Abstract
The diagnosis of
natalizumab-associated progressive multifocal leukoencephalopathy (PML)
in multiple sclerosis patients in an asymptomatic stage is crucial since
it is associated with better clinical outcome measures. Current
diagnostic criteria on PML diagnosis in asymptomatic patients require
the detection of JC virus and corresponding imaging findings. Magnetic
resonance imaging (MRI) is the most sensitive diagnostic method for
these purposes. However, the diagnosis of asymptomatic
natalizumab-associated PML based on MRI findings can be challenging
particularly in case of inconclusive or negative results on JC virus
detection in the cerebrospinal fluid. In this report, we present a case
series demonstrating different diagnostic scenarios of asymptomatic PML
diagnosis based on MRI findings in combination with inconclusive or
negative results on JC virus detection in the cerebrospinal fluid. We
discuss the challenges of applying current PML diagnostic criteria in
asymptomatic natalizumab-associated PML patients and stress the need for
specific diagnostic criteria and guidelines regarding managing these
diagnostic dilemmas in order to facilitate an early and correct
diagnosis of PML presumably leading to a better clinical outcome.
