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