This study aims to characterize the clinical features, therapeutic strategies, and prognostic outcomes in patients with SjD-PD.To provide better clinical experience for clinicians and avoid missed diagnosis and misdiagnosis.

We presented a case series of 10 patients diagnosed with both SjD and PD (SjD-PD). Demographic profiles, clinical manifestations, laboratory findings, neuroimaging results, treatment regimens, and long-term prognosis were retrospectively analyzed.

All 10 patients underwent cranial MRI; 4 underwent transcranial sonography (TCS) of the substantia nigra; 3 underwent minor salivary gland biopsy; and 4 underwent dopamine transporter imaging using medobal load test. Prior to initiation of pharmacological treatment, all patients completed a comprehensive laboratory evaluation, including complete blood count, erythrocyte sedimentation rate (ESR), immunoglobulin levels, C-reactive protein (CRP), thyroid function tests, tumor markers, antinuclear antibody (ANA) panel, anti-neutrophil cytoplasmic antibodies (ANCA), anti-platelet antibodies, and autonomic function testing.

All 10 patients were female, with a mean age of 66.9 ± 7.2 years. Symptoms of SjD included xerostomia (90%) and xerophthalmia (80%); the most common extraglandular manifestation was arthralgia (50%). The most prevalent PD symptom was bradykinesia (100%), followed by muscular rigidity (90%) and resting tremor (50%). Bilateral motor involvement was observed in 70% of patients, while 30% presented with unilateral symptoms. Cognitive impairment was identified in 67% of the cohort. Brain magnetic resonance imaging (MRI) revealed multiple lacunar infarcts and/or ischemic lesions in all cases. Four patients received antiparkinsonian monotherapy; 75% of these showed no significant improvement in PD symptoms, with disease progression noted. Four patients were treated with antiparkinsonian agents combined with glucocorticoids and/or non-hydroxychloroquine immunosuppressants; 75% exhibited clinical improvement. Two patients received immunosuppressive therapy including hydroxychloroquine, both of whom had unfavorable outcomes.

SjD comorbid with PD is a rare clinical entity, predominantly affecting female patients. Such cases are characterized by prominent sicca symptoms, a high frequency of bilateral PD motor involvement, and an elevated incidence of cognitive impairment. Adjunctive therapy with glucocorticoids plus non-hydroxychloroquine immunosuppressants, in combination with standard antiparkinsonian medications, may confer clinical benefits in this population.