European journal of neurology(England)
BACKGROUND: Well-structured hallucinations in Parkinson's disease (PD) are associated with poor prognosis and dementia. However, the predictive value of minor psychotic phenomena in cognitive deterioration is not well-known. Cross-sectional studies have shown that PD patients with minor hallucinations have more severe cortical atrophy than non-hallucinators, but baseline and longitudinal studies addressing the evolution of these brain differences are lacking.
OBJECTIVES: We explored the impact of developing minor hallucinations on cognitive impairment and cortical atrophy progression in early PD.
METHODS: We included one hundred and thirty-one de novo PD patients from the Parkinson's Progression Marker Initiative for whom brain MRI scans were available. We compared cognitive outcome at five years between patients with and without minor hallucinations during follow-up. Additionally, using grey matter volume (GMV) voxel-based morphometry (VBM), we studied cross-sectional (at baseline) and longitudinal (one and two-year GMV loss) structural brain differences between groups.
RESULTS: During follow-up, 35.1% patients developed minor hallucinations. At five years, these patients showed an increased prevalence of subjective cognitive decline compared to non-hallucinators (44.1% vs 13.9%; p<0.001), but not formal cognitive impairment. Additionally, compared to non-hallucinators, they exhibited reduced GMV at baseline in visuoperceptive areas, and increased GMV loss in left temporal areas (p<0.05 corrected).
CONCLUSIONS: Minor hallucinations seem to be an early clinical marker of increased neurodegeneration and are associated with mid-term subjective cognitive decline. Longer follow-up analyses would be needed to further define if these findings could reflect a higher risk of future cognitive deterioration.
Keywords: Hallucinations, Parkinson’s disease, cognition, cognitive decline, cortical atrophy
DOI: 10.1111/ene.14576Full Text Article
Eur. J. Neurol