Der har været indberetninger om, at en sjælden hjerneinfektion, kaldet progressiv multifokal leukoencefalopati (PML), er forekommet hos patienter, som har fået TYSABRI.
What to do if your MS gets worse or you notice new symptoms There have been reports of a rare brain infection called PML (progressive multifocal leukoencephalopathy) that have occurred in patients who have been given TYSABRI.