Acute meningoencephalomyelitis in an exacerbation of primary Sjögren's syndrome.

A middle-aged woman with long-standing primary Sjögren's syndrome presented with a 2 month history of persistent headaches that acutely worsened over 5 days, accompanied by new-onset gait instability, bulbar symptoms, renal impairment and a recurrent cutaneous flare in sun-exposed areas. Neurological examination revealed bradyphrenia, flaccid dysarthria, an absent gag reflex, generalised hyperreflexia and axial ataxia. Neuroimaging demonstrated diffuse brainstem and subcortical hyperintensities, pachymeningeal enhancement, arterial calibre changes and a diffusion-restricted lesion. Cerebrospinal fluid analysis revealed mild protein elevation without pleocytosis and negative results on infectious and autoimmune panels. After excluding alternative aetiologies, central nervous system involvement secondary to Sjögren's syndrome was suspected. A 3-days intravenous methylprednisolone bolus was administered, followed by an initial cycle of cyclophosphamide. Neurological improvement was achieved in 10 days. Complete clinical and imaging resolution was observed in 1 month, with stable outcomes at 1 year follow-up. This case emphasises the importance of early recognition of severe Sjögren's manifestations.