit.
• The findings supported methotrexate-induced neurotoxicity rather than a cerebrovascular event.

Implications:

• Magnetic Resonance Imaging (MRI) is critical in differentiating stroke-like presentations caused by MTX neurotoxicity from actual ischemic stroke.
• Early recognition of MTX-induced encephalopathy can prevent unnecessary and potentially harmful interventions like thrombolytic therapy.
• This case highlights the importance of considering drug-induced neurotoxicity in patients presenting with stroke-like symptoms during chemotherapy.