Association between family history of dementia and hallucinations in Parkinson disease

Objective: To identify familial risk factors for hallucinations in patients with Parkinson disease (PD). Methods: Two hundred seventy-six outpatients with PD participated in the study. The presence of hallucinations was determined using a validated questionnaire, including items regarding the occurrence of visual, auditory, or other types of hallucinations. Family history of PD and dementia was determined by a structured interview and examination of medical records and affected family members. Patients with young-onset PD (<50 years) who reported another PD patient among their siblings were tested for parkin mutations. Stepwise logistic regression was applied for the detection of risk factors. The regression model included a set of family history-related variables (family history of PD and of dementia) and a set of disease-related variables (age, age at onset of PD, stage, duration of PD and of L-dopa therapy, L-dopa dose, and number of antiparkinsonian drugs). Results: Hallucinations were present in 32% of the 276 patients. Risk factors for hallucinations included Mini-Mental State Examination score (p < 0.0001) and positive family history of dementia (p = 0.0005). Conclusion: Family history of dementia and lower Mini-Mental State Examination scores are risk factors for hallucinations in Parkinson disease.