Limbic encephalitis as the presenting feature of sjögren syndrome

Abstract

Autoimmune encephalitis associated with serum and intrathecal antibodies against intracellular and surface neuronal antigens of the limbic system neuropiles, and several neuropsychiatric and neurocognitive disorders have shared mechanisms of origin. Sicca syndrome is present in only 50% of patients with neurologic involvement. However, limbic encephalitis (LE) has been recognized on occasion as a feature of Sjogren’s syndrome (SS). A 40-years-old male patient presented with sudden development of headache, episodic memory failure, focal cognitive epileptic and generalized seizures, fever, complex visual hallucinations, fluctuations in awareness. Neurological examination showed drowsiness, as well as high freceuncy generalized tremor at rest. MRI showed an area of increased signal on fluid-attenuated inversion recovery (FLAIR) sequence bilaterally in the temporal lobe. CSF analysis showed a high protein level; viral screening and bacterial cultures, paraneoplastic antibody panel, anti NMDA were negative, EEG showed bilateral temporal focal slowing, PET scan was negative for malignancy, Anti Ro / SSA and anti La / SSB antibodies were elevated, Schirmer test was positive for reduced tear production and minor salivary gland biopsy demonstrated focal lymphocytic sialadenitis. Treatment with azathioprine and prednisone was started as well as rituximab every 6 months with marked improvement shown by lack of seizure recurrence; However, episodic memory failure remained. Recognizing the association between MRI temporal lobe lesions and LE should prompt further evaluation for paraneoplastic and autoantibody-related entities, including SS. This is the first case where the association of neuropsychiatric symptoms is described between LE and SS.