AbstractBACKGROUND AND PURPOSE
To describe a patient with relapsing remitting MS who was treated with natalizumab for 36 months. First symptoms of presumptive progressive multifocal leukoencephalopathy (PML) appeared 14 weeks after her last natalizumab infusion.METHODS
Neurological examination, MRI and CSF analysis were performed.RESULTS
The lack of anti-inflammatory treatment response, clinical course, and serial MRI examinations showed lesion development typical for PML on diffusion-weighted and FLAIR MRI. CSF analysis for JC virus was tested negative twice.CONCLUSIONS
This case represents a presumptive PML after discontinuation of natalizumab treatment—similar to the definition established for PML in HIV patients.