Sjögren's syndrome (SS) is an autoimmune disorder involving the exocrine glands, which affects 1.9-3.0% of the elderly population. Approximately 20% of all patients with SS have CNS involvement, including dementia, as a result of angiitis.
The aim of the study was to clarify the prevalence and impact of SS among patients in a memory clinic.
This study prospectively recruited patients with cognitive dysfunction in a memory clinic from 2007 to 2010. In addition to the examinations for dementia, the patients' levels of anti-SSA and SSB antibodies were measured. Schirmer's test and/or a lip biopsy were added if required. SS was diagnosed based on the American European consensus criteria.
Out of 276 cases who completed the examinations, 265 (97/168 males/females, mean age: 77.9, median MMSE score: 23) did not demonstrated cognitive decline. Sixteen (6.3%) and seven (2.7%) patients were positive for anti-SS-A and SS-B antibodies, respectively. Twenty patients (7.5%) were diagnosed with primary SS (mean age: 77.2 years old, median MMSE: 21). Seven of these patients had previously been diagnosed with MCI (VCIND: 5, aMCI: 2), and 13 had been diagnosed with dementia. All had asymmetrical focal hypoperfusion on SPECT, and eighteen had subcortical lesions on MRI. Twelve were treated for dementia (median time: 2.1 years), and their MMSE significantly improved (median MMSE: 26, p=0.0019), while the non-SS subjects' MMSE declined (n=126, median: 22).
The patients with SS accounted for 7.5% of those with a cognitive decline as determined at a memory clinic, and are characterized by subcortical white matter lesions and asymmetric hypoperfusion.