Teaching Video NeuroImage: String Hallucinations in Parkinson Disease.

STATEMENT OF THE CLINICAL PROBLEM ADDRESSED BY THE CASE: String hallucination, a complex multimodal hallucination in patients with advanced Parkinson disease (PD).

BRIEF DESCRIPTION OF CASE PRESENTATION: Two older patients with advanced PD and dementia presented with a peculiar type of hallucination, in the form of seeing and feeling threads on the surfaces or coming out from the fingers. They continued manipulating these imaginary threads before putting them aside. Quetiapine was helpful in both cases.

SUMMARY OF THE KEY TEACHING POINT IN THE CASE: Apart from the commonly described passage (a brief hallucination of a person, animal, or object passing sideways, within the periphery of the visual field) and presence (sensation of someone or something being present nearby, in the absence of seeing it) hallucinations, a multimodal (visual and tactile) hallucination can be seen in patients with advanced PD, mostly with dementia. The patients described here did not have any fluctuating cognition or other well-formed visual hallucinations as seen in dementia with Lewy bodies (DLB). An atypical antipsychotic like quetiapine is helpful to control such complex forms of hallucinations.