Dementia in a patient with autoimmune disease and hypercoagulable state worsened by COVID-19 vaccination: A case report.

Background: Systemic autoimmune disorders are associated with an increased risk of hypercoagulability. The hypercoagulable state in people with systemic autoimmune disorders has lately gained attention. Presentation of case: We presented a 44-year-old male with a chief complaint of progressive difficulty concentrating, memory impairment, and weakness in all limbs. Seven months before admission to our Memory Clinic, the patient began to have infrequent short-term memory loss and sometimes got lost when he went for a drive. Three months later, he complained of feeling dizzy when in a crowd, being unable to watch television for a long time, and easily forgetting. Computed tomography (CT) scan showed brain infarction. After receiving the first dose of COVID-19 vaccine (Sinovac), the patient had difficulty communicating verbally and could only point at objects, as well as tetraparesis. These conditions severely intervened in his daily activities. The patient was then referred to an immunologist and diagnosed with autoimmune disease. In our Memory Clinic, his performances of attention, memory, language, visuospatial, and executive function were very poor. We diagnosed him with autoimmune dementia. The administration of methylprednisolone, mycophenolate mofetil, vitamin D3, donepezil, and memantine could improve his condition. Discussion: Autoimmune disease can cause microvascular thrombosis and microembolism at the central nervous system level, which would cause vascular damage and cognitive impairment leading to brain infarction and dementia. Conclusion: There seems to be a link between autoimmune disease, hypercoagulable state, and dementia, although the magnitude of this link and the underlying processes are not fully understood.