Subacute cerebellar ataxia as the primary manifestation of Sjögren’s syndrome in a young male: a case report

Abstract

Case Presentation: A 24-year-old previously healthy male presented with a 48-hour history of acute-onset dysarthria, gait instability, and right-sided appendicular ataxia. The neurological examination revealed no nystagmus or pyramidal signs. Initial non-contrast cranial CT was unremarkable. Cerebrospinal fluid (CSF) analysis demonstrated lymphocytic pleocytosis. Pulse therapy with intravenous methylprednisolone (1 g/day for 5 days) was initiated. Etiological workup revealed an ANA titer of 1:320 (speckled pattern) and strongly positive anti-Ro/SSA antibodies. Brain MRI identified bilateral, non-enhancing T2/FLAIR hyperintense lesions in the cerebellar hemispheres. Due to initial suspicion of systemic lupus erythematosus with CNS involvement, intravenous immunoglobulin (IVIG) was administered. Despite clinical improvement, residual scanning speech and truncal ataxia persisted. Subsequent CSF analysis revealed the presence of Type 2 oligoclonal bands (OCBs). Follow-up MRI showed regression of cerebellar signals but highlighted incidental hyperintensities in the parotid glands. Despite the absence of xerophthalmia or xerostomia, a minor salivary gland biopsy confirmed focal lymphocytic sialadenitis (Focus Score \geq 1), fulfilling the ACR/EULAR criteria for Sjögren’s syndrome. Discussion: Sjögren’s syndrome (SS) is a systemic autoimmune epithelitis characterized by lymphocytic infiltration of exocrine glands and the production of anti-Ro/SSA and anti-La/SSB autoantibodies. Although predominantly associated with sicca symptoms, neurological involvement occurs in approximately 20% of cases and may precede glandular dysfunction. Central nervous system (CNS) manifestations presenting as subacute cerebellar ataxia are exceedingly rare, particularly in young male patients, posing a significant diagnostic challenge. CNS involvement in SS can mimic multiple sclerosis or acute disseminated encephalomyelitis (ADEM), especially when OCBs are present - Type 2 OCBs, although commonly associated with multiple sclerosis, may also be observed in other autoimmune inflammatory conditions, further complicating the diagnostic process. This case highlights that SS should be suspected in subacute cerebellar syndromes even in the absence of sicca symptoms—a presentation seen in up to one-third of neurological SS cases. The pathophysiology likely involves small-vessel vasculitis or direct immune-mediated neuronal injury. The favorable radiological transition after immunotherapy underscores the importance of early aggressive treatment. Final Comments: Sjögren’s syndrome is a critical differential diagnosis for subacute cerebellar ataxia in young adults. This report emphasizes the necessity of screening for systemic autoantibodies and performing minor salivary gland biopsies in patients with unexplained CNS inflammatory lesions, regardless of glandular symptoms.