In dementia, delusions are common with prevalence up to 75%. However, erotomanic delusions, or De Clerambault's syndrome, are a rarity in dementia. To date, only six case-reports have been described in vascular dementia, frontotemporal dementia, and Alzheimer's dementia.

To present a case of De Clerambault's syndrome in an older adult diagnosed with vascular dementia.

To review available literature on De Clerambault's syndrome in dementia.

A case report is presented and discussed followed by a literature review.

We report a 72-year-old female with a history of right posterior cerebral artery infarction. The patient developed a sudden onset erotomanic delusion after she met a male patient of her age during her stay in a dementia day care center. She was agitated, disorientated, presented with confabulation, and showed a dysphoric mood. On MMSE she scored 14/30, the clock-drawing test revealed visuospatial deficits. On MRI, the right occipital lobe showed an encephalomalacia. The patient was treated with sertraline 50 mg/day and olanzapine 5 mg/day. Her erotomanic delusions improved after 3 months of treatment.

De Clerambault's syndrome is a rare and poorly understood disorder with generally a poor response to treatment. Some cases were successfully treated with atypical anti-psychotics. However, further research is needed to explore the course and treatment of this delusion.

The authors have not supplied their declaration of competing interest.