The authors have presented a case-report of a 75-year-old woman receiving psychopharmacological treatment due to five-years’ history of visual pseudohallucinations. Four years after the onset, the patient was examined, and then followed by neurologists due to deterioration of her cognitive functions. She was extensively examined – neuropsychology, MRI volumometry, CSF assessment (including biomarkers total-tau protein, phosphorylated-tau protein, beta-amyloid), SPECT, DaTSCAN and laboratory screening. In accordance with clinical picture the results led to the diagnosis of Alzheimer’s disease, which was initially manifested by Charles Bonnet syndrome. Differential diagnosis of dementias, particularly those with Lewy bodies, and a possible association of cognitive deficit with mental health issues (hallucinations) are discussed.

        Key words: Charles Bonnet syndrome, cognitive deficit, Alzheimer’s disease