Background/Purpose: Several factors has been described as responsible for the association between olfactory impairment and brain regions. In systemic sclerosis (SSc) the olfactory interaction has been little explored. To evaluate the interaction between olfactory impairment, neuropychiatric manifestations, clinical, laboratorial and treatment features in SSc.

Methods:  We screened consecutive SSc patients followed in a longitudinal cohort from 2011 to 2015 and age and sex matched controls. We excluded patients with overlapping rheumatic diseases. Cognitive evaluation was performed using the Montreal Cognitive Assessment (MoCA). Individual with scores≤26 were considered impaired. Mood disorders were determined through Beck´s Depression and Beck´s Anxiety Inventories. SSc patients were further assessed for clinical and laboratory SSc manifestations, disease activity (Valentini Activity Index), severity activity (Medsger Severity Index). Total dose of corticosteroids and other immunosuppressant medications used since the onset of the disease were calculated. MRI scans were performed in a 3T Phillips® scanner. Sagittal T1 weighted images were used for FreeSurfer automatic volumetric measurements. Olfactory functions was evaluated through Sniffin’ Sticks kit (Burghart Medizintechnik, Wedel, Germany). Sniffin’ Sticks kit consists of three stages: odor threshold, discrimination, and identification. The maximum score in each stage was 16 points, with a total score of 48 points. Subjects with a score < 30 were considered impaired [hyposmia (score between 15–30) and anosmia (scores of <15). Data were compared by non-parametric tests.

Results: We included 63 SSc patients [55 (87.3%) women; mean age of 51.01 ±11.32 years; range 20 – 82] with mean disease duration of 10.56 ±4.55 years. The control group consisted of 65 healthy volunteers [52 (80%) women p=0.418 with a mean age of 49.05±7.24; p=0.317]. Olfactory impairment were significantly higher in SSc patients [38 (60.3%)] when compared to controls [29 (44.6%)] (p=0.048). Regarding the three different stage SSc patients had significant abnormalities in the threshold [score media 6.3 vs 7.9 (p=0.016)], discrimination [score media 10.17 vs 11.5 (p=0.008)], score total [media 27.4 vs 31.24 (p=0.001)] when compared to controls. Comparing SSc patients with and without olfactory functions we observed in SSc with olfactory impairment had significant decrease in right and left hippocampus (9.5 cm³ vs 11.3 cm³; p=0.010) and right and left thalamic (6.05 cm³ vs 7.2 cm³; p=0.025) volume. Cognitive impairment was observed in 10 patients (24%) SSc and associated with decreased in discrimination (p=0.023) and identification scores (p=0.002). Significantly decreased of identification scores was associated with increase depression symptoms (p=0.032). We did not observe association between olfactory impairment and clinical, laboratory and treatment manifestations.

Conclusion:  Olfactory impairment was frequently observed in SSc and associated with decreased volumes of hippocampus and thalamus. Cognitive impairment and mood disorders were the only clinical manifestations associated with olfactory function.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/olfactory-impairment-is-associate-with-cognitive-dysfunction-and-regional-brain-atrophy-in-systemic-sclerosis/