MRI Shrimp Sign and Parietooccipital Lesion in Progressive Multifocal Leukoencephalopathy

Area of Science:

• Neurology
• Radiology
• Infectious Diseases

Background:

• Progressive multifocal leukoencephalopathy (PML) is a rare, opportunistic demyelinating disease.
• Early diagnosis of PML is crucial for patient management and outcomes.
• HIV-associated PML remains a significant concern in immunocompromised individuals.

Observation:

• This report details the oldest known case of PML in an 83-year-old male patient.
• The patient presented with rapidly progressive dementia.
• The case involved classic PML associated with Human Immunodeficiency Virus (HIV).

Findings:

• Brain Magnetic Resonance Imaging (MRI) revealed characteristic PML findings.
• Asymmetric, continuous, non-enhancing subcortical lesions were observed in the parietooccipital regions.
• The "shrimp sign" was noted in the cerebellar white matter, a distinctive imaging marker.

Implications:

• Characteristic MRI findings, such as asymmetric lesions and the "shrimp sign", are vital for early PML diagnosis.
• Integrating imaging patterns with clinical context improves diagnostic accuracy.
• This case underscores the importance of recognizing PML imaging features in elderly patients with HIV.