Presentation
Acutely worsening confusion in HIV patient who had been non-compliant with anti-retroviral therapy. CD4 count 15. Further history of chronic liver disease secondary to Hep C.
Patient Data
Multifocal, bilateral, but asymmetric areas of T2 hyperintensity involving the periventricular and deep white matter, with involvement of subcortical U fibers. Importantly, there is no mass effect or enhancement associated with these lesions.
Note also, bilateral basal ganglia T1 hyperintensity associated with background chronic liver disease.
Case Discussion
PML is a multifocal demyelinating disorder in advanced immunocompromised patients.
Asymmetry is a key feature differentiating from HIV encephalopathy. Lack of mass effect and enhancement separate it from other common differentials in this demographic, such as lymphoma and toxoplasmosis.