Immune Reconstitution Inflammatory Syndrome with Recurrent Paradoxical Cerebellar HIV-Associated Progressive Multifocal Leukoencephalopathy

Abstract

Progressive multifocal leukoencephalopathy (PML), presenting as immune reconstitution inflammatory syndrome (IRIS), is a known complication of antiretroviral therapy (ART) in people living with HIV (PLWH). Typically preceded by ART initiation, IRIS may appear simultaneously/unmasked (PML-s-IRIS) or as a delayed/worsening/paradoxical (PML-d-IRIS) presentation of known PML disease. Primary cerebellar tropism continues to be a rare presentation, and paradoxical cerebellar involvement of PML-IRIS syndrome can be a challenge for both diagnosis and management. Steroids have been suggested as a possible therapy in severe cases but the duration of steroid therapy remain elusive. Our case is that of a 34-year-old man with newly diagnosed HIV simultaneously found to have cerebellar PML. His PML lesions however worsened after initiation of ART (PML-d-IRIS) with evidence of increased intracranial pressure. Despite initial favorable response to a short duration of steroids, he had multiple recurrence of his PML lesions after steroids were discontinued. The presence of predominant cerebellar lesions and the question of how long steroids should be provided to prevent or minimize PML recurrence is the highlight of our case. This report emphasizes the need for more controlled studies to assist clinicians in the optimal diagnosis and management of PML-IRIS in PLWH.

Keywords: cerebellar PML-IRIS; paradoxical PML-IRIS; treatment PML-IRIS.

Figure 1

Initial magnetic resonance imaging (MRI) brain demonstrating high T2, and high FLAIR signal in the brainstem (midbrain and pons), inferior cerebellum and bilateral (right more than left) middle cerebellar peduncles suggestive of a demyelinating process (arrow).

Figure 2

Repeat MRI brain 2 months after compliance with antiretroviral therapy (ART) showing interval worsening of multifocal brainstem and cerebellar T2/FLAIR hyperintense lesions with mass effect. New diffuse leptomeningeal and perivascular enhancement in the cerebellum (arrow), brachium ponti, pons, and left midbrain.