Methotrexate-Induced Leukoencephalopathy as a Clinical and Radiological Mimicker of Acute Ischemic Stroke Leading to Thrombolysis.

Methotrexate (MTX) is used to treat acute lymphoblastic leukemia (ALL). It acts by inhibiting cell proliferation through its role as a folate antagonist. Despite its positive impact on patients' survival, high-dose MTX therapy carries risks, notably neurotoxic side effects such as subacute leukoencephalopathy that can mimic stroke symptoms. Recognizing and managing MTX-induced neurotoxicity promptly is crucial. We present a case involving an 18-year-old male diagnosed with B-cell ALL who presented with symptoms of MTX-induced leukoencephalopathy, initially resembling a stroke. The initial neurological examination and imaging results closely resembled those of a stroke, prompting the activation of a stroke code. Due to uncertainty regarding whether it was an acute ischemic stroke, the patient underwent thrombolysis. However, a thorough assessment of the medical history, treatment timeline, and imaging features, combined with the absence of large vessel occlusions on the magnetic resonance angiogram, led to the diagnosis of MTX-induced leukoencephalopathy. Our patient demonstrated complete clinical and radiological improvement within the following ten days. This underscores the significance of thorough history-taking, especially regarding drug history, to distinguish stroke mimics and contemplate MTX-induced leukoencephalopathy as a potential factor in ALL patients receiving MTX treatment. Recognizing these cases is essential to preventing unnecessary thrombolysis.