Background Visual hallucinations (VH), which are common in patients with Parkinson's disease (PD), lead to increased disability and are a significant predictor of the development of dementia. However, the neuroanatomical basis for VH in non-demented PD patients remains controversial.
Methods A total of 110 patients with PD were classified into PD with VH (n=46) and PD without VH (n=64) groups, depending on the presence of VH assessed by the caregiver-based structured interview of the Neuropsychiatric Inventory. We performed voxel-based morphometry (VBM) for grey matter (GM) volume and a region-of-interest-based volumetric analysis of the substantia innominata (SI) between two groups.
Results The comprehensive neuropsychological assessment showed that PD patients with VH showed more severe cognitive deficits in delayed visual memory and frontal executive functions compared with those without VH. A VBM analysis revealed that PD patients with VH had significantly lower GM volume in the right orbitofrontal, left temporal and left thalamic areas compared with those without VH. The normalised SI volume was significantly reduced in PD patients with VH compared with those without VH (1.28±0.22 vs 1.41±0.25, p=0.005).
Conclusions The present study demonstrates that non-demented PD patients with VH exhibited a smaller volume in the frontal, temporal and thalamic areas as well as the SI, suggesting that PD hallucinators may have distinctive neuroanatomical bases relative to PD non-hallucinators.
- Parkinson's disease
- visual hallucination
- neural substrates
- Alzheimer's disease
- movement disorders
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Funding This study was supported by Mid-career Researcher Program through NRF grant funded by the MEST (2010-0007749).
Competing interests None.
Patient consent Obtained.
Ethics approval This study was approved by the Yonsei University Severance Hospital ethical standards committee on human experimentation for experiments using human subjects.
Provenance and peer review Not commissioned; externally peer reviewed.