Visual hallucinations are frequent among Parkinson’s patients, a study published in the Journal of Neurological Sciences confirmed. The findings suggest that visual hallucinations are associated with disease duration, the use of dopamine agonist medications, the quality of sleep, and a patient’s ability to think.
According to the authors, these results “should trigger further inquiry by neurologists.”
For the study, “Prevalence and risk factors for visual hallucinations in Chinese patients with Parkinson’s disease,” the team led by Dr. Li Zhang of the Department of Geriatric Neurology at Nanjing Medical University in China recruited 371 Parkinson’s disease patients.
Visual hallucinations were observed in 72 (19.4%) patients. Among these, 19 patients (26.4% of the 72) experienced minor hallucinations, while 53 (73.6%) experienced complex visual hallucinations.
The researchers then compared the age, disease duration, use of dopamine agonist drugs, and the motor and non-motor symptoms associated with Parkinson’s, measured by Unified Parkinson’s Disease Rating Scale (UPDRS) and Non-Motor Symptoms Questionnaire (NMS-Quest) score, between patients who experienced visual hallucinations and those who did not. They found that all parameters analyzed were significantly higher in patients who experienced visual hallucinations.
They also analyzed the patients’ ability to think and quality of sleep using the Montreal Cognitive Assessment (MOCA) and Parkinson’s Disease Sleep Scale (PDSS) scores, respectively. Scores in both these tests were, again, significantly higher in patients experiencing visual hallucinations — compared to patients who did not — suggesting that such hallucinations are tied to poorer quality of sleep and a subsequently poorer ability to think.
No differences were seen between the two groups in terms of depression and anxiety, as measured by the Hamilton Depression Scale (HAMD) and the Hamilton Anxiety Scale (HAMA) scores.
Researchers, based on these findings, suggested that visual hallucinations should be routinely evaluated in Parkinson’s disease patients “because it might significantly influence well-being.”
According to the Parkinson’s Disease Foundation, there are more than 10 million people living with Parkinson’s worldwide. Some 5 percent to 50 percent of them are thought to experience visual hallucinations, which may predict progression to more severe forms of psychosis. Identifying early those Parkinson’s patients with visual hallucinations may help clinicians to differentiate them from people with other forms of degenerative parkinsonisms, and ensure patients receive the right therapies.