Background and objective: The objective of this study is to clarify clinical, immunological, and neuroimaging features in anti-aquaporin-4 (AQP4) antibody-positive and antibody-negative Sjögren’s syndrome (SS) patients with central nervous system (CNS) involvement. Methods: Medical records and MRI scans were retrospectively analyzed in 22 consecutive SS patients with CNS manifestations. Results: Seven (31.8%) patients were positive for anti-AQP4 antibodies. The frequency of visual impairment was higher in anti-AQP4 antibody-positive patients than in antibody-negative patients (71.4% vs. 0.0%, p = 0.0008). Brain MRI showed that discrete lesions were more commonly found in the cerebrum, brainstem, and optic nerve in anti-AQP4 antibody-positive patients than in antibody-negative patients ( p = 0.002, p = 0.006, and p = 0.004, respectively), while spinal cord MRI showed that posterior column lesions in the cervical spinal cord were more frequent in anti-AQP4 antibody-positive patients than in antibody-negative patients (71.4% vs. 14.3%, p = 0.01). SS-A antibody titers were higher in anti-AQP4 antibody-positive patients than in antibody-negative patients ( p = 0.012) and were also higher in patients with longitudinally extensive spinal cord lesions (LESCLs) than in those without LESCLs ( p = 0.019). Conclusions: In SS, the presence of anti-AQP4 antibodies is associated with involvement of the optic nerve, cerebrum and brainstem, and with cervical posterior column lesions in the spinal cord.
The utility of testing tactile perception of direction of scratch as a sensitive clinical sign of posterior column dysfunction in spinal cord disorders.
