Isolated Bilateral Cerebellar Dysfunction as the Initial Manifestation of HIV Infection: A Diagnostic Challenge, Case Report, and Literature Review.

Despite widespread access to antiretroviral therapy, neurological complications remain common in people living with human immunodeficiency virus (HIV). While opportunistic infections and HIV-associated malignancies are the usual causes, there is growing recognition of atypical, non-opportunistic neurological syndromes as early manifestations of HIV infection—even in the absence of prior diagnosis or treatment. We report the case of a 46-year-old woman with type 2 diabetes mellitus and a history of pulmonary tuberculosis who presented with a two-month history of progressive unsteady gait, dysarthria, and frequent falls. Neurological examination revealed isolated cerebellar dysfunction. Brain magnetic resonance imaging showed T2 and FLAIR hyperintensities in the bilateral middle cerebellar peduncles and adjacent white matter, suggestive of rhombencephalitis. Extensive diagnostic work-up for infectious, autoimmune, and paraneoplastic etiologies was negative. HIV testing revealed dual seropositivity for HIV-1 and HIV-2, with undetectable HIV-1 RNA and a low CD4 + T-cell count. The patient improved clinically with supportive care and was referred for antiretroviral therapy. At the two-month follow-up, she demonstrated marked recovery. Although cerebellar involvement in HIV is typically associated with opportunistic infections or neoplasia, this case illustrates that bilateral cerebellar dysfunction can represent the first clinical manifestation of HIV infection. We also review previously reported cases in which cerebellar signs were the initial presentation, emphasizing the need to consider HIV testing in patients with unexplained cerebellar syndromes.