CNS demyelination after initiating the tyrosine kinase inhibitor imatinib: A report of two cases.

The tyrosine kinase inhibitor, imatinib, used to treat certain malignancies, is in clinical trials as a potential treatment for multiple sclerosis and acute stroke. This is the first report of cases of multifocal central nervous system (CNS) demyelination following exposure to imatinib. One case was severe with bilateral optic neuritis and transverse myelitis that was AQP4 IgG and myelin oligodendrocyte glycoprotein (MOG) IgG negative and improved after plasma exchange and withdrawal of imatinib. The second case involved a unilateral optic neuritis with magnetic resonance imaging (MRI) brain confirming other demyelinating lesions. Although the mechanism is unknown, demyelination on imatinib could be related to activation of previously normal T-cells.