Combined duloxetine and benzodiazepine-induced visual hallucinations in prodromal dementia with Lewy bodies

Objective

We describe a patient with prodromal dementia with Lewy bodies (DLB) presenting with drug-induced visual hallucinations (VHs).

Case report

A 78-year-old woman complained of daytime recurrent VHs characterized by seeing her face and arms covered in fur and viewing moustaches on her daughter's face. VHs started a few days after the beginning of a combination therapy with duloxetine and lorazepam and ceased within 24 h after their discontinuation. Nonamnestic mild cognitive impairment with profound visual perception deficits and very mild extrapyramidal signs, with abnormal brain DaTscan single photon emission tomography, were present. Three years later, cognitive and neurological follow-up assessments supported the diagnosis of DLB.

Conclusion

Perturbation of cerebral serotonergic tone induced by duloxetine, associated with reduced attentional control due to benzodiazepine use, may be the physiopathological substrate of transient VHs in prodromal DLB.