Mild Cognitive Impairment, Severe Visual Processing Errors Increase PD Dementia Risk

Severe intraquadrant and interquadrant errors on visuospatial and visuoperceptual processing tests predict dementia in patients with Parkinson disease and mild cognitive impairment, according to a study published online in the Journal of the International Neuropsychological Society. 

“Subjective cognitive decline and mild cognitive impairment in Parkinson’s disease are considered as the risk factors for dementia,” wrote researchers from the University of La Laguna and La Candelaria University Hospital in Spain. “Posterior cortically based functions, such as visuospatial and visuoperceptual processing, have been described as predictors of Parkinson disease dementia. However, no investigations have focused on the qualitative analysis of the Judgment of Line Orientation Test and the Facial Recognition Test.” 

For the study, researchers evaluated 42 patients with Parkinson disease and 19 controls using a neuropsychological protocol. Follow-up assessment occurred an average 7.5 years after baseline.

Patients with Parkinson disease and mild cognitive impairment had greater alteration in visuospatial and visuoperceptual processing, reflected in poor Judgment of Line Orientation Test and the Facial Recognition Test total score and more severe intraquadrant and interquadrant errors, according to the study. Meanwhile, patients with Parkinson disease and subjective cognitive decline showed mild difficulties with visuospatial and visuoperceptual processing, with poor scores on the Facial Recognition Test and mild errors on the Judgment of Line Orientation Test. 

“Parkinson-disease mild cognitive impairment and intraquadrant/interquadrant errors were independent risk factors for Parkinson disease dementia during the follow-up,” researchers wrote. “Moreover, the combination of both Parkinson disease-mild cognitive impairment diagnosis and intraquadrant/interquadrant errors was associated with a greater risk.” 

—Jolynn Tumolo 

Reference:

Galtier I, Nieto A, Mata M, Lorenzo JN, Barroso J. Analyses of Visuospatial and Visuoperceptual Errors as Predictors of Dementia in Parkinson's Disease Patients with Subjective Cognitive Decline and Mild Cognitive Impairment [published online ahead of print, 2020 Dec 11]. J Int Neuropsychol Soc. 2020;1-11. doi:10.1017/S1355617720001216