Visual Illusions in Parkinsonʼs Disease

Abstract

  Several types of visual illusions can occur in Parkinsonʼs disease (PD) . However, the prevalence and types of specific illusions experienced by patients with PD remain unclear. We aimed to investigate the types of illusions. A questionnaire of visual illusions was developed through a literature review in consultation with clinicians and neurologists. Based on the questionnaire, 40 consecutive patients with PD were asked a series of Yes/No questions regarding 19 types of visual illusions since the onset of PD. If participants answered ʻYesʼ, they were then asked to detail their experience (s) . In total, 30 patients with PD had experienced visual illusions since disease onset ; among them. The most commonly observed illusion types were dysmorphopsia, complex visual illusions, metachromatopsia, and diplopia. Other observed illusions included textural illusions, macropsia, micropsia, teleopsia, pelopsia, kinetopsia, akinetopsia, Zeitraffer/Zeitlupen phenomena, tilt illusion, upside-down illusion, and palinopsia. Visual illusions had detrimental effects on the patientsʼ daily lives in some cases. Systematic interviews regarding the incidence and details of visual illusions experienced by patients with PD could offer important information regarding their quality of life.