Dengue is a highly prevalent arboviral infection in tropical and subtropical regions, with millions of cases reported annually. Although most infections are self-limited, neurologic manifestations may occur, involving both the central and peripheral nervous systems.1 Cerebellitis is an uncommon presentation, characterized by acute or subacute onset of ataxia, dysmetria, nystagmus, and gait instability.2

The underlying mechanisms of dengue-associated cerebellitis are not fully understood and may include direct viral neuroinvasion or post-infectious immune-mediated inflammation.3 Cerebellar symptoms typically develop days to weeks after the initial febrile illness, supporting an immune-mediated process. Magnetic resonance imaging plays an important role by demonstrating cerebellar edema or inflammatory changes and excluding alternative diagnoses such as ischemia or hemorrhage, although imaging may be normal in some cases.1–3

We report a case in a previously healthy female patient aged 17 years who developed fever, headache, and malaise consistent with dengue infection, confirmed by positive rapid arboviral tests. Approximately one week later, she presented with progressive dizziness, ataxia, and gait instability. The brain MRI showed bilateral, symmetric T2/FLAIR hyperintensities in the superior portions of both cerebellar hemispheres, with effacement of cerebellar folia and no diffusion restriction or hemorrhage (Fig. 1). Supportive care was initiated, with progressive clinical improvement.

Figure 1.

Axial T2-weighted FLAIR image (A) and axial (B) and coronal (C) T2-weighted images showing symmetric hyperintense areas involving the superior third of both cerebellar hemispheres (arrows), with effacement of the cerebellar folia.