Characteristics of visual hallucinations in Parkinson disease dementia and dementia with lewy bodies.
OBJECTIVE
Parkinson disease dementia (PDD) and dementia with Lewy bodies (DLB) have overlapping clinical and pathologic features. Recurrent visual hallucinations (RVH) are common in both disorders. The authors have compared details of hallucination characteristics and associated neuropsychiatric features in DLB and PDD.


METHODS
This is a descriptive, cross-sectional study using the Institute of Psychiatry Visual Hallucinations Interview (IP-VHI) to explore self-reported frequency, duration, and phenomenology of RVH in PDD and DLB. The caregivers' ratings of hallucinations and other neuropsychiatric features were elicited with the Neuropsychiatric Inventory (NPI).


RESULTS
Fifty-six patients (35 PDD; 21 DLB) with RVH were assessed. Hallucination characteristics were similar in both disorders. Simple hallucinations were rare. Most patients experienced complex hallucinations daily, normally lasting minutes. They commonly saw people or animals and the experiences were usually perceived as unpleasant. NPI anxiety scores were higher in PDD. Neuropsychiatric symptoms coexisting with hallucinations were apathy, sleep disturbance, and anxiety.


CONCLUSIONS
Patients with mild to moderate dementia can provide detailed information about their hallucinations. Characteristics of RVH were similar in PDD and DLB, and phenomenology suggests the involvement of dorsal and ventral visual pathways in their generation. The coexistence of RVH with anxiety, apathy, and sleep disturbance is likely to impair patients' quality of life and may have treatment implications.
Mosimann
Urs P
UP
Institute for Ageing and Health, Wolfson Research Centre, Newcastle General Hospital, Newcastle upon Tyne, United Kingdom. u.p.mosimann@ncl.ac.uk
Rowan
Elise N
EN
Partington
Cassie E
CE
Collerton
Daniel
D
Littlewood
Elizabeth
E
O'Brien
John T
JT
Burn
David J
DJ
McKeith
Ian G
IG
D000368:Aged; D001007:Anxiety / Q000453:epidemiology; D005260:Female; D006212:Hallucinations / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D020961:Lewy Body Disease / Q000453:epidemiology*; D008297:Male; D010300:Parkinson Disease / Q000453:epidemiology*; D012720:Severity of Illness Index; D012893:Sleep Wake Disorders / Q000453:epidemiology; D011795:Surveys and Questionnaires