Objectives: To assess subclinical central nervous system (CNS) involvement in primary Sjögren’s syndrome (pSS), by comparing standard brain magnetic resonance imaging (MRI), in-depth neuropsychological testing and 99mTc–ECD brain SPECT of pSS patients to matched controls.
Methods: We prospectively investigated 10 women (<55 years old), with pSS defined using European–American criteria, presence of anti-SSA and/or anti-SSB antibodies and no history of neurological involvement, and compared them to 10 age- and sex-matched controls. All subjects underwent, within 1 month, brain MRI, neuropsychological testing, including overall evaluation and focal cognitive function assessment, and 99mTc–ECD brain SPECT.
Results: 99mTc–ECD brain-SPECT abnormalities were significantly more frequent in pSS patients than controls (p<0.05). Cognitive dysfunctions, mainly expressed as executive and visuospatial disorders, were also significantly more frequent in pSS patients (p<0.01). Notably, between-group comparisons enabled a significant correlation to be established between neuropsychological assessment and 99mTc–ECD brain-SPECT abnormalities in pSS patients (rs = 0.49, p<0.01). MRI abnormalities in patients and controls did not differ significantly.
Conclusion: Neuropsychological testing and 99mTc–ECD brain SPECT seem to represent the most sensitive tools to detect subclinical CNS dysfunction in pSS. The strong correlation between cortical hypoperfusion in 99mTc–ECD brain SPECT and cognitive dysfunction suggests an organic etiology of CNS dysfunction in pSS. These data should be confirmed in a larger study.