"Acute methotrexate-related leukoencephalopathy often manifests 2-14 days after administration, with clinical features similar to other encephalopathies 1,4. These clinical features develop over minutes to hours, with common manifestations including a headache, confusion, disorientation, lethargy, seizures, and focal neurological deficits that may be unilateral or bilateral 1,2,5. Of note, and unlike many other encephalopathies, these clinical features often 'wax and wane' over the course of the disease 2. For example, focal neurological deficits may initially manifest on one side of the body and then 'alternate' to affect the other side of the body later 2."
"Case series-level evidence suggests that aminophylline, a non-selective adenosine receptor antagonist, and leucovorin, an active form of folinic acid, may be beneficial in isolation or in combination for acute leukoencephalopathy 2,7,8. It is uncertain whether these agents have any role in prophylaxis, although leucovorin is often part of many methotrexate-containing chemotherapy regimens 2. Symptomatic therapy is also recommended, such as antiseizure medications in patients with seizures 2."