Neuroimaging Features and Outcomes of Progressive Multifocal Leukoencephalopathy (PML): A Single-Center Experience
Hongxuyang Yu1, Kanika Sharma1, Subapriya R1, Shitiz Sriwastava1
1West Virginia University
Objective:

To summarize the clinical and imaging features of progressive multifocal leukoencephalopathy (PML) and highlight the importance of a timely diagnosis.

Background:
PML is a rare but fatal demyelinating disease of the central nervous system caused by the reactivation of the John Cunningham (JC) virus (JCV). It has an exceedingly high mortality rate and exhibits significant cerebrospinal fluid (CSF) and neuroimaging features, which can be identified early in the disease course. 
Design/Methods:
We conducted a single-center retrospective cohort study of patients recruited at the Department of Neurology, West Virginia University, between January 2014 and December 2021. Of the 37 enrolled patients, 12 were included based on our selection criteria. Magnetic resonance imaging (MRI) and confirmation of PML through JCV polymerase chain reaction of CSF were done in all cases.
Results:

Eleven out of the 12 patients (92%) had predisposing risk factors, such as hematologic malignancies (n=5) and human immunodeficiency virus (HIV) infection (n=4). Symptoms included altered mental status (n=5), seizure-like activity (n=4), unilateral weakness/paresthesia (n=3), and visual deficits (n=3). MRI revealed bihemispheric (n=7) and unilateral (n=5) lesions within the fronto-parietal (8/12) and temporo-parietal (4/12) lobes. Subcortical U-fibers were involved, and lesions were predominantly confluent (9/12) with irregular borders and without mass effect. These demonstrated hyperintensities on fluidā€attenuated inversion recovery, with corresponding hypo-intensity on T1-weighted imaging and restricted diffusion. A single faint contrast-enhanced punctate lesion was reported in 3 patients; seven had no documented contrast studies. Nine (75%) received treatment, and only four cases (33.3%) survived; the mean time from diagnosis to death was 1.4 months (±0.69), and all eight patients died within three months of diagnosis. 

Conclusions:

PML should immediately be considered in immunocompromised patients presenting with new-onset neurological symptoms and typical imaging findings. Physicians must familiarize themselves with these presentations since a rapid diagnosis and targeted intervention are critical to reducing overall mortality.

10.1212/WNL.0000000000202060