Apathy and cognitive decline as the first presentation of SLE-associated vascular dementia: a case report.

Apathy is a frequently overlooked yet disabling neuropsychiatric symptom in dementia syndromes, often misdiagnosed as depression. We describe a diagnostically challenging presentation of subcortical ischaemic vascular dementia in a 48-year-old Middle Eastern man, whose primary symptom was progressive apathy rather than overt cognitive decline or focal neurological deficits. Despite repeated emergency visits and antidepressant trials, his condition deteriorated until detailed neuropsychiatric evaluation and neuroimaging revealed right temporal gliosis/encephalomalacia, left frontal periventricular change, and multiple chronic lacunar infarcts in the left thalamus and bilateral centrum semiovale, on a background of small-vessel disease. Autoimmune workup confirmed previously undiagnosed systemic lupus erythematosus (SLE) with antiphospholipid markers, providing a unifying explanation for his vascular pathology. The clinical course was stepwise over ~ 18 months, with intermittent falls. Management included psychosocial interventions, behavioural support planning, and cautious pharmacological strategies; anticoagulation and rheumatological therapy were considered in light of his autoimmune risk. The patient showed modest improvements in affective responsiveness and engagement. This case highlights how apathy can be an early and dominant manifestation of vascular dementia when frontal-subcortical circuits are compromised. It underscores the need to differentiate apathy from depression using behavioural observations, collateral history, and cognitive testing, and to consider autoimmune vasculopathies in younger patients with unexplained vascular lesions. Timely neuroimaging and autoimmune screening could enable earlier diagnosis and intervention, improving outcomes in autoimmune-associated cognitive disorders.