Visual complaints and visual hallucinations in Parkinson's disease

Area of Science:

• Neurology
• Ophthalmology
• Clinical Neuroscience

Background:

• Visual symptoms are frequently under-diagnosed in Parkinson's disease (PD).
• Early detection of visual disturbances is crucial for accurate differential diagnosis and effective patient management in PD.

Purpose of the Study:

• To determine the prevalence of recurrent visual complaints (RVC) and recurrent visual hallucinations (RVH) in Parkinson's disease (PD) patients.
• To investigate the relationship and interaction between RVC and RVH in PD patients compared to controls.

Main Methods:

• A cross-sectional study involving 88 PD patients and 90 controls.
• Assessment of RVC and RVH using a dedicated visual symptom questionnaire and the North-East-Visual-Hallucinations-Interview (NEVHI).

Main Results:

• Parkinson's disease patients showed significantly higher rates of double vision (18.2%), misjudging objects while walking (12.5%), words moving during reading (17.0%), and freezing in narrow spaces (30.7%) compared to controls.
• Recurrent complex visual hallucinations and illusions were also exclusively reported in PD patients (17.0%).
• Multiple RVC (43.2%) and RVH (29.5%) were significantly more common in PD patients than controls (15.8% and 5.6%, respectively).

Conclusions:

• Recurrent and multiple visual symptoms are common findings in Parkinson's disease.
• Recurrent visual complaints (RVC) were identified as risk factors predicting minor forms of hallucinations, but not recurrent complex visual hallucinations.
• Specific visual symptoms like double vision and misjudging objects were predictive of passage hallucinations and the feeling of presence in PD patients.