A 52-year-old female presented with
stroke-like symptoms after high-dose
methotrexate (HDMTX)
therapy and MTX
intrathecal injection (IT-MTX) as central nervous system (CNS) prophylaxis for intravascular large
B-cell lymphoma (IVLBCL). She had been diagnosed as having IVLBCL without CNS involvement 5 months earlier and had received 6 courses of R-CHOP and 2 courses of HDMTX combined with IT-MTX. She experienced acute-onset right
hemiparesis involving the face and arm, along with
dysarthria, 7 days after the second HDMTX infusion. Brain magnetic resonance imaging (MRI) and cerebrospinal fluid results were normal and suggested neither
stroke nor CNS infiltration. Her symptoms gradually resolved within 4 days and follow-up neurologic examination showed no abnormalities. MRI on day 2 (after the onset) showed an area of hyper-intensity on diffusion weighted imaging (DWI). Follow-up MRI performed on day 38 showed resolution of the DWI intensity, while the T2 and FLAIR signals became more evident. Based on her
clinical course and these MRI findings, she was diagnosed as having MTX-induced subacute
encephalopathy. This syndrome has been reported mainly in children with ALL after HDMTX or IT-MTX, but there have been few reports of adult patients. MTX-induced subacute
encephalopathy should be taken into account as a possible cause of
neurologic manifestations because early differentiation from
stroke and CNS infiltration is essential to successful management.